Some superbugs in partially treated or reclaimed sewer water come from home and hospital toilets.
But some are actually created at the treatment plant. Scientists have known for a long time that the mixture of antibiotic drugs and bacteria in wastewater creates superbugs which are resistant to antibiotics. [1]. Both the drugs and the bacteria persist in the soil and in waterways, and are a major source of environmental contamination. Scientists from the US Geological Survey tested for and found 19 pharmaceuticals, including antibiotics, in soil watered with reclaimed wastewater.[2] Scientists fear that wastewater discharges containing large amounts of drugs like the antiviral Tamiflu, which cannot be removed by wastewater treatment, could lead to the evolution of a new and far more dangerous strain of influenza.[3]
Wastewater treatment relies heavily on chlorination for disinfection, but that causes its own problems. Chlorine reduces the number of bacteria but also adds increased virulence and drug resistance to the remaining pathogens.[4] Edo McGowan, M.D., PhD, former US environmental representative to Africa and clean water consultant to the UN and the EPA, has tested reclaimed sewer water from two wastewater treatment plants in California, using the Kirby Bauer test. He found that all of the bacteria were resistant to chlorine and to 11 out of 12 antibiotics tested. The problem is widespread. Rockledge’s aging Sewage Treatment Plant, which on occasion releases reclaimed water with a Total Coliform bacteria rating of Too Numerous to Count (TNCT), is likely also producing high levels of antibiotic resistant superbugs.
According to studies, UV treatment would not solve the problem of the creation of drug resistance in reclaimed water.[6] A 2009 European study, using the latest scientific testing methods, concludes that recharging aquifer water using “aquifer passage and uv treatment……represents a health and environmental hazard because of the presence of pathogenic mircroorganisms and chemical contaminants.”[7]
Sewage Plants could be Creating “Super Bacteria”, Andrew Mc Glashen, Environmental Health News, April 16, 2009.
Pharmaceuticals found in Soil Irrigated with Reclaimed Water, US Geological Society, Kinney CA
et al, 2006.
Tamiflu survives sewage treatment, Science News, 10/04/07.
Toxicgenomic Response to Chlorination includes Induction of Major Virulence Genes in MRSA, Environmental Science, technology, Matthew Wook Chang, et al, (Article cited #10 in Wikipedia reclaimed water page.)
Comments on the Drugs in Drinking Water story, Edo McGowan MD, PhD, The Owl Foundation 2008.
Effect of UV light disinfection on antibiotic resistant colorforms in wastewater effluents, MC Meches, Applied Environmental Microbiology, Feb. 1982.
Quantitative PCR Monitoring of Antibiotic resistance genes and Bacterial Pathogens in three European Artificial ground water recharge systems, Bockelman U. et al, Applied Environmental Microbiology, Jan 2009.