Under the MCP's Method 2 Risk Characterization approach, Method 1 Standards may be supplemented or modified with site- and chemical-specific information. The term "MCP Method 2 Standards" refers both to soil and groundwater standards developed de novo under Method 2 and Method 1 Standards that have been modified under Method 2 to account for site-specific fate-and-transport considerations.

Allowable Method 2 Options:

1.Groundwater and soil standards may be developed, using the approach specified at 310 CMR 40.0983 and 40.0984, for chemicals for which Method 1 Standards have not been promulgated by MADEP.

2.The leaching component of the Method 1 Soil Standards may be modified based on site-specific information, as described at 310 CMR 40.0985. However, any such modification cannot result in Method 2 Standards greater than the Direct Contact Exposure-Based Soil Concentrations listed in Table 5 (310 CMR 40.0985(6)) .

3.The vapor-infiltration component of the Method 1 GW-2 groundwater standards may be modified based on site-specific information, as described at 310 CMR 40.0986. However, any such modification cannot result in Method 2 Standards greater than the Upper Concentration Limits in Groundwater listed in Table 6 (310 CMR 40.0996(7))

4.The groundwater transport and surface water dilution components of the Method 1 GW-3 groundwater standards may be modified based on site-specific information, as described at 310 CMR 40.0987. However, any such modification cannot result in Method 2 Standards greater than the Upper Concentration Limits in Groundwater listed in Table 6 (310 CMR 40.0996(7)) .

5.When developing Method 2 standards for chemicals without promulgated MCP Method 1 standards (#1 above), site-specific fate-and-transport modeling (#'s 2 through 4 above) can be conducted concurrently.

6.Pursuant to 310 CMR 40.0982(7), the Department may make available lists of concentrations in groundwater and soil that can be used under Method 2 to characterize risk for chemicals without promulgated Method 1 Standards. Use of any such MADEP-published values would be an option to developing Method 2 standards de novo.

    • No MADEP-published Method 2 concentrations are available at this time.

Modifications Prohibited Under Method 2:

The Method 1 GW-1 groundwater standards cannot be modified.
List of Current MCP GW-1 Standards - 310 CMR 40.0974(2)

The direct-contact component of the Method 1 soil standards cannot be modified.
List of Current MCP Direct-Contact Soil Standards - 310 CMR 40.0985(6)