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Land application of sludge is simply a method of disposing of pollutants. There can be any of more than 60,000 toxic substances in any particular land application, yet only a few are actually tested for. There are also different pathogens that may be present. Yet only fecal coliform tests are performed, even though it is well known that fecal coliform is not an indicator of the presence of certain pathogens such as viruses. Under these circumstances, no one really knows just what pollutants may be contained in any given land application. Accordingly, there can be no certainty about the degree of risk in any specific land application.
This deficiency is widely understood by those involved in land application of sludge. However, permitting agencies refuse to make this clear to farmers and the public. Instead, it is argued that land applications of sludge must be safe because there are no studies demonstrating harm to the public. Left unsaid is that no such studies have been undertaken, and health complaints are not properly investigated.
The refusal to conduct full testing of sludge following health complaints makes it scientifically impossible to confirm whether the sludge was, or was not the cause of the health problems occurring following land applications of sludge. My father once said that if it looks like a skunk and smells like a skunk, it is probably a skunk. Refusal to admit that it is a skunk because of an unwillingness to take a close look does not mean it is not a skunk. Yet this is how the safety issue of sludge is addressed.
The refusal to use science suggests a sinister motive--to make it impossible for victims to establish the scientific link between their ill health and their forced exposure to sludge. This failure to determine the nature of the health risk makes it impossible for any reasonable person to claim that forced exposure to any given land-applied sludge is safe. Only sludge promoters could be expected to make such an unsupported claim.
2. Failure to Establish Adequate Permit Provisions
Even if proper testing were developed, under current permit provisions there would still be no assurance that any given land application would be safe. The adequacy of permit terms is based on EPA's risk assessment model. However, the many deficiencies of that model are never discussed. For example; the model did not address most of the toxic substances that might be found in a sludge; and it did not take into account local pollution potential characteristics such as karst terrain, soils with pollution-sensitive characteristics, and areas that frequently flood.
Even if those factors had been incorporated into a risk assessment model, it would still not establish the safety of specific land applications because assumptions in the EPA model are often not included in permits. For example, the risk assessment model used slopes limited to 6 percent. In Virginia, slopes up to 15 percent are allowed, and there has been an ongoing refusal to provide any scientific data to demonstrate the impact of this major change.
The EPA risk assessment model also assumes that pH will remain at sufficiently high levels to keep heavy metals from leaching into groundwater. However, current permits in Virginia provide for pH requirements only at the time of application. There is no requirement that it be in perpetuity, and that it run as an obligation against the land. In areas with high acid soils, this is a special problem.
The failure to consider local pollution potential conditions in Virginia is especially troubling because of the karst terrain found in many counties. Everyone associated with land application of sludge should know that karst terrain is very pollution-sensitive. Because of the presence of cracks, fissures and sinkholes, what goes on the ground often goes directly into groundwater.
Permitting agencies in Virginia are quite familiar with the serious pollution potential in these areas, and yet have authorized land applications in karst areas with the greatest pollution potential under the Drastic Index. Admittedly, a limited effort has been made to address this issue by requiring buffers. However, there are no studies to confirm if sludge could be safely land-applied on karst
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