EPA Proposed Performance Standards and Emission Guidelines for Sewage Sludge Incinerators

On October 14, 2010, the Environmental Protection Agency (EPA) published in the Federal Register proposed performance standards for sewage sludge incinerators. The EPA action addresses Clean Air Act requirements to establish new source performance standards (NSPS) for new incinerators and emission guidelines for existing incinerators. This is the first time EPA has proposed regulating sewage sludge incinerators under Section 129 of the Clean Air Act. The action also marks the first time that EPA will be moving forward with rulemaking proposing an affirmative defense to civil penalties for emissions exceedances caused by malfunctions.

The proposed new standards would require wastewater treatment authorities that incinerate sewage sludge to control emissions of hazardous air pollutants, with emissions standards proposed for multiple hearth and fluidized bed incinerators. The proposal would amend 40 C.F.R. Part 60 subparts LLLL and MMMM, and require the incinerators to control emissions of mercury, lead, cadmium, hydrogen chloride, particulate matter, carbon monoxide, dioxins and furans, nitrogen oxides, and sulfur dioxide. EPA estimates that the proposed rule would reduce emissions of the nine pollutants by 6,330 tons per year.

The proposed rule would set numeric emissions limits for both new and existing sewage sludge incinerators with separate standards for existing multiple hearth and fluidized bed incinerators. EPA is proposing the following emission limits: 

Under the proposed rule, new and existing incinerators would be required to perform annual emissions performance and opacity tests. The incinerators could opt to install continuous emissions monitors rather than conducting the annual emissions performance test. All new incinerators, however, would be required to install the continuous emissions monitors for carbon monoxide.

Owners and operators of both new and existing sewage sludge incinerators would be required to meet operator training and qualification requirements, including an initial training course, annual review or refresher course, and maintenance of plant-specific information, updated annually.

EPA estimates 196 of the 218 sewage sludge incinerators in the United States would be required to install additional pollution controls under the proposed rule at a cost of $105 million.

In the proposed rule, EPA also has proposed to create an affirmative defense to civil penalty claims for NSPS emissions limit exceedances shown to be caused by “malfunctions” — defined by 40 CFR 60.2 as “any sudden, infrequent, and not reasonably preventable failure of air pollution control equipment, process equipment, or a process to operate in a normal or usual manner. . .[not] caused in part by poor maintenance or careless operation.” In the context of an enforcement proceeding, the facility would have the burden of proving by a preponderance of the evidence that it has met a series of required elements, including showing that the excess emissions could not have been prevented through proper advance planning/design or better operation and maintenance, that steps were taken to correct/repair the malfunction as quickly as possible, and that emissions were minimized to the maximum extent feasible under the circumstances. Facilities also would be required to submit a phone or fax notification to EPA within two business days of the malfunction, and a written report within 30 days. According to EPA, the merits of the affirmative defense then would be "independently and objectively evaluated in a judicial or administrative proceeding” concerning the potential imposition of civil penalties.

The proposed rule marks the first time EPA has proposed for public comment the affirmative defense approach as part of a proposed NSPS. EPA included similar affirmative defense provisions in the final rule amending the NSPS and National Emission Standards for Hazardous Air Pollutants (NESHAP) for the Portland Cement source category earlier this year, but they did not appear in the proposed rule.

EPA also has proposed the affirmative defense as part of six other proposed rules issued on Oct. 21 amending the NESHAPs for those source categories. These rules, along with the final amendments to the Portland Cement NSPS and NESHAP, and the Sewage Sludge Incinerator NSPS, could provide the first substantive legal test of EPA’s proposed affirmative defense.

Comments to the proposed Sewage Sludge Incinerator NSPS rule must be received by EPA on or before November 15, 2010.