The commissioner has found and hereby defines the following acts or practices related to the settlement of environmental claims to be unfair methods of competition or unfair or deceptive acts or practices in the conduct of the business of insurance. A single violation of this section may be deemed by the commissioner to be an unfair claims settlement practice, an unfair trade practice, or an unfair method of competition.

(1) Failure to pay interest at the statutory rate as set by the state treasurer from time to time, pursuant to RCW 19.52.025:

(a) On payments that an insured has made and which the insurer is legally obligated to pay as damages: Provided however, That interest shall begin to accrue only when a claim is presented or payment is made by the insured, whichever is the later; or

(b) On overdue payments that an insurer agreed to make pursuant to an agreed settlement with an insured: Provided however, That interest shall begin to accrue on the thirty-first day after the date of the settlement or the agreed time, if later.

(2) Failure of an insurer to commence investigation of an environmental claim within fifteen working days after receipt of a notice of an environmental claim.

(a) Insureds and insurers shall fully cooperate with each other in the investigation of environmental claims.

(i) Each shall provide to the other facts known or discovered during an investigation, including the identity of any witnesses with knowledge of facts related to an environmental claim.

(ii) Each shall provide the other with copies of documents establishing facts related to an environmental claim.

(iii) Neither an insured nor an insurer shall be required to produce material subject to the attorney-client privilege or the work product doctrine, or confidential claims documents provided to the insurer by another policyholder.

(b) An excess insurer may rely on the investigation of a primary insurer.

(3) Failure to make payments, under its duty to defend, for costs reasonably incurred in an investigation to determine the source of contamination, the type of contamination, and the extent of the contamination.

(4) Denying a claim on the basis that the insured expected or intended the damage unless, to the best of the insurer's knowledge, information, and belief, formed after reasonable inquiry, the insurer's position is well grounded in fact and is warranted by existing law or a good faith argument for the extension, modification, or reversal of existing law, and that it is not interposed for any improper purpose, such as to harass or to cause unnecessary delay or needless increase in the cost of litigation.

(5) Denying that there is damage to a site that is listed on the National Priorities List under the Comprehensive Environmental Response Compensation and Liabilities Act of 1980, 42 U.S.C. Sections 6901-6992k, or the hazardous sites list under the Model Toxics Control Act of Washington, chapter 70.105D RCW, if the federal Environmental Protection Agency or the state department of ecology has determined that there is actual damage on the site unless an insurer has evidence that no actual damage occurred. It should not be presumed that only sites on the National Priorities List or the hazardous sites list have environmental damage requiring action.

(6) Requiring the insured to provide answers to repetitive questions and requests for information concerning matters or issues unrelated to the insured's environmental claim. This does not prevent an insurer from clearly reserving its rights as to information that is not available at the time of the correspondence.