WASHINGTON (July 3, 2002) -- The government is using outdated science in assessing the health risk of sewage sludge used as fertilizer. According to a new report by the National Research Council, the standards set by the Environmental Protection Agency in 1993 on the use of "biosolids" for treating soil are based on an unreliable survey identifying hazardous chemicals in sewage sludge from wastewater treatment plants. The NRC panel concluded that the agency needs to do more scientific study on the risks to people from exposure to chemicals and disease-causing pathogens in sludge used as fertilizer.
The panel's report underscores that current federal regulations on applying sludge do not protect public health, according to NRDC (Natural Resources Defense Council). Earlier this year, EPA and NRDC reached a legal settlement that requires the agency to develop a plan to address NRC's recommendations.
"The Environmental Protection Agency needs to wake up and address a very unglamorous but critical public health problem -- sludge," said Nancy Stoner, director of NRDC's Clean Water Project. "The agency's current approach of spreading it around is not safe."
Sludge is the solid material in sewage that contains most of the toxic pollutants removed from the wastewater. Over five million tons of sludge are disposed of in the U.S. each year. Until recently, the EPA had been promoting land application as the best solution for sludge disposal. In response to a significant jump in the number of reported health incidents and growing public resistance to sludge spreading, the agency asked the NRC to reassess the practice.
The NRC panel's report found that EPA's sludge regulations may fail to protect the public from infectious diseases as well as toxic chemicals that cause long-term debilitating illnesses, including cancer. The panel did not address the potential impact of sludge spreading on soil, forests or wildlife, limiting its recommendations to human health. These recommendations include:
- Epidemiological studies of the growing number of sludge victims
- Testing to identify the full range of toxins and pathogens in sludge
- An update of EPA's antiquated risk assessment of the impacts of sludge on human health
- More hazard surveillance and enforcement to protect the public from dangerous sludge practices.
The NRC report is just the latest of a number of studies that have concluded that current regulations are inadequate. Two years ago, the Centers for Disease Control identified Class B sewage sludge as a potential hazard for workers handling the material. In 1997, the Cornell University Waste Management Institute warned that federal sludge regulations undermine agricultural productivity and fail to protect the environment and public health. Meanwhile, two EPA inspector general reports have concluded that the agency cannot guarantee that land application protects human health and the environment because there is not enough data or enforcement.
The Natural Resources Defense Council is a national, non-profit organization of scientists, lawyers and environmental specialists dedicated to protecting public health and the environment. Founded in 1970, NRDC has more than 500,000 members nationwide, served from offices in New York, Washington, Los Angeles and San Francisco.