Municipal wastewater treatment plants are required to remove solid residuals before returning treated water to the environment. Residuals come from homes, businesses, industry, public facilities, and storm water runoff. Commonly called "sludge" or "biosolids" (Rampton, 2002), these solids undergo biological, chemical, or thermal treatment prior to disposal. Treated sludge contains chemical and biological materials from the wastewater stream and from treatment processes. Its high nitrogen content makes sludge an attractive agricultural soil amendment. A majority of the approximately six million dry tons of treated sludge produced annually in the U.S. is applied to farmland; most of the rest is incinerated or landfilled (National Research Council [NRC], 2002).
In 2002 the National Research Council (NRC) committee on toxicants and pathogens in biosolids applied to land found that adequate information is not available on human exposures from land application of sewage sludge, and recommended response investigations, exposure assessments, and epidemiologic studies (National Research Council [NRC], 2002). Meanwhile, residents living near land application sites have reported symptoms following sludge application, including mucous membrane irritation, upper and lower respiratory distress, headaches, fatigue, skin rashes, nausea, vomiting, and diarrhea (Harrison & Oakes, 2002; Khuder et al., 2007; Lewis, Gattie, Novak, Sanchez, & Pumphrey, 2002; Shields, 2002). A similar cluster of symptoms has been reported by neighbors of industrial animal operations (Bullers, 2005; Thu, 2002; Thu et al., 1997; Wing & Wolf, 2000). Although numerous residents have reported symptoms to state and federal agencies, records of these reports are not routinely kept (Harrison & Oakes, 2002). Nationally, no system exists for tracking illness reports connected with sewage sludge (U.S. Environmental Protection Agency [U.S. EPA], 2002).
In support of developing a protocol for tracking and investigating human health symptoms reported near land application sites, we surveyed and interviewed officials involved in the production of sewage sludge as well as the regulation, oversight, and practice of land application of sludge. We obtained information about their experiences with the public, their views of the need for tracking and investigating illness around land application sites, and about barriers to implementing such a process. Their input was incorporated into an investigation protocol intended to assist health departments, public health practitioners, and environmental regulators to respond to residents who report symptoms potentially associated with exposure to land application of sludge, and to support basic epidemiologic research on the spatial and temporal variation of illness reports. This article summarizes the methods and results of the web-based survey and phone interviews with officials involved in land application of sludge.
We developed a web-based survey and semistructured telephone interview guide to assess current practices in responding to citizen reports concerning land application and to articulate biosolids officials' opinions about the practicalities and feasibility of implementing an investigation protocol responsive to public concern at local, state, and national levels. The survey and interview guide were approved by the University of North Carolina Public Health Institutional Review Board (06-0405). The survey was designed as a 12-item web-based questionnaire composed of a combination of multiple option responses, five-point rating scales, and open-ended questions to address the following five key factors:
1. existing response to public concern regarding biosolids land application;
2. utility of a protocol to investigate health concerns regarding biosolids land application;
3. coordination of human health …