LDEQ

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LDEQs RECAP

• Soil Protective of Groundwater - SoilGW
• Soil Saturation - Soilsat

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SOILGW SOILSAT

• SoilGW values are soil concentrations for
  constituents of concern that are protective of a
  groundwater use
• Soilsat values are the maximum soil
  concentrations allowed for constituents of
  concern. Above Soilsat free product is assumed
  to exist.

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MO-1 Determination of SoilGW for Organic COC

• 1. Identify the appropriate GW classification
• ex. Shallow groundwater - GW3NDW
• Determine the GW value for the COC
• ex. COC is Benzene, GW3NDW 0.013 mg/l lt
  Watersol
• 2. Use GW value to calculate Csoil
• ex. Csoil 0.00668

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MO-1 SoilGW Organic COC cont.

• 3. Multiply Csoil by vertical DF of 20
• ex. SoilGW 0.00668 20 0.13
• 4. Multiply SoilGW by DF from Table in Appendix I
• ex. From Table x 300 Sd 10 then DF 15
• SoilGW3 0.13 15 1.95

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MO-1 SoilGW Organic COC cont.

• 5. If the SoilGW3 value from Step 4 is lower than
  the next more protective groundwater
  classification SoilGW value then use the more
  protective groundwater classification SoilGW
  value
• ex. SoilGW3 1.95 SoilGW2 0.051
• SoilGW3 gt SoilGW2
• Therefore, use SoilGW3 as the SoilGW value

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MO-1 Determination of Soilsat

• Soilsat 900
• Soilsat is not applicable to constituents that
  are in the solid phase at ambient temperatures
  (i.e., constituents having melting points less
  than or equal to 20o C)

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MO-1 Determination of SoilGW for Inorganic COC

• If TCLP level available SoilGW TCLP level
  20
• If TCLP level not available SoilGW GW1 100
  20

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MO-2 Determination of SoilGW Method 1-Organic
COC

• 1. Identify the appropriate GW classification ex.
  Shallow groundwater - GW3NDW
• Determine the GW value for the COC
• ex. COC is Benzene, GW3NDW 0.013 mg/l lt
  Watersol
• 2. Use GW value to calculate Csoil
• ex. Csoil 0.00668

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MO-2 SoilGW Method 1-Organic COC cont.

• 3. Multiply Csoil by site-specific DF
• SoilGW3 0.00668DAFSummersDAFDomenico
• 4. If the SoilGW3 value from Step 3 is lower than
  the next more protective groundwater
  classification SoilGW value then use the more
  protective groundwater classification SoilGW
  value
• SoilGW3 0.00668DAFSummersDAFDomenico gt or lt
  SoilGW2
• If SoilGW3 gt SoilGW2 use SoilGW3
• If SoilGW3 lt SoilGW2 use SoilGW2

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• MO-2 Determination of SoilGW
• Method 1-Inorganic COC

• If TCLP level available SoilGW TCLP level
  20
• If TCLP level not available SoilGW GW1 100
  20

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• MO-2 Determination of SoilGW
• Method 2-Organic and Inorganic COC

• This method may be used when the following
  conditions are met
• Groundwater and soil data are available,
• Groundwater concentrations are less than soil
  concentrations, and
• Groundwater data indicate the RS GW value has
  been exceeded

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• MO-2 SoilGW
• Method 2-Organic and Inorganic COC cont.

• 1. Calculate site specific water/soil partition
  coefficient to determine SoilGW
• SoilGW (SoilSS / GWSS) GW1,2 or 3
• GWSS SoilSS - site-specific values (see
  footnotes on sample requirements p. I-49)
• GW1,2 or 3 - refer to Table
• 2. Multiply SoilGW by appropriate site-specific
  DF

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MO-2 Determination of SoilGW Method 3-Organic
and Inorganic COC

• Synthetic Precipitate Leaching Procedure
  (SPLP)
• - Used to evaluate Soil Protective of GW
• - SW-846 Method 1312
• - SPLPConcentration lt (GW RS)(20)(DAF) then
  SoilGW is not an issue

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• MO-2 Determination of SoilGW
• Method 3-Organic and Inorganic COC

• How is the SPLP data used to evaluate the soil to
  gw pathway?
• SoilGW1 Compare SPLP to GW1 x DFSummers
• SoilGW2 Compare SPLP to GW2 x DFSummers x DF2
• SoilGW3 Compare SPLP to GW3 x DFSummers x DF3

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• MO-2 Determination of SoilGW
• Method 3-Organic and Inorganic COC contd.

• If SPLP lt, then screen out soil to gw pathway
• If SPLP gt, then delineate area of concern
• SPLP vs TCLP
• SPLP vs LRS

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