Pennsylvania Code › Title 25 - ENVIRONMENTAL PROTECTION › Part I - Department of Environmental Protection › Subpart D - Environmental Health and Safety › Article VI - General Health and Safety › Chapter 250 - ADMINISTRATION OF LAND RECYCLING PROGRAM › Subchapter C - STATEWIDE HEALTH STANDARDS › Section 250.308 - Soil to groundwater pathway numeric values

Current through Register Vol. 54, No. 28, July 13, 2024
(a) A person may use the soil-to-groundwater
						pathway numeric values listed in Appendix A, Tables 3B and 4B, as developed
						using the methods contained in paragraph (1), (2) or (4), may use a
						concentration in soil at the site which does not produce a leachate in excess
						of the MSC for groundwater contained in Appendix A, Tables 1 and 2, when
						subjected to the Synthetic Precipitation Leaching Procedure (Method 1312 of
						SW-84g, Test Methods for Evaluating Solid Waste, promulgated by the U.S. EPA),
						or may use the soil-to-groundwater pathway soil buffer criteria in subsection
						(b) or may use the soil-to-groundwater pathway equivalency demonstration in
						subsection (d).
(1) A value which is 100
						times the applicable MSC for groundwater identified in §
													250.304(c) or (d)
						(relating to MSCs for groundwater), expressed as milligrams per kilogram of
						soil.
(2) For organic compounds, a
						generic value determined not to produce a concentration in groundwater in the
						aquifer in excess of the MSC for groundwater as calculated by the equation in
						paragraph (3).
(i) For soil not in the zone of
						groundwater saturation, the generic value shall be calculated by the equation
						in paragraph (3).
(ii) For soil in
						the zone of groundwater saturation, the generic numeric value is 1/10th of the
						generic value calculated by the equation in paragraph (3).
(3) The equation referenced in paragraphs (1)
						and (2) is the following:
MSCS =
						  MSCGW ((Koc *
						  foc) +
						  [thgr]w/[rho]b).
where: MSCS (mg/kg) = the
						  generic value for a regulated substance in soil
MSCGW (mg/L) = MSC of a
						  regulated substance in groundwater
Koc (L/kg) = organic carbon
						  partition coefficient for a regulated substance
foc = fraction of organic carbon
						  in soil (default value = 0.0025)
[thgr]w = water-filled porosity
						  of soil (default value = 0.2)
[rho]b (kg/L) = dry bulk density
						  of soil (default value = 1.8 kg/l)
DF = dilution factor (default value = 100)
(4) For inorganic regulated
						substances, a generic value determined not to produce a concentration in
						groundwater in the aquifer in excess of the MSC for groundwater as calculated
						by the equation in paragraph (5) and listed in Appendix A, Table 4B.
(i) For soil not in the zone of groundwater
						saturation, the generic value shall be calculated by the equation in paragraph
						(5).
(ii) For soil in the zone of
						groundwater saturation, the standard is 1/10th of the generic value calculated
						by the equation in paragraph (5).
(5) The equation referenced in paragraph (4)
						is the following:
MSCS =
						  MSCGW (Kd +
						  [thgr]w/[rho]b).
where: MSCS (mg/kg) = the
						  generic value for the inorganic regulated substance in soil
MSCGW (mg/L) = MSC of the
						  inorganic regulated substance in groundwater
Kd (L/kg) = soil to water
						  partition coefficient for the inorganic regulated substance
[thgr]w = water-filled porosity
						  of soil (default value = 0.2)
[rho]b (kg/L) = dry bulk density
						  of soil (default value = 1.8 kg/L)
DF = dilution factor (default value = 100)