Report of free product recovery, if required. While the regulatory citation applies only to USTs, the ISC is also required in the event of a release from a leaking AST as well, if it is under the oversight of the RST Division. For Part 280 petroleum releases, evaluation by either the API-DSS or ASTM E1739 program standards will be acceptable. While the staff has training and access to software for both methods, we use the ASTM standard internally, and it is referenced in a variety of ways throughout our program. For cancer risks, the excess risk shall be 1E-6.
All risks are non-additive.
418.1 X While no slope factors or reference doses are associated with TPH, it is frequently used during assessment work, and analysis is requested for that purpose. As a part of the corrective action process, the Division staff may, after review of the Initial Site Characterization and the circumstances of the release, request further assessment of the site for the purposes of defining the risk or establishing the design of a remediation program. Authority to request further assessment and regulatory guidance for investigations for soil and groundwater clean-up is found in 40 CFR 280.65. The Site Assessment Report will be requested in writing by the Department, according to the conditions of 280.65. Specific guidance regarding the goals of the investigation, the content and format of the report, and the schedule for compliance will be provided at the time the SAR is requested.