Real-time water quality monitoring

Coastal water quality affects millions of people in the United States every year from residents of coastal communities to beach visitors. The Environmental Protection Agency (EPA) has set forth standards for surface waters nationwide to reduce the amount of pollution released into them. In order to enforce these standards, methods for monitoring bacterial concentrations in coastal waters have been developed. Currently, the feasibility of molecular-based monitoring methods are being tested. This study investigated the feasibility of using a reusable, flow-through nucleic acid extraction and quantitative PCR (pPCR) module to detect human pathogens using previously published qPCR assays for Enterococcus and human bacteriodes. The module when integrated into the Environmental Sample Processor creates an in situ platform that allows autonomous sampling and analysis of seawater for potential human pathogens. The qPCR assays were tested against a library of 16S rRNA genes from bacteria commonly found in surface waters of Monterey Bay for testing their use in non-point source contamination. The Enterococcus qPCR assay cross-reacted with several bacterial 16S rRNA genes, while the human bacteriodes assay did not. Seawater samples from coastal California were also analyzed with the flow through solid phase extraction and qPCR in a laboratory setting. Ribosomal DNA from Enterococcus and human bacteriodes were both successfully amplified from seawater samples indicating that the assays can be incorporated into the automous Environmental Sample Processor. INTRODUCTION Every year thousands of beaches in the United States are closed to the public due to unsafe water quality or the possibility thereof (Dorfman and Rosselot 2009). With an estimated 89 million people visiting America’s beaches each year (Leeworthy and Bowker 1997), beach closures greatly affect coastal communities and their visitors. These beaches are closed in accordance with the Clean Water Act (CWA), the U.S. federal law regulating water quality. The CWA requires the Environmental Protection Agency (EPA) to set forth standards in order to decrease the amount of point and nonpoint source pollution affecting the nation’s surface waters (USEPA 2009).