In early April, as much of the East Coast continued to sink into COVID-19 crisis mode, a heavy storm dumped rain across Massachusetts and New Hampshire, overwhelming local wastewater treatment plants. Plant operators would later report that millions of gallons of raw sewage overflowed into the Merrimack River, which supplies drinking water to a half million people and is a popular place to swim and fish.
April showers bring May flowers, but heavy rainfall also forces water utilities across the country to discharge raw sewage from outdated sewer systems into lakes, rivers and streams. From Cleveland, Ohio, to California, residents are familiar with the signs posted at beaches and lakeshores warning swimmers to stay out of the water for at least two days after a heavy rainfall. Overwhelmed sewers can contaminate bodies of water with high levels of harmful bacteria found in human waste — and now with SARS-CoV-2, the virus that causes COVID-19.
About 860 billion gallons of wastewater overflow escapes overwhelmed sewer systems in the United States every year, and 3.5 million people get sick from swimming, boating, fishing, and other activities that bring them in contact with contaminated water, according to the environmental group American Rivers. Environmental accountability organizations now say that sewer spills are putting drinking water supplies at risk.
The Centers for Disease Control (CDC) advises that the virus has been found in untreated wastewater, but it remains unclear whether anyone has gotten sick from coming in contact with sewage. Scientists across the world are well aware that coronavirus is found in sewers and are developing methods for using sewage samples to track the spread of the virus, a process that could be more accurate for modeling the pandemic than widespread testing. Many people recover from COVID-19 without getting tested, but everyone flushes the toilet.
During the SARS outbreak of 2003, a sewer leak caused a cluster of cases in Hong Kong, according to a recent op-ed by researchers at the University of California. Like SARS, the novel coronavirus hitchhikes on tiny water droplets. The researchers worry the virus may colonize slimy bacterial growths called “bioslimes” that line aging water pipes, making shower heads a potential source of aerosolized transmission. The researchers said water infrastructure should be updated in COVID-19 hotspots, and more testing is needed to ensure that water treatment methods are effectively removing the virus.
Standard treatment practices for drinking water and “properly designed and maintained sewerage systems” should prevent the spread of the virus, according to the CDC, but sewer overflows are a sign that systems across the country are outdated and in need of maintenance and upgrades. Testing for SARS-CoV-2 in drinking water is limited or nonexistent in most areas. Environmental watchdogs say overflows after heavy rains remain a “blind spot” for tracking sources of coronavirus transmission and must be taken seriously.
“COVID-19 dramatically increases the public health consequences of these combined sewage overflows,” said Kyla Bennett, a former New England water enforcement official for the Environmental Protection Agency (EPA), in a statement. “Our aging water infrastructure represents a growing public health vulnerability as these sewage spills become more common.”
Bennett is now the science policy director at Public Employees for Environmental Responsibility (PEER), a watchdog group that represents current and former employees at agencies like the EPA and Interior Department. PEER said this week that drinking water in the U.S. is not routinely tested for coronavirus, even after storms overwhelm wastewater systems and cause overflows. The Trump administration has not ramped up testing at wastewater treatment plants run by local utilities that are losing billions of dollars in revenue due to the pandemic.
“Much remains to be learned about the role of sewage overflows and disease transmission,” Bennett said. “At a minimum, EPA should be conducting or funding screening of at-risk drinking water for the presence of coronavirus.”
In many cities, decades-old sewer systems combine sanitary waste, rainfall, industrial discharges, and other sources of wastewater into one pipe running to treatment plants. When heavy rainfall or even snowmelt exceeds a treatment plant’s capacity, operators must discharge excess sewage into the environment to avoid flooded basements and backups in homes. The wastewater then flows into lakes and rivers from which utilities draw drinking water.
Some cities have invested in sewer upgrades that keeps stormwater and sewage separate, but approximately 1,000 municipalities have “combined” sewer systems that can experience overflows, according to the EPA. Many are located in older cities in the Eastern U.S. and across the Great Lakes region, where decades-old sewer systems regularly dump sewage into large sources of freshwater. The EPA reports that approximately 772 cities in the U.S. have “major water pollution concerns” due to combined sewer systems.
“Once public health experts determine that we can safely re-open our beaches, swimmers should not face the risk of getting sick from pathogens in the water,” said John Rumpler, the clean water director at Environment America, in a statement on Wednesday.
The good news is that conventional wastewater treatment methods are effective at removing viruses and other pathogens from drinking water, according to the World Health Organization. EPA standards require utilities to remove pathogens from drinking water, and the agency has assured the public that the risk of COVID-19 transmission by drinking water is low.
However, the agency also admits that combined sewer overflows remain a widespread problem. Without testing of drinking water at risk of coronavirus contamination, there is no way to know whether the filtration and disinfectant processes at wastewater treatment plants are working correctly, according to PEER. Meanwhile, water utilities nationwide are anxious about running out of personal protective equipment for workers, and the Trump administration has relaxed environmental enforcement at the EPA in response to the pandemic.
Climate change is also straining outdated wastewater systems as hotter temperatures and intensifying storms bring heavier rainfall, according to PEER Executive Director Tim Whitehouse, who says that the EPA should help local utilities monitor water supplies.
“Given the weaknesses in our general infrastructure, the lack of monitoring, and climate change and heavier rainfalls and the burdens on this system, this certainly should be a priority at the EPA in terms of testing and working with public health departments to test and improve these systems,” Whitehouse said in an interview.
Congress is still debating whether to include billions of dollars for sewer infrastructure upgrades that would reduce combined wastewater overflows in the next COVID-19 stimulus package, but partisan disagreements have stalled the legislation. House Democrats initially pushed for the bill to include $75 billion in water infrastructure spending, including $50 billion for clean water efforts and infrastructure upgrades that would help cash-strapped cities reduce sewer overflow. However, House Speaker Nancy Pelosi indicated last month that the infrastructure spending may have to wait.
On Wednesday, a Senate committee approved a pair of bipartisan bills that would increase funding for a clean water fund for states by $3 billion, providing cities and states with resources for infrastructure projects that would reduce sewer overflow and pollution runoff into lakes and streams, according to Environment America.
Rumpler said lawmakers rejected a loophole that would have allowed some wastewater treatment plants to continue dumping raw sewage at “unacceptable” levels for another decade, but the committee did not include “crucial measures” for removing toxic PFAS chemicals from the water supplies. Industrial polluters are allowed to dump PFAS into public sewer systems, and scientists now say that virtually all major sources of drinking water are contaminated with traces of the persistent chemicals, some of which are linked to cancer and a number of other health risks.
Whitehouse said fixing the wastewater system is expensive because sewers run under streets that must be dug up, so upgrades are difficult for cities with tight budgets to perform on their own. He said robust federal investment in water infrastructure upgrades would help local governments improve wastewater treatment and provide cleaner drinking water while creating large numbers of jobs.
“It’s a really important area that Congress can focus on, and the results will be not only be better drinking water, but fewer sewer overflows and also better public health and more jobs,” Whitehouse said. “This is an area where it’s a win-win-win.”
Correction: This article originally stated that SARS-CoV-2 can persist in human feces for up to 47 days. In fact, researchers detected the virus in the stool of one patient 47 days after the onset of symptoms in one early study, but that is not evidence of how long the virus survives outside the body.