The products of wastewater treatment have been found to contain trace amounts of antibiotic resistant DNA. These products are often reintroduced to the environment and water supply, potentially resulting in the spread of antibiotic resistance. As such, researchers at the University of Southern California Viterbi School of Engineering have been studying the development of these potentially harmful and dangerous genes in wastewater treatment processes. Their findings, published in Environmental Science & Technology, indicate that even low concentrations of just a single type of antibiotic leads to resistance to multiple classes of antibiotics.
Article: Smart Water Magazine