Dealing with Our Excrement

A recent article "Sludge Happens: Recycling sewage into fertilizer might be making us sick. Why doesn't the EPA give a crap," in Mother Jones Magazine (http://www.motherjones.com/environment/2009/05/sludge-happens) came up on my radar. This article is one of many that raises questions regarding the impacts of land application of biosolids.

Land application is the most economical avenue for getting rid of this sludge. Some experts claim that sludge is not good fertilizer and there are numerous health concerns with land application. Added to this problem is that after we invest hundreds of billions to increased biological nutrient reduction pollution controls placed on tens of thousands of wastewater plants, we greatly increase the volumes of biosolids.

EPA should explore greater pollution prevention controls to best address the land application of biosolids. This is warranted since improper sludge application has caused problems throughout the world.

Promoting best management controls for the land application of biosolids is important. Developing greater public dialogue and exploring greater best management responsibilities for safe land application of biosolids can translate into improved health and water quality.

Today over 16,000 sewage treatment facilities serve nearly 190 million Americans (the 72 percent of the U.S. population who are served by sewers not counting those with decentralized septic and wastewater systems). In addition, these facilities serve thousands of industrial and commercial establishments to treat their wastewaters. Roughly eight million dry metric tons of biosolids are produced annually or about 58 pounds per person per year. About 54 percent of the biosolids are land applied as a fertilizer or as a soil conditioner.

Sludge, or biosolids range from 70 percent to greater than 98 percent water. The dry matter in biosolids is mostly inert minerals (i.e., sand and silica) or biological materials comprised of fat, protein, fiber and carbohydrates. Biosolids also have trace amounts of heavy metals and organic chemicals. And, biosolids contain varying levels of pathogenic organisms, vector (e.g., insects and rodents) attractants and odor causing substances. These metals, organic chemicals and pathogens pose a threat to human health unless the biosolids are sufficiently processed and properly placed in the environment.

Part 503 Biosolid Rule allows land application (spreading) of sewage sludge (also known as sludge) needs to be updated. Today there are three main options (each with limitations) to dispose of sludge: landfilling, incineration, and land-spreading. Incineration requires high capital investment, and is limited because of potential air pollution and the production of toxic ash. The science for land applying biosolids is many decades olds when in 1993, the EPA published the 503 Sludge Rule setting standards for the use or disposal of sewage.

EPA’s standards have generated controversy in the scientific and agricultural communities, as well as with the general public. Although the 503 Sludge Rule establishes minimum quality standards for biosolids to be land applied many citizens question the adequacy of these standards. Land applying sludge requires more stringent standards, additional source separation and greater pretreatment of contaminants. Scientists and citizens have expressed concerns about the effects on humans from contaminants concentrated in the sludge during treatment.

Several years ago the EPA Inspector General found: “EPA does not have an effective program for ensuring compliance with the land application requirements of the 503 rules. …While EPA promotes land application, they cannot ensure the public that current land application practices are protective of human health and the environment.”

The National Academies of Sciences in 2002 released a paper called, “Biosolids Applied to Land: Advancing Standards and Practices." They cited their uncertainty about the potential adverse human health effects from exposure to biosolids. Essentially, there is a need to update the scientific basis of the 503 rule so to review the current. exposure and health information on exposed populations. Also the risk-assessment methods need to be updated as does the outdated characterization of sewage sludges.

Educational tools are needed to assist local citizens and local officials with the various implications of land application. This would allow users to identify environmental concerns and to give field assistance to the analysis, maintenance and accounting of sludge land applications.

Finally, what I have observed are the inadequate programs to ensure compliance with biosolids regulation and lack of resources devoted to EPA’s biosolids program. We need innovation to overcome the institutional barriers often imposed by land applying biosolids. There are many challenges including jurisdictional, political, and governmental boundaries when dealing with the hydrogeological and geographical facets of dealing with sludge. In closing I have watched in the Shenandoah Valley hundreds of millions of dollars invested in water quality improvements and very little expended to address the safe management of biosolids. It time we Americans deal with our excrement or pay for the consequences.

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