U.S. Environmental Protection Agency (EPA) renewed the NPDES General Permit for Remediation Activity Discharges in Massachusetts effective April 8, 2017.  This permit authorizes discharges from contaminated sites as well as a collection of miscellaneous discharges that may be contaminated.  A companion permit was issued covering these discharges in New Hampshire.  According to the US EPA Fact Sheet, discharges from about 750 remediation projects were authorized under the 2010 permits, mostly in Massachusetts.  

Changes in Categories and Associated Sampling Requirements

The 2017 Remediation General Permit authorizes essentially the same discharges as the 2010 Remediation General Permit but in slightly different activity categories and contaminant subcategories.  For each activity, the applicant identifies the activity category of the discharge and the applicable subcategories based on what is known about contaminants at the site.  The activity categories are:

• Petroleum-related site remediation;

• Non-petroleum-related site remediation;

• Contaminated site dewatering;

• Pipeline ant tank dewatering;

• Aquifer pump testing;

• Well development / rehabilitation;

• Collection structure dewatering / remediation; and

• Dredge-related dewatering.

Based on the applicable contaminant subcategories (for example, inorganics, fuels) and which specific contaminants are present, the applicant determines, based on the directions in the permit, what monitoring is required and what effluent limitations apply.   For example, for a remediation of a site with lead and trichloroethylene contamination, the activity category is non-petroleum related site cleanup and the contaminant subcategories are inorganics and halogenated volatile organic compounds. For this discharge, the emission limits and monitoring requirements are:  (a) for inorganics, all listed limits and monitoring; and (b) for halogenated volatile organic compound, limits and monitoring for only those compounds present at the site. 

New in the 2017 permit is an explicit statement that if a contaminant is present at the site that is not on the list in the general permit, US EPA may authorize the discharge upon specific request; if it does so, it may require additional monitoring or other requirements.

Additional monitoring and effluent limitations were added in the 2017 Remediation General Permit for ammonia, cyanide, acetone, 1,4-dioxane, ethanol, tert-amyl methyl ether, and tert-butyl alcohol.  Some effluent limitations were removed, and effluent limitations were revised for many contaminants include total residual chlorine, tetrachloroethylene, and mercury.

Emergency Discharges

The 2017 Remediation General Permit provisionally authorizes “emergency discharge” immediately upon initiation of the discharge.  A discharge is considered an emergency discharge when:

1) the discharge is a result of remediation and/or dewatering activities conducted in response to a public emergency (e.g., natural disaster, which includes, but is not limited to tornadoes/hurricanes/tropical storms, earthquakes, mud slides, or extreme flooding conditions; or widespread disruption in essential public services); and

2) the discharge requires immediate authorization to avoid imminent endangerment to human health, public safety, or the environment, or to reestablish essential public services.” 

US EPA must be notified as soon as possible and within 24 hours after the discharge commences, and a Notice of Intent must be submitted within 14 days.  Monitoring and work practice requirements apply during the discharge.

Receiving Water Monitoring

New in the 2017 Remediation General Permit is a requirement to analyze a representative sample of the receiving water and include the results in the Notice of Intent.  Additional sampling of the receiving water may be required by US EPA on a case by case basis.

Notice of Final Permit

The 2017 Remediation General Permit was signed by US EPA on March 9, 2017, and became effective on April 8, 2017.  An aggrieved person may file a petition for review by September 20, 2017 (no later than within 120 days after the permit was issued on May 23, 2017).

A “Notice of Availability of Final NPDES General Permit for Remediation Activity Discharges in Massachusetts and New Hampshire:  The Remediation General Permit” is available here on the US EPA website.  This is described on the website as the “Pre-Publication Federal Register Notice.”  As of June 12, 2017, this notice has not been published in the Federal Register.  It has been US EPA’s longstanding practice to publish such notices in the Federal Register, publication is not required, see 40 CFR Part 124.  It is not clear why US EPA has deviated from this practice at this time.