Section 173-340-450 - Releases from regulated underground storage tank systems(1)Applicability.(a)Releases. This section applies only to underground storage tank (UST) systems regulated under chapter 173-360A WAC from which there has been a confirmed release of a regulated substance that may pose a threat to human health or the environment. Under chapter 173-360A WAC, UST system owners and operators and regulated service providers must report such a release to ecology within 24 hours.(b)Persons. This section applies only to UST system owners and operators. UST system owners and operators must comply with the requirements in this section in addition to the other requirements in this chapter.(c)Other requirements. This section does not alter the applicability of requirements in other sections in this chapter.(2)Purpose. Under chapter 173-360A WAC, UST system owners and operators must investigate and clean up confirmed releases in accordance with the requirements of this chapter. This section specifies interim actions that UST system owners and operators must perform immediately or shortly after confirming a release to reduce threats posed by the release, prevent any further release, and characterize the nature and extent of the release. If the interim actions are insufficient to meet the criteria in WAC 173-340-330(5), UST system owners and operators must conduct further remedial action under the state cleanup law to investigate and clean up the release. WAC 173-340-120 provides an overview of the cleanup process under the state cleanup law.(3)Enforcement. UST system owners and operators who violate any requirement in this chapter are subject to enforcement, including civil penalties and orders, under: (a) Chapter 70A.305 RCW and this chapter; or(b) Chapters 70A.355 RCW and 173-360A WAC.(4)Administrative options. The interim actions specified in this section may be conducted under any of the administrative options for remedial action described in WAC 173-340-510.(5)Interim actions. UST owners and operators must perform the following interim actions after confirming a release.(a)Initial response. Within 24 hours of release confirmation, UST system owners and operators must: (i) Remove as much of the hazardous substance from the UST system as is possible and necessary to prevent further release to the environment;(ii) Eliminate or reduce any fire, explosion, or vapor hazards and do so in a manner that minimizes any release of hazardous substances to surface water and groundwater; and(iii) Visually inspect any aboveground releases or exposed below-ground releases and prevent further migration of released hazardous substances into surrounding soils, groundwater, and surface water.(b)Initial site characterization. Within 30 days of release confirmation, UST system owners and operators must investigate the site to identify the hazardous substances released, the source of the release, the media impacted by the release, and the potential for vapors from contaminated soil or groundwater to enter building, utility vaults, or other structures. At a minimum, UST system owners and operators must: (i) Develop a sampling and analysis plan meeting the requirements of WAC 173-340-820. The sampling and analysis plan must be based on the substances currently or previously stored in the UST system, type of subsurface soils, depth to groundwater, vapor intrusion pathways, and other factors as appropriate for identifying the presence and source of the release;(ii) Collect, handle, and analyze samples in accordance with the requirements in WAC 173-340-830;(iii) Collect samples in the environment where hazardous substances are most likely to be present;(iv) Investigate groundwater for the presence of hazardous substances and free product if there is evidence of any of the following conditions at the site: (A) Contaminated soil is in contact with the groundwater;(B) Contaminated soil extends below the lowest soil sampling depth;(C) Groundwater contamination has been detected or observed;(D) The release has migrated to surface water or wetlands; or(E) There is no evidence of the conditions in (b)(iv)(A) through (D) of this subsection, but UST owners and operators cannot demonstrate to ecology's satisfaction that the release does not pose a threat to groundwater;(v) Analyze collected samples for the hazardous substances released from the UST system, including: (A) For petroleum, the substances specified in Table 830-1 based on the product stored; and(B) For other hazardous substances, the substance stored and any likely decomposition by-products;(vi) Conduct any other investigations required by ecology; and(vii) Properly manage and dispose any waste materials, including contaminated soil and water, generated as a result of the initial site characterization in accordance with applicable state and federal laws. See WAC 173-340-710.(c)Free product removal. If free product is discovered at the site, as soon as possible but no later than 30 days after release confirmation, UST system owners and operators must initiate actions to remove the free product while continuing, as necessary, any other actions required under this section. At a minimum, UST system owners and operators must: (i) Conduct free product removal to the maximum extent practicable and in a manner that minimizes the spread of hazardous substances by using recovery and disposal techniques appropriate to the hydrogeo-logic conditions at the site. At a minimum, the free product removal system must be designed and operated to stop the free product migration;(ii) Properly treat, discharge, or dispose of any hazardous substance, water, sludge or any other materials collected in the free product removal process in accordance with applicable state and federal laws. See WAC 173-340-710;(iii) Handle all flammable products safely to prevent fires and explosions;(iv) Unless otherwise directed by ecology, monitor in accordance with WAC 173-360A-0665(4) for the presence of free product at least quarterly; and(v) Unless otherwise directed by ecology, submit to ecology written quarterly progress reports describing the results of the monitoring and free product removal actions. The first report may be combined with the interim action report required under subsection (6) of this section.(d)Continuing obligations. UST system owners and operators must continue to conduct the following measures to abate hazards at the site while continuing, as necessary, any other remedial action required under the state cleanup law:(i) Monitor and mitigate any additional fire and safety hazards posed by vapors or free product that may have migrated from the UST system into nearby buildings or other structures, such as underground utilities;(ii) Reduce the threat to human health and the environment posed by contaminated soils excavated or discovered as a result of any remedial action; and(iii) Properly manage and dispose any waste materials, including contaminated soil and water, generated as a result of any remedial action in accordance with applicable state and federal laws. See WAC 173-340-710.(6)Interim action report. Within 90 days of release confirmation, UST system owners and operators must submit an interim action report to ecology about the site and nature of the release. This report must comply with the submittal requirements in WAC 173-340-840 and include, at a minimum, the following information: (a) A summary of the initial response actions required under subsection (5)(a) of this section, and any resulting information and data;(b) The results of the initial site characterization required under subsection (5)(b) of this section, and any other investigations conducted at the site, including: (i) The source(s) of the releases;(ii) An explanation of how the releases occurred;(iii) The hazardous substances released, and the estimated quantity of hazardous substances released;(iv) The media contaminated by those releases and, to the extent known, the nature and extent of contamination within those media, and sample locations. (A) If groundwater has not been tested, UST system owners and operators must include a demonstration that the release does not pose a threat to groundwater.(B) If no potential vapor intrusion pathways have been identified, UST system owners and operators must include a demonstration that there is no potential for vapors from contaminated soil or groundwater to enter buildings, utility vaults, or other structures;(v) The results of the free product investigation, if applicable; and(vi) To the extent known, the pathways of exposure at the site and the human or ecological receptors affected by the releases;(c) The physical characteristics of the site, including: (i) The location of tax parcels, property boundaries, right-of-ways, and above and below-ground structures;(ii) The geology of the site, including subsurface soil conditions;(iii) The hydrology of the site, including depth to groundwater, direction of groundwater flow, approximate location of wells potentially affected by the release, proximity of the release to and potential for affecting surface water and wetlands, the quality and use of groundwater and surface water;(iv) The location of underground utilities and other potential conduits for vapor or free product migration;(v) The population and uses of the site and surrounding area; and(vi) The proximity of the release to sensitive environments;(d) Diagrams and cross-sections of the site, as appropriate, reflecting the information required in (b) and (c) of this subsection;(e) At sites where investigations indicate free product is present, information on the free product removal efforts, including:(i) Name of the person responsible for implementing the free product removal measures;(ii) The estimated quantity, type, and thickness of free product observed or measured in wells, boreholes, and excavations;(iii) The type of free product recovery system used;(iv) If the recovery or monitoring of free product results in any discharges, then: (A) The location of such discharges;(B) The type of treatment applied to, and the effluent quality expected from such discharges; and(C) The steps taken and planned to obtain necessary permits for such discharges; and(v) Disposition of recovered free product and other contaminated materials generated by site investigations and cleanup;(f) A description of any other on-going or completed remedial actions, and the results of such actions;(g) A description of any planned remedial actions;(h) The type of mechanism used to meet the financial responsibility requirements of WAC 173-360A-1045(2)(a), and if the mechanism is an insurance policy, then: (i) Whether a claim has been made on the policy; and(ii) Whether the insurer has accepted or denied the claim; and(i) Any other information required by ecology.(7)Further remedial action. If the interim actions required under this section are insufficient to meet the criteria in WAC 173-340-330(5), UST system owners and operators must conduct further remedial action under the state cleanup law to investigate and clean up the release. WAC 173-340-120 provides an overview of the cleanup process under the state cleanup law.(8)Periodic updates on remedial actions. At least every three years after release confirmation or more frequently as directed by ecology, UST system owners and operators must update the interim action report required under subsection (6) of this section and submit it to ecology unless: (a) The site has been removed from the contaminated sites list under WAC 173-340-330;(b) Ecology is conducting remedial actions at the site or is supervising remedial actions at the site under an order or decree; or(c) The site is enrolled in a technical assistance program under WAC 173-340-515(5) or chapter 374-80 WAC.Wash. Admin. Code § 173-340-450
Amended by WSR 23-17-159, Filed 8/23/2023, effective 1/1/2024Statutory Authority: Chapter 70.105D RCW. 01-05-024 (Order 97-09A), § 173-340-450, filed 2/12/01, effective 8/15/01; 91-04-019, § 173-340-450, filed 1/28/91, effective 2/28/91.