Issues Of The Environment: COVID-19, Chemicals, And The Ann Arbor Municipal Water Supply
Maintaining water service and safety remains an essential service during Governor Whitmer's "Stay Home, Stay Safe" executive order. In this week's "Issues of the Environment," WEMU's David Fair talks with the manager of Ann Arbor's water treatment services, Brian Steglitz, about managing the system to filter out virus and chemical contamination.
- Water can be a source of many viruses and bacteria that sicken human beings, and there is some evidence that water contaminated with COVID-19 from human waste could taint a water supply. The CDC says the risk of transmission by this route is low.
- The City of Ann Arbor goes to great lengths to ensure that city water is clean and safe to drink, and keeping COVID-19 out of drinking water is no exception. Clean water is also vital for disinfection, and the CDC maintains that washing for at least 30 seconds with soap and warm water effectively inactivates COVID-19.
- The City of Ann Arbor disinfects drinking water prior to delivery to customers. The water treatment plant utilizes multiple steps in our treatment process that physically remove and chemically inactivate viruses and bacteria, including the virus that causes COVID-19.
- Ann Arbor’s water treatment plant is in the process of adding UV disinfection that will allow the city’s WTP to be able to effectively remove a microscopic parasite, Cryptosporidium, from our source water in the Huron River. UV disinfection is also a great tool to address other microbes that may live in the Huron River, and will serve to improve the already high quality drinking water provided to City of Ann Arbor customers.
- In the event that residents do not have access to clean municipal or well water, the CDC suggests that boiling water at a rolling boil for at least 1 minute will inactivate all viruses and pathogens, including COVID-19.
- Brian Steglitz, Water Treatment Services Manager for the City of Ann Arbor, says that the city continuously monitors and adjusts for the disinfection needs of city water. The city is on the forefront of reducing and eliminating PFAS and other toxins, and will ensure that COVID-19 stays out drinking water.
City of Ann Arbor water system staff are focused on continuing to deliver safe water to our customers for consumption and important daily hygiene. During this unprecedented public health crisis, critical services will continue such as drinking water, waste water, police, fire, emergency operations and waste and recycling pickup.
Is Ann Arbor's drinking water safe?
Yes. The City of Ann Arbor disinfects drinking water prior to delivery to customers. We utilize multiple steps in our treatment process that physically remove and chemically inactivate viruses and bacteria, including the virus that causes COVID-19. The U.S. Environmental Protection Agency (EPA) recommends that Americans continue to use and drink tap water as usual. The city continuously monitors and tests our water throughout the treatment process and distribution system to ensure its quality and safety.
Do I need to purchase bottled water?
No. The City of Ann Arbor will continue to deliver safe drinking water to your tap 24/7/365.
What can I do to help prevent the spread of the coronavirus?
Handwashing using tap water is critical to preventing the spread of COVID-19. CDC and other health organizations recommend frequent handwashing for at least 20 seconds each time. Up-to-date information is available via the EPA.
Can the COVID-19 virus spread through drinking water systems?
The World Health Organization has indicated that the “presence of the COVID-19 virus has not been detected in drinking-water supplies and based on current evidence the risk to water supplies is low."
Spring is right around the corner and we are preparing to ramp up for construction season. Planned for this year are several water main improvement projects including:
• Barton Drive Watermain Replacement project between Pontiac Trail and Brede;
• South University Watermain project between State and East University; and
• South Boulevard Watermain project from Packard to the west end of South Boulevard.
In February, City Council approved authorization to begin the Filter Backwash Improvements Project and a bond ordinance to secure a low interest loan to fund the Ultraviolet (UV) Disinfection System Project at the Water Treatment Plant (WTP).
PFAS Filtration Improvements
The Filter Backwash Improvements project is associated with improvements the WTP has made to improve removal of PFAS from our source water. The new filter media (granular activated carbon) the WTP is using is lighter and when this new carbon is washed for reuse, wash water pumps are used to scour particles from the carbon. The lighter carbon can be washed away if scoured too aggressively at too high of a rate. This project will provide provisions to wash the carbon less aggressively and at a lower rate to prevent loss of carbon during the washing process. The city is fortunate that we received a grant from the State of Michigan that will cover 80 percent of the cost of these improvements.
The UV Disinfection System Project is well underway
The UV Disinfection System Project is well underway and is expected to be commissioned this summer. The additional disinfection that this project will allow the city’s WTP to be able to effectively remove a microscopic parasite, Cryptosporidium, from our source water in the Huron River.
UV disinfection is also a great tool to address other microbes that may live in the Huron River, and will serve to improve the already high quality drinking water provided to City of Ann Arbor customers. By funding this project through the State of Michigan Drinking Water Revolving Loan Fund program, the city is able to secure a lower interest rate that we would otherwise not be able to obtain on the open market, allowing for more capital funds to be available for other water system needs.
Lastly, I want to share an update on our research efforts. WTP staff continue to actively be involved in advancing the science of water treatment. Through a partnership with North Carolina State University, city staff are studying how we can optimize our treatment processes for the removal of PFAS. By using a pilot plant, we are able to try different treatment methods on a smaller scale and evaluate multiple techniques and products to remove PFAS. This work is not just focused on those PFAS that the State of Michigan is currently proposing to regulate, but on the larger suite of chemicals in circulation so the city will be well positioned to address contaminants in the future.
Can the COVID-19 virus spread through drinking water?
The COVID-19 virus has not been detected in drinking water. Conventional water treatment methods that use filtration and disinfection, such as those in most municipal drinking water systems, should remove or inactivate the virus that causes COVID-19.
Is the COVID-19 virus found in feces?
The virus that causes COVID-19 has been detected in the feces of some patients diagnosed with COVID-19. The amount of virus released from the body (shed) in stool, how long the virus is shed, and whether the virus in stool is infectious are not known.
The risk of transmission of COVID-19 from the feces of an infected person is also unknown. However, the risk is expected to be low based on data from previous outbreaks of related coronaviruses, such as severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). There have been no reports of fecal-oral transmission of COVID-19 to date.
Can the COVID-19 virus spread through pools and hot tubs?
There is no evidence that COVID-19 can be spread to humans through the use of pools and hot tubs. Proper operation, maintenance, and disinfection (e.g., with chlorine and bromine) of pools and hot tubs should remove or inactivate the virus that causes COVID-19.
Can the COVID-19 virus spread through sewerage systems?
CDC is reviewing all data on COVID-19 transmission as information becomes available. At this time, the risk of transmission of the virus that causes COVID-19 through sewerage systems is thought to be low. Although transmission of COVID-19 through sewage may be possible, there is no evidence to date that this has occurred. This guidance will be updated as necessary as new evidence is assessed.
SARS, a similar coronavirus, has been detected in untreated sewage for up to 2 to 14 days. In the 2003 SARS outbreak, there was documented transmission associated with sewage aerosols. Data suggest that standard municipal wastewater system chlorination practices may be sufficient to inactivate coronaviruses, as long as utilities monitor free available chlorine during treatment to ensure it has not been depleted.
Wastewater and sewage workers should use standard practices, practice basic hygiene precautions, and wear personal protective equipment (PPE) as prescribed for current work tasks.
Should wastewater workers take extra precautions to protect themselves from the COVID-19 virus?
Wastewater treatment plant operations should ensure workers follow routine practices to prevent exposure to wastewater. These include using engineering and administrative controls, safe work practices, and PPE normally required for work tasks when handling untreated wastewater. No additional COVID-19–specific protections are recommended for employees involved in wastewater management operations, including those at wastewater treatment facilities.
- Potential health effects from ingestion of water contaminated with viruses are:
- Gastrointestinal illness (for example, diarrhea, vomiting, cramps), hepatitis, meningitis.
- Sources of viruses in drinking water are:
- Human and animal fecal waste.
- Boiling (Rolling boil for 1 minute minimum) has a very high effectiveness in killing viruses;
- Filtration is not effective in removing viruses;
- Disinfection with iodine or chlorine has a high effectiveness in killing viruses;
- Disinfection with chlorine dioxide has a high effectiveness in killing viruses;
- Disinfection has a high effectiveness in killing viruses when used with iodine, chlorine, or chlorine dioxide.
- Methods that may remove some or all of viruses from drinking water are:
Things to Remember
Please remember that:
- Boiling can be used as a pathogen reduction method that should kill all pathogens. Water should be brought to a rolling boil for 1 minute. At altitudes greater than 6,562 feet (greater than 2000 meters), you should boil water for 3 minutes.
- Filtration can be used as a pathogen reduction method against most microorganisms, depending on the pore size of the filter, amount of the contaminant, particle size of the contaminant, and charge of the contaminant particle. Manufacturer’s instructions must be followed. More information on selecting an appropriate water filter can be found here. Only filters that contain a chemical disinfectant matrix will be effective against some viruses.
- Disinfection can be used as a pathogen reduction method against microorganisms. However, contact time, disinfectant concentration, water temperature, water turbidity (cloudiness), water pH, and many other factors can impact the effectiveness of chemical disinfection. The length of time and concentration of disinfectant varies by manufacturer and effectiveness of pathogen reduction depends on the product. Depending on these factors, 100% effectiveness may not be achieved. Manufacturer’s instructions must be followed.
- If boiling water is not possible, a combination of filtration and chemical disinfection is the most effective pathogen reduction method in drinking water for backcountry or travel use. Manufacturer’s instructions must be followed.
Other treatment methods can be effective against some of the above pathogens:
- Ultraviolet Light (UV Light) can be used as a pathogen reduction method against some microorganisms. The technology requires effective prefiltering due to its dependence on low water turbidity (cloudiness), the correct power delivery, and correct contact times to achieve maximum pathogen reduction. UV might be an effective method in pathogen reduction in backcountry water; there is a lack of independent testing data available on specific systems. Manufacturer’s instructions must be followed.
- MIOX® systems use a salt solution to create mixed oxidants, primarily chlorine. Chlorine has a low to moderate effectiveness in killing Giardia, and a high effectiveness in killing bacteria and viruses. Manufacturer’s instructions must be followed.
Important: Water that has been disinfected with iodine is NOT recommended for pregnant women, people with thyroid problems, those with known hypersensitivity to iodine, or continuous use for more than a few weeks at a time.
In addition to using the appropriate drinking water treatment methods listed above, you can also protect yourself and others from waterborne illness in the backcountry or while traveling by paying attention to good sanitation practices:
- Burying human waste 8 inches deep and at least 200 feet away from natural waters.
- Practicing good personal hygiene. Wash hands before handling food, eating, and after using the toilet.
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