567—135.6 (455B) Release reporting, investigation, and confirmation.
	 135.6(1) Reporting of suspected releases. Owners and operators of UST systems must report to the department within 24 hours, or within 6 hours in accordance with 567—Chapter 131 if a hazardous condition exists as defined in 567—131.1(455B), or another reasonable time period specified by the department, and follow the procedures in 135.8(1) for any of the following conditions:
	  a.   	 The discovery by owners and operators or others of released regulated substances at the UST site or in the surrounding area (such as the presence of free product or vapors in soils, basements, sewer and utility lines, and nearby surface water);
	  b.   	 Unusual operating conditions observed by owners and operators (such as the erratic behavior of product dispensing equipment, the sudden loss of product from the UST system, or an unexplained presence of water in the tank), unless system equipment is found to be defective but not leaking, and is immediately repaired or replaced; and
	  c.   	 Monitoring results from a release detection method required under 135.5(2) and 135.5(3) that indicate a release may have occurred unless:
	 (1) 	 The monitoring device is found to be defective, and is immediately repaired, recalibrated or replaced, and additional monitoring does not confirm the initial result; or
	 (2) 	 In the case of inventory control, a second month of data does not confirm the initial result.
	 135.6(2) Investigation due to off-site impacts. When required by the department, owners and operators of UST systems must follow the procedures in 135.6(3) to determine if the UST system is the source of off-site impacts. These impacts include the discovery of regulated substances (such as the presence of free product or vapors in soils, basements, sewer and utility lines, and nearby surface and drinking waters) that has been observed by the department or brought to its attention by another party.
	 135.6(3) Release investigation and confirmation steps. Owners and operators must immediately investigate and confirm all suspected releases of regulated substances requiring reporting under 135.6(1) within seven days, or another reasonable time period specified by the department, using either the following steps or another procedure approved by the department:
	  a.   	 System test. Owners and operators must conduct tests (according to the requirements for tightness testing in 135.5(4)“c” and 135.5(5)“b”) that determine whether a leak exists in that portion of the tank that routinely contains product, or the attached delivery piping or both.
	 (1) 	 Owners and operators must repair, replace or upgrade the UST system and begin corrective action in accordance with rule 135.9(455B) if the test results for the system, tank, or delivery piping indicate a leak exists.
	 (2) 	 Further investigation is not required if the test results for the system, tank, and delivery piping do not indicate a leak exists and if environmental contamination is not the basis for suspecting a release.
	 (3) 	 Owners and operators must conduct a site check as described in paragraph “b” of this subrule if the test results for the system, tank, and delivery piping do not indicate a leak exists but environmental contamination is the basis for suspecting a release.
	  b.   	 Site check. A certified groundwater professional must conduct a site check in accordance with the tank closure in place procedures as provided in 135.15(3) or they may conduct a Tier 1 assessment in accordance with subrule 135.9(3). Under either procedure, the certified groundwater professional must follow the policies and procedures applicable to sites where bedrock is encountered before groundwater as provided in 135.8(5) to avoid creating a preferential pathway for soil or groundwater contamination to reach a bedrock aquifer. The certified groundwater professional must measure for the presence of a release where contamination is most likely to be present at the UST site. In selecting sample types, sample locations, and measurement methods, the certified groundwater professional must consider the nature of the stored substance, the type of initial alarm or cause for suspicion, the type of backfill, the depth of groundwater, and other factors appropriate for identifying the presence and source of the release.
	 (1) 	 If the test results of the site check indicate action levels in 135.14(455B) have been exceeded, owners and operators must begin corrective action in accordance with rules 135.7(455B) to 135.12(455B).
	 (2) 	 If the test results for the excavation zone or the UST site do not indicate a release has occurred, further investigation is not required.
	 135.6(4) Reporting and cleanup of spills and overfills.
	  a.   	 Reportable releases. Owners and operators of UST systems must contain and immediately clean up a spill, overfill or any aboveground release, and report to the department within 24 hours, or within 6 hours in accordance with 567—Chapter 131 if a hazardous condition exists as defined in rule 567—131.1(455B) and begin corrective action in accordance with rules 135.7(455B) to 135.12(455B) in the following cases:
	 (1) 	 Spill, overfill or any aboveground release of petroleum that results in a release to the environment that exceeds 25 gallons, causes a sheen on nearby surface water, impacts adjacent property, or contaminates groundwater; and
	 (2) 	 Spill, overfill or any aboveground release of a hazardous substance that results in a release to the environment that equals or exceeds its reportable quantity under CERCLA (40 CFR 302) as of September 13, 1988.
	  b.   	 Nonreportable releases. Owners and operators of UST systems must contain and immediately clean up a spill, overfill or any aboveground release of petroleum that is less than 25 gallons and a spill, overfill or any aboveground release of a hazardous substance that is less than the reportable quantity. If cleanup cannot be accomplished within 24 hours, owners and operators must immediately notify the department.
Note:  Any spill or overfill that results in a hazardous condition as defined in rule 567—131.1(455B) must be reported within 6 hours. This includes the transporter of the product. A release of a hazardous substance equal to or in excess of its reportable quantity must also be reported immediately (rather than within 24 hours) to the National Response Center under Sections 102 and 103 of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and to appropriate state and local authorities under Title III of the Superfund Amendments and Reauthorization Act of 1986.