We have had a 100-year reliance on regulatory policy to address the negative consequences of sewers. Sewage sludge regulations and the policies that made land application the preferred disposal option for sludge are part of that long history of regulatory failure.
The EPA began regulating the land application of sewage sludge in 1993. But because of the inherently unpredictable and inherently hazardous nature of sewage sludge, the EPA is, in fact, unable to implement any program or regulatory scheme to protect public health or the environment from the land application of sewage sludge.
The Clean Water Act authorizes the EPA to administer the National Pollutant Discharge Elimination System (NPDES) permit program. All municipal wastewater treatment facilities are required to get a NPDES permit to operate. But what discharges are eliminated?
Pollution control is implemented by “end-of-pipe” limitations, meaning by effluent limitations on specific constituents in the discharge. These are based on “current available technologies” (what the treatment plant is actually capable of doing).
Treatment plants are designed specifically to reduce conventional pollutants (suspended solids, oxygen-demanding substances, pH, oil and grease, and fecal coliform bacteria.) from wastewater, but not to remove metals and organic chemicals. They do not and cannot address the tens of thousands of chemicals entering the plant each day, not to mention those that are created in the treatment process, such as the carcinogenic “disinfection byproducts” like Trihalomethanes (THMs) and N nitrosodimethylamine (NDMA).
For example, the Carpinteria Wastewater Treatment Plant, in Carpinteria, California, discharges over one half a billion gallons of contaminated wastewater into 25 feet of water off Rincon Point, a popular surfing area, every year. This is a small plant, with a capacity of approximately 2 million gallons a day (mgd), compared to, say, Los Angeles County’s Joint Water Pollution Control Plant’s 510 mgd capacity. Still, the Carpinteria wastewater treatment plant, which has state-of-the-art secondary treatment, has a NPDES permit that allows its treated wastewater, when discharged into the Pacific Ocean off Rincon Point, to contain 10 tons of Arsenic, 3 tons of Lead, 113 pounds of Mercury, 31,000 tons of Toluene, 2 tons of Benzene, 47 tons of Chloroform, 12 tons of Vinyl Chloride, and millions of tons of other hazardous chemicals (on a per year basis).
What about pre-treatment, a mostly voluntary federal program to go up the pipe and stop toxic dumping? To address “indirect discharges” from industries to wastewater treatment plants, the EPA established the National Pretreatment Program as a component of the NPDES Permitting Program. According to the EPA, “The National Pretreatment Program requires industrial and commercial dischargers to treat or control pollutants in their wastewater prior to discharge to POTWs [publicly owned treatment works].” But this, of course, does not happen. In fact, hazardous wastes can be legally discharged into publicly owned treatment works under the Domestic Sewage Exemption of the Resource Conservation and Recovery Act (RCRA).
What are the general pretreatment standards? They are rules that protect the wastewater treatment plant, not you and me. These standards state that discharges must have a pH greater than 5.0 and cannot:
Most of the 100,000 chemicals in commercial use in the United States end up in the sewer, pretreatment or not. The shortcomings of the pretreatment program, like massive permit backlogs, gaps in program coverage, huge amounts of non-regulated pollutants, lack of monitoring, inadequacy of regulatory compliance, the lack of incentives for implementation and enforcements, and the fundamental fact that is cheaper to dump hazardous wastes in the publicly owned and financed sewer than to properly dispose of them, can and should be addressed, but pretreatment will never make wastewater (or sludge) free of toxins or safe to use as a fertilizer.