About the author: Jacob Dorman is region regulatory manager for Contech Engineered Solutions. Dorman can be reached at [email protected].
When I bought my first house, my grandfather, rest his soul, gave me a toolbox filled with the most common tools and some advice. He said, “Son, this box contains all you need to solve most common household problems, but you have to pick the right tool for the right job.” It is sage advice that can be applied to what I see as a potential long-term water quality issue popping up in the Mid-Atlantic region, where I am based. The problem is an over-reliance on nutrient credit trading to improve locally impaired waterways.
The reality is, nutrient credits can be an effective site development tool. Credits are an important option municipalities and the development community should have at their disposal to simplify compliance with federal, state and local regulations. Nutrient credits make it easier in times when capital improvement budgets and permit deadlines do not line up neatly, for sites that do not have adequate space for traditional best management practices for water quality, and for irregular development conditions that dictate non-traditional solutions. Several states already have recognized the value of this compliance tool and have set up or are in the process of setting up nutrient credit trading programs. These include three states in the Chesapeake Bay Watershed: Virginia (phosphorus), Maryland (nitrogen, phosphorus and sediment) and Delaware (nutrients to be determined).
The biggest driver of these programs seems to be compliance with the U.S. Environmental Protection Agency mandate to clean up the bay. However, in the states with credit trading programs, does transferring local water quality concerns downstream get us to a cleaner Chesapeake Bay? And what happens to local water quality when projects can discharge untreated runoff after purchasing credits generated elsewhere?
This is where my grandfather’s advice applies. Since nutrient credit trading programs are an important tool in the compliance toolbox, prioritization should be applied when considering applying this tool. Where available, buying nutrient credits has become the first option in the toolbox. Local water quality is potentially harmed by taking that course of action.
First, local water quality should not be negatively impacted by any proposal to use credits. If a local water quality impairment exists, trading should not be allowed at all. Treating impervious cover at the source is the most effective way of protecting local waters.
Second, trading programs should only be allowed on projects of 1 acre or less or where site constraints make treatment impractical. Sites larger than that generally can accommodate traditional water quality treatment practices or can be designed to optimize location of impervious areas and water quality treatment.
Third, for constrained sites, the project should be required to treat 75% of the new impervious area on site and could purchase credits on the remaining 25% to equal 100% site treatment. This treats runoff at its source and allows for development flexibility.
Lastly, if a development project has gone through the exercise of attempting to locate a water quality practice on site and the site simply does not allow for it, a waiver to allow the purchase of credits should be available. This would allow for constrained sites to be developed, but only after they have proven treating runoff at its source is infeasible.
