A National Academy of Sciences report confirms federal biosolids recycling regulations are protective, but some aspects of the science should be updated.

In early July, a panel of the National Academy of Sciences completed an 18-month review of some of the science behind the federal 40 CFR Part 503 regulations for biosolids recycling. “The term biosolids refers to sewage sludge treated to meet the land application standards in the Part 503 rule or any other equivalent land application standards,” notes the panel’s report.

The NAS panel found “there is no documented scientific evidence that the Part 503 rule has failed to protect public health. However, additional scientific work is needed to reduce persistent uncertainty about the potential for adverse human health effects from exposure to biosolids.” They did not find a need for change in current biosolids utilization practices and regulation. Nor did they find any crisis.

Rather, the NAS panel called for continuing scientific review of current federal biosolids standards and management practices. This makes sense – and state agencies and research institutions (and even the Environmental Protection Agency, to some extent) have been doing this. In New England, for instance, there are recent and current biosolids research projects at the Universities of Maine, Massachusetts and New Hampshire. And all New England states have stricter, updated biosolids management standards than EPA’s Part 503 rule and have well-staffed biosolids regulatory programs that ensure compliance and proper biosolids management.

New England Biosolids and Residuals Association (NEBRA) President Earle M. Chesley of Merrimack, N.H., responded to the new NAS study by noting that “those of us involved in biosolids management in New England appreciate the input from this scientific review panel. We’ve had biosolids recycling programs going on in this region since the 1970s. … The NAS report seems to agree that we are on the right track.”

The new NAS study follows a 1996 NAS review that found “While no disposal or reuse option can guarantee complete safety, the use of these materials [biosolids] 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.”

The new NAS report recommends to EPA specific kinds of research projects, data gathering and monitoring procedures, and risk assessment methods that the NAS panel believes would serve to enhance the scientific basis and further improve public confidence in the federal regulatory and enforcement program. The costs of these additional efforts has not been established, but would likely be tens of millions of dollars.

One recommendation of the NAS panel is that EPA complete a new survey of the nation’s biosolids, in order to better understand current biosolids quality with regard to trace metals, chemicals and pathogens that are present in trace amounts in biosolids. In response to that recommendation, it is important to note that the agency and states already have volumes of biosolids quality data from regular required biosolids testing. This data clearly shows that biosolids quality has improved dramatically over the past 15 to 20 years. A 2001 NEBRA analysis of New England data found that biosolids in this region easily meet EPA and state most-stringent standards. Biosolids recycled in New England are absolutely as safe for public health and the environment as other routinely used composts, manures, fertilizers and other agricultural products.

The NAS report is one important scientific review in the long development of the science of biosolids recycling. It will help guide biosolids research regarding those particular aspects of biosolids recycling on which it focused. But the NAS panel’s call for “updating the science” does not mean the original Part 503 science was wrong, nor does it negate the finding that the federal rule has been protective. And New Englanders are protected by even stricter state regulations.

The new NAS report focused on potential risks, but it is also important to remember that there is little dispute about the well-documented benefits of biosolids recycling. Biosolids improve soil quality, reduce erosion and enhance crop growth. New England biosolids are used routinely to build healthy soils for golf courses, sports fields and parks; provide organic nutrients to grow animal feeds and foods; and add slow-release nutrients and organic matter to topsoils used to reclaim scarred landscapes.

In New England, there are about 600 publicly owned wastewater treatment facilities that produce approximately 425,000 dry tons of sewage sludge annually. Twenty percent of these sewage sludges – those of highest quality – are recycled as biosolids products – mostly in northern New England. Recycled New England biosolids are produced in Boston, Holyoke, Pepperell, Springfield and elsewhere in Massachusetts; from almost all of the large municipalities along the Merrimack River; from Burlington, Barre, Bennington and other Vermont towns; and throughout Maine – which has recycled 75 percent to 90 percent of its biosolids in recent years.

NEBRA estimates that, if the 93,000 dry tons of New England biosolids recycled annually were to be disposed of, it would require the equivalent of six landfills each the size of a football field and 33 feet deep (where do we have that much more landfill space?). The nitrogen fertilizer value of these products alone is more than $1.3 million a year. Adding the value of other biosolids qualities means that the total economic benefit from New England biosolids is far greater.

“Biosolids help farmers, landscapers, golf course managers, and ‘dirt jockeys’ in this region improve soils and grow crops more efficiently by using a local, recycled resource,” says Charley Hanson, a beef cattle farmer who uses biosolids to fertilize grass hay. Hanson also works for a New Hampshire company that recycles biosolids. “By recycling biosolids, we’re helping society put to use a material that could take up a lot of landfill space or take a lot of energy to burn.”

NEBRA is a nonprofit association of agencies, companies and individuals who work on a daily basis with biosolids throughout New England and in eastern Canada. The NAS report summary and NEBRA’s Saving Soil report on biosolids quality and recycling rates in New England are available on the association’s Web site: www.nebiosolids.org. For further information, NEBRA can be reached at 603-323-7654. NEBRA encourages you to visit and learn more about your local wastewater treatment facility and biosolids recycling.

Ned Beecher is executive director of the New England Biosolids and Residuals Association in Tamworth, N.H.