The mysterious deaths of 13 bald eagles on Maryland's Eastern Shore last month captured headlines around the country. While a tragic story, it was also a reminder of just how far bald eagle populations and those of other birds of prey have recovered over the last several decades. From a population of fewer than 1,000 in 1963, almost as many bald eagles now soar in the skies over Maryland alone. The iconic bird's recovery is a case study in the value of regulating toxics in our environment.
The story of the bald eagle's decline and subsequent recovery highlights both our previous failure to understand the acute toxicity in the air and water of industrialized nations and the subsequent success of environmental regulation. In fact, the use of the pesticide DDT and its impact on one of our most cherished national symbols almost singled-handedly galvanized the environmental movement in this country. And while we now have a much more mature and comprehensive regulatory apparatus in the United States, few environmental lawyers, scientists, or other professionals are likely satisfied by the state of progress in reducing the pervasiveness of toxic chemicals today.
Here in the Chesapeake Bay watershed, the Bay restoration framework known as the Bay Total Maximum Daily Load, (TMDL) which has just exited the federal courts unscathed, requires the seven jurisdictions (six states and the District of Columbia) in the watershed to reduce nutrient (nitrogen and phosphorus) and sediment pollution. The high profile of the Bay TMDL, together with the frequent dead zones and algal blooms in the main stem and tributaries of the Chesapeake, have caused Bay and clean water advocates in the region to focus almost entirely on nutrient and sediment pollution and their sources. But many more watersheds in the United States are subject to TMDLs for chemicals like mercury and substances like metals than for nutrients, and a growing list of watersheds are impaired by acutely toxic pollutants like pesticides (including legacy DDTs), PCBs, and polycyclic aromatic hydrocarbons (PAH).
A great many of these toxic pollutants are the product of our urban landscape. That is, rather than being dumped or discharged by traditional point sources, the pollutants find their way to streams and other waters through atmospheric deposition, spills, or leaks, and are carried as runoff from impervious surfaces — roads, parking lots, really anything that's paved. The great expanses of concrete, asphalt, rooftops, and other urban surfaces are the conduit, though not the original source, of these pollutants, because unlike the soil beneath them, these surfaces do nothing to filter out the pollutants.
The good news is that the kinds of best management practices that reduce nutrient and sediment pollution are also highly effective at reducing the loading of toxic pollutants, and vice versa. In other words, the investments made by urban jurisdictions to comply with the Chesapeake Bay and other nutrient and sediment TMDLs, have many important "co-benefits" as far as reducing other pollutants and creating additional environmental benefits.
It is for this reason that policymakers in the Bay watershed, particularly those in areas with high levels of urbanization, need to very carefully review any policy that would shift the pollution reduction burdens from urban areas and the stormwater sector to rural areas and the agriculture sector. Doing so might reduce the dollar cost of meeting the Bay TMDL nutrient and sediment targets, but at the cost of sacrificing other important environmental benefits.
Nutrient trading, for example, seeks to reduce the overall cost of complying with a TMDL or other watershed restoration effort by allowing those with more expensive pollution reduction options to purchase nutrient or sediment reduction "credits" from those able to reduce pollution at lower cost. That might seem worthwhile on its face, but it ignores the true costs and benefits of a trading policy. Most nutrient trading policies fail to account for the co-benefits of urban best management practices. Such practices not only reduce nutrient and sediment to local waterways (as opposed to solely focusing on the Bay), but also reduce toxic pollutants and pathogens, and in some cases can also enhance local property values, reduce energy usage, moderate local temperature extremes, and allow for rainwater capture and recycling, among other benefits.
A nutrient trading policy that fails to properly incorporate all benefits and costs of each practice not only fails to protect local communities and optimize public investment decisions, but licenses and even subsidizes the continued pollution by toxic chemicals of waters in urban areas, which often have higher levels of poverty and numbers of vulnerable communities.
Nutrient trading is just one of many policies and decisions resulting from an overblown concern about the cost of achieving the Bay TMDL and other water quality goals. These cost estimates are usually digested by officials in a vacuum. Not only are these estimates discussed in the absence of any context – such as the cost per capita and on an annual basis, or how those costs compare to other budgetary items – but costs are considered without reference to benefits. Too little consideration is given to the direct and indirect economic benefits of clean water generally, and specific practices are often evaluated without any regard to their co-benefits, such as a concomitant reduction in human or wildlife exposure to toxic substances. Hospital bills are a cost, too, after all, and dead zones have a profound impact on the seafood and tourism industry.
The Bay TMDL, like all TMDLs, is a creature of the Clean Water Act, designed to protect the nation's waters from the many chemicals, pollutants, and other stressors that degrade those waters, through a comprehensive and holistic watershed approach. Any TMDL that accounts for costs but ignores benefits or that elevates the importance of one pollutant source over all others fails as an interpretation of the Clean Water Act or as a policy to protect human habitat and the environment.