LA County Sanitation District Testing Wastewater for Coronavirus

By on July 13, 2020

The Los Angeles County Sanitation Districts (LACSD) has announced results from testing untreated wastewater for the presence of novel coronavirus (SARS-CoV-2).

Untreated sewage has been used for years to track viruses as well as to analyze opioid use by neighborhood. Now LACSD is focused on determining whether the virus is completely removed by the treatment process and assisting public health experts manage the pandemic if testing shows the amount of infected people is increasing or decreasing in the region.

The LACSD Laboratories staff developed a lab test method that detects coronavirus genetic material (ribonucleic acid or RNA) in wastewater. (The method is based on the same RNA test method developed by the Centers for Disease Control and Prevention that is currently being used for patient testing in clinical laboratories throughout the United States.) To date, LACSD has tested more than 20 incoming wastewater samples and the results show that the virus RNA signal was detected in all incoming wastewater samples. Samples were also sent to independent laboratories, who also detected coronavirus RNA with only a few exceptions.

Samples of cleaned water were also analyzed for coronavirus and, in all cases, the virus was not detected. The lack of coronavirus RNA in cleaned water is not surprising as previous reports indicate that enveloped viruses such as coronavirus are generally more susceptible to the disinfection process than non-enveloped viruses. Thus, conventional wastewater treatment processes that effectively destroy non-enveloped viruses were expected to easily kill coronavirus.

If you have any questions or would like to discuss methodology with LACSD, contact Nikos Melitas, Research Manager, at 562-908-4288, ext. 2816, or nmelitas@lacsd.org.