The term “action level” may have different meanings depending upon the individual and the context. Within the DEQ Storage Tank Program, “action levels” are mostly related to : (a) reporting requirements; and (b) clean-up levels or requirements, which are usually risk-based and determined on a case-by-case basis.
Reporting Requirements
Owners and operators of regulated USTs are required to report suspected or confirmed releases to DEQ within 24 hours of discovering the release. Releases from unregulated USTs (such as residential heating oil tanks and small farm tanks) and all ASTs must be reported to DEQ immediately. See Reporting A Release on DEQ's website or Section 2.1 of the Storage Tank Technical Manual for additional information on both suspected and confirmed release.
Regulated and Unregulated UST Closures: Persons closing USTs must report the following concentrations to DEQ:
a.) a TPH concentration in soil that is greater than or equal to 100 mg/kg
b.) a TPH concentration in water that is greater than or equal to 1 mg/l
c.) the concentration of any regulated substance that exceeds the detection limit for that substance
Regulated AST Closures: Persons closing ASTs having a capacity of greater than 660 gallons of oil must report the following concentrations immediately upon receiving analytical results:
a.) a TPH concentration in soil that is greater than or equal to 100 mg/kg
b.) a TPH concentration in water that is greater than or equal to 1 mg/l
c.) the concentration of any petroleum constituent (e.g. benzene) that exceeds the detection limit for that constituent.
Tank-related non-closure samples: If samples are collected at any time other than UST closure (example: environmental site assessments for property transfer), persons must report analytical results that are greater than the detection limit for any regulated substance.
For spills, overfills, and other signs of a petroleum release (example: contaminated drinking water wells) from both regulated and unregulated USTs and ASTs (including home heating oil), DEQ should be contacted within 24 hours for UST releases and immediately for AST release.
For additional information on reporting requirements, persons should refer to Chapter 2 of the Technical Manual.
Clean-up Levels
Clean-up levels or remedial endpoints are site specific and risk based. The reporting thresholds listed above are not remedial endpoints.