In 2007, the Natural Resources Defense Council (NRDC) and ten other environmental non-governmental organizations (together, the “Environmental NGOs”) petitioned USEPA to establish nationally applicable technology-based secondary treatment standards for publically owned treatment works (POTWs) to control nitrogen and phosphorous. After sitting on it for over 5 years, USEPA recently denied the Environmental NGOs’ petition on December 14, 2012.

In its response, USEPA declined to set such nutrient limits for POTWs because it would require POTWs to incur significant expenses, estimated at tens of billions of dollars nationally, yet would not provide a clear benefit to water quality.  In addition, technological difficulties such as land constraints would prevent many POTWs from upgrading their existing treatment systems or installing more advanced systems.  Finally, the agency also found that there is high variability in what each POTW could achieve at its specific location, which presents a significant challenge to the development of a uniform national rule with a single set of requirements.

Although rejecting universal limitations, USEPA did agree to consider the Environmental NGOs’ concerns on a case-by-case basis through individual permits.  POTWs vary significantly as to size, control technology (including whether a retrofit or a replacement would be necessary), availability and cost of land for any potential facility expansion, whether combined stormwater systems are present, nutrient discharge levels, the amount of treatment chemicals needed and the resulting water quality.  Therefore, the agency determined that individual permitting will be the most effective avenue for establishing nutrient discharge limitations and will allow USEPA to better tailor limitations to each POTW.

Additionally, not all POTWs contribute equally to the water quality of a region.  For example, a study performed jointly by the USEPA, the Chesapeake Bay states and the District of Columbia found that only 420 out of approximately 3,720 POTWs in the region are responsible for the vast majority of POTW nutrient loading in the Chesapeake Bay.  Given the significant variability between POTWs, the agency concluded that it should address nutrient control through secondary control technology on a case-by-case basis.

Owing to USEPA’s position, we expect to see permitting agencies (i.e., the States) consider introducing additional limitations on POTWs as permits are renewed.  Factors evaluated in the imposition of these limits may include the economic and logistical feasibility of installing secondary treatment technology and the POTW’s contribution to the nutrient loadings in the applicable watershed.  Thus, as permits come up for renewal, it will be important for POTWs to be prepared to address more stringent limitations or control technology upgrades that the permitting agency may seek to impose.  Additionally, POTWs should expect that Environmental NGOs will raise their concerns during the permitting process given USEPA’s response on the petition.  Environmental NGOs will likely comment on draft permits and seek to have POTWs install secondary control technology and be subject to more stringent nutrient limitations as part of this process.