Policy Pulse - NH Env-Or 600 rule revisions

NHDES Contaminated Site Management Rules updates are effective 11/4/25.  The NHDES has finalized and implemented the Env-Or 600 rule revisions, which were proposed in April 2025.  Notable changes to the rules include:

The Soil Remediation Standard (SRS) for lead changed from 400 milligrams per kilogram (mg/kg) to 200 mg/kg.

The SRS for total petroleum hydrocarbons changed from 10,000 mg/kg to individual diesel range organics (DRO) and gasoline range organics (GRO) SRS in residential (less than 2 feet from the ground surface) or commercial (greater than 2 feet from the ground surface) exposure scenarios as follows:

	DRO SRS (mg/kg)	GRO SRS (mg/kg)
For soil less than or equal to 2 feet from the ground surface	480	390
For soil greater than 2 feet from the ground surface	4,200	4,000

A new section (Env-Or 603.05) was added requiring construction dewatering activities to obtain and comply with NHDES groundwater discharge permits and EPA NPDES permits for construction dewatering activities, as applicable.

A new section (Env-Or 615) was added relative to administrative fines relating to violations of the Env-Or 600 rules.  These administrative fines were previously established by statute and are being moved from the former rules at Env-C 600 to the program-specific rules, including Env-Or 600.

For more information, contact George Holt.