New Tools for Water Quality Trading

Posted on September 26, 2016 by Ridgway Hall

For well over a decade states and stakeholders have been trying to develop water quality trading and offset programs to facilitate compliance with the Clean Water Act.  The goal of “trading” is to allow a discharger who can cost-effectively reduce pollutants to a lower level than legally required to sell the resulting “credit” to another source whose per-unit cost of reducing that same pollutant is greater. The “credit” is the amount of reduction achieved by the credit generator beyond compliance. The result is more cost-effective compliance. 

An “offset” involves using a “credit” to offset a new or increased discharge to a water body which is not achieving water quality standards (often referred to as “impaired”) for that pollutant.  Without such an offset, any new discharge to an impaired water body is illegal, because it would exacerbate the standards violation. Typically the credit or offset is incorporated into the permit of the user, and is thereby enforceable.

Recognizing these benefits, EPA supports trading, and issued a policy and guidance memo in 2003.  One of the most promising opportunities for trading is the reduction of nitrogen, phosphorus and sediment, which are causing water quality problems across the country.  Farms typically have nonpoint source discharges of all three of these pollutants, and can reduce the volume much more cost-effectively than a municipal or industrial point source, which is the typical buyer. However, efforts to establish trading programs have run into problems, such as determining a measurable “baseline” compliance level for a nonpoint source credit generator before a credit can be generated. Nonpoint sources typically use “best management practices” (BMPs) to achieve pollution reductions representing their fair share of loading allocations for the water body to which they discharge. Before a farmer can generate a credit, his “fair share”, or baseline, must be both determined and met.

Additional problems include protecting local water quality where the credit is used, verifying the implementation of a credit, and accounting for uncertainty in the amount of pollution reduction which a BMP implemented at a non-point source will actually achieve. As a result, while many states have tried to establish such programs, including the development of regulations, very few have been successful. 

To address these problems, EPA over the past 3 years has issued 8 “technical  memoranda” (TMs) which set forth EPA’s “expectations” for the contents of an effective trading program within the Chesapeake Bay watershed. This is, in effect, a pilot.  The reason for the focus on this 64,000 square mile watershed is that in 2010 EPA published the biggest total maximum daily load (TMDL) ever issued under the CWA, which sets forth pollutant loading allocations which must be achieved throughout the watershed in order to achieve compliance with applicable water quality standards. I described this TMDL in a previous post entitled EPA Issues Biggest TMDL Ever for Chesapeake Watershed, posted on March 4, 2011. Faced with huge costs to achieve the reductions, many of the states are looking at trading.

To maximize the likelihood that such trades will be carried out in compliance with the CWA, EPA issued the TMs for use by the Bay states in designing their programs. They address baseline determination, duration of credits, components of a credit calculation, protection of local water quality, accounting for uncertainty of the water quality benefit of a BMP, representative sampling, verification and certification (including inspections and public availability of all relevant documents), and accounting for growth (including need for an “offset” program). The “credit calculation” TM addresses, among other things “additionality” (the requirement that any trade must result in a net reduction of pollution) and “leakage” (when a pollutant load reduction at one location indirectly causes an increase in pollution elsewhere). These can be accessed on EPA’s “Trading and Offsets in the Chesapeake Bay Watershed” web site. They are not regulations or even “official agency guidance” (says EPA), and do not have the force of law. They do set forth EPA’s “expectations”.  EPA officials have said that each state trading program will be reviewed for consistency with these TMs.

For those around the country who are trying to design and implement trading programs, these TMs can be enormously helpful.  They are fairly brief (typically 6 to 12 pages), clear and concise.  And who among us would not support more cost-effective reduction of pollution?