(1) Upon confirmation of a release in accordance with ARM 17.56.504, or after a release from the PST or UST system is identified in any other manner, owners and operators, any person who installs or removes an UST, or who performs subsurface investigations for the presence of regulated substances, and any person who performs a tank tightness or line tightness test pursuant to ARM 17.56.407 or 17.56.408, must report releases to the department and the implementing agency within the specified timeframes and in the following manner:

(a) Except as provided in (1) (b) , all confirmed releases must be reported to a person within the remediation division of the department, the implementing agency, or the 24-hour disaster and emergency services duty officer available at telephone number (406) 841-3911 within 24 hours of confirming the release. Messages left on answering machines, received by facsimile, e-mail or voice mail, or other messaging device are not adequate 24-hour notice. For further assistance, the department's release reporting hotline may be reached at 1 (800) 457-0568.

(b) When a release is confirmed from laboratory analysis of samples collected from a site, the release must be reported to the department and implementing agency by a method that ensures the department or the implementing agency receives the information within seven days of release confirmation. The date of release confirmation, for purposes of this rule, is the date the owner, operator, installer, remover, or person who performs subsurface investigations for the presence of regulated substances received notification of the sample results from the laboratory. Laboratory analytical results that exceed the following values confirm that a release has occurred:

(i) risk-based screening levels (RBSLs) established for petroleum contaminants in surface soil at UST sites, published in Table 1 of Montana Tier 1 Risk-based Corrective Action Guidance for Petroleum Releases (RBCA) for petroleum compounds and mixtures in surface and subsurface soil;

(ii) preliminary remediation goals or soil screening levels published in the United States Environmental Protection Agency, Region 9 Preliminary Remediation Goals for soil analyses of contaminants in soil that are not listed in RBCA; or

(iii) contaminant levels in water that exceed background levels in the receiving water.