COVID-19 and Beach Water Quality: Updates from the Research Community
Last updated in 2021
As communities across the country experience the threat and disruption from COVID-19, many are wondering what they can do to keep themselves and their families safe. In addition to practicing social distancing, washing hands and spending more time at home, those of us in coastal communities may also seek the solitude, solace and maybe even a wave or two at our local beach. But does spending time in coastal waterways increase your risk of getting sick?
To help answer this question, Surfrider is working to stay abreast of emerging science and community concerns to keep the beachgoing public as informed and safe as possible. An informative Coronavirus Research Update webinar was hosted on March 12, 2020, by the Water Research Foundation. Key takeaways for the beachgoing community, both near saltwater and freshwater, from the webinar and additional research to date are provided below. Presenters included infectious disease experts Jonathan Yoder from the Centers for Disease Control and Prevention (CDC), Dr. Mark Sobsey from the Gillings Schools of Global Public Health at UNC Chapel Hill, and Dr. Lisa Casanova from Georgia State University, among others.
Those interested in taking a deeper dive are encouraged to watch the recorded webinar and check out the additional resources listed at the end of this article. Please note that there is still high uncertainty and this research is ongoing, so information is changing frequently. We will do our best to keep this article updated.
What do we know about the virus?
COVID-19 is a highly contagious disease that started in China but is now considered a global pandemic. The disease is caused by the coronavirus, SARS-CoV-2, which is closely related to other viruses in the coronavirus family that cause respiratory illness and can transfer between species. With seven known coronaviruses, much of the information we have on this virus is from previous research on other coronaviruses assumed to exhibit similar behavior, but research specific to the COVID-19 virus is underway. For now, we know the virus spreads from close, person-to-person contact, mainly through respiratory droplets in the air (after a sneeze or cough), but also through touching contaminated surfaces and then touching your eye, nose or mouth. It’s been documented in all 50 states, and symptoms appear within 2 to 14 days from exposure (though there have also been asymptomatic cases). Roughly 80% of cases are mild with 20% requiring hospitalization. Fortunately the virus is enveloped, meaning it’s highly susceptible to chlorination - so chlorine and bleach are effective at disinfecting contaminated surfaces and water sources.
Does the virus spread through recreational waterways?
The virus has been shown to remain viable and infectious, at least temporarily, in natural freshwater environments including lakes and streams. While dilution is suspected to keep the risk low, high concentrations of the viable COVID-19 virus could put freshwater recreation users at risk. There was no information shared on the ability of the COVID-19 virus to remain viable in saltwater, so it’s unclear if swimming at saltwater beaches elevates the risk of contracting COVID-19. However, communal spread is a serious issue so spending time at popular beaches, if in close contact to other beachgoers, will increase your risk.
How could the virus even get into recreational waterways?
Like many harmful viruses and pathogens, the main exposure risk to the water recreation community is from sewage pollution. The release of raw or undertreated sewage into our surface waterways can cause diseases to spread through the “fecal-oral transmission route.” In other words, when we recreate at the beach during a sewage spill or release of undertreated wastewater, we risk ingesting fecal-borne pathogens that can cause symptoms like stomach upset; ear, eyes, nose and throat infections; as well as more severe infections like E. Coli, MRSA, giardia, hepatitis, and worse.
At this point, the research community does not know if people can contract the COVID-19 virus from exposure to feces in recreational waters but the overall consensus is that it might be possible.* The RNA of the virus was found in stool samples of infected patients, but we do not know if the virus remains infectious after passing through the human digestive system. In order to be infectious, the virus needs both intact RNA and an intact outer envelope- which has not yet been observed by scientists in viruses obtained from stool samples. To note, a preliminary study from Germany indicates that the virus is no longer infectious once it passes through the digestive system (AKA sewage may not be a transmission route) but this study has yet to be peer-reviewed, so additional information is still needed to confirm. For this reason, and the fact that other coronaviruses are susceptible to UV radiation and unable to persist over long periods of time in waterways, researchers stated that the “likelihood of catching COVID-19 from feces seems low,” but additional research is needed to confirm.
Due to the current uncertainty, areas affected by sewage spills, leaks or overflows, or have high numbers of septic tanks, cesspools or homeless populations, could have increased risk for potential transmission of the virus in affected waterways. Local health authorities post warnings to protect public health from exposure to many different harmful pathogens in sewage that can make you sick. Surfrider’s Clean Water initiative strives to protect clean water and to eliminate these sources of pollution that can put public health at risk. Note that cities are already starting to close beaches to prevent the spread of COVID-19 (due to elevated likelihood for person-to-person contact), so please follow city, state and federal recommendations and restrictions. And as always, Surfrider urges you to check your local beach water quality before heading to the beach, as high bacteria is an indication of raw or undertreated sewage in the water. Even if recreating in sewage-polluted waterways is determined not to be a transmission route for COVID-19, it could still expose you to other pathogens which could tax your overall immune system.
Do sewage treatment practices remove or disinfect the virus?
Typical treatments that include sterilization with chlorine and other disinfectants are highly effective at eradicating the virus. However, if you are in a place that uses only primary treatment at your sewage treatment plant, it could be possible that the viable virus might be discharged with effluent into waterways through offshore outfalls or groundwater injection wells. Please note that there are also concerns about biosolids, which are waste solids from treatment plants used as fertilizer, being able to accumulate viruses and other pathogens. Additional research is needed to confirm if current treatment methods for biosolids are able to destroy the virus.
What are best practices to stay safe?
The CDC keeps an updated list of best practices to stay safe. Researchers stressed the fact that community mitigation is key and everyone has a role to play to protect themselves and others. Some key steps include:
- Wash your hands for at least 20 seconds frequently and thoroughly
- If soap and water are not available, use at least 60% alcohol-based hand sanitizer
- Do not touch your face (especially eyes, nose or mouth) with unwashed hands
- Clean frequently touched surfaces often with home cleaning products and then follow with disinfectants that contain either adequate concentrations of bleach or are minimum 70% alcohol-based. Note that you can easily make your own disinfectant for surface cleaning by mixing 4 tsp bleach per 1 quart of water.
- Wash and disinfect your reusable bag after each use
- Stay home if you are sick
- Stay home as much as possible, even if you don't feel sick
- If you choose to go to the beach, check current swim advisories and water quality conditions in your area
- Practice social distancing and avoid large gatherings (greater than 10 people, but this recommendation is changing rapidly as state and cities close down restaurants, bars and theaters to mitigate community exposure)
- Visit this CDC website for daily practices to keep you and your community safe
There’s a lot we don’t know. Please use the following trusted resources to stay up to date.
Everything is happening quickly and the truth of the matter is we don’t know a lot about this virus. Surfrider recommends caution and encourages communities to stay abreast with the latest information and research as things are changing rapidly and ongoing research provides new results: