Section 40.0973 - Method 1 Risk CharacterizationUnder Method 1, the risk of harm to health, public welfare and the environment shall be characterized as follows:
(1) The Method 1 Risk Characterization shall evaluate each current and reasonably foreseeable Site Activity and Use identified pursuant to 310 CMR 40.0923.(2) The groundwater and soil categories determined for the site in 310 CMR 40.0932 and 310 CMR 40.0933 shall be identified and documented.(3) The Exposure Point(s) in groundwater and soil for all current and reasonably foreseeable Site Activities and Uses shall be identified and documented as described in 310 CMR 40.0924.(4) The MCP Method 1 Standards assume exposure to the concentrations of oil and/or hazardous material in the soil and groundwater under current or foreseeable future conditions. For the Exposure Point Concentrations to be directly comparable to the MCP Method 1 Standards, they shall:(a) be determined for each oil and/or hazardous material at each Exposure Point as described in 310 CMR 40.0926; and(b) be representative of the actual concentration of oil and/or hazardous material at that Exposure Point, unmodified by other exposure assumptions.(5) The applicable MCP Method 1 Groundwater and Soil Standards shall be identified as described in 310 CMR 40.0974 and 310 CMR 40.0975, and listed in the documentation of the Risk Characterization.(6) The Exposure Point Concentrations identified in 310 CMR 40.0973(4) shall be compared to all applicable MCP Method 1 Standards identified in 310 CMR 40.0973(5).(7) A condition of no significant risk of harm to health, public welfare and the environment exists if no Exposure Point Concentration is greater than the applicable MCP Method 1 Soil or Groundwater Standard. If the Method 1 Soil or Groundwater Standard for Total Petroleum Hydrocarbon is exceeded, a condition of No Significant Risk shall still be considered to exist if the Exposure Point Concentrations of the Aliphatic and Aromatic Hydrocarbon Fractions comprising the TPH are less than or equal to the applicable Method 1 Soil and Groundwater Standards.(8) The documentation of the Method 1 Risk Characterization shall clearly state whether or not a condition of no significant risk of harm to health, public welfare and the environment exists or has been achieved at the disposal site.Amended by Mass Register Issue 1503, eff. 3/1/2024.Amended by Mass Register Issue S1516, eff. 3/1/2024.