Section 176.310  Release Investigation Reporting and Site Assessment

a)         Investigation Due to Off-Site Impact. When required in writing by OSFM, owners or operators of USTs shall follow the procedures in Subpart C to determine if the UST 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 or utility lines or nearby surface or drinking water that have been observed by OSFM or brought to its attention by another party.

b)         Release Investigations and Confirmation Steps. Unless corrective action is initiated in accordance with 35 Ill. Adm. Code 734, owners or operators shall immediately investigate and within 7 days shall confirm the presence or absence of all suspected releases of regulated substances requiring reporting, using the following procedures:

1)         System Test.  Owners and operators must conduct tests (according to the requirements for precision testing in 41 Ill. Adm. Code 175.630(b) and 175.640(a)(4) or, as appropriate, secondary containment testing described in 41 Ill. Adm. Code 175.700(d).)

A)        The test must determine whether:

i)          A leak exists in that portion of the tank that routinely contains product, or the attached delivery piping; or

ii)         A breach of either wall of the secondary containment has occurred.

B)        If the system test confirms a leak into the interstice or a release, owners and operators shall repair, replace, upgrade or decommission the UST.  In addition, owners and operators shall begin corrective action pursuant to 35 Ill. Adm. Code 734 if the test results for the system, tank or delivery piping indicate that a release exists;

2)         Further investigation is not required if the test results for the tank system and delivery piping do not indicate that a release exists and if environmental contamination is not the basis for suspecting a release; and

3)         Owners or operators shall conduct a site assessment (utilizing the requirements of Section 176.330) if environmental contamination is the basis for suspecting a release.  In the event lab results are not forthcoming within 7 days, the owner/operator shall have such reasonable additional time as is necessary to receive the results, but the total time period to confirm the presence or absence of a release and report any confirmed release shall not in any event exceed 45 days.

c)         Initial Site Assessment.  An initial site assessment shall follow the procedures and requirements identified in Section 176.330.

1)         If the site assessment results for the excavation zone or the UST site indicate that a release has occurred, owners or operators shall begin initial response and initial abatement procedures under Sections 176.350 and 176.320(b) and (c), and begin corrective action pursuant to 35 Ill. Adm. Code 734.

2)         If the site assessment results for the excavation zone or the UST site do not indicate that a release has occurred, further investigation is not required.

(Source:  Amended at 42 Ill. Reg. 10621, effective October 13, 2018)