EPA and DES Propose Novel Permit to Reduce Nitrogen Pollution to Great Bay Estuary

Since Congress passed the Clean Water Act in 1972, the United States has made tremendous progress in cleaning up our nation’s waterways. Infrastructure and technology improvements at municipal wastewater plants were fundamental in those changes. Prior to 1972, many cities and towns discharged raw sewage directly into adjacent rivers, lakes, and oceans. Building and upgrading wastewater treatment plants was an easy first step. While some of the most direct impacts of raw sewage, such as dangerous pathogens and high biological oxygen demand, have been addressed by these initial technological changes, cities and towns are struggling to balance the higher costs of addressing other sources of longer-term pollution, such as nutrient pollution, with the delayed benefits. There is little scientific debate that nutrient loading to many lakes and estuaries is threatening those ecosystems, but the costs of adding tertiary treatment to wastewater treatment plants to address those problems are high. Now that we have tackled the “low-hanging fruit,” cities and towns are struggling with how to take the next step.

In New Hampshire, the Great Bay estuary is threatened by excess nitrogen pollution. The higher nitrogen loads to the estuary threaten to upset the fragile ecosystem by causing algal blooms, further eelgrass declines, and continued stress to shellfish populations. Some of that excess nitrogen enters the estuary via the municipal wastewater treatment plants that drain to the Bay. But a lot of the nitrogen comes in through other sources, known as non-point source pollution. This has created tension between the regulator, the EPA, and the regulated, the cities and towns in the Great Bay watershed. What’s the “best” way to reduce the nitrogen getting into the estuary, and how can that be regulated?

Initially, the EPA and New Hampshire Department of Environmental Services (DES) used the same tools they employed in the past—more stringent permits for effluents from wastewater treatment plants. The EPA calculated how much nitrogen was passing through the treatment plants into the watershed, and how much nitrogen needed to be removed from those plants to prevent eutrophication (the situation where excessive nutrients cause algal blooms, dead zones and fish kills) in Great Bay. The problem, however, was that the cost to improve the wastewater plants to meet those permit levels exceeded $500 million. This led to a series of lawsuits in 2012 to block those permits from going into effect. EPA and DES then went back to the drawing board.

Earlier this year, EPA and DES released a revised draft permit, the Nitrogen General Permit, which is designed to reduce the total nitrogen entering the estuary. Rather than just focusing on the nitrogen coming from wastewater treatment plants as the initial proposal did, the Nitrogen General Permit sets a new target for nitrogen loading to the estuary and lets the towns in the watershed decide how to meet that target. Towns can look to reduce nitrogen pollution from stormwater runoff, leaky septic systems, or other non-point sources. Or towns can address nitrogen pollution by upgrading their wastewater treatment systems. This novel approach provides the cities and towns much more flexibility, but it is also potentially harder to document.

Whether this permit is implemented as proposed or how it might change will depend on the comments EPA and DES receive from towns, environmental organizations, and interested citizens.  Comments can be submitted to the Federal Register by March 9, 2020.

About the Author: Nat Morse, JD, PhD

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