# WAC 173-340-300: WAC 173-340-300. Site discovery and reporting > Washington · Regulations · In force URL: https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_300 ## Section - **Citation:** WAC 173-340-300 - **Heading:** WAC 173-340-300. Site discovery and reporting - **Jurisdiction:** Washington - **Kind:** Regulations - **Status:** In force - **Text as of:** August 14, 2026 - **Source:** Compiled text - **Location:** Washington Administrative Code / Title 173 / Chapter 173-340 / Section 173-340-300 ## Text (1) Purpose. This section sets forth the requirements for reporting a release or threatened release of a hazardous substance to the environment that may pose a threat to human health or the environment. (2) Applicability and timing. Except as provided under (a) of this subsection, within 90 days of discovering a release or threatened release of a hazardous substance to the environment that may pose a threat to human health or the environment, an owner or operator must report the release to ecology. All other persons are encouraged to report such a release to ecology. (a) Exemptions. An owner or operator does not need to report the following releases under this section: (i) A release previously reported to ecology in fulfillment of a reporting requirement in this chapter or in another law or regulation, including a release previously reported to ecology under chapter 173-360A WAC; (ii) A release from a heating oil tank previously reported to PLIA under WAC 374-45-030 ; (iii) A release previously reported to the United States Environmental Protection Agency under CERCLA, Section 103(c) (42 U.S.C. Sec. 9603(c)); (iv) A release previously reported to the state division of emergency management under RCW 90.56.280 ; (v) Application of pesticides and fertilizers for their intended purposes and according to label instructions; (vi) Lawful and nonnegligent use of hazardous substances by a natural person for personal or domestic purposes; (vii) A release in accordance with a permit that authorizes the release; (viii) Except for a release specified under (b)(iii) of this subsection, a release to the air; (ix) A release discovered in a public water system regulated by the department of health; or (x) A release to a permitted wastewater facility. An exemption from the reporting requirements in this section does not imply a release from liability under the state cleanup law. mit that authorizes the release; (viii) Except for a release specified under (b)(iii) of this subsection, a release to the air; (ix) A release discovered in a public water system regulated by the department of health; or (x) A release to a permitted wastewater facility. An exemption from the reporting requirements in this section does not imply a release from liability under the state cleanup law. (b) Examples. An owner or operator should use best professional judgment in deciding whether a release or threatened release of a hazardous substance to the environment may pose a threat to human health or the environment. The following, which is not an exhaustive list, are examples of situations that an owner or operator should generally report under this section: (i) Contamination in a water supply well; (ii) Contaminated seeps, sediment or surface water; (iii) Vapors in a building, utility vault or other structure that appear to be entering the structure from nearby contaminated soil or groundwater; (iv) Nonaqueous phase liquid, such as a petroleum product or chlorinated solvent, on the surface of the ground or in the groundwater (free product); (v) Any contaminated soil or unpermitted disposal of waste materials that would be classified as a hazardous waste under federal or state law; (vi) Any abandoned containers such as drums or tanks, above ground or buried, still containing more than trace residuals of hazardous substances; (vii) Sites where unpermitted industrial waste disposal has occurred; (viii) Sites where hazardous substances have leaked or been dumped on the ground; and (ix) Leaking underground petroleum storage tanks not already reported under chapter 173-360A WAC. (3) Content of release report. An owner or operator must include the following information in a release report, to the extent known: (a) The identity and location of the hazardous substance; (b) The circumstances of the hazardous substance release and its discovery; and been dumped on the ground; and (ix) Leaking underground petroleum storage tanks not already reported under chapter 173-360A WAC. (3) Content of release report. An owner or operator must include the following information in a release report, to the extent known: (a) The identity and location of the hazardous substance; (b) The circumstances of the hazardous substance release and its discovery; and (c) Any planned, ongoing, or completed independent remedial actions to investigate or clean up the release. (i) See WAC 173-340-515 (4) and 173-340-450 for additional reporting requirements for independent remedial actions. (ii) See WAC 173-340-310 (5) for ecology's authority to defer completing an initial investigation of a release to review independent remedial actions completed within 90 days of release discovery. (4) Other release reporting requirements . Nothing in this section eliminates any obligations to comply with reporting requirements in other laws or permits including, but not limited to, the following: (a) Releases from regulated UST systems. Under chapter 173-360A WAC, UST system owners and operators and regulated service providers must report a confirmed release of a regulated substance from an UST system to ecology within 24 hours. As specified in subsection (2)(a)(i) of this section, a release previously reported to ecology under chapter 173-360A WAC is exempt from the release reporting requirements in this section; however, the release must still be investigated and cleaned up in accordance with the state cleanup law. WAC 173-340-450 specifies interim actions that UST system owners and operators must perform immediately or shortly after confirming a release to reduce the threats posed by the release, prevent any further release, and characterize the nature and extent of the release; irements in this section; however, the release must still be investigated and cleaned up in accordance with the state cleanup law. WAC 173-340-450 specifies interim actions that UST system owners and operators must perform immediately or shortly after confirming a release to reduce the threats posed by the release, prevent any further release, and characterize the nature and extent of the release; (b) Releases from heating oil tanks. Under chapter 374-45 WAC, owners and operators of a heating oil tank and owners of the property where the tank is located must report a suspected or confirmed release from the tank to PLIA within 90 days. As specified in subsection (2)(a)(ii) of this section, a release previously reported to ecology under chapter 374-45 WAC is exempt from the release reporting requirements in this section; however, the release must still be investigated and cleaned up in accordance with the state cleanup law. (5) Reservation of rights. Nothing in this section precludes ecology from taking any actions it deems appropriate to identify contaminated sites consistent with chapter 70A.305 RCW. ## Nearby sections - [WAC 173-340-100 WAC 173-340-100. Purpose](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_100.md) - [WAC 173-340-110 WAC 173-340-110. Applicability](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_110.md) - [WAC 173-340-120 WAC 173-340-120. Overview](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_120.md) - [WAC 173-340-130 WAC 173-340-130. Administrative principles](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_130.md) - [WAC 173-340-200 WAC 173-340-200. Definitions](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_200.md) - [WAC 173-340-210 WAC 173-340-210. Usage](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_210.md) - [WAC 173-340-300 WAC 173-340-300. Site discovery and reporting](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_300.md) - [WAC 173-340-310 WAC 173-340-310. Initial investigation](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_310.md) - [WAC 173-340-320 WAC 173-340-320. Site hazard assessment and ranking](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_320.md) - [WAC 173-340-330 WAC 173-340-330. Contaminated sites list](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_330.md) - [WAC 173-340-335 WAC 173-340-335. No further action sites list](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_335.md) - [WAC 173-340-340 WAC 173-340-340. Program planning and assessment](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_340.md) - [WAC 173-340-350 WAC 173-340-350. Remedial investigation](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_350.md) - [WAC 173-340-351 WAC 173-340-351. Feasibility study](https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_351.md) --- Source: Frix Law Library, https://www.frixlaw.com/law-library/statutes/STATE_WA_ADC_173_340_300. Check the current official text before relying on it. Not legal advice.