Marin County, north of San Francisco, began a pilot program in February to collect wastewater samples from its sanitation agency and test them for the presence of substances like fentanyl, methamphetamines, cocaine, and nicotine.

Local authorities hope the data could be beneficial in assisting prevention and intervention efforts. For example, if there is an abundance of opioids present in the samples, they could boost the distribution of Narcan, which rapidly reverses the effects of the illegal drug, especially when given within minutes of the first signs of an overdose.

“The problem of overdose is a public health crisis. We’re losing one resident every five days in Marin County,” said Dr. Matt Willis, Marin County’s public health officer. “And so we really think it’s important for us to develop the same kind of surveillance methods, the same kind of intelligence we had applied to the COVID-19 pandemic, to this new crisis of overdoses.”

Marin County, like many other places in the U.S., is grappling with a drug epidemic. Overdose deaths rose from 30 in 2018 to 65 in 2021, according to the county’s department of health and human services.

The county used the same method and partners to monitor for evidence of the spread of the coronavirus, so the infrastructure for the pilot program is largely in place.

Twice a week, workers with the Central Marin Sanitation Agency collect a 50-milliliter sample of wastewater from the roughly 8 million gallons that flow into its San Rafael facility daily. That wastewater comes from residential, commercial, and industrial sources like kitchen and bathroom sinks, toilets, and showers.

The sample is then shipped to Biobot Analytics, based in Cambridge, Massachusetts. Biobot researchers then analyze the sample for the presence of drugs.

Biobot declined to say how many U.S. counties are specifically testing for substances but said they test samples from more than 700 locations across more than 50 states, territories, and provinces. The locations include sites that are testing for either infectious diseases, high-risk substances, or both.

By Nathan Frandino

(Reporting by Nathan Frandino in San Rafael, Additional reporting by Brian Snyder in Cambridge, Editing by Rosalba O’Brien)