Tracking COVID19 in sewage - time series examples from CA and VA
Data disclosed to public by LACSD and by HRSD
In California and Virginia, time-series results of wastewater sampling and analysis are being publicly disclosed by at least two large utilities: Los Angeles County Sanitation Districts (LACSD) and Hampton Roads Sanitation District (HRSD). (Possibly, utilities at other USA locations may be doing the same.)
LACSD:
On July 17, Los Angeles County Sanitation Districts (LACSD), having posted updated weekly average results of wastewater surveillance analyses through week of July 10, announced they will continue to post updates every two weeks.
— “Since the outbreak of the COVID-19 pandemic, we have been closely following developments and taken all appropriate measures to ensure that we are protecting the health of our workers, the general public, as well as the environment. We have also recently started research that could potentially help public health officials manage the pandemic.”
— LACSD has made analytic results available to the public as well as to CA agencies and CDC, for more than 40 samples so far.
— LACSD manage wastewater for more than 5.6 million residents in 78 cities and unincorporated areas in Los Angeles County. The Sanitation Districts are a partnership of "special districts" formed under California law. Special districts are governed by a board of directors made up of elected officials from the local government agencies served by the district. The board of directors for a county sanitation district is made up of elected officials from each city within the sanitation district and the Chairperson of the Board of Supervisors representing unincorporated areas.
HRSD:
Hampton Roads Sanitation District (HRSD), besides reporting to Virginia Department of Health (VDH), has freely shared (and will soon post) updated wastewater surveillance analytic results through mid-July. (You can ask RGonzalez@HRSD.com for copies now, before posting by HRSD.)
— HRSD, a wastewater utility which serves 1.8 million people in 18 cities & counties,is monitoring SARS-CoV-2 genetic material in eastern Virginia:
— HRSD has sampled sewage inflows at its 9 largest wastewater treatment plants (WWTPs) since week of March 9 (first utility to do so) and continued weekly monitoring since. It has also worked to develop and optimize methods.
— HRSD has taken and analyzed about 370 samples so far. HRSD has had own in-house microbiology lab for five or six years. Lab now uses RT-digital PCR method for COVID-19.
— HRSD used all three CDC assays (N1, N2, N3) at first, but work showed the 3 tests to have very good agreement; so HRSD now uses the test with the lowest detection limit (N2) for all load-based analyses. [Personal e-mail communication to me from Dr. Raul Gonzalez, July 12, 2020.]