PERFLUOROOCTANE SULFONATE (PFOS) cleanup levels in Pennsylvania

These are the Pennsylvania Department of Environmental Protection's published values for PERFLUOROOCTANE SULFONATE (PFOS), from its Statewide Health Standard tables and its PFAS groundwater table, updated 7/10/2024. DEP's page says the Statewide Health Standard tables present the standards published November 20, 2021. Each value is shown as the agency prints it, with the same number written out beside it where that reads differently.

Pennsylvania: Statewide Health Standard Medium-Specific Concentrations

DEP's PFAS groundwater table

DEP's file dated July 24, 2024.

Pennsylvania Department of Environmental Protection

The United States Environmental Protection Agency (EPA) has established maximum contaminant levels (MCL) for the per- and polyfluoroalkyl substances (PFAS) compounds listed below. These MCLs will become the Statewide health standard medium-specific concentration (MSC) values for groundwater effective June 25, 2024. The new values are:

Used Aquifers, TDS ≤ 2500

Column	Value	Code
R (µg/L)	0.004	M
NR (µg/L)	0.004	M

Used Aquifers, TDS > 2500

Column	Value	Code
R (µg/L)	0.4	M
NR (µg/L)	0.4	M

Nonuse Aquifers

Column	Value	Code
R (µg/L)	0.004	M
NR (µg/L)	0.004	M

Footnotes to DEP's PFAS groundwater table, as the agency prints them

* In addition to meeting the individual MSC, if more than one of the marked compounds (Gen-X, PFBS, PFHxS, PFNA) are detected at any concentration in a sample, a Hazard Index (HI) must be calculated using the equation below. The HI MSC is met in this case by maintaining a rolling average HI of less than one for the most recent four quarters of samples utilizing the equation:

HI = (C_Gen-X/0.01)+(C_PFBS/2)+(C_PFNA/0.01)+(C_PFHxS/0.01)

Where: All concentrations are in µg/L

C_Gen-X = concentration of Gen-X

C_PFBS = concentration of PFBS

C_PFNA = concentration of PFNA

C_PFHxS = concentration of PFHxS

Updated: 7/10/2024

Pennsylvania Department of Environmental Protection

PFAS Soil MSC Notice (January 2026)

PA DEP has determined that the Hazard Index portion of the EPA’s April 26, 2024 PFAS MCL Rule does not apply to soil. The rationale behind that decision is explained in the Technical Notice below.

January 2026 Technical Notice (PDF)

Table 3a: Medium-Specific Concentrations (MSCs) for Organic Regulated Substances in Soil: A. Direct Contact Numeric Values

DEP's file dated January 4, 2022.

Residential

Column	Value	Code
0-15 feet (mg/kg)	4.4	G

Non-Residential

Column	Value	Written out	Code
Surface Soil, 0-2 feet (mg/kg)	64		G
Subsurface Soil, 2-15 feet (mg/kg)	190000	190,000	C

Footnotes to Table 3a, as the agency prints them

All concentrations in mg/kg

G - Ingestion

N - Inhalation

C - Cap

Table 3b: Medium-Specific Concentrations (MSCs) for Organic Regulated Substances in Soil: B. Soil to Groundwater Numeric Values¹

DEP's file dated January 19, 2022.

Used Aquifers, TDS ≤ 2500, Residential

Column	Value	Code
100 X GW MSC (mg/kg)	0.007
Generic Value (mg/kg)	NA

Used Aquifers, TDS ≤ 2500, Nonresidential

Column	Value	Code
100 X GW MSC (mg/kg)	0.007
Generic Value (mg/kg)	NA

Used Aquifers, TDS > 2500, Residential

Column	Value	Code
100 X GW MSC (mg/kg)	0.7
Generic Value (mg/kg)	NA

Used Aquifers, TDS > 2500, Nonresidential

Column	Value	Code
100 X GW MSC (mg/kg)	0.7
Generic Value (mg/kg)	NA

Nonuse Aquifers, Residential

Column	Value	Code
100 X GW MSC (mg/kg)	0.007
Generic Value (mg/kg)	NA

Nonuse Aquifers, Nonresidential

Column	Value	Code
100 X GW MSC (mg/kg)	0.007
Generic Value (mg/kg)	NA

Soil Buffer Distance (feet)

Column	Value
Soil Buffer Distance (feet)	NA

Footnotes to Table 3b, as the agency prints them

1 For other options see Section 250.308

E - Number calculated by the soil to groundwater equation in Section 250.308

All concentrations in mg/kg

C - Cap

NA - The soil buffer distance option is not available for this substance

The agency's current table governs. This page is a reference copy and not a cleanup decision. Check the agency's page for a newer table before relying on a value.

Source

• Pennsylvania Department of Environmental Protection, Statewide Health Standard Medium-Specific Concentrations.
• PFAS groundwater table: DEP's file dated July 24, 2024, read October 5, 2026.
• Table 3a: DEP's file dated January 4, 2022, read October 5, 2026.
• Table 3b: DEP's file dated January 19, 2022, read October 5, 2026.