1. LDEQ’s RECAP Soil Protective of Groundwater - Soil GW Soil Saturation - Soil sat

2.  Soil GW values are soil concentrations for constituents of concern that are protective of a groundwater use  Soil sat values are the maximum soil concentrations allowed for constituents of concern. Above Soil sat free product is assumed to exist. SOIL GW & SOIL SAT

3.  1. Identify the appropriate GW classification  ex. Shallow groundwater - GW 3NDW  Determine the GW value for the COC  ex. COC is Benzene, GW 3NDW = 0.013 mg/l < Water sol  2. Use GW value to calculate C soil  ex. C soil = 0.00668 = MO-1: Determination of Soil GW for Organic COC

4.  3. Multiply C soil by vertical DF of 20  ex. Soil GW = 0.00668 * 20 = 0.13  4. Multiply Soil GW by DF from Table in Appendix I  ex. From Table x = 300 & S d = 10 then DF = 15  Soil GW3 = 0.13 * 15 = 1.95 MO-1: Soil GW Organic COC cont.

5.  5. If the Soil GW3 value from Step 4 is lower than the next more protective groundwater classification Soil GW value then use the more protective groundwater classification Soil GW value  ex. Soil GW3 = 1.95 Soil GW2 = 0.051  Soil GW3 > Soil GW2  Therefore, use Soil GW3 as the Soil GW value MO-1: Soil GW Organic COC cont.

6.  Soil sat = 900 =  Soil sat 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 20 o C) MO-1: Determination of Soil sat

7.  If TCLP level available: Soil GW = TCLP level * 20  If TCLP level not available: Soil GW = GW 1 * 100 * 20 MO-1: Determination of Soil GW for Inorganic COC

8.  1. I dentify the appropriate GW classification ex. Shallow groundwater - GW 3NDW  Determine the GW value for the COC  ex. COC is Benzene, GW 3NDW = 0.013 mg/l < Water sol  2. Use GW value to calculate C soil  ex. C soil = 0.00668 = MO-2: Determination of Soil GW Method 1-Organic COC:

9.  3. Multiply C soil by site-specific DF  Soil GW3 = 0.00668*DAF Summers *DAF Domenico  4. If the Soil GW3 value from Step 3 is lower than the next more protective groundwater classification Soil GW value then use the more protective groundwater classification Soil GW value  Soil GW3 = 0.00668*DAF Summers *DAF Domenico > or < Soil GW2  If Soil GW3 > Soil GW2 use Soil GW3  If Soil GW3 < Soil GW2 use Soil GW2 MO-2: Soil GW Method 1-Organic COC cont.

10.  If TCLP level available: Soil GW = TCLP level * 20  If TCLP level not available: Soil GW = GW 1 * 100 * 20 MO-2: Determination of Soil GW Method 1-Inorganic COC

11.  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 MO-2 Determination of Soil GW Method 2-Organic and Inorganic COC

12.  1. Calculate site specific water/soil partition coefficient to determine Soil GW  Soil GW = (Soil SS / GW SS ) * GW 1,2 or 3  GW SS & Soil SS - site-specific values (see footnotes on sample requirements p. I-49)  GW 1,2 or 3 - refer to Table  2. Multiply Soil GW by appropriate site-specific DF MO-2: Soil GW Method 2-Organic and Inorganic COC cont.

13. MO-2: Determination of Soil GW Method 3-Organic and Inorganic COC Synthetic Precipitate Leaching Procedure (SPLP) -Used to evaluate Soil Protective of GW -SW-846 Method 1312 -SPLP Concentration < (GW RS)(20)(DAF) then Soil GW is not an issue

14. How is the SPLP data used to evaluate the soil to gw pathway?  Soil GW1 : Compare SPLP to GW 1 x DF Summers  Soil GW2 : Compare SPLP to GW 2 x DF Summers x DF2  Soil GW3 : Compare SPLP to GW 3 x DF Summers x DF3 MO-2: Determination of Soil GW Method 3-Organic and Inorganic COC

15.  If SPLP <, then screen out soil to gw pathway  If SPLP >, then delineate area of concern  SPLP vs TCLP  SPLP vs LRS MO-2: Determination of Soil GW Method 3-Organic and Inorganic COC cont’d.