Cities and counties don't have to worry about tougher regulation of their sewage sludge incinerators (SSIs)—at least not yet.

After 10 years of consideration, the U.S. Environmental Protection Agency (EPA) announced Jan. 22 that it will no longer classify SSIs as “other solid waste incineration units,” allowing it to regulate their emissions under Section 112 of the Clean Air Act instead of Section 129. The decision relieves wastewater treatment plants of having to obtain a permit to operate their sludge incinerators.

Had the EPA decided to use Section 129, which the Sierra Club was urging, cities and counties would have faced very costly mandates on emissions of carbon monoxide and nitrogen oxide (to name just a few chemicals), making it cost-prohibitive to burn sewage sludge, an EPA-approved method for biosolids management.

At least 22% of biosolids generated at publicly owned treatment plants in the United States is disposed of through incineration. The process cuts biosolids volume by 80% to 95%; destroys pathogens; degrades toxic organic compounds; and produces a sanitary, odorless, and nonhazardous byproduct (i.e., ash).

Section 112 of the Clean Air Act, on the other hand, lets the EPA regulate toxic-chemical emitters using less-burdensome “generally available control technologies or management practices.” In establishing appropriate levels, the agency can consider potential costs to a city or county. Moreover, unlike Section 129, which would require sewage sludge incinerators to obtain Title V permits, Section 112 lets the agency determine whether a permit is necessary. The cost to small sources, such as sewage sludge incinerators, of a permitting program would be relatively high.

The EPA has not tipped its hand as to when it may issue Section 112 standards. But it did sign a consent decree with the Sierra Club in March 2006 obligating it to publish standards for toxic chemical source categories every six months between Dec. 15, 2006, and June 15, 2009.

Bottom line: Expect new standards anytime between now and June 15, 2009.


May 4 is the deadline for registering with the EPA's electronic-reporting system at as the first step in meeting new contaminant-monitoring requirements announced in January.

This new monitoring program is part of the EPA's second Unregulated Contaminant Monitoring Rule, which names 25 additional chemicals that must be monitored by public water departments. The EPA pushed back the deadline for when monitoring must begin from July 2007 to January 2008, and dropped perchlorate from the contaminants list.

The program is expected to cost local water departments a total of $35 million over the four-year monitoring period.