Congress must ask the Environmental Protection Agency why, after more than 40 years of increasingly costly watershed management (WSM) technologies and best-management practices, water quality is continuing to deteriorate. Since enactment of the Clean Water Act in 1972, controlling point- and nonpoint-source nutrient and pollutant loading from watersheds into waterbodies has been the EPA’s sole method of addressing waterbody impairment. The agency failed to implement the third pillar of the CWA, waterbody management (WBM). A systems approach is needed to improve water quality using effective and cost-efficient WSM practices and WBM interventions so that freshwater impairment can be reversed and prevented in the near term at a much lower overall cost.
Waterbodies that no longer provide their designated uses — such as healthy fisheries, suitable drinking-source water, safe swimming and other recreational activities — are considered impaired pursuant to the Clean Water Act Section 303(d). Freshwater impairment endangers human and animal health, aquatic ecosystems and our economy. Improved freshwater management is essential for ensuring a sustainable supply of usable freshwater and is critical for the security and well-being of our nation.
Impairments are primarily caused by excessive concentrations of nutrients, toxic substances and pathogens. Government surveys estimate that about 44 percent of river and stream miles and 64 percent of lake and reservoir acres are impaired.
Whereas the EPA estimated in 1972 that 10 to 20 percent of lakes and reservoirs were eutrophic (nutrient over-enrichment that enables toxic algae to predominate over beneficial microorganisms), the agency now estimates that about 50 percent are eutrophic or hypereutrophic. A recent EPA assessment of 2008-2009 data for our nation’s rivers and streams found that 66 percent contained excessive levels of phosphorus, a primary cause of eutrophication, up from 47 percent in 2004.
Highly toxic blue-green algae (cyanobacteria) are forming “harmful algal blooms” at a rapidly increasing rate in the U.S. and worldwide. HABs occur when cyanobacteria outcompete nontoxic green algae, diatoms and other organisms that form the base of the aquatic food web. HABs are increasing due to increasingly excessive nutrient loads, increasing temperatures and decreasing water flow. Their cyanotoxins are among the most potent toxins known. Inhalation, ingestion and dermal exposures to higher concentrations cause illness and death, and repeated low-level exposures cause neurodegenerative, carcinogenic, developmental and reproductive diseases. HABs cause fish kills due to suffocation when bacteria that deplete all dissolved oxygen in the water eventually decompose the large HAB biomass.
The point- and nonpoint-source WSM programs are two of the three pillars of the CWA. WSM reduces point- and nonpoint-source inputs of nutrient and other pollutant into waterbodies. WSM is the sole focus of the EPA’s freshwater management policy. The point-source program is successful. Point sources now account for only 5 percent to 10 percent of input. Little is left to be gained by further reducing point-source input limits; the cost-benefit ratio is very high. The nonpoint-source program is much less successful. Many of the nonpoint-source best-management practices are marginally effective and very expensive.