Continental Casualty Co. v. Rohr, Inc. ( 2020 )


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    CONTINENTAL CASUALTY COMPANY ET AL.
    v. ROHR, INC., ET AL.
    (AC 41537)
    (AC 41538)
    (AC 42613)
    DiPentima, C. J., and Prescott and Bear, Js.*
    Syllabus
    The plaintiff insurance companies sought a declaratory judgment to deter-
    mine the rights and obligations of the parties under certain policies that
    the plaintiffs and certain of the defendant insurance companies had
    issued to the defendant manufacturer R Co. with respect to underlying
    lawsuits against R Co. concerning environmental contamination at vari-
    ous locations, principally in California, dating back to the 1940s. The
    plaintiffs sought a judgment declaring that they had no duty to defend
    or to indemnify R Co. in connection with the underlying claims and
    that, if the trial court found that they were obligated to defend or to
    indemnify R Co., they were entitled to contribution from the defendant
    primary, umbrella and excess insurers. The plaintiff insurance compa-
    nies included C Co., L Co., and certain London market insurers. The
    defendants included secondary insurers E Co., S Co., F Co., T Co. and
    U Co., which had issued certain excess policies to R Co. between 1982
    and 1986. Prior to this litigation, the substantive issues of which are
    governed by California law, R Co. settled certain of its coverage claims
    with the defendant A Co., the successor in interest to I Co., which had
    issued to R Co. two primary policies that were in effect between 1959
    and 1971. The plaintiffs, which had issued policies to R Co. that were
    in excess to the 1959–1971 policies, claimed that R Co. had settled with
    A Co. for less than the total amount of coverage under the 1959–1971
    I Co. policies and, thus, R Co. did not fully exhaust its coverage under
    those policies. The trial court stayed the plaintiffs’ contribution claims
    and bifurcated the proceedings, the first phase of which was limited to
    the question of when the obligations, if any, of the excess insurers
    arose in light of the limits of the underlying primary policy or policies.
    Thereafter, C Co. and several other plaintiffs filed a motion for partial
    summary judgment in which they claimed that the I Co. primary policies
    first had to be exhausted before the excess policies could be implicated.
    The C Co. plaintiffs further claimed that the I Co. policies provided
    combined limits of $24 million in coverage per occurrence, which had
    not been exhausted because I Co. had not paid or been held liable to
    pay its full indemnity limits by judgment or settlement. F Co. and E Co.
    then filed motions in which they joined the motion for partial summary
    judgment filed by the C Co. plaintiffs. R Co. thereafter filed motions for
    partial summary judgment as against the C Co. plaintiffs, F Co. and E
    Co. R Co. maintained that it was entitled to coverage under its excess
    policies and that, pursuant to controlling California law and the language
    of the excess policies, it was required to satisfy only a single per occur-
    rence limit of $2 million to reach the excess insurers’ coverage. R Co.
    further claimed that vertical exhaustion was mandated by the excess
    policies and that recovery from the excess insurers was not precluded
    by its settlement under the I Co. primary policies. The trial court rendered
    judgment granting the motion for partial summary judgment filed by
    the C Co. plaintiffs, and the joinder motions filed by F Co. and E Co.,
    and denying the motions for partial summary judgment filed by R Co.
    The court determined that the I Co. primary policies had been in force
    for four consecutive policy periods, each of which provided $2 million
    in coverage per occurrence, for a total of $8 million per occurrence for
    the years the I Co. policies were in effect. The court also determined
    that the underlying primary policies had to be horizontally exhausted
    before any of the C Co. plaintiffs’ excess policies could attach to provide
    coverage. The court further determined that R Co. was required to be
    paid the limits of its underlying primary policies before it could access
    certain of the excess policies. The court determined that a 1982–1983
    policy that was issued by F Co. was specifically excess to a certain
    excess policy issued by T Co. that provided $10 million in coverage
    above an additional $40 million in other underlying insurance. The court
    also determined that a 1984 policy and a 1985 policy that were issued
    by F Co. were general excess policies and that the limits of all three F
    Co. policies could not be triggered because certain underlying policies
    issued by S Co., T Co. and I Co. constituted other valid insurance that
    was collectible by the insured. The court determined that the coverage
    limits of a 1984–1985 excess policy and three 1985–1986 excess policies
    that were issued by E Co. could not be triggered because underlying
    policies issued by S Co., T Co., U Co. and I Co. constituted other valid
    insurance that was collectible by the insured. R Co. filed separate appeals
    challenging the trial court’s judgment for the C Co. plaintiffs and for F
    Co. and E Co., and the C Co. plaintiffs cross appealed. Held:
    1. The trial court improperly granted the motion for partial summary judg-
    ment filed by the C Co. plaintiffs, as the court’s conclusion that their
    excess policies could never attach was incorrect because A Co. had
    paid R Co. more than the per occurrence limits of the underlying I Co.
    primary policies:
    a. The C Co. plaintiffs could not prevail on their claim that the I Co.
    primary policies had a total liability of $24 million over the 1959–1971
    period, which was based on their assertion that the three year policy
    period endorsements to the primary policies were to be treated as annual
    periods that were subject to a per occurrence limit and that the policy
    period of each multiyear primary policy was defined as three consecutive
    annual periods: the trial court properly concluded that each I Co. policy
    provided a per occurrence limit of $2 million that could not be annu-
    alized, the court having correctly determined that the limit of liability
    provision in each policy set a per occurrence limit for each three year
    period of the policy and an aggregate limit for multiple occurrences
    during any annual period; moreover, the provisions of the policies were
    not ambiguous, as the endorsements stated that the three year policy
    periods were made up of three annual periods, which was relevant in
    that rates were based on annual periods, nowhere in the policies or
    their endorsements was the policy period defined as three consecutive
    annual periods, and there was no language in the policies or their declara-
    tions that provided for coverage on a per occurrence, per year basis.
    b. Contrary to the trial court’s determination that the I Co. primary
    policies provided $8 million in coverage because their $2 million per
    occurrence limits were in force for four consecutive policy periods, R
    Co. was entitled to $2 million in coverage per policy for a total of $4
    million in coverage; the policies’ renewal certificates and endorsements
    constituted continuations of the original contracts such that the limit
    of liability was the amount stated in the contracts regardless of the
    number of years involved or the number of premiums that were paid.
    c. This court concluded, after an examination of California law, that
    the trial court did not err in determining that R Co. was required to
    horizontally exhaust all of its primary insurance before the liability of
    its excess insurers could attach: this court determined that it would
    apply the rule of horizontal exhaustion set forth by the California Court
    of Appeal in Community Redevelopment Agency v. Aetna Casualty &
    Surety Co. (
    50 Cal. App. 4th 329
    ) and other California cases that adhere
    to the settled rule under California law that an excess policy does not
    cover a loss until all primary insurance has been exhausted.
    d. Although the trial court properly determined that payment of the full
    limits of the primary policies was necessary for exhaustion to be satis-
    fied, it improperly determined that the necessary exhaustion of the I Co.
    primary policies remained unsatisfied: because R Co. received payment
    pursuant to the settlement of the I Co. primary policies for an amount
    that exceeded the $4 million in coverage under those policies, under
    the circumstances here, exhaustion by payment of the full amount of
    the limits of those policies was satisfied, and, as that determination
    also applied to the H Co. and London excess policies, the trial court
    improperly determined that a certain London market insurance policy
    was inaccessible and that no liability could attach under a certain H
    Co. umbrella policy.
    2. R Co.’s claim that the trial court improperly granted F Co.’s motion for
    summary judgment was unavailing, as R Co. failed to exhaust certain of
    its excess insurance policies when it entered into settlement agreements
    with S Co. and T Co.; F Co.’s 1982–1983 and 1984 and 1985 excess
    policies applied only after the exhaustion of the T Co. and S Co. $10
    million excess policies and $40 million in other underlying insurance,
    and even if R Co. had horizontally exhausted the $40 million in underlying
    insurance, it failed to exhaust the T Co. and S Co. policies when it
    settled with T Co. and S Co. for less than the limits of their policies.
    3. The trial court properly granted E Co.’s motion for summary judgment
    as to the 1984–1985 excess policy it issued to R Co. but improperly
    granted the motion as to three 1985–1986 excess policies it issued to
    R Co.:
    a. Although the trial court improperly concluded that the limits of E
    Co.’s 1984–1985 policy were not triggered because the I Co. primary
    policies had not been exhausted, the court’s decision as to the 1984–1985
    policy was nevertheless proper, that policy having been specifically
    excess to a directly underlying policy issued by S Co. that had been
    settled with R Co. for less than its full limits.
    b. E Co. was not entitled to summary judgment as to its three 1985–1986
    policies, the trial court having incorrectly determined that, to the extent
    those policies involved the same occurrences covered by the I Co.
    policies, the limits of E Co.’s 1985–1986 policies had not been triggered
    because the coverage limits of the I Co. policies had not been satisfied.
    4. The C Co. plaintiffs could not prevail on their cross appeal, in which they
    claimed that the 1959–1971 I Co. primary policies had annual period
    per occurrence limits that totaled $24 million, this court having rejected
    similar arguments the C Co. plaintiffs raised on direct appeal with respect
    to whether the $2 million per occurrence limits in the I Co. policies
    may be annualized.
    Argued February 13—officially released December 15, 2020
    Procedural History
    Action for a declaratory judgment to determine, inter
    alia, the rights of the parties under certain insurance
    policies issued to the named defendant by the plaintiffs
    and certain of the defendants concerning underlying
    claims of environmental contamination brought against
    the named defendant, and for other relief, brought to
    the Superior Court in the judicial district of Hartford,
    where the defendant Federal Insurance Company et
    al. filed cross claims and the named defendant filed a
    counterclaim and a cross claim; thereafter, the court,
    Hon. A. Susan Peck, judge trial referee, bifurcated the
    trial and ordered that the parties’ declaratory judgment
    claims be tried to the court in the first phase; subse-
    quently, the court granted the motions for partial sum-
    mary judgment filed by the named plaintiff et al. and the
    motions for summary judgment filed by the defendant
    Federal Insurance Company et al., and denied the
    named defendant’s motions for partial summary judg-
    ment, and the named defendant appealed and the
    named plaintiff et al. cross appealed to this court, which
    consolidated the appeals. Reversed in part; judgment
    directed; further proceedings.
    Marilyn B. Fagelson, with whom were Proloy K. Das,
    Rachel Snow Kindseth, Benjamin H. Nissim and, on
    the brief, Steven M. Greenspan, Amanda M. Leffler,
    pro hac vice, and Paul A. Rose, pro hac vice, for the
    appellant-cross appellee (named defendant).
    Matthew B. Anderson, pro hac vice, with whom were
    William A. Meehan and, on the brief, Stephen T.
    Roberts, for the appellees-cross appellants (named
    plaintiff et al.).
    Brian C. Coffey, pro hac vice, with whom were Stuart
    G. Blackburn, Laura Pascale Zaino and, on the brief,
    William M. Cohn, pro hac vice, for the appellees (defen-
    dant Century Indemnity Company et al.).
    Opinion
    BEAR, J. These appeals and cross appeal involve
    issues relating to whether certain umbrella and excess
    policies issued by the plaintiff and defendant insurers
    provide coverage for environmental property damage
    remediation claims brought against the named defen-
    dant, Rohr, Inc. (Rohr).
    In Docket No. AC 42613, Rohr appeals from the judg-
    ment of the trial court granting the motion for partial
    summary judgment filed by the plaintiff Continental
    Casualty Company (Continental), in its own capacity
    and as successor in interest to certain Harbor Insurance
    Company insurance policies (Harbor excess policies)
    and as successor by merger to CNA Casualty of Califor-
    nia; the plaintiff Certain Underwriters at Lloyd’s, Lon-
    don (Lloyd’s); and certain plaintiff London market
    insurance companies (London insurers), specifically,
    The Ocean Marine Insurance Company (Ocean Marine)
    as successor to certain policies severally subscribed to
    by Commercial Union Assurance Company PLC and/or
    General Accident Fire & Marine Life Assurance Corpo-
    ration, and Scottish Lion Insurance Company, Ltd.
    (Scottish Lion).1 In Docket No. AC 42613, the Continen-
    tal plaintiffs cross appealed from the judgment.
    In Docket No. AC 41537, Rohr appeals from the judg-
    ment of the trial court granting the motion for summary
    judgment filed by the defendant Federal Insurance
    Company (Federal), and in Docket No. AC 41538, Rohr
    appeals from the summary judgment rendered in favor
    of the defendant Century Indemnity Company (Cen-
    tury), formerly known as California Union Insurance
    Company.
    On appeal in Docket No. AC 42613, Rohr claims that
    the trial court erred in concluding that (1) the underly-
    ing primary insurance policies issued to Rohr by Royal
    Indemnity Company (Royal) for the period between
    August 1, 1959, and August 1, 1971 (Royal primary poli-
    cies), provided per occurrence limits of $8 million, (2)
    the underlying primary insurance policies must be hori-
    zontally exhausted before any of the excess policies
    could attach to provide coverage, and (3) Rohr was
    required to be paid those policy limits before it could
    access certain excess insurance policies. On the cross
    appeal, the Continental plaintiffs challenge the trial
    court’s determination that the Royal primary policies
    have a total per occurrence limit of $8 million and claim
    that the total per occurrence limit of the Royal primary
    policies is $24 million. For the reasons discussed more
    fully herein, we reverse in part the judgment of the
    trial court.
    The following undisputed factual and procedural his-
    tory is relevant to our resolution of the claims on appeal.
    Over the course of several decades, dating back to the
    1940s, environmental contamination occurred at vari-
    ous sites located principally in California2 as a result
    of manufacturing operations at those sites by Rohr,
    which is a wholly owned subsidiary of United Technolo-
    gies Corporation with its principal place of business
    located in Farmington. Consequently, claims were
    brought against Rohr seeking recovery for the costs of
    remediation of those sites, and Rohr, in turn, sought
    coverage from its insurers for defense and indemnity
    costs it has incurred, and will continue to incur, related
    to the remediation. Prior to this litigation, Rohr settled
    certain of its coverage claims with the defendant
    Arrowood Indemnity Company (Arrowood), as succes-
    sor in interest to Royal. Two of the Royal primary poli-
    cies are directly at issue in the present case: policy RLP
    144014, which was in effect between August 1, 1959,
    and August 1, 1965; and policy RTS 902235, which was
    in effect between August 1, 1965, and August 1, 1971.3
    The plaintiffs4 issued policies to Rohr that are excess to
    the 1959–1971 Royal primary policies. A central dispute
    between the parties to these appeals concerns the claim
    by the excess insurers that the amount paid to Rohr
    under its settlement with Arrowood was less than the
    total amount of the coverage under the Royal primary
    policies and, thus, did not fully exhaust the coverage
    provided under those policies.
    In 2016, the plaintiffs commenced the present action
    against the defendants5 seeking a declaratory judgment
    as to the rights and obligations of the parties under
    certain insurance policies issued to Rohr by the plaintiff
    insurers and certain of the defendant insurers concern-
    ing the underlying environmental property damage
    claims.6 Specifically, the plaintiffs sought a judgment
    declaring: in count one of their complaint, that they
    have no duty to defend Rohr in connection with the
    underlying claims; in count two, that they have no obli-
    gation to indemnify Rohr concerning the underlying
    claims; and in count three, that, in the event the court
    finds that they are obligated to defend or indemnify
    Rohr, they are entitled to contribution from the defen-
    dant primary, umbrella and excess insurers.7
    On September 26, 2016, the court granted a joint
    motion of the parties to stay the contribution claims
    alleged in count three. In a scheduling order issued the
    same day, the litigation was divided into two phases,
    with the first phase being limited to the following ques-
    tion: ‘‘At what point will the obligations of the excess
    insurers, if any, arise in light of the limits of the underly-
    ing primary policy or policies?’’ The remaining issues
    were scheduled to be decided in phase two, if necessary.
    On December 16, 2016, the Continental plaintiffs filed
    a motion for partial summary judgment. In their motion,
    they claimed that there was no genuine issue of material
    fact and that they were entitled to summary judgment
    in their favor because (1) all of the Royal primary poli-
    cies first had to be exhausted before the excess policies
    could be implicated, (2) the Royal primary policies pro-
    vide combined limits of $24 million in coverage per
    occurrence, and (3) the Royal primary policies have
    not been exhausted because Royal has not paid, or been
    held liable to pay, their full indemnity limits either by
    judgment or settlement.8 On January 6, 2017, Federal
    and Century filed motions joining in the motion for
    summary judgment filed by the Continental plaintiffs.
    On January 23, 2017, Rohr filed a motion for partial
    summary judgment as to the Continental plaintiffs. In
    its memorandum in support of its motion and in
    response to the motion for partial summary judgment
    filed by those plaintiffs, Rohr maintained that, with
    respect to the underlying claims, it is entitled to cover-
    age under its excess comprehensive liability policies.
    Specifically, Rohr claimed, inter alia, that it was
    ‘‘required to satisfy only a single per occurrence limit
    of $2 million in order to reach the excess insurers’
    coverage,’’ that ‘‘vertical exhaustion is mandated by the
    language of the excess policies,’’ and that its ‘‘settlement
    [under the Royal primary policies] does not preclude
    it from recovering against the excess insurers.’’ Rohr
    further claimed that the excess insurers could not
    ‘‘avoid their obligations to Rohr by complaining that
    Rohr did not collect enough money in settlement from
    its primary insurer, Royal. Recent controlling California
    law, as well as the language of the excess policies and
    [the] Royal primary policies, compel the conclusion that
    Rohr need collect only $2 million from Royal before it
    can recover from the excess insurers.’’ Also on January
    23, 2017, Rohr filed a motion for partial summary judg-
    ment as to Federal and Century, incorporating by refer-
    ence its combined memorandum in opposition to the
    motions for summary judgment filed by Federal and
    Century and in support of its motion for partial sum-
    mary judgment as to those defendants, and all of the
    exhibits thereto. Rohr claimed, inter alia, that the join-
    der motions for summary judgment filed by Federal
    and Century failed for the same reasons set forth in
    Rohr’s opposition to the motion for partial summary
    judgment filed by the Continental plaintiffs.
    In a memorandum of decision dated March 19, 2018,
    the court, Hon. A. Susan Peck, judge trial referee, ren-
    dered judgment granting the motion for partial sum-
    mary judgment filed by the Continental plaintiffs and
    the joinder motions for summary judgment filed by
    Federal and Century, and denying Rohr’s motions for
    partial summary judgment. On April 9, 2018, Rohr filed
    its appeal in Docket No. AC 41537 challenging the sum-
    mary judgment rendered in favor of Federal, its appeal
    in Docket No. AC 41538 challenging the summary judg-
    ment rendered in favor of Century, and its appeal in
    Docket No. AC 41540 challenging the summary judg-
    ment rendered in favor of the Continental plaintiffs. On
    that day, Rohr also filed a motion, pursuant to Practice
    Book § 61-4, for a written determination of appealability
    of the court’s decision regarding the parties’ motions
    for summary judgment. In its motion, Rohr alleged that
    the decision was a final appealable judgment as to Fed-
    eral and Century because it resolved all claims between
    Rohr and those parties. With respect to the Continental
    plaintiffs, Rohr acknowledged that the decision did not
    resolve all issues concerning coverage obligations for
    all policies with those parties and left issues regarding
    the remaining policies to be addressed in the next phase
    of the litigation. Rohr claimed, however, that because
    the issues to be addressed in its appeal from the sum-
    mary judgment rendered in favor of Federal and Cen-
    tury were related closely to those raised in the summary
    judgment rendered in favor of the Continental plaintiffs,
    ‘‘it would be the most efficient use of judicial resources
    to grant the . . . motion so that an appeal from [the
    summary judgment rendered in favor of the Continental
    plaintiffs] . . . can be consolidated with the aforemen-
    tioned appeals and argued by all of the affected parties
    at the same time.’’ (Citation omitted.) The trial court
    granted Rohr’s motion on May 25, 2018.
    Subsequently, on January 16, 2019, this court granted
    Rohr’s motion to consolidate its appeals in Docket Nos.
    AC 41537 and AC 41538, dismissed the appeal and cross
    appeal in Docket No. AC 41540 for lack of a final judg-
    ment, as the decision appealed from did not dispose of
    the entire complaint or all causes of action with respect
    to the Continental plaintiffs, and denied Rohr’s request
    for permission to appeal pursuant to Practice Book
    § 61-4. On February 15, 2019, this court granted Rohr’s
    motion for reconsideration, as well as its motion for
    permission to appeal. Thereafter, Rohr filed the appeal
    in Docket No. AC 42613 challenging the summary judg-
    ment rendered in favor of the Continental plaintiffs,
    which, in turn, filed a cross appeal. The three appeals
    subsequently were consolidated.
    The parties do not dispute that the substantive issues
    in this action are governed by California law. It is well
    established, however, ‘‘that in a choice of law situation
    the forum state will apply its own procedure . . . .
    Paine Webber Jackson & Curtis, Inc. v. Winters, 
    22 Conn. App. 640
    , 650, 
    579 A.2d 545
    , cert. denied, 
    216 Conn. 820
    , 
    581 A.2d 1055
    (1990); see, e.g., Ferri v. Pow-
    ell-Ferri, 
    326 Conn. 438
    , 447, 
    165 A.3d 1137
    (2017)
    ([a]lthough the choice of law provision in the [trust at
    issue] dictates that matters of substance will be ana-
    lyzed according to Massachusetts law, procedural
    issues such as the standard of review [and standing]
    are governed by Connecticut law); Montoya v. Montoya,
    
    280 Conn. 605
    , 612 n.7, 
    909 A.2d 947
    (2006) ([a]lthough
    the [premarital] agreement’s choice of law provision
    dictates that the substance of the contract will be ana-
    lyzed according to New York law, procedural issues
    such as the applicable standard of review are governed
    by Connecticut law) . . . .’’ (Citation omitted; internal
    quotation marks omitted.) Reclaimant Corp. v.
    Deutsch, 
    332 Conn. 590
    , 603, 
    211 A.3d 976
    (2019).
    Accordingly, we set forth our standard of review pursu-
    ant to Connecticut law.
    The standard of review applicable to a trial court’s
    decision to grant a motion for summary judgment is
    well established. ‘‘Practice Book § 17-49 provides that
    summary judgment shall be rendered forthwith if the
    pleadings, affidavits and any other proof submitted
    show that there is no genuine issue as to any material
    fact and that the moving party is entitled to judgment
    as a matter of law. A party moving for summary judg-
    ment is held to a strict standard. . . . To satisfy his
    burden the movant must make a showing that it is quite
    clear what the truth is, and that excludes any real doubt
    as to the existence of any genuine issue of material
    fact. . . . As the burden of proof is on the movant, the
    evidence must be viewed in the light most favorable
    to the opponent.’’ (Internal quotation marks omitted.)
    Raczkowski v. McFarlane, 
    195 Conn. App. 402
    , 408, 
    225 A.3d 305
    (2020); see also Cyr v. VKB, LLC, 194 Conn.
    App. 871, 877, 
    222 A.3d 965
    (2019). ‘‘A material fact is
    a fact that will make a difference in the outcome of the
    case. . . . Once the moving party has presented evi-
    dence in support of the motion for summary judgment,
    the opposing party must present evidence that demon-
    strates the existence of some disputed factual issue
    . . . . It is not enough, however, for the opposing party
    merely to assert the existence of such a disputed issue.
    Mere assertions of fact . . . are insufficient to estab-
    lish the existence of a material fact and, therefore, can-
    not refute evidence properly presented to the court
    under Practice Book § [17-45].’’ (Internal quotation
    marks omitted.) Streifel v. Bulkley, 
    195 Conn. App. 294
    ,
    300, 
    224 A.3d 539
    , cert. denied, 
    335 Conn. 911
    , 
    228 A.3d 375
    (2020). ‘‘Our review of the trial court’s decision to
    grant [a] motion for summary judgment is plenary.’’
    (Internal quotation marks omitted.) Lucenti v. Laviero,
    
    327 Conn. 764
    , 773, 
    176 A.3d 1
    (2018).
    I
    INSURANCE LAW PRINCIPLES
    Because the trial court’s resolution of the issues
    raised in the motions for summary judgment involved
    a discussion and application of various technical con-
    cepts and terms related to insurance contract interpre-
    tation under California law, before we address the mer-
    its of the court’s decision, a discussion of those
    principles and concepts, as well as the terms of the
    insurance policies at issue, is necessary.
    A
    Primary and Excess Insurance
    We first discuss the distinctions between primary
    and excess insurance coverage. ‘‘Primary coverage is
    insurance coverage whereby, under the terms of the
    ing of the occurrence that gives rise to liability. . . .
    Primary insurers generally have the primary duty of
    defense. Excess or secondary coverage is coverage
    whereby, under the terms of the policy, liability attaches
    only after a predetermined amount of primary coverage
    has been exhausted.’’ (Emphasis omitted; internal quo-
    tation marks omitted.) Century Surety Co. v. United
    Pacific Ins. Co., 
    109 Cal. App. 4th 1246
    , 1255, 135 Cal.
    Rptr. 2d 879 (2003), review denied, California Supreme
    Court, Docket No. S117884 (September 17, 2003); see
    also Legacy Vulcan Corp. v. Superior Court, 185 Cal.
    App. 4th 677, 689, 
    110 Cal. Rptr. 3d 795
    (2010), review
    denied, California Supreme Court, Docket No. S184633
    (September 1, 2010). ‘‘[E]xcess insurance is insurance
    that is expressly understood by both the insurer and
    insured to be secondary to specific underlying coverage
    which will not begin until after that underlying coverage
    is exhausted and which does not broaden that underly-
    ing coverage. . . . California case law has consistently
    protected the limited and shielded position of the
    excess carrier when the obligations of the excess carrier
    are set in clear phrases.’’ (Citations omitted; internal
    quotation marks omitted.) Qualcomm, Inc. v. Certain
    Underwriters at Lloyd’s, London, 
    161 Cal. App. 4th 184
    , 194, 
    73 Cal. Rptr. 3d 770
    (2008), review denied,
    California Supreme Court, Docket No. S163293 (June
    11, 2008); see also Century Surety Co. v. United Pacific
    Ins. 
    Co., supra
    , 1255. ‘‘Unless the provisions of an
    excess policy provide otherwise, an excess insurer has
    no obligation to provide a defense to its insured before
    the primary coverage is exhausted.’’ Community Rede-
    velopment Agency v. Aetna Casualty & Surety Co., 
    50 Cal. App. 4th 329
    , 338, 
    57 Cal. Rptr. 2d 755
    (1996); see
    also North River Ins. Co. v. American Home Assurance
    Co., 
    210 Cal. App. 3d 108
    , 112, 
    257 Cal. Rptr. 129
    (1989)
    (‘‘[l]iability under an excess policy attaches only after
    all primary coverage has been exhausted’’).
    As in the present case, an insured may have several
    layers of excess or secondary insurance, and ‘‘[w]hen
    secondary insurance is written to be excess to identified
    policies, it is said to be ‘specific excess.’ ’’ Olympic Ins.
    Co. v. Employers Surplus Lines Ins. Co., 
    126 Cal. App. 3d
    593, 598, 
    178 Cal. Rptr. 908
    (1981). ‘‘When California
    courts refer to differing ‘levels’ of coverage in excess
    insurance policies, they are referring to whether the
    policy is a ‘specific excess’ or a ‘general excess’ insur-
    ance policy. A specific excess insurance policy is an
    insurance policy that ‘provide[s] excess coverage only
    over specified primary policies.’ . . . Thus, a specific
    excess policy must pay as soon as the limits of the
    specified underlying insurance are exhausted. . . . In
    contrast, general excess insurance policies ‘provide
    coverage only when all primary policies are exhausted.’
    . . . This is called ‘horizontal exhaustion’ because each
    primary policy on the lower ‘level’ must exhaust before
    a general excess policy, which sits on a higher level,
    becomes implicated.’’ (Citations omitted; emphasis in
    original.) St. Paul Fire & Marine Ins. Co. v. Ins. Co.
    of the State of Pennsylvania, Docket No. 15-CV-02744-
    LHK, 
    2017 WL 897437
    , *14 (N.D. Cal. March 7, 2017);
    see also Padilla Construction Co. v. Transportation
    Ins. Co., 
    150 Cal. App. 4th 984
    , 986–87, 
    58 Cal. Rptr. 3d 807
    (2007) (‘‘California’s rule of ‘horizontal exhaustion’
    in liability insurance law requires all primary insurance
    to be exhausted before an excess insurer must ‘drop
    down’ to defend an insured, including in cases of contin-
    uing loss. . . . Unless there is excess insurance that
    describes underlying insurance and promises to cover
    a claim when that specific underlying insurance is
    exhausted (‘vertical exhaustion’), the rule of horizontal
    exhaustion applies to cases of alleged continuing prop-
    erty damage . . . .’’ (Citation omitted; footnote
    omitted.)).
    In contrast, under vertical exhaustion, ‘‘coverage atta-
    ches under an excess policy when the limits of a specifi-
    cally scheduled underlying policy [are] exhausted and
    the language of the excess policy provides that it shall
    be excess only to that specific underlying policy.’’ Com-
    munity Redevelopment Agency v. Aetna Casualty &
    Surety 
    Co., supra
    , 
    50 Cal. App. 4th 339
    –40. Moreover,
    the principle that a secondary policy ‘‘does not apply
    to cover a loss until the underlying primary insurance
    has been exhausted . . . holds true even where there
    is more underlying primary insurance than contem-
    plated by the terms of the secondary policy.’’ Olympic
    Ins. Co. v. Employers Surplus Lines Ins. 
    Co., supra
    ,
    
    126 Cal. App. 3d
    600.
    B
    Principles Governing Continuous Loss Cases
    Environmental injury cases such as the present one,
    in which the harm is alleged to have occurred over the
    course of multiple years and policy periods, involve
    what has been termed ‘‘long-tail’’ injuries. Such injuries
    involve ‘‘a series of indivisible injuries attributable to
    continuing events without a single unambiguous cause.
    Long-tail injuries produce progressive damage that
    takes place slowly over years or even decades.’’ (Inter-
    nal quotation marks omitted.) California v. Continen-
    tal Ins. Co., 
    55 Cal. 4th 186
    , 195–96, 
    281 P.3d 1000
    , 
    145 Cal. Rptr. 3d 1
    (2012) (Continental Ins. Co. I). In cases
    involving long-tail injuries, the relationship between pri-
    mary and excess insurance can be complex, as ‘‘[i]t is
    often virtually impossible for an insured to prove what
    specific damage occurred during each of the multiple
    consecutive policy periods in a progressive property
    damage case.’’ (Internal quotation marks omitted.)
    Id., 196;
    see
    id. (explaining that ‘‘many
    insurers are unwill-
    ing to indemnify insureds for long-tail claims’’ and that
    their refusal to do so often causes insureds to bring
    complex actions seeking coverage, which involve large
    numbers of litigants and insurance policies covering
    multiple years and policy periods).
    There are three California Supreme Court cases that
    primarily inform our discussion of the general princi-
    ples governing long-tail injury or continuous loss cases:
    Montrose Chemical Corp. of California v. Admiral Ins.
    Co., 
    10 Cal. 4th 645
    , 
    913 P.2d 878
    , 
    42 Cal. Rptr. 2d 324
    (1995) (Montrose I), Aerojet-General Corp. v. Transport
    Indemnity Co., 
    17 Cal. 4th 38
    , 
    948 P.2d 909
    , 70 Cal.
    Rptr. 2d 118 (1997) (Aerojet), and Continental Ins. Co.
    
    I, supra
    , 
    55 Cal. 4th 186
    .
    In the first case, Montrose I, the question before the
    court was ‘‘whether four comprehensive general liabil-
    ity . . . policies issued by [the] defendant . . . Admi-
    ral Insurance Company (Admiral) to [the] plaintiff . . .
    Montrose Chemical Corporation of California [Mon-
    trose Chemical] obligate Admiral to defend Montrose
    [Chemical] in lawsuits seeking damages for continuous
    or progressively deteriorating bodily injury and prop-
    erty damage that occurred during the successive policy
    periods.’’ Montrose 
    I, supra
    , 
    10 Cal. 4th 654
    . The losses
    were allegedly caused by the disposal of hazardous
    wastes by Montrose Chemical ‘‘at times predating the
    commencement of Admiral’s policy periods.’’
    Id. In addressing the
    ‘‘issue of when potential coverage
    is triggered under a [comprehensive general liability]
    policy where the underlying third party claims involve
    continuous or progressively deteriorating damage or
    injury’’;
    id., 661;
    the court concluded that ‘‘the continu-
    ous injury trigger of coverage9 should be applied to the
    underlying third party claims of continuous or progres-
    sively deteriorating damage or injury alleged to have
    occurred during Admiral’s policy periods. Where, as
    here, successive [comprehensive general liability] pol-
    icy periods are implicated, bodily injury and property
    damage which is continuous or progressively deterio-
    rating throughout several policy periods is potentially
    covered by all policies in effect during those periods.’’
    (Footnote added.)
    Id., 689.
    The court explained: ‘‘[I]t
    has long been understood that the standard form [com-
    prehensive general liability] policy provides liability
    coverage for damage or injury occurring during the
    policy period which results from an accident, or from
    continuous or repeated exposure to injurious condi-
    tions. There is no requirement that the sudden, acciden-
    tal damage-causing act or event, or the conditions giving
    rise to the damage or injury, themselves occur within
    the policy period in order for potential liability coverage
    to arise. . . . [W]here successive [comprehensive gen-
    eral liability] policies have been purchased, bodily
    injury and property damage that is continuing or pro-
    gressively deteriorating throughout more than one pol-
    icy period is potentially covered by all policies in effect
    during those periods.’’ (Citation omitted; emphasis
    omitted; footnote omitted.)
    Id., 686–87;
    see also Padilla
    Construction Co. v. Transportation Ins. 
    Co., supra
    , 
    150 Cal. App. 4th 987
    (explaining that, in Montrose I, the
    California Supreme Court ‘‘adopted a ‘continuous injury
    trigger’ as the test for the defense obligation of tradi-
    tional, occurrence-based primary commercial liability
    insurance when the underlying claims involve continu-
    ous or deteriorating damage’’ and that ‘‘[t]he continuous
    injury trigger generally means . . . that all primary
    insurers over the time of the alleged continuous injury
    will be obligated to defend an underlying action claim-
    ing such continuous damage’’).
    In the second case, 
    Aerojet, supra
    , 
    17 Cal. 4th 38
    ,
    the California Supreme Court adopted the ‘‘all sums’’
    approach. Specifically, the court held that, ‘‘based on
    standard policy language, in which the insurer promises
    to pay ‘all sums’ that the insured becomes legally obli-
    gated to pay as damages, the insurer’s duty to indemnify
    the insured ‘extends to all specified harm caused by an
    included occurrence, even if some such harm results
    beyond the policy period.’ ’’ California v. Continental
    Ins. Co., 
    15 Cal. App. 5th 1017
    , 1029–30, 
    223 Cal. Rptr. 3d
    716 (2017) (Continental Ins. Co. II) (quoting 
    Aerojet, supra
    , 56–57), review denied, California Supreme Court,
    Docket No. S245241 (December 20, 2017).
    Finally, in the third case, Continental Ins. Co. 
    I, supra
    , 
    55 Cal. 4th 186
    , the California Supreme Court
    addressed the issue of stacking. First, the court
    explained its prior ruling in Aerojet, noting, ‘‘the settled
    rule of the case law is that an insurer on the risk when
    continuous or progressively deteriorating [property]
    damage or [bodily] injury first manifests itself remains
    obligated to indemnify the insured for the entirety of
    the ensuing damage or injury. . . . In other words,
    under Aerojet, as long as the policyholder is insured at
    some point during the continuing damage period, the
    insurers’ indemnity obligations persist until the loss is
    complete, or terminates.’’ (Citations omitted; emphasis
    omitted; internal quotation marks omitted.)
    Id., 197.
       In light of the language of the applicable policies
    obligating the insurers to pay ‘‘ ‘all sums which the
    [i]insured shall become obligated to pay . . . for dam-
    ages . . . because of injury to or destruction of prop-
    erty’ ’’;
    id., 199;
    the court in Continental Ins. Co. I was
    constrained to apply the all sums coverage principles
    and concluded that the policies at issue obligated ‘‘the
    insurers to pay all sums for property damage attribut-
    able to [a particular waste] site, up to their policy limits,
    if applicable, as long as some of the continuous property
    damage occurred while each policy was on the loss.’’
    (Internal quotation marks omitted.)
    Id., 200.
    Specifi-
    cally, the court explained: ‘‘[T]he all sums indemnity
    coverage . . . envisions that each successive insurer
    is potentially liable for the entire loss up to its policy
    limits. When the entire loss is within the limits of one
    policy, the insured can recover from that insurer, which
    may then seek contribution from the other insurers on
    the risk during the same loss. Recognizing, however,
    that this method stops short of satisfying the coverage
    responsibilities of the policies covering a continuous
    long-tail loss, and potentially leaves the insured vastly
    uncovered for a significant portion of the loss, the . . .
    Court of Appeal allowed the insured to stack the consec-
    utive policies and recover up to the policy limits of
    the multiple plans. ‘Stacking’ generally refers to the
    stacking of policy limits across multiple policy periods
    that were on a particular risk. In other words, ‘[s]tacking
    policy limits means that when more than one policy is
    triggered by an occurrence, each policy can be called
    upon to respond to the claim up to the full limits of the
    policy.’ ’’
    Id. Accordingly, ‘‘[t]he all-sums-with-stacking
    indemnity principle properly incorporates the Montrose
    [I] continuous injury trigger of coverage rule and the
    Aerojet all sums rule, and ‘effectively stacks the insur-
    ance coverage from different policy periods to form
    one giant ‘‘uber-policy’’ with a coverage limit equal to
    the sum of all purchased insurance policies. Instead of
    treating a long-tail injury as though it occurred in one
    policy period, this approach treats all the triggered
    insurance as though it were purchased in one policy
    period. The [insured] has access to far more insurance
    than it would ever be entitled to within any one period.’
    . . . The all-sums-with-stacking rule means that the
    insured has immediate access to the insurance it pur-
    chased. It does not put the insured in the position of
    receiving less coverage than it bought. It also acknowl-
    edges the uniquely progressive nature of long-tail injur-
    ies that cause progressive damage throughout multiple
    policy periods.’’ (Citation omitted; emphasis in origi-
    nal.)
    Id., 201.
                                 C
    
          Rules of Insurance Contract Interpretation
    We next set forth the well established rules of insur-
    ance contract interpretation under California law that
    guide our analysis of the claims on appeal. The Califor-
    nia Supreme Court has stated: ‘‘Insurance policies are
    contracts and, therefore, are governed in the first
    instance by the rules of construction applicable to con-
    tracts. Under statutory rules of contract interpretation,
    the mutual intention of the parties at the time the con-
    tract is formed governs its interpretation. . . . Such
    intent is to be inferred, if possible, solely from the
    written provisions of the contract. . . . The clear and
    explicit meaning of these provisions, interpreted in their
    ordinary and popular sense, controls judicial interpreta-
    tion unless used by the parties in a technical sense, or
    unless a special meaning is given to them by usage.
    . . . If the meaning a layperson would ascribe to the
    language of a contract of insurance is clear and unam-
    biguous, a court will apply that meaning. . . .
    ‘‘In contrast, [i]f there is ambiguity . . . it is resolved
    by interpreting the ambiguous provisions in the sense
    the promisor (i.e., the insurer) believed the promisee
    understood them at the time of formation. . . . If appli-
    cation of this rule does not eliminate the ambiguity,
    ambiguous language is construed against the party who
    caused the uncertainty to exist. . . . This rule, as
    applied to a promise of coverage in an insurance policy,
    protects not the subjective beliefs of the insurer but,
    rather, the objectively reasonable expectations of the
    insured. . . . Only if this rule does not resolve the
    ambiguity do we then resolve it against the insurer.
    . . . [I]n the insurance context, we generally resolve
    ambiguities in favor of coverage. . . . Similarly, we
    generally interpret the coverage clauses of insurance
    policies broadly, [in order to protect] the objectively
    reasonable expectations of the insured. . . . These
    rules stem from the fact that the insurer typically drafts
    policy language, leaving the insured little or no meaning-
    ful opportunity or ability to bargain for modifications.’’
    (Citations omitted; internal quotation marks omitted.)
    Montrose 
    I, supra
    , 
    10 Cal. 4th 666
    –67; see also Falkow-
    ski v. Imation Corp., 
    132 Cal. App. 4th 499
    , 505–506,
    
    33 Cal. Rptr. 3d 724
    (2005), review denied, California
    Supreme Court, Docket No. S137944 (November 30,
    2005); Wells Fargo Bank, N.A. v. California Ins. Guar-
    antee Assn., 
    38 Cal. App. 4th 936
    , 942–43, 
    45 Cal. Rptr. 2d
    537 (1995). ‘‘[C]onstruction of a contract of insurance
    presents a question of law [that] this court reviews de
    novo. . . . Lexington Ins. Co. v. Lexington Healthcare
    Group, Inc., 
    311 Conn. 29
    , 37, 
    84 A.3d 1167
    (2014).
    Because all of the . . . claims on appeal relate to an
    interpretation of the [insurance] polic[ies], our review
    is plenary.’’ (Internal quotation marks omitted.) Gabriel
    v. Mount Vernon Fire Ins. Co., 
    186 Conn. App. 163
    , 167,
    
    199 A.3d 79
    (2018), cert. denied, 
    331 Conn. 903
    , 
    201 A.3d 1023
    (2019); see also Chicago Title Ins. Co. v.
    Bristol Heights Associates, LLC, 
    142 Conn. App. 390
    ,
    405, 
    70 A.3d 74
    , cert. denied, 
    309 Conn. 909
    , 
    68 A.3d 662
    (2013).
    II
    INSURANCE POLICIES OF ROYAL AND
    THE CONTINENTAL PLAINTIFFS
    A
    Royal Primary Policies
    We next set forth the terms of the primary policies
    issued by Royal, now known as Arrowood, to Rohr.
    Pursuant to comprehensive general liability policy RLP
    144014, Royal agreed ‘‘[t]o pay on behalf of the insured
    all sums which the insured shall become legally obli-
    gated to pay as damages because of injury to or destruc-
    tion of property, including the loss of use thereof.’’ The
    policy period covered August 1, 1959, to August 1, 1962,
    and provided coverage in the amount of $2 million in
    the aggregate annually and $2 million per occurrence
    during the policy period. An occurrence is defined as
    ‘‘an event or continuous or repeated exposure to condi-
    tions, which unexpectedly cause injury or damage dur-
    ing the policy period. All such exposure to substantially
    the same general conditions or arising from the same
    cause shall be deemed one occurrence.’’ Pursuant to
    the policy declarations, ‘‘[t]he policy period stated in
    the declaration is comprised of three consecutive
    annual periods.’’
    The policy is also subject to the following condition:
    ‘‘The limit of liability stated in the declarations as appli-
    cable to ‘each occurrence’ is the limit of the Company’s
    liability for all damages, including damages for care and
    loss of services arising out of bodily injury, sickness or
    disease, including death at any time resulting therefrom
    sustained by one or more persons or damages arising
    out of injury to or destruction of all property of one or
    more persons or organizations, including the loss of use
    thereof, as a result of any one occurrence, regardless
    of whether such damages are payable under one or
    more coverages. Subject to the limit of liability with
    respect to ‘each occurrence,’ the limit of liability stated
    in the declarations as ‘aggregate’ is the total limit of
    the Company’s liability with respect to all occurrences
    taking place during any annual term of this policy.’’
    Policy RLP 144014 was extended by three years from
    August 1, 1962, to August 1, 1965, pursuant to a renewal
    certificate, which provided that the same terms and
    conditions in the policy would continue in full force
    and effect.
    Royal also issued to Rohr comprehensive general
    liability policy RTS 902235. The policy period for that
    policy was in effect from August 1, 1965, to August 1,
    1968, and it also provided coverage in the amount of
    $2 million per occurrence and $2 million in the aggre-
    gate per annual period. Policy RTS 902235 contained
    essentially the same terms, conditions, definitions and
    exclusions as policy RLP 144014. Policy RTS 902235 was
    extended for a second three year period from August
    1, 1968, to August 1, 1971.
    B
    Harbor and London Excess Policies
    1
    Harbor Excess Policies
    Harbor Insurance Company (Harbor) issued a num-
    ber of excess comprehensive liability policies to Rohr.
    The language of policy 102211 is indicative of many of
    those policies, and, therefore, we discuss it more fully
    herein.10 Policy 102211, which was in effect from August
    1, 1964, to August 1, 1967, provided coverage limits of
    up to $5 million per occurrence and $5 million in the
    aggregate per policy year. An occurrence is ‘‘deemed
    to have the same meaning . . . as is attributed to [it]
    in the [policies] of the primary insurers,’’ and a policy
    year is defined as ‘‘a period of one calendar year . . . .’’
    Harbor excess policy 102211 identifies Royal primary
    policy RLP 144014 as a primary insurance policy with
    respect to comprehensive general liability.
    Pursuant to policy 102211, Harbor agreed ‘‘to pay on
    behalf of the Assured all sums which the Assured shall
    become legally obligated to pay, or by final judgment
    be adjudged to pay, to any person or persons as dam-
    ages . . . (b) for damage to or destruction of property
    of others . . . occurring during the period of this Insur-
    ance . . . .’’ Furthermore, liability attaches to the
    insurer ‘‘only in respect of such hazards as are set forth
    in item 1 of the [accompanying] Schedule and . . . only
    after the Primary and Underlying Excess Insurers have
    paid or have been held liable to pay the full amount of
    their respective ultimate net loss liability . . . .’’ Specif-
    ically, the policy states that liability to pay shall not
    attach ‘‘unless and until the Primary and Underlying
    Excess Insurers shall have admitted liability for the
    Primary and Underlying Excess Limit(s) or unless and
    until the Assured has by final judgment been adjudged
    to pay an amount which exceeds such Primary and
    Underlying Excess Limit(s) and then only after the Pri-
    mary and Underlying Excess Insurers have paid or have
    been held liable to pay the full amount of the Primary
    and Underlying Excess Limit(s).’’ Finally, the policy
    defines ‘‘ultimate net loss’’ to mean ‘‘the amount payable
    in settlement of the liability of the Assured after making
    deductions for all recoveries and for other valid and
    collectible insurances, excepting, however, the policy/
    ies of the Primary and Underlying Excess Insurers, and
    shall exclude all expenses and Costs.’’11
    2
    London Excess Policies
    Paragraph 159 of the complaint alleges that certain
    of the plaintiffs, including Lloyd’s, Scottish Lion, Ocean
    Marine, Winterthur Swiss Insurance Corporation, Ltd.,
    Tenecom, formerly known as Yasuda Insurance Com-
    pany, Nissan Fire & Marine Insurance Company, Ltd.,
    and NRG N.V., ‘‘individually severally subscribed, each
    in his/her/its own proportionate share and not for any
    other,’’ to sixteen listed excess liability insurance poli-
    cies, which are collectively referred to in this opinion
    as the London excess policies.12 The complaint further
    alleges that ‘‘[t]he London excess policies provide limits
    of liability in excess of the underlying insurance, which
    must be exhausted before’’ there is any liability to pay
    under those excess policies.
    Like the Harbor excess policies, the London excess
    policies contain similar provisions governing the attach-
    ment of liability and defining ultimate net loss, although
    they vary in the amount of coverage provided for an
    occurrence. For example, the London excess policies
    contain the following or similar provision regarding
    the attachment of liability: ‘‘Liability to pay under this
    Insurance shall not attach unless and until the Primary
    and Underlying Excess Insurers shall have admitted
    liability for the Primary and Underlying Excess Limit(s)
    or unless and until the Assured has by final judgment
    been adjudged to pay an amount which exceeds such
    Primary and Underlying Excess Limit(s) and then only
    after the Primary and Underlying Excess Insurers have
    paid or have been held liable to pay the full amount
    of the Primary and Underlying Excess Limit(s).’’13 The
    London excess policies similarly define ultimate net
    loss to mean ‘‘the amount payable in settlement of the
    liability of the Assured after making deductions for all
    recoveries and for other valid and collectible insur-
    ances, excepting however the policy/ies of the Primary
    and Underlying Excess Insurers, and shall exclude all
    expenses and Costs.’’
    3
    Whether the Harbor and London Excess Policies
    Are Specific or General Excess Policies
    Before we can address the claims raised in this
    appeal, we must first determine whether the trial court
    properly concluded that the Harbor excess policies and
    the London excess policies are general, instead of spe-
    cific, excess policies.
    Rohr claims that ‘‘the language in nearly all of the
    excess policies here [shows that they] are excess to
    specifically identified underlying policies and/or to a
    specified sum of underlying limits and, therefore,
    clearly require vertical exhaustion.’’ Rohr further
    alleges that the court in Community Redevelopment
    Agency v. Aetna Casualty & Surety 
    Co., supra
    , 50 Cal.
    App. 4th 329, ‘‘recognized that where a policy provides
    that it is excess only to a specific underlying policy,
    vertical exhaustion applies.’’ In opposition, the Conti-
    nental plaintiffs contend that the Harbor and London
    excess policies are general excess policies, to which
    the rule of horizontal exhaustion applies. Specifically,
    they claim that, ‘‘[h]ere, because the excess policies
    provide that they are excess above the other insurance
    which contribute[s] to payment of the loss, along with
    the specified primary insurance, they are similarly not
    limited to only the specifically described underlying
    insurance.’’ They further assert that ‘‘Rohr’s contention
    that the excess policies’ attachment point is dependent
    only on the payment of a single specified sum is contrary
    to the policies’ ultimate net loss and other insurance
    provisions, as well as the [holding] in Peerless [Casualty
    Co. v. Continental Casualty Co., 
    144 Cal. App. 2d 617
    ,
    
    301 P.2d 602
    (1956)]14 . . . . Accordingly, when read-
    ing the schedule of underlying insurance and attach-
    ment of liability and ultimate net loss provisions
    together, it is clear the excess policies are only reached
    once the underlying insurers have paid or been held
    liable to pay and the calculation of ultimate net loss,
    which reduces the amounts of ‘all recoveries’ and ‘for
    valid and collectible insurances,’ including all insurance
    not directly underlying (which, in turn, must be
    exhausted by payment).’’ (Footnote added.)
    In its memorandum of decision, the trial court
    addressed this issue and stated: ‘‘In this case, while the
    schedule pages of the excess policies reference the
    Royal primary policy RLP 144014, the excess policies
    specifically provide that the policies will attach ‘only
    after the Primary and Underlying Excess Insurers
    have paid or have been held liable to pay the full
    amount of the Primary and Underlying Excess Lim-
    it(s).’ . . . Based upon this language, the Harbor and
    London policies provide for the upper layer excess poli-
    cies to pay their respective limits only once the insured
    has recovered all proceeds from all valid and collectible
    underlying insurance, including all primary policies.
    ‘‘That the excess policies make reference to15 the
    Royal primary policy in the schedule or declaration is
    not enough, in and of itself, to warrant a conclusion
    that the policies are ‘specific excess’ and subject to a
    vertical exhaustion allocation scheme; as previously
    stated, horizontal exhaustion is the rule in California
    in long-tail cases unless specific policy language both
    describes and limits the underlying policies. . . .
    Moreover, there are no other specific references here
    to the Royal primary policies, which, when read in con-
    junction with the ‘ultimate net loss’ and ‘other insur-
    ance’ provisions, would overcome the usual presump-
    tion requiring exhaustion of all primary coverage
    policies in effect during the period of continuing dam-
    age. Liability under the Harbor and London [excess]
    policies, therefore, attaches only after all primary poli-
    cies have been exhausted. Accordingly, the Harbor and
    London policies, construed in their entirety, are general
    excess policies, and liability under these contracts will
    not attach before all primary insurance has been
    exhausted.’’ (Citation omitted; emphasis in original;
    footnote added.) We agree with the trial court’s con-
    clusion.
    We find Community Redevelopment Agency v. Aetna
    Casualty & Surety 
    Co., supra
    , 
    50 Cal. App. 4th 329
    ,
    instructive on this issue. In that case, the court stated:
    ‘‘[W]e must conclude that when a policy which provides
    excess insurance above a stated amount of primary
    insurance contains provisions which make it also
    excess insurance above all other insurance which con-
    tributes to the payment of the loss together with specifi-
    cally stated primary insurance, such clause will be given
    effect as written. . . . In other words, an excess
    insurer can require in its policy that all primary insur-
    ance be first exhausted. Consistent with the horizontal
    rule, that is what [the excess insurer] effectively did in
    this case. Because exhaustion of all available primary
    (or underlying) insurance never occurred, [the excess
    insurer’s] duty, under the terms of its policy, to ‘drop
    down’ and provide a defense never arose.’’ (Citation
    omitted; emphasis in original.)
    Id., 341;
    see also Peerless
    Casualty Co. v. Continental Casualty 
    Co., supra
    , 
    144 Cal. App. 2d 626
    ; cf. Travelers Casualty & Surety Co.
    v. Transcontinental Ins. Co., 
    122 Cal. App. 4th 949
    , 959,
    
    19 Cal. Rptr. 3d 272
    (2004) (concluding that, unlike in
    Community Redevelopment Agency, language of
    excess policy was ‘‘ ‘sufficiently clear’ ’’ to trigger
    defense obligations of excess insurer upon exhaustion
    of underlying insurance as defined in policy, regardless
    of existence of other insurance), review denied, Califor-
    nia Supreme Court, Docket No. S127264 (September
    29, 2004).
    In St. Paul Fire & Marine Ins. Co. v. Ins. Co. of the
    State of 
    Pennsylvania, supra
    , 
    2017 WL 897437
    , *14,
    the court further explained: ‘‘California courts consider
    specific excess policies to be on a lower level than
    general excess policies and, thus, specific excess poli-
    cies must pay before general excess policies. . . . In
    cases involving continuing losses over multiple years,
    thus triggering multiple annual policies, the default in
    California is for an excess insurance policy to be a
    general excess policy. . . . However, this default is
    rebutted if the insurance policy contains language stat-
    ing that the policy is excess to a specific underlying
    policy. . . . Even where a specific underlying policy is
    listed, other provisions in the policies such as the ‘other
    insurance’ provision may indicate that the policy
    remains a general excess policy.’’ (Citations omitted.)
    In the present case, the Harbor and London excess
    policies contain similar language providing that liability
    shall attach to the insurer only after the primary and
    underlying excess insurers have paid or have been held
    liable to pay the full amount of the primary and underly-
    ing excess limits or their respective ultimate net loss
    liability, which is defined as an amount payable in settle-
    ment of the liability of the insured ‘‘after making deduc-
    tions for all recoveries and for other valid and collect-
    ible insurances . . . .’’ (Emphasis added.) The policies
    of those excess insurers, which clearly require that the
    primary insurance first be exhausted before any obliga-
    tions of those excess insurers arise and contain provi-
    sions making those policies excess above ‘‘other valid
    and collectible insurances,’’ do not contain language
    specifically limiting those policies to be excess above
    only the Royal primary policy. See Travelers Casualty &
    Surety Co. v. Transcontinental Ins. 
    Co., supra
    , 122 Cal.
    App. 4th 959. Accordingly, we conclude that the trial
    court properly determined that the Harbor and London
    excess policies are general excess policies.16
    C
    Harbor Umbrella Policy
    Harbor umbrella policy 108909 contains some terms
    that vary from the other Harbor excess policies. The
    limit of liability in the Harbor umbrella policy is $3
    million per occurrence and $3 million in the aggregate,
    and the policy is excess to, inter alia, Royal primary
    policy RTS 902235, and Harbor excess policies 108908
    and 108907. Pursuant to the ‘‘Loss Payable’’ provision
    of the umbrella policy, liability with respect to any
    occurrence ‘‘shall not attach unless and until the
    Assured, or the Assured’s Underlying Insurer, shall have
    paid the amount of the underlying limits on account of
    such occurrence.’’ The ‘‘Limit of Liability’’ provision
    states that, ‘‘[i]n the event of reduction or exhaustion
    of the aggregate limits of liability under said underlying
    insurance by reason of losses paid thereunder, this
    Insurance shall (1) in the event of reduction pay the
    excess of the reduced underlying limit; (2) in the event
    of exhaustion continue in force as underlying insur-
    ance.’’ Under the ‘‘Other Insurance’’ clause, ‘‘[i]f other
    valid and collectible coverage with any other Insurer
    is available to the Assured covering a loss also covered
    by this Insurance, other than coverage that is in excess
    of the Insurance afforded hereunder, the Insurance
    afforded hereunder shall be in excess of and shall not
    contribute with such other Insurance. Nothing herein
    shall be construed to make this Insurance subject to
    the terms, conditions and limitations of other Insur-
    ance.’’ The trial court, after examining those provisions,
    stated: ‘‘The umbrella policy’s language thus provides
    that, in the event that a loss is not fully covered under
    the underlying insurances, the umbrella policy itself
    will continue to provide coverage as though it were an
    underlying insurance policy. The policy’s plain language
    also provides that, if a loss is covered by the underlying
    insurance, then the policy shall not contribute with the
    underlying insurance policy. Additionally, the language
    plainly provides that, in the event the underlying insur-
    ance is exhausted, then the Harbor umbrella policy has
    the capacity to continue on as underlying insurance, or
    act as an excess insurance policy.
    ‘‘In these circumstances, there exists valid and col-
    lectible insurance in the form of the Royal primary
    policy [RTS] 902235. According to its plain terms, the
    Harbor umbrella policy shall not contribute with the
    Royal primary policy. Additionally, if the Royal primary
    policy has exhausted its limits, then the Harbor
    umbrella policy will continue as underlying insurance,
    or act as excess insurance. Both options under the
    Harbor policy contemplate that the underlying primary
    insurer shall have paid its underlying limits before liabil-
    ity attaches under the policy. If the underlying primary
    insurance has not been exhausted, then liability shall
    not attach under the Harbor umbrella policy.’’ We will
    address whether liability has attached under the Harbor
    umbrella policy in part III C of this opinion.
    III
    THE CONTINENTAL PLAINTIFFS’ MOTION
    FOR PARTIAL SUMMARY JUDGMENT
    The trial court explained the essence of the dispute
    between the parties as follows: ‘‘For purposes of the
    present motions for summary judgment, there is no real
    dispute regarding the relevant facts . . . [including]
    . . . the fact that the underlying claims arise from
    alleged damages resulting over the course of decades
    from the gradual or continuous release of toxic chemi-
    cals into the environment. Nor do the parties disagree
    regarding the fact that Rohr reached a settlement with
    its primary insurer and the dollar amount of that set-
    tlement.17
    ‘‘The issues before the court, therefore, are purely
    questions of law, namely, the interpretation of the terms
    of the various insurance policies issued to Rohr by
    the excess insurers, and the legal effect, if any, of the
    settlement on the excess insurers’ liability to Rohr in
    light of that interpretation. Central to the resolution of
    these issues is the court’s interpretation of language
    in Rohr’s primary and excess [comprehensive general
    liability] policies. A key point of disagreement is the
    interpretation of provisions in Rohr’s primary [compre-
    hensive general liability] policies defining the limits of
    liability under those policies. The excess insurers main-
    tain that the $2 million ‘per occurrence’ and ‘aggregate’
    limits in the primary policies, under the circumstances
    of this case, effectively provide $2 million of coverage
    per year that the policies were in effect, for a total
    effective limit of $24 million that must be exhausted
    before the excess policies may be accessed. Rohr, on
    the other hand, takes the position that the primary pol-
    icy limits are exhausted once $2 million have been paid
    out for any one occurrence, and that the excess policies
    become accessible at that point.’’ (Footnote added; foot-
    note omitted.)
    We first address Rohr’s claims on appeal with respect
    to the judgment of the trial court granting the motion
    for partial summary judgment filed by the Continen-
    tal plaintiffs.
    A
    Per Occurrence Limits
    Rohr’s first claim on appeal is that the trial court
    erred in concluding that the Royal primary policies pro-
    vided per occurrence limits of $8 million. Specifically,
    Rohr claims that the trial court’s conclusion that there
    was $8 million in per occurrence coverage under the
    Royal primary policies was improper because the court
    ‘‘incorrectly treated each of the two policies, and each
    of the two policy extensions, as providing separate $2
    million limits that could be added together.’’ We agree.
    The following additional facts are necessary to our
    resolution of this claim. As stated previously, there are
    two Royal primary policies that are directly at issue in
    the present case, each of which covered a three year
    period and was extended for an additional three years:
    policy RLP 144014, which was in effect between August
    1, 1959, and August 1, 1962, and was extended to cover
    the period between August 1, 1962, and August 1, 1965;
    and policy RTS 902235, which was in effect between
    August 1, 1965, and August 1, 1968, and was extended
    to cover the period between August 1, 1968, and August
    1, 1971. Both policies provided coverage in the amount
    of $2 million in the aggregate and $2 million per occur-
    rence and similarly define an occurrence as follows:
    ‘‘ ‘Occurrence’ means an event or continuous or
    repeated exposure to conditions which unexpectedly
    cause injury or damages during the policy period. All
    such exposure to substantially the same general condi-
    tions or arising from the same cause shall be deemed
    one occurrence.’’ (Emphasis added.)
    In support of its claim, Rohr relies on the language
    of the limit of liability clause in each of the policies,
    which provides that ‘‘[t]he limit of liability stated in the
    declarations as applicable to ‘each occurrence’ is the
    limit of the Company’s liability for all . . . damages
    arising out of injury to or destruction of all property of
    one or more persons or organizations . . . as a result
    of any one occurrence, regardless of whether such dam-
    ages are payable under one or more coverages.’’
    According to Rohr, pursuant to this plain language,
    liability under the Royal primary policies ‘‘can be no
    more than $2 million for a single occurrence no matter
    how many years or how many policies of the [insurer]
    are implicated by the occurrence.’’ In claiming that the
    policies make a distinction between aggregate and per
    occurrence limits, Rohr further relies on the language
    of the limit of liability provision providing that ‘‘[s]ub-
    ject to the limit of liability with respect to ‘each occur-
    rence’, the limit of liability stated in the declarations
    as ‘aggregate’ is the total limit of the Company’s liability
    with respect to all occurrences taking place during any
    annual term of this policy.’’ (Emphasis added.) Because
    the policies include language demonstrating that the
    aggregate limit is annualized and omit such language
    as to the per occurrence limit, Rohr claims that it is
    clear from the policies that the per occurrence limits
    of $2 million cannot be annualized. In support of its
    claim that a single occurrence can take place over multi-
    ple years, Rohr relies on the definition of an occurrence
    as meaning ‘‘an event or continuous or repeated expo-
    sure to conditions’’ that causes injury or damage, and
    the limiting language that the exposure to substantially
    the same conditions arising from the same cause ‘‘shall
    be deemed one occurrence.’’ Thus, Rohr alleges that
    the environmental contamination that occurred over
    the period of 1959 to 1971 covered by the policies consti-
    tuted a single occurrence and resulted in coverage of
    $2 million for that one occurrence.18 Finally, Rohr claims
    that the three year extension of each policy did not
    provide additional per occurrence limits and that,
    ‘‘[e]ven if each of the two Royal [primary] policies pro-
    vided separate per occurrence limits . . . then, at
    most, the two Royal policies provide a total of $4 million
    in per occurrence limits.’’
    Contrary to Rohr’s claims, the Continental plaintiffs
    claim that the Royal primary policies that were in effect
    from 1959 to 1971 have annual per occurrence limits
    of $2 million, for a total liability over the twelve years
    of $24 million. In support of their claim, the Continental
    plaintiffs rely primarily on the language of the three
    year policy period endorsements, which provide that
    ‘‘[t]he policy period stated in the declaration is com-
    prised of three consecutive annual periods.’’ According
    to the Continental plaintiffs, those endorsements dem-
    onstrate that the Royal primary policy periods ‘‘are to
    be treated as annual periods, each subject to a per
    occurrence limit,’’ rather than ‘‘as a multiyear policy
    with a single per occurrence limit,’’ and that ‘‘[t]he ‘pol-
    icy period’ of each multiyear Royal primary policy is
    specifically defined by endorsement as ‘three consecu-
    tive annual periods.’ ’’ (Emphasis omitted.) The Conti-
    nental plaintiffs also rely on Stonewall Ins. Co. v. Palos
    Verdes Estates, 
    46 Cal. App. 4th 1810
    , 1849, 
    54 Cal. Rptr. 2d
    176 (1996) (Stonewall), review denied, California
    Supreme Court, Docket No. S027319 (October 23, 1996),
    in support of their position.
    1
    Annualization
    In order for this court to resolve the first issue raised
    on appeal, we must first determine whether the per
    occurrence limit of $2 million may be annualized pursu-
    ant to the terms of the policies. As stated previously,
    the interpretation of an insurance contract involves a
    question of law over which we must exercise de novo
    review. See Chicago Title Ins. Co. v. Bristol Heights
    Associates, 
    LLC, supra
    , 
    142 Conn. App. 405
    ; Nation-
    wide Mutual Ins. Co. v. Allen, 
    83 Conn. App. 526
    , 537,
    
    850 A.2d 1047
    , cert. denied, 
    271 Conn. 907
    , 
    859 A.2d 562
    (2004).
    ‘‘Words used in an insurance policy are to be interpre-
    ted according to the plain meaning which a layman
    would ordinarily attach to them. Courts will not adopt
    a strained or absurd interpretation in order to create
    an ambiguity where none exists.’’ Reserve Ins. Co. v.
    Pisciotta, 
    30 Cal. 3d 800
    , 807, 
    640 P.2d 764
    , 180 Cal.
    Rptr. 628 (1982); see also Legacy Vulcan Corp. v. Supe-
    rior 
    Court, supra
    , 
    185 Cal. App. 4th 688
    (‘‘We interpret
    words in accordance with their ordinary and popular
    sense, unless the words are used in a technical sense
    or a special meaning is given to them by usage. . . .
    If contractual language is clear and explicit and does
    not involve an absurdity, the plain meaning governs.’’
    (Citation omitted.)). ‘‘In California, a contract must be
    interpreted ‘to give effect to the mutual intention of the
    parties as it existed at the time of contracting.’ . . . If
    possible, the Court will infer that mutual intention
    solely from the plain language of the contract, read as
    a whole.’’ (Citation omitted.) Atain Specialty Ins. Co.
    v. Sierra Pacific Management Co., Docket No. 2:14-cv-
    00609 (TLN), 
    2016 WL 6568678
    , *2 (E.D. Cal. November
    3, 2016), aff’d, 
    725 Fed. Appx. 557
    (9th Cir. 2018).
    In addressing this issue, the trial court agreed with
    Rohr that the aggregate limits and the per occurrence
    limits are treated differently in the policies. After setting
    forth the limit of liability provision of the policies, the
    court explained: ‘‘The first sentence of the clause
    defines the limits of what the policy will pay for one
    occurrence, whether the damages ‘are payable under
    one or more coverages.’ The insuring agreements define
    the three types of coverage provided under the policy:
    Coverage A (bodily injury), Coverage B (property dam-
    age), and Coverage C (malpractice). The plain meaning
    of this language is that if one occurrence results in more
    than one type of injury as defined under the available
    coverages, the policy limit for one occurrence is a total
    of $2 million for the combined injuries. The natural,
    unrestrained reading of the clause is that if one occur-
    rence results in both bodily injury and property damage,
    the policy’s limits do not provide coverage in the
    amount of $2 million for bodily injury and an additional
    $2 million for property damage. Instead, the combined
    bodily injury and property damage arising from that
    occurrence are subject to a limit of $2 million per
    occurrence.
    ‘‘The second sentence under the limits of liability
    clause defines the policies’ aggregate limits. The lan-
    guage provides that the aggregate limit is ‘subject to’
    the per occurrence limit, and that the aggregate limit
    is the total amount of coverage that the policy will
    provide for all occurrences ‘during any annual term.’
    The Royal policies do not define ‘aggregate.’ Accord-
    ingly, critical to construction of the policies’ terms is
    the meaning of the word ‘aggregate’ as interpreted in
    its ordinary and popular sense. ‘Aggregate,’ as an adjec-
    tive, is defined to mean ‘formed by the collection of
    units or particles into a body, mass, or amount.’ Mer-
    riam-Webster’s Collegiate Dictionary (10th Ed. 2000).
    As a noun, ‘aggregate’ means ‘the whole sum or amount:
    sum total.’ . . .
    Id. Thus, the most
    natural reading of
    the clause is that, regardless of the number of occur-
    rences causing injury within one annual term (one year)
    of the policy, the greatest amount of coverage that the
    policy will provide in that year is $2 million. Therefore,
    if one occurrence had already resulted in payment of
    $500,000 in claims, and a second occurrence within the
    annual term yields $2 million in claims, the greatest
    amount of coverage that the policy will provide for the
    second occurrence is $1.5 million.’’ (Footnote omitted.)
    The trial court found that the reference to ‘‘ ‘any
    annual term’ ’’ only in the aggregate limit of liability
    clause demonstrated an intent of the parties to treat
    the aggregate and per occurrence limits differently. The
    court concluded that ‘‘a natural, unrestrained reading
    of the limits of liability clauses compels an interpreta-
    tion that the first sentence sets a per occurrence limit
    for the three year policy period, while the second sen-
    tence establishes an aggregate limit for multiple occur-
    rences during any annual term.’’ (Emphasis in origi-
    nal.) Thus, the court concluded that the per occurrence
    limits could not be annualized.19 We agree with that con-
    clusion.
    The plain language of the Royal primary policies ref-
    erencing an annual term in the sentence defining the
    aggregate limit of liability in the declarations, while
    making no such reference to an annual time period in
    the sentence defining the limit of liability with respect
    to each occurrence as stated in the declarations, indi-
    cates a clear intent of the parties that the reference to
    ‘‘any annual term’’ applies to the aggregate limit only.
    See Northrop Grumman Corp. v. Factory Mutual Ins.
    Co., 
    805 F. Supp. 2d 945
    , 952 (C.D. Cal. 2011) (failure
    of insurer to include limiting language in insurance con-
    tract with respect to certain peril, even though insurer
    had done so within same section for another peril, indi-
    cated intent of parties not to so limit coverage); see
    also Fireman’s Fund Ins. Cos. v. Atlantic Richfield
    Co., 
    94 Cal. App. 4th 842
    , 852, 
    115 Cal. Rptr. 2d 26
    (2001) (‘‘an insurance company’s failure to use available
    language to exclude certain types of liability gives rise
    to the inference that the parties intended not to so limit
    coverage’’). The policy period for each policy as set
    forth in the declarations is a three year period, and the
    language of each policy providing coverage of $2 million
    for each occurrence is not stated in terms of per occur-
    rence, per year. The provisions are not ambiguous, and
    we must read them as written. See Continental Ins.
    Co. I
    I, supra
    , 
    15 Cal. App. 5th 1031
    (‘‘[i]f contractual
    language is clear and explicit, it governs’’ (internal quo-
    tation marks omitted)); Peerless Casualty Co. v. Conti-
    nental Casualty 
    Co., supra
    , 
    144 Cal. App. 2d 626
    (insur-
    ance clause ‘‘will be given effect as written’’).
    We are not persuaded by the claim of the Continental
    plaintiffs that ‘‘[t]he ‘policy period’ of each multiyear
    Royal primary policy is specifically defined by endorse-
    ment as ‘three consecutive annual periods.’ ’’ (Emphasis
    omitted.) Each policy contains an endorsement titled,
    ‘‘Three Year Policy Period,’’ which provides in part: ‘‘It
    is agreed that such insurance as is afforded by the policy
    applies subject to the following provision: (1) The policy
    period stated in the declaration is comprised of three
    consecutive annual periods.’’ That endorsement does
    not define a policy period as three consecutive annual
    periods; rather, it states that the three year policy period
    is ‘‘comprised’’ of three annual periods. (Emphasis
    added.) Comprised is defined by Merriam-Webster’s
    Dictionary as ‘‘to be made up of . . . compose; consti-
    tute . . . .’’ Merriam-Webster’s Collegiate Dictionary
    (10th Ed. 1998) p. 237. The endorsement simply states
    that the three year policy period is made up of three
    annual periods, which is relevant in that rates are based
    on annual periods, as further stated in the endorsement.
    Nowhere in the policies or the endorsements is the
    policy period defined as three consecutive annual peri-
    ods, so that each year is a separate policy period, as
    alleged by the Continental plaintiffs.
    Moreover, the reliance on 
    Stonewall, supra
    , 46 Cal.
    App. 4th 1810, by the Continental plaintiffs is misplaced.
    The policy at issue in that case was for a three year
    period from November 1, 1975, to November 1, 1978.
    Id., 1849.
    The policy covered ‘‘liability for property damage
    with limits per [an attached endorsement]. There [were]
    three separate endorsements for the years 1975 through
    1978, each including a limit of $300,000 per occurrence
    and in the aggregate and a deductible of $1,000 per
    claim. There [were] three separate [d]eclarations, each
    for a separate policy period.’’ (Internal quotation marks
    omitted.)
    Id. The trial court
    in that case concluded that
    the subject policy ‘‘covered three separate periods with
    a limit of $300,000 for each period, an aggregate of
    $900,000 in coverage. [The insurer] argue[d] that its
    policy included one $300,000 limit applicable to the
    entire three-year period.’’
    Id. The California Court
    of
    Appeal agreed with the trial court, finding that the pol-
    icy was ambiguous and that the ambiguity had to be
    construed against the insurer.
    Id. Moreover, the ambigu-
    ity was resolved against the insurer also on the basis
    of a stipulation it had entered into, which provided that
    ‘‘ ‘[t]he subject policies of insurance issued by . . . [the
    insurer] . . . provided coverage of $300,000 per occur-
    rence per year as respects property damage.’ ’’ (Empha-
    sis added.)
    Id. In the present
    case, each Royal primary policy con-
    tained one endorsement providing for a policy period
    of three years and setting the limit of coverage at $2
    million per occurrence, which is factually different from
    the three separate endorsements at issue in Stonewall,
    each of which set forth a per occurrence limit of
    $300,000. Nor is there any language in the Royal primary
    policies or their declarations providing for coverage
    on a per occurrence, per year basis. We, therefore,
    conclude that Stonewall is distinguishable from the
    present case. Accordingly, the per occurrence language
    of each Royal primary policy provides coverage of up
    to $2 million for an occurrence that takes place during
    the policy period and not for each year of that policy
    period.
    2
    Policy Extensions
    Having determined that the per occurrence limits of
    the Royal primary policies may not be annualized under
    the terms of those policies, we next address Rohr’s
    claim that the extensions of the two Royal primary
    policies did not result in additional per occurrence lim-
    its. We agree.
    Rohr’s claim is based on its assertion that the
    endorsements did not create new stand-alone policies
    but, rather, simply extended the policy period for each
    policy. Thus, Rohr claims, ‘‘[a]t most, the two Royal
    policies together provide a total of $4 million in per
    occurrence limits,’’ and that because Arrowood, as suc-
    cessor to Royal, paid more than $4 million in settling
    with Rohr, the policies were exhausted and, thus, the
    trial court improperly rendered summary judgment in
    favor of the Continental plaintiffs on this issue. Rohr
    relies on A.B.S. Clothing Collection, Inc. v. Home Ins.
    Co., 
    34 Cal. App. 4th 1470
    , 
    41 Cal. Rptr. 2d 166
    (1995)
    (A.B.S. Clothing), review denied, California Supreme
    Court, Docket No. S047360 (August 10, 1995), in support
    of its claim. That case involved a breach of contract
    action by a policyholder against its insurance company
    and concerned the following issue: ‘‘When an employee
    embezzles funds from an employer over a period of
    years during which the employer carries insurance
    against employee dishonesty from the same insurer,
    may the employer recover up to the insurer’s limit of
    liability for each year in which the embezzlement
    occurs?’’
    Id., 1473.
    The insurer had ‘‘issued a separate
    policy document each year. Each policy was effective
    for a specified ‘policy period’ [of one year]. The second
    policy stated it was a ‘renewal’ of the first; the third
    stated it was a ‘renewal’ of the second.’’
    Id., 1483.
    Rohr
    points to the fact that, in finding that the parties had
    entered into separate, independent contracts, the court
    in A.B.S. Clothing ‘‘considered that the insure[d] [had]
    issued three separate policies, each with different pol-
    icy numbers and policy periods, notwithstanding that
    the second and third policies were identified as ‘renew-
    als.’ ’’ Thus, Rohr asserts that because those circum-
    stances are different from those in the present case,
    the extensions here merely constituted continuations
    of the original contracts.
    The Continental plaintiffs disagree with Rohr’s con-
    tention that the two policy extensions did not constitute
    separate contracts with separate policy limits. Instead,
    they claim that because endorsements to the Royal
    primary policies state that the policy period ‘‘ ‘is com-
    prised of three consecutive annual periods,’ ’’ each three
    year policy and each three year extension, at a mini-
    mum, ‘‘constitute separate policy periods, totaling four
    policy periods.’’ The Continental plaintiffs cite A.B.S.
    
    Clothing, supra
    , 
    34 Cal. App. 4th 1476
    , for the proposi-
    tion that, ‘‘[w]here indemnity is afforded through sepa-
    rate and distinct contracts for specific policy periods
    the insurer is generally held liable up to its limit of
    liability for each policy period.’’ Furthermore, to sup-
    port their claim that the policy extensions for each
    policy do not constitute one continuous contract, they
    claim that A.B.S. Clothing left open one situation in
    which an extension does not constitute a new policy
    with a new contract period, namely, ‘‘where the terms
    of the contract, taken as a whole, establish an intention
    the policy be continued indefinitely . . . .’’20 (Empha-
    sis added.)
    Id. We first examine
    the general rules governing insur-
    ance contract renewals or extensions, and the decision
    in A.B.S. Clothing before addressing the merits of the
    parties’ claims. ‘‘Renewal or to renew means the issu-
    ance and delivery by an insurer of a policy replacing
    at the end of the policy period a policy previously issued
    and delivered by the same insurer, or the issuance and
    delivery of a certificate or notice extending the term
    of a policy beyond its policy period or term . . . .’’
    (Internal quotation marks omitted.) Borders v. Great
    Falls Yosemite Ins. Co., 
    72 Cal. App. 3d 86
    , 93, 140 Cal.
    Rptr. 33 (1977). ‘‘The renewal of insurance contracts
    may raise many questions, including whether there is
    a right to renew, whether nonrenewal has been effected
    in accordance with the terms of all relevant policy and
    statutory provisions, and whether a renewal, once
    effected, is to be regarded as a continuation or exten-
    sion of the original policy or as a new policy or contract
    of insurance. An accurate definition of renewal cannot
    be made until it is first determined whether the renewal
    takes effect as an extension or continuation of the origi-
    nal policy or whether it represents the formation of a
    new, although identical, contract of insurance.’’ 2 S.
    Plitt et al., Couch on Insurance (3d Ed. Rev. 2010) § 29:1,
    p. 29-4. Moreover, ‘‘[w]hether the renewal of a policy
    constitutes a new and independent contract or continu-
    ation of the original contract primarily depends upon
    the intention of the parties as ascertained from the
    instrument itself. In the absence of any contrary statu-
    tory provision, the parties may effectively designate that
    the renewal policy shall be regarded as a continuation
    of the policy or that it shall not be so regarded. Accord-
    ingly, it has been held that the rule that a renewal policy
    constitutes a separate and distinct contract for the
    period of time covered by the renewal does not apply
    where the extension agreement shows a contrary inten-
    tion as by stipulating that the original agreement ‘con-
    tinues in force.’ ’’ (Emphasis added; footnotes omitted.)
    Id., § 29:33, p.
    29-65. ‘‘In the absence of a clear provision
    in the policy defining the nature of the renewal, some
    courts regard the renewed or renewal contract as
    though it were merely a continuation or extension of
    the original contract. By this view, the renewal of a
    policy continues it in force without interruption, and
    the renewal certificate is simply a contract to continue
    in force a preexisting policy of insurance.’’ (Footnotes
    omitted.)
    Id., § 29:35, p.
    29-68.
    In California, ‘‘[t]he renewal of an insurance policy
    constitutes a separate and distinct contract for the
    period of time covered by the renewal and is not a
    continuous contract ‘unless there is clear and unambig-
    uous language showing the parties intended to enter
    into one continuous contract.’ ’’ Charles Dunn Co. v.
    Tudor Ins. Co., 
    308 Fed. Appx. 149
    , 151 (9th Cir. 2009),
    quoting A.B.S. 
    Clothing, supra
    , 
    34 Cal. App. 4th 1478
    .
    In Charles Dunn Co., the United States Court of Appeals
    for the Ninth Circuit found the existence of separate
    and distinct contracts where the insurance company
    ‘‘issued separate policy documents for each renewal
    policy and each renewal policy identified a separate
    policy period.’’
    Id. In A.B.S. Clothing,
    the California
    Court of Appeal found that the policies at issue in that
    case did not contain clear and unambiguous language
    demonstrating an intent of the parties to enter into one
    continuous contract. A.B.S. 
    Clothing, supra
    , 1478. In
    reaching that conclusion, the court first explained that
    the issue before it was one of first impression in Califor-
    nia and that ‘‘[c]ourts in other jurisdictions have gener-
    ally held if coverage is based on a series of separate,
    independent contracts, then the [insured] is entitled to
    recover up to the limit of liability for each policy period
    in which a loss occurs. On the other hand, if there
    is but one continuous contract, then the [insured’s]
    recovery cannot exceed the limit of liability stated in
    the contract regardless of the number of years the cov-
    erage has been in force, the number of policies issued
    or the number of premiums the [insured] has paid.’’
    Id., 1473–74.
    The court further explained: ‘‘Over the years,
    the rule has developed that a renewal of a fidelity policy
    or bond constitutes a separate and distinct contract for
    the period of time covered by such renewal unless it
    appears to be the intention of the parties as evidenced
    by the provisions thereof that such policy or bond and
    the renewal thereof shall constitute one continuous
    contract.’’ (Internal quotation marks omitted.)
    Id., 1476.
    Because the insurer had issued separate policy docu-
    ments, the court examined the provisions of the poli-
    cies, finding that certain provisions were ambiguous
    and did not demonstrate a clear and unambiguous intent
    of the parties to enter into one continuous contract.
    Id., 1480–83.
    In particular, the court found that ‘‘[t]he
    issuance of separate policy documents, each of which
    refers to terms, conditions and losses under that partic-
    ular policy, is strong evidence the original policy and
    the subsequent renewal policies were intended to be
    separate and distinct contracts.’’
    Id., 1484.
       With this backdrop in mind, the question that we
    must answer is whether it is clear from the language
    of the policy renewal certificate and endorsement that
    the parties intended to enter into one continuous con-
    tract. With respect to Royal primary policy RLP 144014,
    the record contains a ‘‘Renewal Certificate’’ dated
    August 1, 1962. The certificate includes the same policy
    number, ‘‘RLP 144014,’’ and indicates the name of the
    insured as Rohr and the name of the insurer as ‘‘Royal
    Indemnity [Company].’’ It provides as follows: ‘‘It is
    hereby understood and agreed that the term of [the]
    above policy is extended for a period of three years.
    ‘‘August 1, 1962 to August 1, 1965
    ‘‘It is further agreed that all coverages now provided
    by the policy, with same insuring agreements, condi-
    tions, exclusions and provisions of retrospective pre-
    mium endorsement, continue in full force and effect.’’
    (Emphasis added.) The certificate also contains the fol-
    lowing provision: ‘‘This endorsement is issued for
    attachment to and is hereby made a part of the policy
    designated above, and is effective as of the date indi-
    cated . . . .’’
    We conclude from the language used in the August
    1, 1962 renewal certificate that the parties intended for
    the extension to be a part of one continuous contract.
    First, the renewal certificate contains the same policy
    number as the original policy, and no new policy docu-
    ment was issued; the parties simply executed the
    renewal certificate. The clear language of the renewal
    certificate states that the ‘‘term’’ of Royal policy RLP
    144014 is being ‘‘extended for a period of three years.’’
    Moreover, the language that all coverages already pro-
    vided by policy RLP 144014 ‘‘continue in full force and
    effect’’ is indicative of an intent to continue in force
    the preexisting policy of insurance. See 2 S. Plitt et al.,
    supra, § 29:33, p. 29-65 (‘‘it has been held that the rule
    that a renewal policy constitutes a separate and distinct
    contract for the period of time covered by the renewal
    does not apply where the extension agreement shows
    a contrary intention as by stipulating that the original
    agreement ‘continues in force’ ’’ (emphasis added)); see
    also Grand Lodge of United Bros. of Friendship &
    Sisters of Mysterious Ten v. Massachusetts Bonding &
    Ins. Co., 
    324 Mo. 938
    , 952, 
    25 S.W.2d 783
    (1930) (‘‘[t]he
    words ‘continue in force’ as used in the continuation
    certificate clearly indicate that it was the intention of
    the parties to extend the duration or term of the original
    bond and not to make a new contract’’). The word
    continue is defined to mean ‘‘to maintain without inter-
    ruption a condition, course, or action . . . to remain
    in existence . . . .’’ Merriam-Webster’s Collegiate Dic-
    tionary (10th Ed. 1998) p. 251. An unrestrained reading
    of the language of the renewal certificate supports a
    conclusion that Royal primary policy RLP 144014,
    which was in effect from August 1, 1959, to August 1,
    1962, was merely extended to cover the period from
    August 1, 1962, to August 1, 1965, and that the renewal
    constituted a continuation of the existing policy. It fol-
    lows, therefore, that the insurer’s liability cannot
    exceed that which is stated in the limit of liability of
    the policy—$2 million—regardless of the number of
    years the coverage has been in force.
    With respect to Royal primary policy RTS 902235,
    which was in effect from August 1, 1965, to August 1,
    1968, the record contains an endorsement that identifies
    the same policy number, the name of the insured as
    Rohr and the name of the insurer as Royal Indemnity
    Company. The endorsement contains the following pro-
    vision: ‘‘This endorsement is issued for attachment to
    and is hereby made a part of the policy designated
    above, and is effective as of the date indicated . . . .’’
    The endorsement provides: ‘‘It is agreed that the policy
    is extended for a second three year term effective
    August 1, 1968 to August 1, 1971 and that the deposit
    is increased from $4,000.00 to $6,500.00. It is further
    agreed that for the term from August 1, 1968 to August
    1, 1969 the earned premium under this policy for cover-
    age A, B and C will be determined on the basis of the
    following rates . . . .’’ Although the language of the
    endorsement differs slightly from that of the renewal
    certificate for policy RLP 144014, in that the endorse-
    ment states that the ‘‘policy is extended for a second
    three year term’’; (emphasis added); whereas the
    renewal certificate for policy RLP 144014 states that
    ‘‘the term of [the] above policy is extended for a period
    of three years’’; (emphasis added); the end result is the
    same in both circumstances: each policy was extended
    for a three year period. See 2 A. Windt, Insurance
    Claims & Disputes (6th Ed. 2013) § 6:48 (‘‘If extra years
    of coverage are added to a policy, the insured will not
    be entitled to a separate policy limit for each year
    (unless the policy provides for a separate per year limit).
    If the endorsement that provides extra years of cover-
    age states that the policy term is being ‘extended,’ there
    is still only one policy, not a new policy, for the
    years added.’’).
    As with policy RLP 144014, the extension of policy
    RTS 902235 carries the same policy number, and no
    separate policy document was executed, which has
    been found to be indicative of an intent to have one
    continuous contract, rather than separate contracts. Cf.
    A.B.S. 
    Clothing, supra
    , 
    34 Cal. App. 4th 1474
    , 1484; see
    also Charles Dunn Co. v. Tudor Ins. 
    Co., supra
    , 
    308 Fed. Appx. 151
    . Furthermore, the endorsement itself
    states that it was ‘‘attach[ed] to’’ and ‘‘made a part of’’
    the original policy, RTS 902235. Finally, and perhaps
    most telling of an intent for the policy extensions to
    be part of one continuous contract, rather than new
    separate, independent contracts, is the fact that Royal
    issued policy RLP 144014 in 1959 for an initial three
    year period, which was extended to provide coverage
    through August 1, 1965, when Royal issued policy RTS
    902235. The fact that Royal issued a new separate pol-
    icy, with a different policy number, in 1965, whereas it
    had previously executed a renewal certificate extending
    the policy period for the policy that previously had
    been in place, further supports a determination that
    the renewal certificate to policy RLP 144014 and the
    endorsement to policy RTS 902235 merely extended
    and continued those policies and did not create new,
    separate contracts with separate policy limits.
    In the present case, the trial court concluded that,
    because ‘‘the policies unambiguously provide a per
    occurrence limit that applies per policy period . . . the
    Royal policies were in force for a total of four consecu-
    tive policy periods, each providing $2 million in cover-
    age per occurrence for a total of $8 million per occur-
    rence for the years that the Royal policies were in
    force.’’ In light of our review of the relevant law on this
    issue, as well as the language of the renewal certificate
    and the endorsement themselves, we cannot agree with
    the trial court’s conclusion. We conclude that the
    renewal and endorsement constituted continuations of
    the original contracts; accordingly, the limit of the insur-
    er’s liability is ‘‘the amount stated in the contract regard-
    less of the number of years involved or number of
    premiums paid.’’ A.B.S. 
    Clothing, supra
    , 
    34 Cal. App. 4th
    1476. Because the per occurrence limit of liability
    in each policy is $2 million, Rohr is entitled to coverage
    in the amount of $2 million per policy, for a total of $4
    million, as we more fully discuss in the next part of
    this opinion.
    B
    Horizontal Exhaustion of Primary Policies
    Rohr next claims that the trial court erred in
    determining that the underlying primary policies must
    be horizontally exhausted before liability under the
    excess policies may attach. In light of our determination
    that the $2 million per occurrence limit of liability in
    the Royal primary policies cannot be annualized and
    that the extensions of the two Royal primary policies
    did not result in additional per occurrence limits, the
    limit of liability for each of the Royal primary policies,
    which provide that an occurrence is ‘‘an event or contin-
    uous or repeated exposure to conditions which unex-
    pectedly cause injury or damage during the policy
    period,’’ is $2 million. Thus, regardless of whether this
    court finds that vertical or horizontal exhaustion must
    be applied, at most, Rohr must exhaust $4 million of
    the 1959–1971 Royal primary insurance coverage before
    it can access certain of its excess policies. Because
    Rohr settled with Arrowood with respect to those Royal
    primary policies for an amount that exceeded $4 mil-
    lion, Rohr can meet its exhaustion requirement for cer-
    tain of its excess policies under either a vertical or
    horizontal exhaustion application.
    This court, nevertheless, must address the exhaustion
    claims for the following reasons. First, this case
    involves a number of different policies with different
    exhaustion requirements, in that one of the Harbor
    excess policies is an umbrella policy, which has differ-
    ent provisions governing its applicability, some of the
    policies are first layer excess policies and some, like
    certain of the Federal and Century policies, are second
    layer excess policies, to which different exhaustion
    rules may apply. Thus, although Rohr may meet the
    exhaustion requirement of some of the excess policies
    regardless of whether a rule of vertical or horizontal
    exhaustion applies, a determination of which rule
    applies will have an effect on whether or when it can
    meet the exhaustion requirements of certain of the
    other policies. Second, the first phase of this litigation
    before the trial court concerned the following question:
    ‘‘At what point will the obligations of the excess insur-
    ers, if any, arise in light of the limits of the underlying
    primary policy or policies?’’ For this court to determine
    whether the trial court properly answered that question
    for certain of the excess policies, we must first deter-
    mine whether vertical or horizontal exhaustion applies.
    Finally, under California law, each policy must be inter-
    preted according to its terms. See Continental Ins. Co.
    
    I, supra
    , 
    55 Cal. 4th 195
    (fundamental goal of insurance
    contract interpretation is to give effect to mutual intent
    of parties, which should be inferred, if possible, solely
    from written provisions of contract). Because of the
    variation in the types of policies involved in these
    appeals, as well as their exhaustion requirements, we
    must examine the rules and case law governing vertical
    and horizontal exhaustion and address whether the trial
    court’s determination that a horizontal exhaustion
    requirement applied here was proper.
    Before we address the merits of this claim, we first
    set forth our standard of review and the applicable law
    on this issue. Because this claim concerns the interpre-
    tation of an insurance contract, it involves a question
    of law over which we must exercise de novo review.
    See Chicago Title Ins. Co. v. Bristol Heights Associates,
    
    LLC, supra
    , 
    142 Conn. App. 405
    ; Nationwide Mutual
    Ins. Co. v. 
    Allen, supra
    , 
    83 Conn. App. 537
    . As this
    court previously discussed, California courts apply the
    continuous injury trigger of coverage and the all sums
    plus stacking rules to long-tail environmental injury
    claims like the one in the present case. Continental
    Ins. Co. 
    I, supra
    , 
    55 Cal. 4th 191
    , 201–202. Under those
    rules, an insurer that is liable when continuous or pro-
    gressively deteriorating property damage occurs
    throughout several policy periods is obligated to pay
    the insured all sums for the property damage, up to
    the policy limits, ‘‘as long as some of the continuous
    property damage occurred while each policy was ‘on
    the loss’ ’’;
    id., 200;
    and when the ongoing environmental
    damage triggers multiple policies across many policy
    years, the insurance coverage from several policy peri-
    ods may be stacked ‘‘to form one giant ‘uber-policy’
    with a coverage limit equal to the sum of all purchased
    insurance policies. Instead of treating a long-tail injury
    as though it occurred in one policy period, this approach
    treats all the triggered insurance as though it were pur-
    chased in one policy period.’’
    Id., 201.
      First, we examine and determine the applicability of
    certain recent California case law on which the parties
    rely in making their claims for and against a rule of
    horizontal exhaustion.
    1
    Montrose II and Montrose III Decisions
    In Montrose Chemical Corp. of California v. Supe-
    rior Court, 
    14 Cal. App. 5th 1306
    , 1312, 
    222 Cal. Rptr. 3d
    748 (2017) (Montrose II), rev’d, 
    9 Cal. 5th 215
    , 
    460 P.3d 1201
    , 
    260 Cal. Rptr. 3d 822
    (2020), Montrose Chemi-
    cal brought a declaratory judgment action seeking a
    determination regarding the sequence in which it could
    access its excess general comprehensive liability poli-
    cies to cover its liability for certain environmental injur-
    ies caused by its manufacturing of a pesticide. Specifi-
    cally, Montrose Chemical sought a judgment declaring
    that ‘‘it may ‘electively stack’ excess policies—i.e., that
    it may access any excess policy issued in any policy
    year so long as the lower lying policies for the same
    policy year have been exhausted.’’ (Emphasis omitted.)
    Id. The insurers in
    that case alleged that ‘‘well-estab-
    lished California law and the language of the relevant
    policies required Montrose [Chemical] to ‘exhaust cov-
    erage from all underlying insurers in each of the trig-
    gered policy periods, such that higher-level excess
    insurers’ obligations are triggered only when all primary
    and lower-level excess policies have been exhausted.’ ’’
    (Emphasis in original.)
    Id., 1316–17.
    The trial court in
    that case had concluded that, under the stacking
    approach endorsed by the California Supreme Court
    in Continental Ins. Co. 
    I, supra
    , 
    55 Cal. 4th 186
    , ‘‘the
    aggregate value of all underlying policies throughout
    the duration of a continuous loss must be exhausted
    before excess coverage is accessible to the insured’’;
    (internal quotation marks omitted) Montrose I
    I, supra
    ,
    1319; and that ‘‘the parties must employ a horizontal
    exhaustion approach, whereby the aggregate limits of
    underlying policies for the applicable policy periods
    must first be exhausted before any excess policies incur
    a duty to indemnify Montrose [Chemical] for its liabili-
    ties . . . .’’ (Internal quotation marks omitted.)
    Id., 1320.
       On appeal in Montrose II, the California Court of
    Appeal reversed in part the judgment of the trial court.
    Although the Court of Appeal agreed with the trial court
    that Montrose Chemical could not electively stack poli-
    cies for a single coverage year and vertically exhaust
    policies for that single year once the underlying policy
    had been exhausted;
    id., 1321;
    it concluded that the
    excess policies do not need to ‘‘be horizontally
    exhausted at each coverage level and for each year
    before higher-level policies may be accessed. Instead
    . . . the sequence in which policies may be accessed
    must be decided on a policy-by-policy basis, taking into
    account the relevant provisions of each policy.’’
    (Emphasis in original.)
    Id., 1312.
    Specifically, the court
    explained that, ‘‘because there is tremendous variation
    among the policies at issue, [it] decline[d] to adopt a
    single exhaustion scheme that applie[d] to [Montrose
    Chemical’s] entire coverage portfolio, and instead
    direct[ed] that each policy be interpreted according to
    its terms.’’
    Id., 1321.
       After the parties presented oral argument in the pres-
    ent case, on April 6, 2020, the California Supreme Court
    issued its decision in Montrose Chemical Corp. of Cali-
    fornia v. Superior Court, 
    9 Cal. 5th 215
    , 
    460 P.3d 1201
    ,
    
    260 Cal. Rptr. 3d 822
    (2020) (Montrose III).21 In Mon-
    trose III, the California Supreme Court reversed the
    judgment of the Court of Appeal in Montrose II and
    concluded that ‘‘California law permits Montrose
    [Chemical] to seek indemnification under any excess
    policy once Montrose [Chemical] has exhausted the
    underlying excess policies in the same policy period.
    Montrose [Chemical] [was] not required to exhaust
    excess insurance at lower levels for all periods triggered
    by continuous injury before obtaining coverage from
    higher level excess insurance in any period.’’
    Id., 238.
       We must examine the basis for the court’s decision in
    Montrose III before we can determine how that decision
    applies, if at all, to the present case. The California
    Supreme Court explained that the issue before it con-
    cerned the sequence in which Montrose Chemical could
    access certain excess insurance policies covering the
    period from 1961 to 1985, during which Montrose Chem-
    ical had obtained primary insurance and multiple layers
    of excess insurance.
    Id., 222.
    The court noted that the
    parties in that case were in agreement that the dispute
    did not concern the exhaustion of Montrose Chemical’s
    primary insurance.
    Id., 223.
    The language of each policy
    at issue provided that Montrose Chemical was required
    to exhaust the limits of its underlying insurance cover-
    age before it could obtain coverage under the policy;
    id.; and the excess policies also provided, in a number
    of ways, that ‘‘ ‘other insurance’ must be exhausted
    before the excess policy can be accessed.’’
    Id., 224.
    The parties’ disagreement concerned whether the other
    insurance clauses required the exhaustion of other
    insurance from other policy periods.
    Id., 225.
    Montrose
    Chemical proposed a rule of ‘‘ ‘vertical exhaustion’ or
    ‘elective stacking,’ whereby it [could] access any excess
    policy once it has exhausted other policies with lower
    attachment points in the same policy period.’’
    Id. In contrast, the
    insurers argued for a rule of horizontal
    exhaustion whereby an excess policy could be accessed
    only after Montrose Chemical exhausted ‘‘other policies
    with lower attachment points from every policy period
    in which the environmental damage resulting in liability
    occurred.’’ (Emphasis in original.)
    Id. The California Supreme
    Court granted the petition for
    review in Montrose III ’’to determine whether vertical
    exhaustion or horizontal exhaustion is required when
    continuous injury occurs over the course of multiple
    policy periods for which an insured purchased multiple
    layers of excess insurance’’;
    id., 226;
    and concluded that
    ‘‘a rule of vertical exhaustion is appropriate.’’
    Id. In explaining the
    basis for its decision, the court stated:
    ‘‘The parties’ dispute centers on the meaning of the
    ‘other insurance’ clauses in the excess insurance poli-
    cies. These clauses provide, in a variety of ways, that
    each policy shall be excess to other insurance available
    to the insured, whether or not the other insurance is
    specifically listed in the policy’s schedule of underlying
    insurance. The insurers argue that these clauses call
    for a rule of horizontal exhaustion because they restrict
    indemnification from any excess policy until the insured
    has exhausted all other available insurance—which, in
    a case of long-tail injury, means every policy with a
    lower attachment point from every policy period trig-
    gered by the continuous injury.
    ‘‘Although the insurers’ interpretation is not an unrea-
    sonable one, it is not the only possible interpretation
    of the policy language. The ‘other insurance’ clauses at
    issue clearly require exhaustion of underlying insur-
    ance, but none clearly or explicitly states that Montrose
    [Chemical] must exhaust insurance with lower attach-
    ment points purchased for different policy periods.’’
    (Emphasis in original; footnote omitted.)
    Id., 230.
    The
    court concluded that the other insurance clauses did
    ‘‘not clearly specify whether a rule of horizontal or
    vertical exhaustion applie[d]’’ and that, ‘‘in the absence
    of any more persuasive indication that the parties
    intended otherwise, the policies are most naturally read
    to mean that Montrose [Chemical] may access its excess
    insurance whenever it has exhausted the other directly
    underlying excess insurance policies that were pur-
    chased for the same policy period.’’
    Id., 234.
    The court
    further explained that ‘‘[a] rule of vertical exhaustion
    does not restrict the insured from accessing excess
    coverage from other policy periods if the terms and
    conditions are otherwise met; it merely relieves the
    insured of the obligation of establishing whether all of
    the applicable terms and conditions at any given ‘layer’
    of excess coverage are met before it accesses the next
    ‘layer’ of coverage.’’ (Emphasis in original.)
    Id., 235–36.
      In its decision, the California Supreme Court noted
    the parties’ reliance on Community Redevelopment
    Agency v. Aetna Casualty & Surety 
    Co., supra
    , 50 Cal.
    App. 4th 329, but found that case to be distinguishable
    for reasons that are important to the present case. Mon-
    trose II
    I, supra
    , 
    9 Cal. 5th 237
    . The court in Montrose III
    explained: ‘‘In Community Redevelopment [Agency], a
    primary insurer sought contribution from an excess
    insurer for defense costs on behalf of the insured in a
    case involving continuous loss. To resolve the conflict,
    the court applied what it termed a ‘horizontal exhaus-
    tion rule’; under that rule, the court held, an excess
    insurer in a continuous injury case is not required ‘to
    ‘‘drop down’’ and provide a defense to a common
    insured before the liability limits of all primary insurers
    on the risk have been exhausted.’ . . . In adopting that
    rule, the court explained: ‘Absent a provision in the
    excess policy specifically describing and limiting the
    underlying insurance, a horizontal exhaustion rule
    should be applied in continuous loss cases because it
    is most consistent with the principles enunciated in
    Montrose [
    I, supra
    , 
    10 Cal. 4th 645
    ]. . . . Under the
    principle of horizontal exhaustion, all of the primary
    policies must exhaust before any excess will have cov-
    erage exposure.’ . . .
    ‘‘This case differs from Community Redevelopment
    [Agency] in fundamental respects. This case, unlike
    Community Redevelopment [Agency], is not a contribu-
    tion action between primary and excess insurers; it is,
    rather, a coverage dispute between excess insurers and
    their insured. Regardless of whether Community Rede-
    velopment [Agency] was correct to apply a rule of hori-
    zontal exhaustion in that distinct context—a question
    not presently before us—we are unpersuaded that the
    reasoning of Montrose I requires us to apply a rule
    of horizontal exhaustion that would limit [Montrose
    Chemical’s] ability to access the excess insurance cov-
    erage it has paid for.’’ (Citations omitted; emphasis in
    original.) Montrose II
    I, supra
    , 
    9 Cal. 5th 237
    . In fact, the
    court in Montrose III specifically stated that, ‘‘[b]ecause
    the question is not presented here, we do not decide
    when or whether an insured may access excess policies
    before all primary insurance covering all relevant policy
    periods has been exhausted.’’
    Id., 226
    n.4.
    Following the release of the decision in Montrose III,
    this court ordered the parties in the present case to
    file simultaneous supplemental briefs to address the
    impact, if any, of Montrose III on the issues in the
    pending appeals. In its supplemental brief, Rohr asserts
    that, pursuant to Montrose III, the trial court’s decision
    must be reversed. Although Rohr acknowledges that
    Montrose III involved circumstances different from
    those in the present case, in that the parties in Montrose
    III stipulated that all of the primary insurance had been
    exhausted and the issue in that case concerned whether
    vertical or horizontal exhaustion applied to layers of
    excess policies, Rohr claims that ‘‘the ‘all sums’ princi-
    ples enunciated [in] Montrose III necessarily lead to
    the same result here: vertical exhaustion of directly
    underlying policies is all that is required for Rohr to
    access its excess policies.’’ Rohr further claims that its
    policies contain the ‘‘all sums’’ language and that ‘‘there
    is no reason to distinguish primary policies from excess
    policies based on [that] language’’; the reasonable
    expectations of the parties are best satisfied by a rule of
    vertical exhaustion; to the extent that ‘‘other insurance’’
    provisions existed, there is no clear or explicit policy
    language that requires the exhaustion of all underlying
    insurance, including primary insurance, regardless of
    the policy period, nor is there any indication in the
    construction of other insurance provisions in Montrose
    III suggesting that a different exhaustion rule applies
    for primary policies; and Community Redevelopment
    Agency is distinguishable because it involved a dispute
    between insurers, whereas the present case involves a
    dispute between an insured and its insurers.
    In their supplemental brief, in contrast, the Continen-
    tal plaintiffs raise a number of arguments essentially
    asserting that Montrose III has no impact on our resolu-
    tion of the issues in the present case. Specifically, the
    Continental plaintiffs claim that because Montrose III
    addressed only the sequence in which an insured may
    access its excess policies where all primary insurance
    had been exhausted, and because it did not address
    or change the rule that all primary insurance must be
    exhausted before the obligations of an insurer under a
    general excess policy are triggered, it was neither bind-
    ing nor persuasive authority and has no impact on the
    issues before this court. They claim, therefore, that this
    court should follow decisions of the California Courts
    of Appeal that universally require horizontal exhaustion
    of primary policies before liability of an excess insurer
    attaches. We agree with the Continental plaintiffs.
    The court in Montrose III specifically stated that it
    was not addressing the issue decided in Community
    Redevelopment Agency, which is similar to the issue
    presently before this court—whether a horizontal
    exhaustion rule requiring the exhaustion of all primary
    policies before any excess insurance will attach should
    be applied in continuous loss cases; Montrose II
    I, supra
    ,
    
    9 Cal. 5th 237
    ; and that it was not deciding ‘‘when or
    whether an insured may access excess policies before
    all primary insurance covering all relevant policy peri-
    ods has been exhausted.’’
    Id., 226
    n.4. The parties in
    Montrose III having stipulated that all primary insur-
    ance had been exhausted, the dispute in that case con-
    cerned the sequence in which certain excess policies
    could be accessed, specifically, ‘‘whether vertical
    exhaustion or horizontal exhaustion is required when
    continuous injury occurs over the course of multiple
    policy periods for which an insured purchased multiple
    layers of excess insurance.’’
    Id., 226
    . Thus, the court’s
    application of a rule of vertical exhaustion under those
    circumstances has no bearing on our determination of
    the issue in the present case of whether the trial court
    erred in determining that the underlying primary poli-
    cies had to be horizontally exhausted before liability
    under the excess policies could attach.
    2
    SantaFe Braun Decision
    On July 13, 2020, the California Court of Appeal for
    the First District issued its decision in SantaFe Braun,
    Inc. v. Ins. Co. of North America, 
    52 Cal. App. 5th 19
    ,
    
    265 Cal. Rptr. 3d 692
    (2020) (SantaFe Braun), review
    denied, California Supreme Court, Docket No. S264060
    (September 30, 2020). That case involved a declaratory
    judgment action brought by an insured against its insur-
    ers in which the insured sought to obtain coverage for
    asbestos related claims under various excess liability
    insurance policies.
    Id., 21.
    The trial court rendered judg-
    ment in favor of the defendant excess insurers after
    determining that SantaFe Braun, Inc. (Braun), had
    failed to establish exhaustion of primary and certain
    layers of underlying excess insurance.
    Id. Braun claimed on
    appeal that the trial court improperly deter-
    mined that the insurance policies at issue required the
    exhaustion of all layers of underlying insurance,
    namely, horizontal exhaustion, instead of requiring ver-
    tical exhaustion of only those policies specified in each
    excess policy.
    Id. During the pendency
    of the appeal in
    SantaFe Braun, the California Supreme Court decided
    Montrose III. In SantaFe Braun, the Court of Appeal
    for the First District agreed with Braun, concluding
    that, on the basis of ‘‘the reasoning in Montrose III . . .
    the trial court erred in interpreting the policies at issue
    in this case to require horizontal exhaustion of all pri-
    mary and underlying excess insurance coverage before
    accessing coverage under the excess policies at issue.’’
    Id., 22.
       On July 16, 2020, Rohr filed a notice with this court
    of supplemental authority pursuant to Practice Book
    § 67-10, directing this court’s attention to the decision
    in SantaFe Braun, claiming that it was relevant to the
    arguments raised by Rohr on appeal. Thereafter, on
    July 23, 2020, this court issued an order requiring ‘‘the
    parties [to] file supplemental briefs of no more than
    [ten] pages on or before August 7, 2020, to discuss the
    impact, if any, of the opinion in [SantaFe Braun] on
    previous holdings of the California Courts of Appeal,
    including, but not limited to, that in Community Rede-
    velopment Agency v. Aetna Casualty & Surety Co.,
    [supra, 
    50 Cal. App. 4th 342
    ] and [Continental Ins. Co.
    I
    I, supra
    , 
    15 Cal. App. 5th 1034
    ] (‘It is settled under
    California law that an excess or secondary policy does
    not cover a loss, nor does any duty to defend the insured
    arise, until all of the primary insurance has been
    exhausted. . . . Under the principle of horizontal
    exhaustion, all of the primary policies must exhaust
    before any excess will have coverage exposure.’
    (Emphasis omitted.)); and on Olympic Ins. Co. v.
    Employers Surplus Lines Ins. Co., [supra, 
    126 Cal. App. 3d
    600] (the principle that a secondary policy ‘does
    not apply to cover a loss until the underlying primary
    insurance has been exhausted . . . holds true even
    where there is more underlying primary insurance than
    contemplated by the terms of the secondary policy’).’’
    Before we address the arguments raised in the par-
    ties’ supplemental briefs, we must first set forth the
    basis for the court’s decision in SantaFe Braun. At the
    outset, the court in SantaFe Braun acknowledged that
    the decision in Montrose III left unanswered the ques-
    tion that was before the court in SantaFe Braun,
    namely, ‘‘when the insured has incurred continuous
    losses extending over the coverage periods in multiple
    primary policies, whether all primary insurance cov-
    ering all time periods must be exhausted (‘horizontally’)
    before the first level excess policies are triggered, or,
    as Braun contends, whether coverage under the excess
    policies is triggered once the directly underlying pri-
    mary policies specified in each excess policy is
    exhausted (‘vertically’).’’ SantaFe 
    Braun, supra
    , 52 Cal.
    App. 5th 27. Nevertheless, the court based its decision
    on the holding in Montrose III, stating: ‘‘Interpreting
    the provisions of the excess policies to mean what the
    Supreme Court in Montrose III held they mean will, in
    the absence of explicit language to the contrary, require
    the excess carriers to assume responsibility for defense
    and indemnity once the directly underlying primary pol-
    icies have been exhausted. Whatever the rights of the
    excess carriers may be to contribution from primary
    insurers whose policies do not directly underlie the
    excess policy is a different question that is not now
    before us, and on which we express no opinion. We
    hold simply that (absent an explicit policy provision
    to the contrary) the insured becomes entitled to the
    coverage it purchased from the excess carriers once
    the primary policies specified in the excess policy have
    been exhausted.’’
    Id., 29.
       After noting the argument of the excess carriers con-
    cerning the differences between primary and excess
    policies, the court in SantaFe Braun rejected the argu-
    ment that such differences compel a conclusion that
    horizontal exhaustion of primary coverage is required
    before excess coverage is triggered.
    Id., 28–29.
    The
    court stated that ‘‘the differences between primary and
    excess coverage hold true whether vertical or hori-
    zontal exhaustion applies’’ and that they provide ‘‘little
    justification for construing the policy language interpre-
    ted in Montrose III differently simply because primary
    coverage purchased often many years later for other
    policy periods remains outstanding.’’
    Id., 28.
    The court
    in SantaFe Braun further stated: ‘‘Prior to the Supreme
    Court’s decision in Montrose III, some appellate courts
    concluded that in a continuing loss situation, an excess
    insurer has no obligation ‘to ‘‘drop down’’ and provide
    a defense to a common insured before the liability limits
    of all primary insurers on the risk have been exhausted.’
    . . . Community Redevelopment Agency v. Aetna
    Casualty & Surety Co. [supra, 
    50 Cal. App. 4th 332
    ];
    see also Padilla [Construction] Co. v. Transportation
    Ins. Co. [supra, 
    150 Cal. App. 4th 986
    ] [‘California’s rule
    of ‘‘horizontal exhaustion’’ in liability insurance law
    requires all primary insurance to be exhausted before an
    excess insurer must ‘‘drop down’’ to defend an insured,
    including in cases of continuing loss.’]. . . . These
    cases, however, rely on an interpretation of policy lan-
    guage rejected by the [California] Supreme Court in
    Montrose III. . . . While those cases hold, for example,
    that ‘other insurance’ clauses preclude attachment of
    coverage until there has been horizontal exhaustion,
    Montrose III holds otherwise. Moreover, insofar as
    Community Redevelopment [Agency] . . . addresses
    the relative obligations as between the various insurers,
    and not the excess insurer’s obligations to the insured,
    it is distinguishable. While . . . Padilla [Construction
    Co.] . . . involved an action by an insured seeking
    declaratory relief against its excess insurer, the court’s
    extension of Community Redevelopment [Agency] can
    no longer be justified after Montrose III.’’ (Citations
    omitted; emphasis in original.) SantaFe 
    Braun, supra
    ,
    
    52 Cal. App. 5th 30
    .
    In its second supplemental brief, Rohr claims that
    the decision in SantaFe Braun ‘‘squarely addresses the
    dispute over the exhaustion of primary policies raised
    in this appeal . . . .’’ Specifically, Rohr claims that the
    language of the policies at issue in SantaFe Braun is
    nearly identical to that of the policies at issue in the
    present case, that prior rulings of the Courts of Appeal
    in California in Community Redevelopment Agency and
    Olympic Ins. Co. are distinguishable because they con-
    cerned claims between insurers, which Rohr alleges
    have no relevance to direct claims between policyhold-
    ers and their excess insurers, and that the differences
    between primary and excess insurance do not justify
    a horizontal exhaustion approach. Rohr further alleges
    that, ‘‘in policyholder claims for coverage for long-tail
    claims, California courts have consistently focused on
    the construction of policy language rather than equita-
    ble principles, and that distinction is critical in
    determining the type of exhaustion to be applied.’’
    Finally, Rohr alleges that Padilla Construction Co. is
    no longer good law in light of SantaFe Braun.
    In contrast, the Continental plaintiffs, along with Fed-
    eral and Century, claim in their joint supplemental brief
    that the decision in SantaFe Braun, a decision of the
    Fourth Division of the First District Court of Appeal,
    has no impact on the decisions by equal sister districts
    or divisions of the California Courts of Appeal in Com-
    munity Redevelopment Agency v. Aetna Casualty &
    Surety 
    Co., supra
    , 
    50 Cal. App. 4th 329
    (Third Division of
    Second District Court of Appeal), Padilla Construction
    Co. v. Transportation Ins. 
    Co., supra
    , 
    150 Cal. App. 4th 984
    (Third Division of Fourth District Court of Appeal),
    Continental Ins. Co. I
    I, supra
    , 
    15 Cal. App. 5th 1017
    (Second Division of Fourth District Court of Appeal),
    and Olympic Ins. Co. v. Employers Surplus Lines Ins.
    
    Co., supra
    , 
    126 Cal. App. 3d
    593 (Third Division of First
    District Court of Appeal). They point out that it is the
    sole decision ‘‘by a division or district appellate court
    within California to reject long-standing California juris-
    prudence holding that all general primary policies must
    first be exhausted before any excess policy may cover
    the loss.’’ Specifically, they claim that SantaFe Braun
    ‘‘created a singularly minority rule inconsistent with
    over forty years of California law and contrary to the
    previous decisions of its sister California Court of
    Appeal districts and divisions,’’ and that, ‘‘[u]nder Cali-
    fornia procedural rules, SantaFe Braun is not binding
    on any other California court [because] ‘a decision by
    one court of appeal is not binding on other courts of
    appeal. Thus, one district or division within a district
    can refuse to follow a prior decision by a different
    district or division.’ Precedential Effect of Appellate
    Court Opinions, Cal. Prac. Guide Civ. App. & Writs Ch.
    14-D; McCallum v. McCallum, 
    190 Cal. App. 3d 308
    ,
    315 n.4, 
    235 Cal. Rptr. 396
    (1987).’’ Citing McCallum v.
    
    McCallum, supra
    , 315 n.4, for the proposition that a
    decision by one division does not overturn a separate
    division’s decision, they further allege that Olympic
    Ins. Co., a decision by the Third Division of the First
    District, is also not impacted by SantaFe Braun. Finally,
    they claim that Montrose III should not be applied
    beyond its clear and specific holding, which did not
    address the issue presented in the present case involv-
    ing the exhaustion of primary insurance, and that San-
    taFe Braun does not apply because the court in that
    case did not analyze the interaction between stand-
    alone other insurance provisions and ultimate net loss
    provisions in the excess policies, which they claim
    require horizontal exhaustion of all primary policies.
    We agree with the Continental plaintiffs, Federal and
    Century.
    Under California law, ‘‘[a] decision of a court of
    appeal is not binding in the courts of appeal. One district
    or division may refuse to follow a prior decision of a
    different district or division . . . .’’ (Internal quotation
    marks omitted.) McCallum v. 
    McCallum, supra
    , 190 Cal.
    App. 3d 315 n.4; see also McGlothlen v. Dept. of Motor
    Vehicles, 
    71 Cal. App. 3d 1005
    , 1017, 
    140 Cal. Rptr. 168
    (1977); Swinerton & Walberg Co. v. City of Inglewood-
    Los Angeles County Civic Center Authority, 40 Cal.
    App. 3d 98, 101, 
    114 Cal. Rptr. 834
    (1974); see also 9
    B. Witkin, Cal. Procedure (3d Ed. 1985) Appeal, § 772,
    pp. 740–41. Accordingly, we conclude that we are not
    required to follow the decision of the First District Court
    of Appeal in SantaFe Braun.22 Instead, we follow the
    long line of California cases that adhere to the well
    settled rule under California law that an excess policy
    does not cover a loss until all primary insurance has
    been exhausted. See McConnell v. Underwriters at
    Lloyd’s of London, 
    56 Cal. 2d 637
    , 646, 
    365 P.2d 418
    ,
    
    16 Cal. Rptr. 362
    (1961) (‘‘excess insurance does not
    attach until all primary insurance has been exhausted’’);
    Deere & Co. v. Allstate Ins. Co., 
    32 Cal. App. 5th 499
    ,
    516, 
    244 Cal. Rptr. 3d 100
    (2019) (‘‘excess insurance
    contracts do not respond to losses unless and until
    there has been full and proper exhaustion of primary
    insurance’’ (internal quotation marks omitted)), review
    denied, California Supreme Court, Docket No. S255410
    (June 12, 2019); North American Capacity Ins. Co. v.
    Claremont Liability Ins. Co., 
    177 Cal. App. 4th 272
    ,
    293, 
    99 Cal. Rptr. 3d 225
    (2009) (‘‘under the California
    rule of ‘horizontal exhaustion,’ all primary insurance
    must be exhausted before an excess carrier must ‘drop
    down’ to defend an insured, particularly in cases of
    continuing loss’’); Padilla Construction Co. v. Trans-
    portation Ins. 
    Co., supra
    , 
    150 Cal. App. 4th 986
    (‘‘Califor-
    nia’s rule of ‘horizontal exhaustion’ in liability insurance
    law requires all primary insurance to be exhausted
    before an excess insurer must ‘drop down’ to defend an
    insured, including in cases of continuing loss’’); Carmel
    Development Co. v. RLI Ins. Co., 
    126 Cal. App. 4th 502
    ,
    514, 
    24 Cal. Rptr. 3d 588
    (2005) (‘‘[t]he inapplicability of
    secondary coverage until exhaustion of primary limits
    generally holds true even where there is more underly-
    ing primary insurance than contemplated by the terms
    of the secondary policy’’ (internal quotation marks omit-
    ted)), review denied, California Supreme Court, Docket
    No. S131568 (March 30, 2005); American Casualty Co.
    v. General Star Indemnity Co., 
    125 Cal. App. 4th 1510
    ,
    1520, 
    24 Cal. Rptr. 3d 34
    (2005) (excess carrier had no
    liability under excess policy ‘‘until exhaustion of all
    applicable primary policies’’); Travelers Casualty &
    Surety Co. v. Transcontinental Ins. 
    Co., supra
    , 122 Cal.
    App. 4th 959 (referencing settled rule that excess policy
    does not cover loss until all primary insurance has been
    exhausted); Reliance National Indemnity Co. v. Gen-
    eral Star Indemnity Co., 
    72 Cal. App. 4th 1063
    , 1076–77,
    
    85 Cal. Rptr. 2d 627
    (1999) (‘‘[t]he Courts of Appeal
    have held [that] ‘[i]t is settled under California law that
    an excess or secondary policy does not cover a loss,
    nor does any duty to defend the insured arise until all of
    the primary insurance has been exhausted’ ’’ (emphasis
    omitted)); Fireman’s Fund Ins. Co. v. Maryland Casu-
    alty Co., 
    65 Cal. App. 4th 1279
    , 1305, 
    77 Cal. Rptr. 2d 296
    (1998) (‘‘true excess insurer—one that is solely and
    explicitly an excess insurer providing only secondary
    coverage—has no duty to defend or indemnify until all
    the underlying primary coverage is exhausted’’); Com-
    munity Redevelopment Agency v. Aetna Casualty &
    Surety 
    Co., supra
    , 
    50 Cal. App. 4th 340
    (‘‘Absent a provi-
    sion in the excess policy specifically describing and
    limiting the underlying insurance, a horizontal exhaus-
    tion rule should be applied in continuing loss cases
    . . . . In other words, all of the primary policies in force
    during the period of continuous loss will be deemed
    primary policies to each of the excess policies covering
    that same period. Under the principle of horizontal
    exhaustion, all of the primary policies must exhaust
    before any excess will have coverage exposure.’’
    (Emphasis in original.)); 
    Stonewall, supra
    , 
    46 Cal. App. 4th
    1850 (‘‘‘[l]iability under a secondary [excess] policy
    will not attach until all primary insurance is exhausted,
    even if the total amount of primary insurance exceeds
    the amount contemplated in the secondary policy’ ’’);
    Hartford Accident & Indemnity Co. v. Superior Court,
    
    23 Cal. App. 4th 1774
    , 1779, 
    29 Cal. Rptr. 2d 32
    (1994)
    (‘‘[l]iability under an excess policy attaches only after
    all primary coverage has been exhausted’’ (internal quo-
    tation marks omitted)); Diamond Heights Homeown-
    ers Assn. v. National American Ins. Co., 
    227 Cal. App. 3d
    563, 570, 
    277 Cal. Rptr. 906
    (1991) (‘‘all primary or
    underlying insurance must be exhausted before excess
    coverage becomes effective’’), review denied, California
    Supreme Court, Docket No. S019821 (May 16, 1991);
    North River Ins. Co. v. American Home Assurance 
    Co., supra
    , 
    210 Cal. App. 3d 112
    (‘‘[l]iability under an excess
    policy attaches only after all primary coverage has been
    exhausted’’); Olympic Ins. Co. v. Employers Surplus
    Lines Ins. 
    Co., supra
    , 
    126 Cal. App. 3d
    600 (‘‘A secondary
    policy, by its terms, does not apply to cover a loss until
    the underlying primary insurance has been exhausted.
    This principle holds true even where there is more
    underlying primary insurance than contemplated by the
    terms of the secondary policy.’’).
    The California Supreme Court stated its support for
    this well settled rule of law in McConnell v. Underwrit-
    ers at Lloyd’s of 
    London, supra
    , 
    56 Cal. 2d 637
    . In that
    case, the excess insurer alleged that, if the court deter-
    mined that two primary policies covered the accident
    at issue, then the liability of the excess insurer could
    not attach until the combined limits of both of those
    policies had been exhausted.
    Id., 646.
    The California
    Supreme Court stated that that contention ‘‘appear[ed]
    to be correct.’’
    Id. The language of
    the excess policy at
    issue in that case, which is similar to the language of
    the policies at issue in the present case, provided that
    liability ‘‘ ‘shall not attach unless and until the Primary
    Insurers shall have admitted liability for the Primary
    Limit or Limits, or unless and until the Assured has
    by final judgment been adjudged to pay a sum which
    exceeds such Primary Limit or Limits.’ Under such cir-
    cumstances it is held that the excess insurance does
    not attach until all primary insurance has been
    exhausted.’’
    Id. Furthermore, to the
    extent that one of
    the primary insurers had become insolvent, the court
    stated that ‘‘it is noted that insolvency of a primary
    insurer gives rise to liability under the excess policy,
    after, of course, any other primary coverage has been
    exhausted.’’
    Id. It is important
    to note that, although
    McConnell did not involve a long-tail claim, the court,
    at no point, limited its determination that all primary
    coverage must be exhausted before liability of the
    excess policy could attach to the primary coverage
    stated in the excess policy only, as evidenced by its
    reference to the exhaustion of ‘‘any other primary cover-
    age . . . .’’
    Id. Accordingly, under the
    facts of the present case, we
    disagree with Rohr’s claim that SantaFe Braun should
    apply to the issue of whether horizontal exhaustion of
    the primary policies is required.
    3
    California Case Law
    Having determined that the California Supreme
    Court’s application of a rule of vertical exhaustion to
    excess policies in Montrose III has no bearing on our
    determination of the issue in the present case of
    whether the trial court erred in determining that the
    underlying primary policies had to be horizontally
    exhausted before liability under the excess policies
    could attach, and also having determined that we are
    not required to follow the decision of the First District
    Court of Appeal in SantaFe Braun, we next look to
    relevant California case law for guidance in our resolu-
    tion of the issue concerning horizontal exhaustion of
    primary policies in this case involving a continuous loss
    claim. We conclude, on the basis of that case law, that
    the trial court properly determined that horizontal
    exhaustion of all primary insurance was required in the
    present case.
    The primary issue addressed by the California Court
    of Appeal in Community Redevelopment Agency v.
    Aetna Casualty & Surety 
    Co., supra
    , 
    50 Cal. App. 4th 329
    , which is directly on point to the issue presented
    in the present appeals, was ‘‘whether an excess insurer,
    under policy provisions such as those presented [in that
    case], has any obligation, in a continuing loss case, to
    ‘drop down’ and provide a defense to a common insured
    before the liability limits of all primary insurers on the
    risk have been exhausted.’’ (Emphasis in original.)
    Id., 332.
    The court answered that question in the negative,
    and its reasoning is relevant to our analysis of the issue
    concerning horizontal exhaustion in the present case.
    See
    id. Community Redevelopment Agency
    involved a rede-
    velopment project in the Los Angeles area in which
    mass grading and filling was performed improperly,
    resulting in building pads that were defective and dam-
    aged, which, in turn, caused continuing damage to the
    structures and improvements located thereon as a
    result of the continual settling of the pads.
    Id., 333–34.
    United Pacific Insurance Company (United) and State
    Farm Fire and Casualty Insurance Company (State
    Farm) had issued commercial general liability policies
    that provided coverage for the related property damage
    claims.
    Id., 334.
    Additionally, the developer had pur-
    chased an umbrella policy from Scottsdale Insurance
    Company (Scottsdale) that was specifically excess to
    the State Farm policy, although not exclusively excess.
    Id. Although State Farm’s
    liability limits had been
    reached and exhausted, United’s limits had not been
    exhausted.
    Id., 340
    . 
    United argued that because Scotts-
    dale’s policy expressly provided that it was excess to
    the State Farm policy, Scottsdale’s duty to provide a
    defense arose upon the exhaustion of State Farm’s lia-
    bility limits.
    Id., 341.
       The California Court of Appeal rejected United’s
    claim that Scottsdale’s duty to provide a defense arose
    upon the exhaustion of State Farm’s liability limits,
    explaining that because the other provisions of the Scot-
    tsdale policy do not limit coverage to only the excess
    over the limits of the State Farm policy but, rather,
    expressly extend coverage to ‘‘ ‘the applicable limits
    of any other underlying insurance collectible by the
    [insureds]’ . . . [t]he only reasonable interpretation of
    this policy language is that the term ‘underlying insur-
    ance’ must be read to include all available primary insur-
    ance, not just the policy expressly listed on the schedule
    of underlying insurance.’’ (Emphasis in original.)
    Id. In reaching that
    conclusion, the court explained: ‘‘If an
    excess policy states that it is excess over a specifically
    described policy and will cover a claim when that spe-
    cific primary policy is exhausted, such language is suffi-
    ciently clear to overcome the usual presumption that
    all primary coverage must be exhausted. However, that
    is not the case here. As the quoted provisions of Scotts-
    dale’s policy make clear . . . it was intended to be
    excess to all underlying insurance, whether such insur-
    ance was described in the schedule of underlying insur-
    ance or not.’’ (Citation omitted; emphasis in original.)
    Id., 340
    n.6. The court further stated: ‘‘ ‘[W]e must con-
    clude that when a policy which provides excess insur-
    ance above a stated amount of primary insurance con-
    tains provisions which make it also excess insurance
    above all other insurance which contributes to the pay-
    ment of the loss together with specifically stated pri-
    mary insurance, such clause will be given effect as
    written.’ . . . In other words, an excess insurer can
    require in its policy that all primary insurance be first
    exhausted. Consistent with the horizontal rule, that is
    what Scottsdale effectively did in this case. Because
    exhaustion of all available primary (or underlying)
    insurance never occurred, Scottsdale’s duty, under the
    terms of its policy, to ‘drop down’ and provide a defense
    never arose.’’ (Citation omitted; emphasis in original.)
    Id., 341;
    see also Peerless Casualty Co. v. Continental
    Casualty 
    Co., supra
    , 
    144 Cal. App. 2d 625
    ; cf. Travelers
    Casualty & Surety Co. v. Transcontinental Ins. 
    Co., supra
    , 
    122 Cal. App. 4th 959
    (concluding that, unlike
    language of umbrella policy in Community Redevelop-
    ment Agency, language of excess policy was ‘‘ ‘suffi-
    ciently clear’ ’’ to trigger defense obligations of excess
    insurer upon exhaustion of underlying insurance as
    defined in policy, regardless of existence of other
    insurance).
    The court in Community Redevelopment Agency fur-
    ther stated: ‘‘It is settled under California law that an
    excess or secondary policy does not cover a loss, nor
    does any duty to defend the insured arise, until all of
    the primary insurance has been exhausted. . . . The
    California general rule that all primary insurance must
    be exhausted before a secondary insurer will have expo-
    sure favors and results in what is called ‘horizontal
    exhaustion.’ This is contrasted with ‘vertical exhaus-
    tion’ where coverage attaches under an excess policy
    when the limits of a specifically scheduled underlying
    policy [are] exhausted and the language of the excess
    policy provides that it shall be excess only to that spe-
    cific underlying policy.
    ‘‘This is a particular problem in continuous loss cases,
    such as the one before us. In such cases, primary liabil-
    ity insurers may have exposure to defend (and perhaps
    indemnify) claims arising before or after the effective
    dates of such policies. As a result of the [California]
    Supreme Court’s conclusion that a continuing or pro-
    gressively deteriorating condition which causes damage
    or injury throughout more than one policy period will
    potentially be covered by all policies in effect during
    those periods . . . the ‘horizontal exhaustion’ versus
    ‘vertical exhaustion’ issue will become an increasingly
    common one to be resolved. . . . Absent a provision
    in the excess policy specifically describing and lim-
    iting the underlying insurance, a horizontal exhaustion
    rule should be applied in continuous loss cases because
    it is most consistent with the principles enunciated in
    Montrose [I]. In other words, all of the primary policies
    in force during the period of continuous loss will be
    deemed primary policies to each of the excess policies
    covering that same period. Under the principle of hori-
    zontal exhaustion, all of the primary policies must
    exhaust before any excess will have coverage expo-
    sure.’’ (Citations omitted; emphasis in original; footnote
    omitted.) Community Redevelopment Agency v. Aetna
    Casualty & Surety 
    Co., supra
    , 
    50 Cal. App. 4th 339
    –40.
    Applying the principles of Community Redevelop-
    ment Agency to the present case, we conclude that the
    trial court properly applied a rule of horizontal exhaus-
    tion.23 The Harbor and London excess policies similarly
    define ultimate net loss to mean ‘‘the amount payable
    in settlement of the liability of the Assured after making
    deductions for all recoveries and for other valid and
    collectible insurances . . . .’’ Where, as here, general
    excess policies like the ones at issue in the present
    case provide ‘‘excess insurance above a stated amount
    of primary insurance [and] [contain] provisions which
    make [them] also excess insurance above all other
    insurance which contributes to the payment of the loss
    together with the specifically stated primary insurance,
    such clause[s] will be given effect as written.’’ Peerless
    Casualty Co. v. Continental Casualty 
    Co., supra
    , 
    144 Cal. App. 2d 625
    . For this court to ignore the plain
    language of the excess policies making them excess to
    ‘‘other valid and collectible insurances,’’ in addition to
    the specifically stated underlying policies, would be to
    ignore the language of the contracts as written, which
    is contrary to rules of insurance contract interpretation
    under California law. See, e.g., La Jolla Beach & Tennis
    Club, Inc. v. Industrial Indemnity Co., 
    9 Cal. 4th 27
    ,
    37, 
    884 P.2d 1048
    , 
    36 Cal. Rptr. 2d 100
    (1994); see also
    Travelers Casualty & Surety Co. v. Transcontinental
    Ins. 
    Co., supra
    , 
    122 Cal. App. 4th 955
    . We conclude,
    therefore, that an examination of the policy provisions
    at issue in the excess policies supports our decision
    not to apply the rule of vertical exhaustion set forth in
    SantaFe Braun. Instead, the rule of horizontal exhaus-
    tion set forth in Community Redevelopment Agency
    and the other California cases cited in part III B 2 of
    this opinion should be applied in the circumstances of
    the present case.
    Rohr cites Continental Ins. Co. I
    I, supra
    , 
    15 Cal. App. 5th
    1017, in support of its claim that a rule of vertical
    exhaustion should apply. In that case, the state of Cali-
    fornia brought an action to recover from various insur-
    ers for costs related to the cleanup of hazardous waste.
    Id., 1022.
    Following a remand from the California
    Supreme Court, the parties filed motions for summary
    judgment concerning the issue of whether the policies
    issued by Continental Insurance Company and Conti-
    nental Casualty Company ‘‘attached immediately upon
    exhaustion of the specified retention for the specified
    policy period (vertical exhaustion) or only upon exhaus-
    tion of all retentions across all policy periods (hori-
    zontal exhaustion).’’
    Id., 1026.
    The trial court ruled that
    vertical exhaustion applied, and the Court of Appeal
    agreed. Id.; see
    id., 1037.
    In reaching that conclusion,
    the court found that Community Redevelopment
    Agency was not controlling because it ‘‘involved true
    primary policies’’;
    id., 1036;
    whereas, in Continental
    Ins. Co. II, ‘‘the applicable policies were not neatly
    divided into a primary level and an excess level. With
    one negligible exception, all of the applicable policies
    were excess to a retention.24 . . . Thus, no policy was
    written as excess to any other specified policy . . . .’’
    (Emphasis omitted; footnote added; footnote omitted.)
    Id., 1034.
    The court further explained: ‘‘Community
    [Redevelopment Agency] reasoned that a primary policy
    is qualitatively different from an excess policy; the
    defense and indemnity obligations under a primary pol-
    icy are immediate, whereas under an excess policy,
    they are merely contingent. Thus, an excess insurer
    should not be required to defend or to indemnify as
    long as any primary insurer is still sitting on its hands.
    The same is not true of two insurers [that] have issued
    policies that are excess to a retention. Their defense
    and indemnity obligations are both contingent, and they
    have priced their premiums accordingly. We cannot say,
    from their relationship alone, that either one should
    have to exhaust before the other is liable.’’ (Footnote
    omitted.)
    Id., 1034–35;
    see also Montgomery Ward &
    Co. v. Imperial Casualty & Indemnity Co., 
    81 Cal. App. 4th
    356, 364, 
    97 Cal. Rptr. 2d 44
    (2000) (self-insurance
    retentions ‘‘are not primary insurance and the principle
    of horizontal exhaustion does not apply’’). Accordingly,
    the circumstances of Continental Ins. Co. II, in which
    the court applied a rule of vertical exhaustion, do not
    apply to the present case.
    We conclude that the trial court did not err in
    determining that Rohr was required to horizontally
    exhaust all primary insurance before the liability of its
    excess insurers could attach.
    C
    Exhaustion of Primary Policies
    Rohr’s final claim related to the summary judgment
    rendered in favor of the Continental plaintiffs is that
    the trial court erred in concluding that actual payment
    by Royal of its policy limits was required to exhaust
    those policies in order for Rohr to be able to access
    the excess policies of the Continental plaintiffs. Rohr’s
    claim is based on the fact that the trial court, in its
    memorandum of decision, stated that Arrowood had
    ‘‘paid less than [the] per occurrence limits of its policies
    to Rohr. Because the limits have not been paid in full,
    the exhaustion necessary before the Harbor and London
    excess policies may be triggered remains unsatisfied.’’
    (Emphasis added.) We disagree with Rohr.
    In support of its claim, Rohr claims that a reversal of
    the trial court’s judgment is required for three reasons.
    First, Rohr claims that ‘‘the language of all of the Federal
    and Century excess policies and one Continental
    umbrella policy makes clear that actual payment of
    underlying policies is not required. Instead, exhaustion
    can be proved by evidence that the loss attributable to
    a single occurrence is greater than the attachment point
    of the excess policies—the subject of a future phase
    of trial.25 Second, the remaining Continental policies and
    Lloyd’s policies only require maintenance of underlying
    primary policies during the ‘currency’ of the policy
    term—meaning that once the policy term had expired,
    Rohr was free to compromise the underlying policies
    and fill any gap created by that compromise. Third, and
    alternatively, Royal and all relevant underlying insurers
    continue to be defendants in this litigation, subject to
    contribution claims of other insurers. As such, the liabil-
    ity of the Royal and other policies for coverage of the
    underlying environmental claims can be determined in
    this case, thereby fulfilling the exhaustion requirements
    in the Continental and Lloyd’s policies.’’ (Footnote
    added.)
    In opposition to Rohr’s claim, the Continental plain-
    tiffs allege that full payment by Royal of the limits of
    the Royal primary policies is necessary for the excess
    policies to respond. Specifically, they claim that the
    trial court ‘‘correctly held that where excess policies,
    like the Continental and London policies here, contain
    language that states the policies will not attach until
    the primary insurer has paid or been held liable to pay
    the full underlying limit (the exhaustion clause), full
    payment of the underlying primary policy by the pri-
    mary insurer is required before the excess policy
    responds.’’
    Our analysis of this claim is guided by Qualcomm,
    Inc. v. Certain Underwriters at Lloyd’s, 
    London, supra
    ,
    
    161 Cal. App. 4th 184
    . In that case, the defendant excess
    insurer had refused to pay under its excess policy after
    Qualcomm, Inc. (Qualcomm), entered into a settlement
    with its primary insurer over a coverage dispute related
    to a class action lawsuit, which was for an amount
    that was less than the $20 million limit of the primary
    insurer’s policy.
    Id., 187–88, 189.
    Qualcomm filed an
    appeal after the trial court ruled that the excess cover-
    age had not been triggered.
    Id. Pursuant to the
    language
    of the exhaustion provision in the limit of liability clause
    of the excess policy, the excess insurer would be liable
    ‘‘only after the insurers under each of the Underlying
    policies have paid or have been held liable to pay the
    full amount of the Underlying Limit of Liability,’’ which
    was $20 million under the primary policy. (Emphasis
    in original; internal quotation marks omitted.)
    Id., 195.
       The California Court of Appeal for the Fourth District
    concluded that ‘‘the phrase ‘have paid . . . the full
    amount [of $20 million]’ . . . cannot have any other
    reasonable meaning than actual payment of no less than
    the $20 million underlying limit.’’
    Id. Moreover, with respect
    to the language, ‘‘ ‘have been held liable to pay
    the full amount of [$20 million]’ ’’;
    id., 196;
    the court
    stated: ‘‘We need not decide whether the phrase ‘held
    liable to pay’ is susceptible of more than one reasonable
    meaning, because even assuming arguendo the phrase
    is ambiguous and we interpret it in Qualcomm’s favor
    to include responsibility for payment under a settlement
    agreement, Qualcomm’s complaint does not indicate
    (nor does Qualcomm argue) that the settlement
    between it and [its primary insurer] required [the pri-
    mary insurer] to accept responsibility or liability for
    the full amount of the $20 million limit on the underly-
    ing policy. Nor does the complaint plead that [the pri-
    mary insurer] was obligated to pay $20 million pursuant
    to a court order or judgment, which would plainly fall
    within such policy language. By the term of the excess
    policy requiring [the primary insurer] be ‘held liable to
    pay’ the ‘full amount’ of the underlying limit before [the
    excess insurer’s] liability attaches (even if it does not
    actually pay . . .) [the excess insurer] is under no obli-
    gation to provide excess coverage.’’ (Citation omitted;
    emphasis in original; footnote omitted.)
    Id., 196-97.
    Accordingly, the court in Qualcomm, Inc., concluded
    that, pursuant to the plain and unambiguous language
    of the excess policy, the defendant excess insurer’s
    obligation did not arise because ‘‘the primary insurer
    neither paid the ‘full amount’ of its liability limit nor
    had it become legally obligated to pay the full amount
    of the primary liability limit in the parties’ settlement
    agreement.’’26
    Id., 188;
    see also Span, Inc. v. Associated
    International Ins. Co., 
    227 Cal. App. 3d
    463, 468, 
    277 Cal. Rptr. 828
    (1991) (language of excess policy was not
    ambiguous where it required exhaustion of underlying
    limit by payment before excess insured was required
    to respond and, therefore, exhaustion by insolvency
    of primary insurer was not sufficient), review denied,
    California Supreme Court, Docket No. S019870 (April
    25, 1991).
    Pursuant to the attachment of liability clause in Har-
    bor excess policy 102211, liability to pay under the
    policy does not attach ‘‘unless and until the Primary
    and Underlying Excess Insurers shall have admitted
    liability for the Primary and Underlying Excess Limit(s)
    or unless and until the Assured has by final judgment
    been adjudged to pay an amount which exceeds such
    Primary and Underlying Excess Limit(s) and then only
    after the Primary and Underlying Excess Insurers have
    paid or have been held liable to pay the full amount of
    the Primary and Underlying Excess Limit(s).’’ With the
    exception of the Harbor umbrella policy, the other Har-
    bor excess policies at issue in these appeals contain
    either identical or substantially similar language; see
    footnotes 10 and 11 of this opinion; as do the London
    excess policies. See footnote 12 of this opinion. There-
    fore, in light of the plain language of the policies, the
    trial court’s determination that payment of the full limits
    of the primary policies was necessary for exhaustion
    to be satisfied was proper. The court, however, never-
    theless improperly determined that the necessary
    exhaustion of the Royal primary policies remained
    unsatisfied. This court has determined that the exhaus-
    tion of all primary insurance is required before an
    excess insurer is obligated to respond; see part III B
    of this opinion; and that the Royal primary policies each
    provide coverage of $2 million per occurrence for a
    combined total of $4 million. See part III A of this
    opinion. Because Rohr has entered into and received
    payment pursuant to a settlement concerning the Royal
    primary policies for an amount that exceeds $4 million,
    under the circumstances here, exhaustion by payment
    of the full amount of the limits of the Royal primary
    policies has been satisfied.27 This determination applies
    to the Harbor and London excess policies with two
    noted distinctions. With respect to London policy
    V20621, which was found to be specifically excess to
    London policy V20620, the trial court found that policy
    V20621 will be immediately triggered upon exhaustion
    of policy V20620, but that because V20620 could not be
    accessed prior to exhaustion of all primary policies,
    which the court found could not take place, policy
    V20621 likewise would be inaccessible. In light of our
    determination of the liability limits of the Royal primary
    policies and that, because the amount of the settlement
    with and payment by Arrowood under those policies
    exceeded their limits, exhaustion of those primary poli-
    cies has been satisfied, we disagree with the trial court’s
    conclusion regarding the inaccessibility of policy
    V20621.28 Moreover, with respect to Harbor umbrella
    policy 108909, the trial court again determined that no
    liability under the umbrella policy could attach until
    the underlying primary insurance has been exhausted
    by payment of the liability limits. Given our determina-
    tion regarding the exhaustion of the underlying insur-
    ance, liability under the Harbor umbrella policy
    attaches.
    D
    Conclusion
    In summary, because Arrowood, as successor to
    Royal, has paid Rohr more than the per occurrence
    limits of its policies, the exhaustion requirement with
    respect to the Royal primary policies has been satisfied.
    Thus, the trial court’s conclusion that the excess poli-
    cies of the Continental plaintiffs could never attach was
    incorrect. Therefore, the trial court improperly granted
    the motion for partial summary judgment filed by the
    Continental plaintiffs and determined that they were
    entitled to judgment as a matter of law. Instead, the
    court should have granted the motion for summary
    judgment filed by Rohr with respect to the Continen-
    tal plaintiffs.
    IV
    FEDERAL’S MOTION FOR SUMMARY JUDGMENT
    In its appeal in Docket No. AC 41537, Rohr challenges
    the judgment of the trial court granting the motion for
    summary judgment filed by Federal.29 We conclude that
    the trial court properly granted Federal’s motion for
    summary judgment.
    In addressing Federal’s motion for summary judg-
    ment, the trial court stated: ‘‘Federal issued three excess
    policies to Rohr effective from August 1, 1982 through
    August 1, 1985. Federal argues that, pursuant to the
    principle of horizontal exhaustion, all policies in effect
    during any part of the period of continuous loss poten-
    tially are liable up to their limits. Federal reasons that
    the present case involves claims of property damage
    beginning in the 1940s and continuing past 1985, and
    that the Royal policies and the Federal policies were
    both on the risk for portions of that period. Accordingly,
    it argues that all primary policies are deemed primary
    to any excess policies covering any part of the period
    of continuous loss. See Community Redevelopment
    Agency v. Aetna Casualty & Surety 
    Co., supra
    , 50 Cal.
    App. 4th 339. Federal concludes that, accordingly,
    although its policies were issued to cover later policy
    periods than the Royal policies, they cannot be reached
    until all primary policies have been exhausted.
    ‘‘In support of its assertion that all underlying policies
    have not been exhausted, Federal relies on the fact that
    Rohr entered into settlement agreements for less than
    the full limits with Arrowood on the Royal primary
    policies, and also with First State Insurance Company
    (First State) and Twin City Fire Insurance Company
    (Twin City),30 which issued excess policies directly
    underlying the Federal policies during the August 1,
    1982, to August 1, 1985 policy periods.
    ‘‘In its opposition, Rohr maintains that the Federal
    policies do not require it to collect any specific amount
    from any particular insurer as a condition to coverage,
    and that the Federal policies are liable toward the loss
    once Rohr’s damages meet the fixed attachment points
    of the Federal excess policies. Additionally, Rohr argues
    that Federal’s policies do not contain an exhaustion
    provision or a provision requiring full payment from
    any underlying policies before the Federal policies are
    triggered. In the absence of such a provision, Rohr
    asserts, settlement with underlying insurers does not
    forfeit Rohr’s coverage under the Federal policies. In
    such circumstances, Rohr asserts that it becomes ‘self-
    insured’ for the loss until the amount of the claims
    reach the Federal policies’ excess layer. Moreover, Rohr
    argues that the Federal policies do not clearly and
    unequivocally inform Rohr that they intend to be in
    excess of all primary insurance and all excess insurance
    and, accordingly, do not require horizontal exhaustion.’’
    (Footnote added.)
    On appeal, Federal and Century joined in and adopted
    the brief filed by the Continental plaintiffs concerning
    the issues of horizontal exhaustion and the lack of
    exhaustion of the underlying policies. They also filed
    a separate brief to address the legal issues related to
    the excess policies they had issued between 1982 and
    1986. Their specific arguments will be addressed sepa-
    rately as they relate to each of the policies.
    A
    Federal Excess Policy 7936-07-90
    We examine the provisions of the Federal excess
    policies. With respect to Federal excess policy 7936-07-
    90, the trial court stated: ‘‘The declarations applicable
    to policy 7936-07-90 for the period August 1, 1982, to
    August 1, 1983, identify it as an excess liability policy
    providing $10 million in excess coverage above the
    [Twin City] policy, which, in turn, provides $10 million
    above an additional $40 million in other underlying
    insurance. . . . The insuring agreement provides:
    [T]he Company agrees to pay on behalf of the Insured
    loss resulting from any occurrence Insured by the terms
    and provisions of the First Underlying Insurance policy
    scheduled in Item 6 of the Declarations . . . . The
    insurance afforded by this policy shall apply only in
    excess of and after all underlying insurance . . . has
    been exhausted. . . . Underlying insurance is defined
    to mean all policies scheduled in Item 6 . . . . The
    Federal policy adopts and follows all the terms, condi-
    tions and provisions of policy 103926 issued by Twin
    City . . . .
    ‘‘The court concludes that there is a specific relation-
    ship between the Federal and Twin City policies. This
    conclusion is underscored by the fact that the Federal
    policy adopts and follows the terms, conditions and
    provisions of the Twin City policy. Accordingly, a natu-
    ral, unrestrained reading of the language permits the
    court to conclude that the Federal policy is specifically
    excess to the Twin City policy.
    ‘‘The relevant provisions of the Twin City policy are
    as follows:
    ‘‘Limits of Liability . . . The total liability of the
    Company for all ultimate net loss as the result of any
    one occurrence shall not exceed the limit of liability
    stated [in] the declarations as applicable to each occur-
    rence. . . . [T]he total liability of the Company for all
    ultimate net loss because of . . . property damage to
    which this policy applies . . . shall not exceed the limit
    of liability stated in the declarations as aggregate . . . .
    ‘‘Ultimate Net Loss: The total of the following
    amounts . . . (1) all sums which the insured . . .
    shall become legally obligated to pay as damages,
    whether by reason of adjudication or settlement,
    because of . . . property damage . . . .
    ‘‘Other Insurance: The Insurance afforded by this pol-
    icy shall be excess insurance over any other . . . Insur-
    ance . . . available to the Insured, whether or not
    described in the Schedule of Underlying Insurance Poli-
    cies, and applicable to any part of ultimate net loss,
    whether such other insurance is stated to be primary,
    contributing, excess or contingent . . . .
    ‘‘The court previously concluded that horizontal
    exhaustion of the primary policies is applicable to this
    case in which continuing property damage has been
    alleged across several decades, triggering multiple pol-
    icy periods. The Royal [primary] policies, which are
    considered primary to all excess policies, have not paid
    their full limits. Additionally, the directly underlying
    Twin City policy [insurer] has settled with the insured
    for less than its full limits. The fact that the Federal
    policy is specifically excess to, and follows, the Twin
    City policy creates a sequential expectation as to when
    the Federal policy pays its limits because the Federal
    limits shall immediately follow the Twin City limits.
    The Twin City policy’s other insurance clause provides,
    however, that its coverage is excess over any other
    valid and collectible insurance available to the insured.
    Moreover, the terms of the Federal policy expressly
    contemplate that a specified amount of coverage within
    the policy period will be exhausted, including the limits
    of the Twin City policy, before its own limits are
    triggered.
    ‘‘Construing the terms of the Federal and Twin City
    policies together and as a whole, the court acknowl-
    edges that, although horizontal exhaustion generally is
    being applied to the collective policy limits and policy
    periods in this case, the specific relationship between
    the Federal and Twin City policies would ordinarily
    require a vertical allocation scheme between the two
    policies, and the limits of the Federal policy would be
    immediately triggered once Twin City paid its limits.
    . . . In the present case, however, the court cannot
    conclude that the limits of this Federal excess policy
    are triggered, because the Twin City excess policy, and
    the Royal primary policies, which settled for less than
    their specified limits, constitute other valid insurance
    collectible by the insured. Therefore, the plain terms
    of the policies must be given effect as written. As an
    excess insurance policy providing coverage above a
    stated amount, the Federal policy must be considered
    excess insurance above all other available insurance
    . . . and cannot be expected to pay its limits until the
    applicable limits of any other underlying insurance col-
    lectible by the insured, including primary coverage
    which is still available, have been paid.’’ (Citations omit-
    ted; internal quotation marks omitted.)
    Federal claims that, although ‘‘the trial court to some
    degree fused the two distinct legal concepts on which
    the judgments for Century and Federal were based—
    and on which such judgments should be affirmed—any
    shortcomings in the trial court’s analysis were ulti-
    mately immaterial because the final judgments are fully
    supported by the record.’’ Specifically, Federal claims
    that ‘‘the fact that the trial court conflated the concept
    that an excess policy can ‘follow form’ to underlying
    policy terms and conditions with the concept that an
    excess policy can ‘specifically follow’ an underlying
    policy does not detract from the trial court’s ultimate
    correct judgment for Federal.’’ Federal explains that its
    1982–1983 policy is a general excess policy that cannot
    be reached until ‘‘Rohr exhausts the $50 million in
    scheduled limits directly underlying it,’’ and that,
    because its policy ‘‘does not contain any language spe-
    cifically identifying and limiting the underlying cover-
    age,’’ it is excess over all of Rohr’s primary insurance.
    (Emphasis in original.) Finally, Federal claims that its
    excess policy cannot be reached in light of Rohr’s settle-
    ment with Twin City for less than the limits of the Twin
    City policy, and cites Qualcomm, Inc., in support of its
    claim. In contrast, Rohr claims that, ‘‘[i]f the trial court
    was correct in concluding that [the Federal 1982–1983
    policy] was specific excess, then vertical exhaustion
    should apply without regard to the existence of unex-
    hausted policies in other years.’’
    Pursuant to the plain terms of the 1982–1983 Federal
    excess policy, Federal agreed to pay for loss resulting
    to the insured from any occurrence insured by the terms
    and provisions of the first underlying insurance policy—
    the Twin City policy. The Federal policy further pro-
    vides that its coverage applies only in excess of and after
    the exhaustion of all underlying insurance as defined
    in item 6 of the schedule, which refers to the Twin City
    policy as the first underlying insurance policy and to
    various other insurance policies on file with the com-
    pany totaling $40 million, and does not specifically men-
    tion the Royal primary policy. We need not decide
    whether the Federal 1982–1983 policy is a general
    excess policy or whether, as Federal claims, the trial
    court conflated any concepts. Regardless of whether
    the policy is specific or general excess, pursuant to
    its plain language, Rohr must exhaust $50 million in
    scheduled limits directly underlying the Federal policy
    before the Federal policy provides coverage. Notwith-
    standing our determination that the coverage limits of
    the Royal primary policies have been exhausted, the
    1982–1983 Federal policy lists the $10 million Twin City
    policy as the first underlying insurance policy, with
    $40 million in other underlying insurance that must be
    exhausted for the insurer to cover a loss under the
    policy. The Twin City policy and the Federal policy
    constitute multiple layers of excess insurance, to which
    a rule of vertical exhaustion applies. See Montrose II
    I, supra
    , 
    9 Cal. 5th 226
    . Thus, even if horizontal exhaustion
    of all of the $40 million in underlying insurance has
    occurred, exhaustion of the Twin City policy would still
    be required before coverage under the Federal policy
    attaches. Because Rohr has settled with Twin City, a
    directly underlying excess insurer to the Federal 1982–
    1983 policy, for less than the specified limits of the
    Twin City policy, the requisite exhaustion has not
    occurred. See Qualcomm, Inc. v. Certain Underwriters
    at Lloyd’s, 
    London, supra
    , 
    161 Cal. App. 4th 196
    –97.
    Accordingly, the trial court properly rendered summary
    judgment in Federal’s favor with respect to its 1982–
    1983 excess policy.
    B
    Federal Excess Policies (84) 7936-07-90
    And (85) 7936-07-90
    With respect to Federal excess policies (84) 7936-07-
    90 and (85) 7936-07-90, the trial court stated: ‘‘Unlike
    Federal 7936-07-90, Federal policies (84) 7936-07-90 and
    (85) 7936-07-90 do not follow form to a directly underly-
    ing insurance policy; however, the insuring agreements
    for both policies require that the first designated under-
    lying insurance and all underlying insurance pay their
    limits before the Federal policies pay their own limits.
    Federal policy (84) 7936-07-90 provides $10 million in
    excess coverage above the Twin City policy, which, in
    turn, provides $10 million above an additional $40 mil-
    lion in other underlying insurance. . . . The declara-
    tions page for Federal policy (84) 7936-07-90 provides
    that coverage ‘shall apply only in excess of and after
    all underlying insurance (as scheduled in Item 6 of
    the Declarations) has been exhausted.’ . . . Item 6 of
    the Declarations identifies the Twin City policy as the
    first underlying insurance, in addition to various other
    underlying policies ‘on file with company.’ . . .
    ‘‘Federal policy (85) 7936-07-90 provides $10 million
    in excess coverage above the First State policy, which
    in turn provides $10 million excess coverage. . . . The
    terms of Federal (85) 7936-07-90 include the same sub-
    stantive language as Federal (84) 7936-07-90, except
    that it identifies the First State policy as the first under-
    lying insurance. . . .
    ‘‘Pursuant to their plain language, the court concludes
    that Federal policy (84) 7936-07-90 and (85) 7936-07-90
    are general excess policies. In this case, the terms of
    the policies specify that coverage is intended to be ‘in
    excess of and after all underlying insurance.’ The Royal
    policies, which are considered primary to all excess
    policies covering the claims, and the directly underlying
    First State and Twin City excess policies, are ‘underly-
    ing insurance.’
    ‘‘The terms of the Federal policies expressly contem-
    plate that a specified amount of underlying coverage
    will be exhausted, including the limits of the First State
    and Twin City policies. These policies have not paid
    their full limits, and, additionally, primary coverage
    under the Royal policies also remains available to the
    insured. The plain terms of the Federal policies must
    be given effect as written. As excess insurance policies
    providing coverage above a stated amount, the Federal
    policies must be considered excess insurance above all
    other available insurance . . . and cannot be expected
    to pay their respective limits until the applicable limits
    of any other underlying insurance, including primary
    coverage, have been paid.’’ (Citations omitted; empha-
    sis in original.) The court, thus, determined that Federal
    demonstrated that it was entitled to summary judgment
    in its favor.
    For the same reasons we discussed with respect to
    the Federal 1982–1983 policy, we conclude that the trial
    court properly rendered summary judgment in favor of
    Federal with respect to the 1984 and 1985 policies.
    Regardless of whether horizontal exhaustion of all
    underlying primary insurance has occurred, the exhaus-
    tion of the first layer excess insurance policies—the
    First State policy and the Twin City policy—is required
    for coverage under these Federal policies to attach.
    Because Rohr entered into a settlement with First State
    and Twin City for less than the limits of their respective
    policies, there can be no exhaustion through payment
    of the limits of those policies. See Qualcomm, Inc. v.
    Certain Underwriters at Lloyd’s, 
    London, supra
    , 
    161 Cal. App. 4th 196
    –97.
    Accordingly, the trial court properly granted Feder-
    al’s motion for summary judgment.
    V
    CENTURY’S MOTION FOR SUMMARY JUDGMENT
    In its appeal in Docket No. AC 41538, Rohr challenges
    the judgment of the trial court granting the motion for
    summary judgment filed by Century.31 We conclude that
    the trial court properly granted Century’s motion for
    summary judgment with respect to policy 00 73 01, but
    should have denied the motion as to policies ZCX8459,
    ZCX8609 and ZCX8634.
    A
    Century Excess Policy 00 73 01
    The first of four policies issued by Century to Rohr
    was policy 00 73 01. The trial court stated the following
    with respect to this policy: ‘‘The declarations applicable
    to policy 00 73 01 for the period August 1, 1984, to
    August 1, 1985, identify it as a policy of excess insur-
    ance, providing $5 million in excess coverage above
    $25 million. . . . Item 3 of the declarations specifies
    that the $5 million policy limit is in excess of limits
    specified in item 2. Item 2 identifies the designated
    underlying insurance as a First State insurance [policy]
    with limits of $25 million excess of primary limits. . . .
    The policy further provides: This is a policy of excess
    insurance . . . . The insurance afforded by this Policy
    shall follow that of the designated underlying insurance
    . . . . Additionally, it provides that [t]his policy indem-
    nifies the insured in accordance with the applicable
    insuring agreements, conditions . . . of the designated
    underlying insurance for excess loss . . . . The court
    concludes that there is a specific relationship between
    the Century and First State policies. This conclusion is
    underscored by the fact that the Century policy shares
    the same insuring agreements and conditions applicable
    to the First State policy. The Century policy also plainly
    provides that its coverage shall follow the First State
    policy. Accordingly, a natural, unrestrained reading of
    the policy leads the court to conclude that the Century
    policy is specifically excess to the First State policy.
    ‘‘The relevant provisions of the First State policy are
    as follows:
    ‘‘Underlying Limit-Retained Limit: The Company shall
    be liable only for the ultimate net loss in excess of
    the greater of the insured’s: (A) Underlying Limit—an
    amount equal to the limits of liability indicated beside
    the underlying insurance listed in the Schedule A of
    underlying insurance, plus the applicable limits of any
    other underlying insurance collectible by the insured
    . . . .
    ‘‘Ultimate Net Loss: Means the sums paid as damages
    in settlement of a claim or in satisfaction of a judgment
    for which the insured is legally liable after making
    deductions for all other recoveries, salvages and other
    insurances whether recoverable or not, other than the
    underlying insurance and excess insurance purchased
    specifically to be in excess of this policy . . . .
    ‘‘Other Insurance: If other collectible insurance with
    any other insurer is available to the insured covering
    a loss covered hereunder . . . the insurance hereunder
    shall be in excess of, and not contribute with such other
    insurance. . . .
    ‘‘The court has already concluded that horizontal
    exhaustion is applicable to this case in which continuing
    property damage has been alleged across several
    decades, triggering multiple policy periods. The Royal
    policies, which are considered primary to all excess
    policies, have not paid their full limits. Additionally, the
    directly underlying First State policy has settled with
    the insured for less than its full limits. The fact that the
    Century policy is specifically excess to, and follows,
    the First State policy creates a sequential expectation
    as to when the Century policy pays its limits because
    the Century limits shall immediately follow the First
    State limits. The First State policy’s other insurance
    clause provides, however, that coverage shall be in
    excess of, and not contribute with other collectible
    insurance. The First State policy’s underlying limit-
    retained limit clause also requires the applicable limits
    of any other underlying insurance collectible by the
    insured to be paid before it will pay its own limits.
    Moreover, the terms of the Century policy expressly
    contemplate that a specified amount of coverage within
    the policy period will be exhausted, including the limits
    of the First State policy, before its own limits are
    triggered.
    ‘‘Construing the terms of the Century and First State
    policies together and as a whole, the court acknowl-
    edges that, although horizontal exhaustion is being
    applied as a general rule to the collective policy limits
    and policy periods in this case, the specific relationship
    between the Century and First State policies would
    ordinarily require a vertical allocation scheme between
    the two policies, and the limits of the Century policy
    would be immediately triggered once First State paid
    its limits. . . . In the present case, however, the court
    cannot conclude that the limits of this Century excess
    policy are triggered because the First State excess pol-
    icy, and the Royal primary policies, which settled for
    less than their specified limits, constituted other valid
    insurance collectible by the insured. Therefore, the
    plain terms of the policies must be given effect as writ-
    ten. As an excess insurance policy providing coverage
    above a stated amount, the Century policy must be
    considered excess insurance above all other available
    insurance . . . and cannot be expected to pay its limits
    until the applicable limits of any other underlying insur-
    ance collectible by the insured, including primary cover-
    age which is still available, have been paid.’’ (Citations
    omitted; emphasis in original; internal quotation
    marks omitted.)
    Although we disagree with the trial court’s conclusion
    that the limits of the Royal primary policies have not
    been exhausted, its decision rendering summary judg-
    ment in favor of Century was nevertheless proper as
    to this Century policy. Because the directly underlying
    First State policy settled with the insured for less than
    its full limits, the coverage provided under Century pol-
    icy 00 73 01 has not been triggered.
    B
    Century Excess Policies ZCX8459,
    ZCX8609 and ZCX8634
    From the period of August 1, 1985, to August 1, 1986,
    Century issued to Rohr three other excess policies that
    were substantially similar in content. The trial court
    concluded that those policies provided ‘‘three layers of
    excess coverage: ZCX8459 providing $5 million in
    excess coverage above $6.5 million; ZCX8609 providing
    $2.5 million in excess coverage above $21.5 million;
    ZCX8634 providing $2.5 million in excess coverage
    above $26.5 million. All of these policies indemnify the
    insured in accordance with the applicable insuring
    agreements, exclusions, and conditions of the desig-
    nated underlying insurance. The designated underlying
    insurance is umbrella policy 15 71 09 issued by United
    Insurance Company (United policy).’’ (Citation omitted;
    internal quotation marks omitted.)
    The court further stated: ‘‘The declarations of each
    respective policy plainly state that it is a policy of excess
    insurance and identifies the United policy as its desig-
    nated underlying insurance. The Century policies
    clearly follow form to the United policy, as noted by
    the provision: The insurance afforded by this Policy
    shall follow that of the designated underlying insurance.
    . . . Accordingly, the court concludes that the Century
    policies issued during this period are specifically excess
    to the United policy.
    ‘‘In the section entitled, Retained Limit-Limit of Liabil-
    ity, the United policy specifically limits its ultimate net
    loss to the total of the applicable limits of the underlying
    policies listed in Schedule A hereof, and the applicable
    limits of any other insurance collectible by the
    insured . . . .
    ‘‘The plain language of the Century excess policies
    communicate the highly specific nature of each Century
    policy’s relationship to a specifically identified underly-
    ing policy. The Century excess policy language also
    plainly provides that the limits are triggered once the
    specifically identified underlying policy has paid its lim-
    its. While the rule of horizontal exhaustion is generally
    applicable to policies covering claims involving a con-
    tinuous long-tail loss, the Century policies, pursuant
    to their plain terms, are specific excess policies. This
    interpretation results from a natural, unrestrained read-
    ing of the terms, which provide that the Century limits
    are triggered once the designated underlying insurance
    pays its limits. In this circumstance, the language can
    only be interpreted as requiring a vertical exhaustion
    allocation scheme.
    ‘‘The Century excess policies, therefore, must pay
    their limits immediately once the designated underlying
    insurance policy pays its limits. The designated underly-
    ing insurance policy, pursuant to its terms, is scheduled
    to pay its limits after all other collectible insurance has
    been paid to the insured. To the extent that the policies
    called upon involve the same occurrences covered by
    the Royal policies, the limits of the Century policies
    have not been triggered, given that all underlying insur-
    ance collectible by the insured has not been exhausted,
    as previously discussed in this memorandum.’’ (Cita-
    tions omitted; emphasis in original; internal quotation
    marks omitted.)
    Again, we disagree with the trial court’s conclusion
    that, with respect to the Royal primary policies, exhaus-
    tion of the underlying limits has not occurred. To the
    extent that this case concerns the issue of the satisfac-
    tion of the Royal primary policies, the trial court incor-
    rectly determined that such satisfaction had not
    occurred. Accordingly, the court improperly deter-
    mined that Century was entitled to summary judgment
    with respect to these policies because of the failure to
    fully exhaust the Royal primary policies.32
    VI
    CROSS APPEAL
    In their cross appeal, the Continental plaintiffs claim
    that the trial court erred ‘‘when it held that the 1959 to
    1971 Royal primary policies have per policy occurrence
    limits of only $8 million despite the policies’ endorse-
    ments, which provide that each of the four Royal pri-
    mary policies have annual period per occurrence limits
    that total $24 million . . . .’’ We disagree.
    The arguments raised by the Continental plaintiffs in
    their cross appeal are similar to the ones they raised
    on direct appeal with respect to the issue of whether
    the $2 million per occurrence limits in the Royal primary
    policies may be annualized, which this court addressed
    and rejected in part III A 1 of this opinion. In addressing
    the annualization question in this opinion, we con-
    cluded that ‘‘the per occurrence language of each Royal
    primary policy provides coverage of up to $2 million
    for an occurrence that takes place during the policy
    period and not for each year of that policy period.’’
    See part III A 1 of this opinion. We also rejected the
    Continental plaintiffs’ reliance on 
    Stonewall, supra
    , 
    46 Cal. App. 4th
    1849, on which they also rely to support
    their claim on the cross appeal. Specifically, we con-
    cluded that because each Royal primary policy con-
    tained one endorsement providing for a policy period
    of three years and setting the limit of coverage at $2
    million per occurrence, and because there is no lan-
    guage in the Royal primary policies or their declarations
    providing for coverage on a per occurrence, per year
    basis, Stonewall is factually distinguishable from the
    present case. We further concluded in part III A 2 of
    this opinion that because the extensions of the Royal
    primary policies did not provide additional per occur-
    rence limits, the per occurrence limit of liability in each
    policy is $2 million and, thus, Rohr is entitled to cover-
    age in the amount of $2 million per policy, for a com-
    bined total for the two policies of $4 million. In light
    of those determinations, we reject the claim of the Con-
    tinental plaintiffs in the cross appeal that the Royal
    primary policies have annual period per occurrence
    limits that total $24 million. Accordingly, the cross
    appeal fails.
    The judgment is reversed with respect to the granting
    of partial summary judgment in favor of the Continental
    plaintiffs, the granting of summary judgment in favor
    of Century with respect to policies ZCX8459, ZCX8609
    and ZCX8634, and the denial of Rohr’s motion for sum-
    mary judgment with respect to the Continental plain-
    tiffs, and the case is remanded with direction to deny the
    motions for summary judgment filed by the Continental
    plaintiffs and by Century with respect to policies
    ZCX8459, ZCX8609 and ZCX8634, and to grant Rohr’s
    motion for summary judgment with respect to the Conti-
    nental plaintiffs and for further proceedings thereon;
    the judgment is affirmed in all other respects.
    In this opinion the other judges concurred.
    * The listing of judges reflects their seniority status on this court as of
    the date of oral argument.
    1
    In this opinion, we refer to Continental, Lloyd’s and the London insurers
    individually by name where necessary and collectively as the Continental
    plaintiffs.
    2
    The environmental claims involve seven sites located in California (Chula
    Vista, Riverside, Agricultural Park, Casmalia Resources Hazardous Waste
    Facility, BKK Landfill, Basin By-Product and Gibson Environment) and one
    site located in Missouri known as Hayford Bridge.
    3
    Although only two of the Royal primary policies are at issue in these
    appeals, paragraph 235 of the plaintiffs’ complaint identifies six policies
    issued to Rohr by Arrowood, as successor to Royal. The additional four
    policies are RTS 902220, PLX 120077, RTS 902223, and PTS 902224.
    4
    The plaintiffs are Continental; Lloyd’s; Berkshire Hathaway Direct Insur-
    ance Company, formerly known as American Centennial Insurance Com-
    pany; Berkshire Hathaway Specialty Insurance Company, formerly known
    as Stonewall Insurance Company; Ocean Marine, as successor to certain
    policies subscribed to by Commercial Union Assurance Company PLC and/
    or General Accident Fire & Marine Life Assurance Corporation; Scottish
    Lion; Winterthur Swiss Insurance Corporation, Ltd.; Tenecom, formerly
    known as Yasuda Insurance Company; Nissan Fire & Marine Insurance
    Company, Ltd.; NRG N.V.; and Republic Insurance Company.
    5
    The defendants are Rohr; Hartford Accident & Indemnity Company;
    Transport Insurance Company; Arrowood; First Charter Insurance Com-
    pany, as successor in interest to Transportation Insurance, Ltd.; Allianz
    Underwriters Insurance Company; Allstate Insurance Company, as succes-
    sor in interest to Northbrook Excess & Surplus Insurance Company; Chicago
    Insurance Company; Employers Mutual Casualty Company; Federal; Fire-
    man’s Fund Insurance Company; Westport Insurance Corporation, as succes-
    sor in interest to Puritan Insurance Company; Tudor Insurance Company;
    United Insurance Company; Twin City Fire Insurance Company; First State
    Insurance Company; Century; and Middlesex Insurance Company.
    6
    Pursuant to paragraph 37 of their complaint, the plaintiffs alleged that
    the trial court had ‘‘jurisdiction over this matter pursuant to . . . General
    Statutes §[§] 52-59b and . . . 33-929 because, on information and belief,
    each of the parties transacts and does business in Connecticut and/or seeks
    the performance of the insurance contracts in Connecticut,’’ and that the
    court had ‘‘authority to provide the declaratory relief requested pursuant
    to . . . General Statutes § 52-29 and . . . Practice Book [§§] 17-54 and
    17-55.’’
    7
    After the plaintiffs commenced this action, Federal and Century each
    filed thirty-two special defenses as well as cross claims against Rohr, to
    which Rohr filed special defenses. Rohr also filed special defenses in
    response to the complaint as well as a counterclaim against certain of
    the plaintiffs, including Continental; Lloyd’s; Berkshire Hathaway Specialty
    Insurance Company, formerly known as Stonewall Insurance Company;
    Ocean Marine; Winterthur Swiss Insurance Corporation, Ltd.; Tenecom,
    formerly known as Yasuda Insurance Company; Nissan Fire & Marine Insur-
    ance Company, Ltd.; NRG N.V.; and Scottish Lion. Additionally, Rohr filed
    a cross claim against certain of the defendant insurers, and the counterclaim
    and cross claim defendants filed special defenses in response to Rohr’s
    cross claim and counterclaim.
    8
    In accordance with motions to seal filed by the parties, and after a
    hearing held thereon, the court, on April 5, 2017, ordered sealed, pursuant
    to Practice Book § 11-20A, certain documents that reflected the dollar
    amount and terms of the settlement, finding that ‘‘[t]he unredacted docu-
    ments subject to [the] motion[s] to seal contain confidential settlement
    information’’ and that ‘‘[t]he privacy interests of certain of the parties to
    [the] litigation concerning the information in the unredacted documents
    overrides the public’s interest in viewing the material.’’ The documents that
    are subject to the order to seal include the memorandum in support of the
    motion for partial summary judgment filed by the Continental plaintiffs,
    Federal’s memorandum in support of its joinder motion for summary judg-
    ment, Century’s memorandum in support of its joinder motion for summary
    judgment, Rohr’s memorandum in opposition to the motion for partial sum-
    mary judgment filed by the Continental plaintiffs, Rohr’s opposition to the
    joinder motions for summary judgment filed by Federal and Century, and
    the memorandum in opposition to Rohr’s motion for summary judgment
    filed by the Continental plaintiffs. Subsequently, the documents in question
    were refiled with redactions concerning the information that is subject to
    the sealing order.
    9
    The court also explained its use of the term ‘‘trigger of coverage’’: ‘‘In
    the third party liability insurance context, ‘trigger of coverage’ has been
    used by insureds and insurers alike to denote the circumstances that activate
    the insurer’s defense and indemnity obligations under the policy. The term
    ‘trigger of coverage’ should not be misunderstood as a doctrine to be auto-
    matically invoked by a court to conclusively establish coverage in certain
    categories of cases, or under certain types of policies. The word ‘trigger’ is
    not found in the [comprehensive general liability] policies themselves, nor
    does the [California] Insurance Code enumerate or define ‘trigger of cover-
    age.’ Instead, ‘trigger of coverage’ is a term of convenience used to describe
    that which, under the specific terms of an insurance policy, must happen
    in the policy period in order for the potential of coverage to arise. The issue
    is largely one of timing—what must take place within the policy’s effective
    dates for the potential of coverage to be ‘triggered’? Whether coverage is
    ultimately established in any given case may depend on the consideration
    of many additional factors, including the existence of express conditions
    or exclusions in the particular contract of insurance under scrutiny, the
    availability of certain defenses that might defeat coverage, and a determina-
    tion of whether the facts of the case will support a finding of coverage.’’
    (Emphasis omitted.) Montrose 
    I, supra
    , 
    10 Cal. 4th 655
    n.2.
    10
    Paragraph 101 of the complaint alleges that Harbor issued thirteen
    excess comprehensive liability policies to Rohr. In support of their motion
    for partial summary judgment, the Continental plaintiffs submitted the affida-
    vit of Kelly M. Wolfe, an associate with the law firm that represents the
    Continental plaintiffs. In her affidavit, Wolfe references seven of those poli-
    cies that were in effect at various times between 1964 and 1971, which
    include policies 102211, 103152, 106597, 103633, 108053, 108908, and 108909.
    With the exception of the Harbor umbrella policy 108909, the six Harbor
    excess policies contain substantially the same terms and conditions, and
    the trial court found that ‘‘the slight differences between individual policies
    [were] of no significance.’’ For convenience, we discuss policy 102211 and
    set forth key provisions and language that it has in common with the other
    policies. The trial court, in rendering its judgment, examined those policies
    contained in the trial court record, and we do the same. We also note that
    each of the Harbor excess policies that became effective January 1, 1971,
    or later contain a provision that excludes from coverage ‘‘any loss arising
    out of contamination or pollution.’’ Accordingly, we limit our discussion to
    those policies in effect prior to January 1, 1971.
    11
    Harbor excess policy 103152, which was in effect from August 1, 1965,
    to August 1, 1968, contained similar coverage limits, terms, definitions and
    conditions, as did Harbor excess policy 103633, which provided $5 million
    in coverage limits per occurrence and in the aggregate, and was effective
    February 26, 1966, to August 1, 1969. Harbor excess policy 103633 was
    excess to Harbor excess policies 103152 (until March 14, 1968) and 106597
    (from March 14, 1968), and it was also excess to Royal primary policy RLP
    144014. Furthermore, Harbor excess policy 108053, effective August 1, 1969,
    to December 1, 1969, and policy 108908, effective December 1, 1969, to June
    1, 1973, both contained coverage limits up to $5 million per occurrence and
    in the aggregate, and contained terms that were substantially similar to the
    other Harbor excess policies. Finally, Harbor issued umbrella policy 108909,
    which was in effect from December 1, 1969, to June 1, 1973, provided
    coverage in the amount of $3 million per occurrence and in the aggregate,
    and was in excess to Harbor excess policy 108908 and to Royal primary
    policy RTS 902235. We discuss Harbor umbrella policy 108909 separately
    from the other Harbor excess policies. See parts II C and III C of this opinion.
    12
    The Continental plaintiffs submitted an affidavit of Kelly M. Wolfe, an
    associate with the law firm that represents the Continental plaintiffs. In her
    affidavit, Wolfe references six of those policies that were in effect from
    1966 to 1969, including policies V20620, V20621, V20622, V23801, V23802
    and Certificate LA 41019, all of which contain substantially similar terms
    and conditions, except for policy V20621. The trial court, in rendering its
    judgment, examined those policies contained in the trial court record, and
    we do the same. See also parts II B 3 and III C of this opinion.
    13
    See London excess policies V20620, V20622, V23801, V23802 and London
    Certificate LA 41019.
    14
    The Continental plaintiffs cite Peerless for the rule that, ‘‘when a policy
    which provides excess insurance above a stated amount of primary insur-
    ance contains provisions . . . which make it also excess insurance above
    all other insurance which contributes to the payment of the loss together
    with the specifically stated primary insurance, such clause will be given
    effect as written.’’ Peerless Casualty Co. v. Continental Casualty 
    Co., supra
    ,
    
    144 Cal. App. 2d 626
    .
    15
    Harbor excess policies 102211, 103152, 106597, 103633, and 108053,
    and London excess policies V20620, V20622, V23801, V23802 and London
    certificate LA 41019 include schedules and endorsements that refer to Royal
    primary policy RLP 144014 as an underlying primary insurance policy. Harbor
    excess policy 108908 refers to Royal primary policy RTS 902235 as an
    underlying primary insurance policy, and London policy V20621 references
    ‘‘Royal Indemnity Company’’ as a primary insurer, along with three other
    primary insurers.
    16
    The trial court found one exception—London excess policy V20621—
    to its conclusion that the Harbor and London excess policies were general
    excess policies. Specifically, the court stated: ‘‘Policy V20621 was ‘subscribed
    to on the same terms, conditions, definitions and exclusions applicable to
    London . . . policy V20620.’ . . . London . . . V20621 sits directly above
    London . . . V20620 in the coverage ‘tower.’ The language of London . . .
    V20621 plainly provides that this particular excess policy attaches to and
    forms part of London . . . V20620. . . .
    ‘‘This language specifically describes the relationship between policies
    V20620 and V20621, and sufficiently overcomes the general presumption
    that all underlying insurance must be exhausted before V20621 responds to
    the claim. See Community Redevelopment Agency v. Aetna Casualty &
    Surety 
    Co., supra
    , 
    50 Cal. App. 4th 340
    n.6. Instead, the language permits a
    natural conclusion that it is the intention of the parties for these two specific
    policies to be linked in such a manner so as to form one policy. Accordingly,
    the court concludes that London . . . V20621 is specifically excess to Lon-
    don . . . V20620, and the policy limits provided under London . . . V20621
    will be immediately triggered in accordance with its terms and upon exhaus-
    tion of London . . . V20620. Nevertheless, because V20620 itself, as pre-
    viously concluded, cannot be exhausted or even accessed prior to exhaustion
    of all primary policies, V20621 will likewise be inaccessible prior to the
    exhaustion of all primary policies.’’ (Citations omitted.) Although we agree
    that policy V20621 is specifically excess to policy V20620, we address the
    exhaustion issue and whether policy V20620 can be accessed in parts III A
    and C of this opinion.
    17
    See footnote 8 of this opinion.
    18
    The trial court did not make a determination regarding the number of
    occurrences at issue in this case. The court stated: ‘‘The court reaches no
    conclusion as to the number of occurrences at issue, and the record is
    insufficient at this time for a definitive determination of that question. Never-
    theless, the court concludes, for the reasons that follow, that the Royal
    policies have not been exhausted, regardless of the number of occurrences
    at issue. . . . Accordingly, regardless of whether the case involves one
    occurrence, which would limit coverage under the policies to $8 million,
    or several occurrences, for which coverage, under the per occurrence and
    annual aggregate limits, might be as much as $24 million, the settlement
    amount did not exhaust the Royal policies.’’
    19
    The court, however, found that the aggregate limits could be annualized.
    Specifically, the court found that because the aggregate limits under the
    Royal primary policies were triggered for each annual term that those poli-
    cies were in effect, and because those policies provided ‘‘aggregate limits
    of $2 million for each of twelve annual terms, the total coverage potentially
    available in the aggregate under the Royal policies [was] $24 million.’’
    20
    We disagree with the Continental plaintiffs with respect to this claim.
    Nowhere in A.B.S. Clothing did the court state that the only situation in
    which an extension would not constitute a new policy with a new contract
    period would be a circumstance in which the policy was continued indefi-
    nitely. Rather, the court merely stated, as an example of a continuous
    contract, a contract that includes terms establishing an intention that the
    policy be continued indefinitely. A.B.S. 
    Clothing, supra
    , 
    34 Cal. App. 4th 1476
    . If that were a prerequisite to finding the existence of one continuous
    contract, the court would not have had to examine the policy provisions
    for ambiguity, as the policies at issue in that case had specific beginning
    and ending dates of coverage. See
    id., 1481. 21
          The decision, as modified, was published on May 27, 2020.
    22
    Moreover, we find SantaFe Braun distinguishable for another reason
    as well. Despite the fact that the California Supreme Court in Montrose III
    clearly stated that its holding did not address the issue of ‘‘when or whether
    an insured may access excess policies before all primary insurance covering
    all relevant policy periods has been exhausted’’; Montrose II
    I, supra
    , 
    9 Cal. 5th
    226 n.4; the court in SantaFe Braun nevertheless rendered its decision
    on the basis of Montrose III, concluding that it was compelled by the decision
    in Montrose III to find that all primary insurance covering all time periods
    did not need to be horizontally exhausted before the first level excess
    policies could be triggered. SantaFe 
    Braun, supra
    , 
    52 Cal. App. 5th 28
    –30.
    As we have stated previously in this opinion, the application by the California
    Supreme Court of a rule of vertical exhaustion under the circumstances
    present in Montrose III has no bearing on our determination of the issue
    in the present case of whether the trial court erred in determining that the
    underlying primary policies had to be horizontally exhausted before liability
    under the excess policies could attach. We, thus, necessarily disagree with
    the decision of the court in SantaFe Braun that Montrose III governed its
    determination of the issue before it concerning the exhaustion of primary
    insurance, as opposed to the exhaustion of multiple layers of excess policies,
    which was at issue in Montrose III.
    23
    We note that Rohr attempts to distinguish Community Redevelopment
    Agency on the ground that it involved a dispute between insurers. Specifi-
    cally, Rohr alleges that ‘‘this case involves a dispute between Rohr and its
    insurers and, when a policyholder is involved, the priority must be on
    providing the policyholder with access to the excess insurance coverage
    it has paid for. Community Redevelopment [Agency], a dispute between
    insurers, is inapplicable here.’’ Related to its attempt to distinguish Commu-
    nity Redevelopment Agency, Rohr also asserts that the differences between
    excess and primary insurance do not compel a conclusion supporting a rule
    of horizontal exhaustion. We are not persuaded by either claim, especially
    given that the application of a rule of horizontal exhaustion will not deprive
    Rohr of access to its excess insurance from the Continental plaintiffs.
    24
    In Continental Ins. Co. I
    I, supra
    , 
    15 Cal. App. 5th
    1030, the court
    explained that ‘‘[m]ost excess policies are written as excess to a specified
    primary policy. Alternatively, however, a policy may be written as excess
    to an insured’s retention. The term retention . . . refers to a specific sum
    or percentage of loss that is the insured’s initial responsibility and must be
    satisfied before there is any coverage under the policy.’’ (Internal quotation
    marks omitted.)
    25
    We address the summary judgment rendered in favor of Federal and
    Century separately in this opinion. See parts IV and V of this opinion, respec-
    tively.
    26
    The court in Qualcomm, Inc. v. Certain Underwriters at Lloyd’s, Lon-
    
    don, supra
    , 
    161 Cal. App. 4th 204
    , also rejected Qualcomm’s claim that the
    public policy of promoting settlement compelled the conclusion that the
    defendant excess insurer was obligated to pay, even if the obligation contra-
    vened the language of the policy. The court stated: ‘‘Whatever merit there
    may be to conflicting social and economic considerations, they have nothing
    whatsoever to do with our interpretation of the unambiguous contractual
    terms. . . . If contractual language in an insurance contract is clear and
    unambiguous, it governs, and we do not rewrite it for any purpose. . . .
    Our conclusion is consistent with the authority on which Qualcomm relies,
    Signal [Cos.] v. Harbor Ins. Co., [
    27 Cal. 3d 359
    , 365–67, 
    612 P.2d 889
    , 
    165 Cal. Rptr. 799
    (1980)], in which the California Supreme Court found no
    compelling equitable consideration to impose an obligation on an excess
    carrier, contrary to the language of its excess policy, to reimburse a primary
    carrier for defense costs where those costs were incurred before exhaustion
    of the primary policy limits. . . . The court expressly decline[d] to formu-
    late a definitive rule applicable in every case in light of varying equitable
    considerations which may arise, and which may affect the insured and the
    primary and excess carriers, and which depend upon the particular policies
    of insurance, the nature of the claim made, and the relation of the insured
    to the insurers. . . . Taking Signal’s lead, we affirm the judgment based
    on the excess policy language and underlying circumstances of this particu-
    lar case.’’ (Citations omitted; internal quotation marks omitted.) Qualcomm,
    Inc. v. Certain Underwriters at Lloyd’s, 
    London, supra
    , 204.
    27
    The trial court noted that it made ‘‘no determination at [that] time that
    the primary policies are the only policies that must be exhausted before
    the Harbor and London policies will provide coverage. As previously noted,
    some of the policies may have other levels of coverage intervening between
    them and the primary policies. The present motions, however, seek only a
    determination of whether coverage under the Harbor and London policies
    is unavailable because the primary policies have not been exhausted.
    Accordingly, the court is not called upon at this time to determine whether
    any additional policies within Rohr’s insurance coverage portfolio must also
    be exhausted before coverage is available under the Harbor and London
    policies.’’ (Emphasis in original.)
    28
    We further note that London policy V20621 lists Royal Indemnity Com-
    pany as one of four primary insurers under the policy. See footnote 15 of
    this opinion. Our determination that the exhaustion requirement has been
    satisfied is limited to the exhaustion of the Royal primary policies only. See
    footnote 27 of this opinion.
    29
    Rohr raises the same claims on appeal concerning the granting of the
    motions for summary judgment filed by Federal and Century as it does with
    respect to the granting of the Continental plaintiffs’ motion for summary
    judgment, namely, that the trial court erred in concluding that (1) the Royal
    primary policies provided per occurrence limits in the amount of $8 million,
    (2) the underlying primary insurance policies had to be horizontally
    exhausted before any excess policies could attach to provide coverage, and
    (3) Rohr was required to be paid the $8 million policy limit before it could
    access its excess insurance policies.
    30
    In addition to its settlement with Arrowood, on December 10, 2014, Rohr
    entered into a settlement agreement with the defendant insurers Hartford
    Accident & Indemnity Company, First State and Twin City.
    31
    See footnote 29 of this opinion.
    32
    Additionally, pursuant to the plain terms of these Century policies, their
    coverage obligations are not triggered unless and until the directly underlying
    United policy has paid its limits, which can occur only after the insured
    has been paid all other collectible insurance. The issue concerning the
    exhaustion of the United policy is not before us in these appeals and is a
    matter to be addressed in the next stage of the proceedings before the
    trial court.