By Bart Fischer, Sr Public Administrator, WSB

People often don’t think about drinking water. They turn their tap on or buy a bottle of water and move on with their day. But safe, clean drinking water is vital to a community. In recent years, communities have been faced with many water challenges ranging from contamination to drought. In honor of Drinking Water Month, Bart Fischer, Sr. Public Administrator, explores these challenges.

Q: What are some of the biggest challenges communities face in terms of drinking water supply management?

A: It seems that the biggest challenges are always unexpected and are mostly out of our control. Between drought and contamination issues, cities are learning to expect the unexpected.

In recent years, one of the biggest challenges has been water supply. Last summer, many communities across the U.S. experienced severe drought – resulting in higher demand for water. Some communities were on the verge of running out of water and couldn’t keep enough water in their water towers to provide adequate water pressures and fire protection. The drought really tapped a lot of communities. A shortage of water supply is causing many communities to explore water reuse options and alternative water sources while trying to conserve water at the same time.

Q: Yes, it was certainly dry last summer. What are some creative ways cities are working to solve the water shortage issue?

A: Weather patterns are cyclical every year, but the number of extreme weather events has an impact on water supply. Many communities are exploring new water sources, water reuse systems, and educating the public on the need to conserve water. Twenty years ago, we talked a lot about water conservation efforts. Since then, our appliances such as dishwashers, faucets and washing machines have become more efficient, but there are still ways individuals and communities can work together to conserve water.

Q: There have been a lot of articles in the news about PFAS – how do they get into our water supply and how can we mitigate it?

A: Per- and polyfluoroalkyl substances, commonly referred to as PFAS, are synthetic chemical compounds that are found in water, air and soil. They are widely used chemicals found in commercial and industrial products that break down very slowly over time and are sometimes called forever chemicals because they don’t stick to sediments in the groundwater and get filtered out naturally in the environment before reaching ground water sources. PFAS are being detected more frequently than in the past, mainly due to lower laboratory detection limits. Environmental Protection Agency (EPA) studies indicate that they can be harmful to our health when consumed at concentrations that are above the EPA and Minnesota Department of Health (MDH) recommended health risk values and for extended periods of time. Environmentalists are working to better understand the risks and impacts these chemicals have on our environment and people. The good news is that technology has advanced, and we can detect, mitigate and reduce the level of PFAs in our drinking water supply.

Q: So, are the presence of any PFAS dangerous?

A: Not exactly. A big challenge for communities is that many residents assume that any trace of PFAS in their drinking water means that their water is contaminated. The public may not understand maximum contaminant levels, health risk limits, or concentrations – they just know that there’s something in their water that they should not be drinking. Technology has advanced, and we’re now able to measure down to the parts per trillion for many contaminants. This was not the case in the past. MDH has established recommended health risk limits and health indexes that account for the most commonly detected PFAS compounds in the environment. The associated long-term health risks and understanding these maximum levels is important for the general public to understand what is dangerous and what is not. 

Q: What can communities do to ensure their residents feel safe drinking city water?

A: It’s about education. MDH is creating a statewide PFAS online dashboard that will soon be available to the public. Seeing any trace of contamination in water could cause concern for residents without any baseline knowledge or understanding of safe PFAS levels. Proactive community outreach can help alleviate any potential resident concerns in the future.

In general, water supply is deeply impacted by mother nature and human activities. WSB’s team of water and wastewater engineers support our communities when the unexpected, anticipated, specific or special circumstances arise.  Learn how we support our communities’ water needs here.

The Minnesota Pollution Control Agency (MPCA) and Minnesota Department of Natural Resources (DNR) recently released their $700 million plan for improving the drinking water supply in 14 communities that are currently dealing with unsafe levels of perfluoroalkyl and polyfluoroalkyl substances (PFAS) in their water. The government’s plan includes building or expanding:

• Six new water treatment plants
• Treating 33 municipal wells
• Connecting 296 homes to municipal water systems
• Providing home water filtration systems to homeowners with private wells

WSB was fortunate to be involved with the city of St. Paul Park to help them find a solution to increasingly dangerous PFAS levels in their community. In June of 2018, the Minnesota Department of Health informed St. Paul Park that the PFAS levels in two of its three water wells was exceeding the recommended levels that are safe for public consumption. WSB partnered with the city to design a water treatment facility and remove PFAS from the community drinking water and surrounding environment.

PFAS are a family of manmade chemicals that do not naturally decompose due to their heat and water-resistant structure. Studies have found that consuming drinking water with elevated levels of PFAS, overtime, can be associated with high cholesterol, reduced immune response, thyroid disease, kidney cancer and other distressing health problems.

After completing a rapid column filtration pilot study, acid-washed granular activated carbon filtration was selected as the most feasible, long term solution to treat PFAS in the city’s drinking water.

1. Steel pressure filtration vessels contain granular activated carbon filter media that facilitate the transfer of contaminants onto the media as the liquid stream passes through the vessels.
2. When the contaminant level in the carbon bed reaches the saturation point, the carbon is removed and regenerated at an off-site facility or disposed.
3. After the media becomes fully absorbed with PFAS, the media is removed from the vessel and refilled with high quality activated carbon.

The project utilized an innovative modeling software, Matterport, to video scan the interior of the plant and provide a three-dimensional layout. This model allows city staff to provide accurate virtual tours of the plant remotely. Matterport also serves as an asset management tool for storing critical operations and maintenance data for each piece of equipment inside the plant. This innovative tool allows staff supervisors to reference and provide instructions to their teams from a remote location. Leveraging Matterport software ensures important equipment data, plant drawings, and schematics can be accessed from any location with Wi-Fi or internet connection.

Great emphasis was placed on the design to protect the environment and provide a sustainable facility. The plant produces almost no emissions that affect the environment other than space heating during the winter months. Nearly no wastewater will be emitted from the plant in the long term other than discharging backwash wastewater into the sanitary sewer system about once every two to three years when the filter media is exchanged for new media. On site, a large oak tree situated about 20 feet from the plant was preserved during construction. Since the plant was constructed in a city park, all areas that were affected by construction were restored with landscaping and grass that creates a natural flow to the surrounding athletic fields.

Since the plant was placed into service, no PFAS contaminants have been detected in the effluent water that is distributed to city customers. The quality of the drinking water has been excellent and exceeds all drinking water and health standards.