Safety and Environmental Concerns
Synagro believes that organic waste streams should be recycled as safely and resposibly as possible. We work day in and day out to utilize biosolids and other organic materials in ways that protect the environment and benefit agricultural systems. Our programs for municipal and industrial customers assist in the reduction of pollution in our environment and have helped to improve the country’s water quality more than anything else to date.
Long-standing research studies show that the use of recycling biosolids is safe. The National Academy of Sciences has reviewed current practices, public health concerns and regulator standards, and has concluded that "the use of these materials in the production of crops for human consumption when practiced in accordance with existing federal guidelines and regulations, presents negligible risk to the consumer, to crop production and to the environment."
Biosolids contain trace amounts of "heavy metals," as do natural soils, manures, and commercial fertilizers. These trace metals come from human wastes, household plumbing systems, household products, businesses and industries. These components in biosolids have been most thoroughly researched and are stringently regulated and controlled. Biosolids recycling programs must, by law, ensure that trace metals do not accumulate in soils to levels that can cause harm.
The U.S. Environmental Protection Agency (EPA) thoroughly studied the potential risks from these trace metals and set strict maximum levels in biosolids to ensure protection of public health and the environment. Because of required industrial pretreatment and the risk-based standards for biosolids recycling, the risks posed by trace metals in biosolids are minimal.
Note that many of the regulated metals in biosolids are beneficial in correct amounts. Chromium, copper, iron, manganese, selenium, and zinc are micronutrients for plants, animals, and humans (contained in multi-vitamin and mineral tablets). It is the presence of these micronutrients that accounts for the greater effectiveness of biosolids as fertilizer when compared to traditional chemical fertilizers.
The scientific evidence shows that through the variety of physical and biological processes involved in treatment, composting, and/or land application, almost all trace chemicals either degrade or volatilize. The few that are more persistent are at very low levels – similar to levels found in background soils and manures – and do not create any increased risk to public health or the environment.
Human disease-causing organisms may also be of concern. Research has shown no increase in health problems at wastewater treatment facilities or on farms where biosolids are used.
There has never been a documented case of illness due to biosolids recycling. Many illnesses and deaths, however, have been attributed to the use of manures which is a widely-accepted practice.
All of us at Synagro are proud to be an active part of helping to create a more sustainable environment.
