Coronavirus detection: sample city sewage to help diagnose its presence and plan for preparedness

Why guess where the coronavirus is and how many people might be infected if we can use our wastewater systems to give us the facts? 

Right now our communities, public policy experts, emergency services and planners want to know where and how far the coronavirus is spreading. Could we be sampling wastewater in our sewage systems to get that information?

My experience as a water sampler

The first field sample of water I ever collected was on Dec 5th, 1996, on the shores of Kingston Ontario. A landfill that had been closed by the city was leaking into Lake Ontario, and I went to the water looking for heavy metals for evidence. I brought sampling bottles from a lab for that purpose.

After I collected the water samples, I asked the lab for a full suite of tests for metals: copper, nickel, cobalt, and more. It cost me $75. The results revealed that the landfill was, in fact, discharging high levels of metals to Lake Ontario, which rendered the sediment toxic to aquatic life. The City of Kingston eventually fixed the leak and paid for repairing the damage done. 

Later on, I sampled for another variety of toxic chemicals called polychlorinated biphenyls (PCBs), in the waters adjacent to Hamilton, Montreal, Moncton as well as in other locations. Each time, I told the lab beforehand what I was looking for and was given the bottles and instructions to collect it.

I knew which toxics to sample for in each location because the source of the contamination was obvious (an old landfill, sewage pipes, a PCB storage site, etc.). I also knew that if particular toxics were present above certain concentrations and harmful to aquatic life, then offenders were violating the Federal Fisheries Act. 

The continuation of water quality sampling

In 2006, Lake Ontario Waterkeeper started to focus on recreational water, because sewage and stormwater were restricting people’s access to the lake. We again went to labs and were given bottles with preservatives and instructions for how to collect bacteria, E.coli specifically, the indicator for recreational water health.

Today, Swim Drink Fish shares bacterial water quality data from 8 thousand locations, in 11 countries on an online public sharing platform called Swim Guide, which has over 4 million users. We sample E.coli to assess freshwater health and Enterococci to monitor saltwater health. We follow scientific guidelines and take at least 5 samples in each location to assess public safety using local standards. We share our results with communities and provide them with accessible information regarding their safety in swimming at particular beach locations. We also use the water quality information we collect to identify problems and restore public access to water.

Bacteria isn’t the only contaminant in sewage pollution, but it’s the one experts have agreed is the best indicator of sewage pollution. It’s relatively cheap, fast, and reliable to test for. If you test for bacteria, you know pharmaceuticals, oils, metals and other contaminants are also in the water; you just don’t need to spend the extra time and money looking for all of them. 

Water samples are powerful diagnostic tools. If you know what to sample for and where to sample, you can build endless knowledge about water quality and identify what needs to be done to restore problem areas.

When sampling sewage in particular, the results can tell us valuable information about what people are consuming, and the types of waste that is making its way from land to water. Sewage tells us which pharmaceuticals people are taking, how much caffeine we’re drinking, which soaps we’re using, how much plastic we are littering, as well as which viruses are in our communities.

The relationship between Coronavirus and wastewater

Sewage samples taken from hospital outflows where SARS victims were recuperating in 2003 told us a lot about the spread of that virus. The RNA of the virus was present in the stools of SARS patients, and therefore in untreated sewage. A trail of indicators was left behind in the sewage. 

In order to better understand and help deal with the coronavirus, we need to know if it is present in our communities and in what concentrations it might be present. One fast, easy way to find out how widespread the virus is could be to test sewage before it is treated. The University of Arizona has already begun monitoring the presence of the coronavirus in wastewater to better understand its presence, and to better assess the risk to people working at wastewater facilities. 

This article talks about studies being done showing that the coronavirus is present in human feces. Researchers are finding that after someone is sick and no longer has the virus according to respiratory tests, the virus is still present in the feces of some patients for up to 12 days. This research is ongoing, and there are updates daily. 

If we tested wastewater for coronavirus in Ontario

Ontario has over 600 sewage treatment plants and vast networks of pipes throughout our communities and cities. We are already testing many places all day every day. If diagnostic tests for the virus were conducted across this network, we could know much more about the problem, and be able to identify where we’ll need resources in the coming weeks. 

Diagnostic sampling for the coronavirus in our wastewater systems, where daily discharges are collected prior to treatment, could provide information our public health and safety leaders need to better understand the spread of the virus and help us navigate future problems. 

All one needs to know is what to sample for, and where to look for it.