Section 40.0405 - Overview of Preliminary Response Actions(1)Initial Site Investigation Activities.(a) Initial Site Investigation Activities shall consist of limited investigative and assessment actions of sufficient scope and level of effort to make and/or guide determinations on required and appropriate response actions at a site. Initial Site Investigation Activities may include, without limitation: 1. evaluation of records relating to the release, threat of release or impacted site;2. evaluation of underground storage tank testing results;3. testing and/or retesting of underground storage tanks;4. evaluation of environmental monitoring data;5. limited sampling and analysis of soil, sediment, groundwater, surface water, soil gas, indoor air or ambient air; and6. any other limited investigations, monitoring, surveys, testing or information gathering activities necessary to evaluate releases and threats of release of oil and/or hazardous material, excluding removal and containment actions.(b) The objective of Initial Site Investigation Activities is to obtain preliminary information and data on a release, a threat of release and/or site in order to: 1. determine the existence, source, nature and approximate extent of the release or threat of release;2. determine if the release or threat of release poses or could pose an Imminent Hazard, as described in 310 CMR 40.0321;3. determine if an Immediate Response Action is necessary, as described in 310 CMR 40.0412;4. determine if a Limited Removal Action is appropriate at the site, as described in 310 CMR 40.0318;5. determine if a Release Abatement Measure is appropriate at the site, as described in 310 CMR 40.0440;6. identify persons who are responsible or potentially responsible for the release or threat of release;7. obtain, assemble and record information and data needed to evaluate the release or threat of release; and8. determine if a demonstration can readily be made that a condition of No Significant Risk exists or has been achieved at the site, before or after the completion of a Limited Removal Action, Immediate Response Action, or Release Abatement Measure.(c) The results of Initial Site Investigation Activities shall:1. be used to support a Permanent Solution Statement at the conclusion of Preliminary Response Actions; or2. be used as the basis for a Phase I Report, as described in 310 CMR 40.0480, whenever a Permanent Solution Statement is not filed for a site within one year of the initial notification to the Department of a release or threat of release at the site by any person listed at 310 CMR 40.0331.(d) When used to support a Permanent Solution Statement, the results of Initial Site Investigation Activities shall be reported in a response action report or in a Phase I Report, pursuant to 310 CMR 40.0481, and shall contain all information, data, records and documents necessary for that purpose.(e) Assessment activities conducted at a site prior to Tier Classification, as described in 310 CMR 40.0500, shall not require approval from the Department.(2)Immediate Response Actions(a) Immediate Response Actions are assessment and/or remedial actions that shall be undertaken in an expeditious manner to address sudden releases, Imminent Hazards and other time-critical release or site conditions. Immediate Response Actions shall be taken whenever and wherever timely actions are required to assess, eliminate, abate or mitigate adverse or unacceptable release, threat of release and/or site conditions, as set forth in 310 CMR 40.0412.(b) Except as provided in 310 CMR 40.0420(12), remedial actions conducted as part of an Immediate Response Action require prior approval from the Department.(3)Release Abatement Measures. Release Abatement Measures are remedial actions that may be voluntarily undertaken by persons conducting response actions at disposal sites. The purposes of Release Abatement Measures are to remediate limited or localized releases, and/or to mitigate the impacts of larger releases until such time as more comprehensive remedial actions can be instituted at the disposal site, in accordance with 310 CMR 40.0800.Amended by Mass Register Issue 1503, eff. 3/1/2024.Amended by Mass Register Issue S1516, eff. 3/1/2024.