New Hampshire’s New Soil PFAS Regulations Now in Effect

As required by State law, the New Hampshire Department of Environmental Services (NHDES) has adopted soil remediation standards (SRS) for certain perfluoroalkyl and polyfluoroalkyl substances (PFAS), which are in effect as of December 25, 2024. These standards give NHDES the authority to direct site investigation and remediation activities and require responsible parties to comply with the standards if these contaminants are found in soil.

PFAS are manmade compounds that have been used for multiple purposes since the 1940s, including industrial applications, consumer products, and firefighting. There are thousands of PFAS, and they do not readily break down in the environment. PFAS can be transported in air, surface water, and groundwater and have been determined to be toxic at concentrations in parts per trillion. The PFAS SRS are risk-based standards that have been derived by NHDES to be protective of New Hampshire’s drinking water quality.

The adopted SRS include four PFAS: 

• Perfluorooctanoic acid, (PFOA) set at 0.4 nanograms per gram (ng/g)
• Perfluorooctane sulfonic acid, (PFOS) set at 0.5 ng/g
• Perfluorohexane sulfonic acid (PFHxS) set at 0.4 ng/g
• And perfluorononanoic acid (PFNA) set at 1.3 ng/g

These new standards reflect statewide occurrence of PFAS in shallow soil (< 1 foot below ground surface) and factors that influence PFAS mobility in New Hampshire-specific soils.

The regulation does not specifically require PFAS sampling for any given Site or property. However, when PFAS contamination in soil is found, responsible parties may be subject to 60-day reporting requirements, followed by potential requirements for additional investigation and remediation. 

PFAS SRS do not apply to contamination when it has been determined to be attributed solely to background conditions, such as deposition from the atmosphere. While these soils may not be subject to SRS, the applicability of certain solid waste rules should be considered in project decisions not only at Sites currently being managed under the Env-Or 600 Contaminated Site Management rules but up and coming projects ranging from due diligence to Alternation of Terrain Permitting. 

If you have any questions, GZA can assist you with understanding the new standards and engaging in proper compliance. To learn more, contact Amy Renzi at amy.renzi@gza.com or 603-232-8749.