PFAS Treatment: What We Know in 2023

PFAS (formally known as per- and polyfluoroalkyl substances) are widely used, long lasting chemicals that break down very slowly over time. They break down so slowly that they end up in water, air, fish, and soil all over the world, and trace amounts have even been detected in human blood. Scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals, but we do not know to what extent they may affect us.

PFAS possess chemical properties that mean traditional drinking water treatment technologies are not able to remove them. Researchers have been working on a variety of treatment technologies to determine which methods work best to remove PFAS from drinking water. Some of the most successful methods include: activated carbon adsorption, ion exchange resins, and high-pressure membranes. 

Granular activated carbon (GAC) adsorption: GAC has been shown to effectively remove PFAS from drinking water when it is used in a flow through filter mode after particulates have already been removed. According to EPA researcher Thomas Speth, this method can be extremely effective “depending on the type of carbon used, the depth of the bed of carbon, flow rate of the water, the specific PFAS you need to remove, temperature, and the degree and type of organic matter as well as other contaminants, or constituents, in the water.”

Ion exchange resins: Negatively charged ions of PFAS are attracted to positively charged anion resins. Anion exchange resins (AER) have proved to have a high capacity for many PFAS; but this method can be more expensive than GAC. The most promising version of this method is an AER in a single use mode, followed by incineration of the resin. This technology has no contaminant waste stream to treat or dispose due to the lack of need for resin regeneration.

High-pressure membranes: Research shows that membranes, such as nanofiltration or reverse osmosis, are typically more than 90 percent effective at removing a wide range of PFAS. However, these methods generate a large volume of high-strength waste stream which can be difficult to treat or dispose of for a water system. This technology may be better suited for a homeowner since it would generate a much smaller volume of waste.

PFAS Resources:

• Drinking Water Treatability Database
  • The Drinking Water Treatability Database (TDB) can be used to identify effective drinking water treatment processes, to plan for future treatment plant upgrades, to provide information to first responders for spills/ emergencies, and to recognize research needs.
• PFAS Analytic Tools hub
  • This page contains location-specific information related to PFAS manufacture, release, and occurrence in the environment as well as facilities potentially handling PFAS.
• CWA Analytical Methods for Per- and Polyfluorinated Alkyl Substances (PFAS)
  • This page contains information regarding the EPA’s development of new analytical methods to test for PFAS compounds in wastewater, as well as other environmental media.

Focus on Chemical Feed Control

Chemical dosing at the water treatment plant is a critical, but often underrated step in producing safe drinking water. Historically, process control points have focused on the hazards present in incoming source water - with emphasis on the filtration and disinfection steps to minimize microbial risks. But while many hazards do indeed enter the plant with the raw water, it is just as important to identify the multiple risks associated with treating this raw water.   

Spooky Sewers and Things That Go Bump at the Treatment Plant: 2018 Edition

Featured Video: Using Powdered Activated Carbon to Remove Cyanotoxins

In May of this year, the city of Salem, Oregon discovered the state's first-ever algae breach in finished drinking water. Since then, there has been quite a bit of soul-searching, as well as a third-party assessment of exactly what happened and the effectiveness of the water utility's response after the event. In the end, the assessment concluded that the city was not prepared to deal with the public relations fallout, or the more practical matter of helping citizens access emergency water supplies. 

In the meantime, the Oregon Health Authority responded by creating almost unprecedented new cyanotoxin monitoring regulations for systems across the state, and the city of Salem was left to figure out how to cope with what may turn out to be a long-standing threat.

As an emergency measure, the utility started using powdered activated carbon (see video below from Statesman Journal reporter Dick Hughes) but it can cause clogging of the filtration plant.  The city is now also looking into ozone filtration, as well as other improvements including hazard response and crisis communication planning in order to be better prepared to handle future events.  

Drinking Water and Lead Service Lines: Partnering to Protect Human Health

Last month, the Lead Service Line Replacement Collaborative, a group that includes the AWWA, NRWA, ASDWA, NAWC, RCAP and WRF among others, hosted a panel discussion entitled "Drinking Water and Lead Service Lines:  Partnering to Protect Human Health." The focus of this discussion was how partnerships between water utilities and public health agencies are key to helping lead service pipe replacement programs really get off the ground. 

Dr. Lynn Goldman from the Milken Institute School of Public Health started off the discussion by providing historical context, pointing to precedents that allowed lead to be "managed in place" while also allowing higher lead levels in water to be acceptable practice. She explained that when EPA's first Lead and Copper standard (1992) began to improve health outcomes for water consumers, lower-level effects began to be unmasked. This phenomenon, according to Goldman, underscores the importance of enacting revisions to the Lead & Copper Rule, as well as best practices for lead sampling strategies. Goldman emphasized the importance of developing carefully crafted lead pipe removal programs so that more lead isn't released into drinking water supplies during the remediation process.

Other takeaways from the panel of speakers include the following:

• Some communities bear disproportional consequence of lead contamination.
• Lead poisoning can go undetected in individuals, but even low levels of lead affect the brain.
• Action alerts vary state-by-state, but Amanda Reddy from the National Center for Healthy Housing recommends an action level of 5 ug/dL.
• Lead-based paint is the most widespread cause of lead poisoning, but we need comprehensive solutions to address ALL hazards. 
• There are proven & cost effective solutions. In fact, replacing lead service lines for just the children born in 2018 would protect 350,000 individuals from future lead poisoning.
• Solutions must include diverse stakeholders including drinking water professionals, public health officials, elected officials, community leaders and concerned consumers.
• Lead contamination resources need to be easily accessible for individuals affected by lead in their drinking supply. 
• Simply providing bottled water is not a long-term solution.

Public Health representatives from two municipalities (Milwaukee and Cincinnati) also spoke at the forum, and offered their lessons learned:

• Partial Lead Service Line replacement can cause more lead to be released into drinking water supplies. Full line replacement should be the desired strategy, and working with all stakeholders to pass city-wide ordinances requiring full replacement is the most effective way to do this. 
• Developing lead protocols for emergency leaks and repairs is critical.
• City-wide outreach and education/awareness campaigns are a must.
• Prioritizing schools or childcare facilities for line replacement makes sense. 
• Milwaukee used Wisconsin's Drinking Water State Revolving Funds to replace service lines at schools, Cincinnati used a HUD grant to replace service lines for low-income residents.  
• Cincinnati formed a county-level collaborative and pooled resources, technical providers, outreach professionals. They also targeted their outreach to PTAs, Church groups, community organizations. 
• Challenges include: switching out interior plumbing (inside private residences), missing out on targeting some childcare/schools because they are not licensed, and finding the time and resources to communicate effectively with customers. 

Finally, Cathy Bailey, from Greater Cincinnati Water Works, a system that encompasses an area with the second highest child poverty rate and second-highest number of lead lines in the country, offered her perspective. Her system has adopted a 15-year program for full service line replacement, with cost-assistance for low-income residents and cost-sharing arrangements for other property owners. Her advice for water systems? 

• Water Utilities should lead the effort to start the conversation about lead in drinking water and service line replacement. Utilities have a  big stake in this issue. 
• Utilities can be proactive in providing tools and education to their community. Cincinnati provides online resources such as a lead "map' and free lead testing as well as assistance to schools funded by their general operating budget.
• Utilities can be proactive in communicating within their organization. Cincinnati Water Works has an internal dashboard to compile lead test results, health statistics and more. They then can identify homes that qualify for free P.O.U filters. 
• Cincinnati Water Works partners with the health department to share data, understand water quality issues and help individuals and schools mediate problems. 

The panel participant's message was clear: lead service line replacement is simply the right thing to do for communities, and partnerships with health departments and water utilities are critical to that process. Want to find out more? Check out the Lead Service Line Collaborative's online roadmap/toolkit or follow #safewater on Twitter. 

Featured Videos: Invisible Heroes, Minnesota's Drinking Water Providers

This week's featured videos are part of a new series produced by the Minnesota Department of Health showcasing the "invisible heroes" of Minnesota's drinking water supply. In these 3-minute videos, small town water system heroes face and overcome a variety of challenges including contamination, source water shortages and aging infrastructure in order to provide safe, reliable water for their communities. Three of the videos feature small or very small water systems and the innovative strategies and partnerships they have developed to overcome their challenges. 

The first video looks at how the tiny community of St. Martin (pop. 350) has become the first town in the state with a biologically active treatment plant in order to effectively respond to high levels of iron and ammonia in their water. 

The next video explains the unique wellhead protection program developed by the City of Worthington, MN (pop. 13,000). In order to protect the City's drinking water wells from contamination, the city, along with partner Pheasants Forever, created the Worthington Wells Wildlife Management Area. 

And finally, here is a video about how the small city of Fairmont, MN (pop. 10,000) sprang into action when faced with increasing nitrate levels. 

Top 2017 Resources from WaterOperator.org's Bi-Weekly Newsletter

2017 was a great year for the WaterOperator.org newsletter team. We not only reached our 200th edition milestone this past fall, but we also were successful in connecting a significant number of water professionals with useful and relevant resources, resources that could be used on-the-spot to solve pressing issues, or help guide utility best practices, or help water decision-makers plan ahead for their communities. 

While many of the events, articles and resources featured in our newsletters garnered interest, here is a list of our most clicked-on resources of 2017.

• A Water Security Handbook: Planning for and Responding to Drinking Water Contamination Threats and Incidents, US EPA This document provides guidelines for utilities to plan for possible contamination incidents, including sampling, public health procedures, and recovery.
• At the Confluence of Nutrients, Pharmaceuticals and Sustainability: Emerging Issues in Wastewater Management, University of Michigan/Central States Water Environment Association  This presentation discusses the effects of emerging contaminants on wastewater treatment and possible solutions.
• Sampling Guidance for Unknown Contaminants in Drinking Water, US EPA This document provides new guidance to first responders and drinking water utility operators on the collection, storage, and testing of potentially contaminated drinking water when the contaminant is unknown.
• Water Conservation Techniques For Small and Medium Water Systems, Florida Rural Water Association This paper provides thorough descriptions of water conservation measures that have been demonstrated to be effective for small water systems.
  
• The State of Public Water in the United States, Food & Water Watch A compilation of water rates of the 500 largest community water systems in the country (the largest water rate survey of its kind in the country). 
• Emergency Disinfection of Small Water Systems, Washington State Department of Health  Emergency, stop-gap measures to get water quickly to the public in a crisis situation. 

Did you use one these resources at your utility this year? If so, we'd love to hear from you! Do you have a favorite "go-to" resource to share? Again, we'd love to know! Our email is info@wateropertor.org , or connect with us on Facebook or Twitter. 

Common Treatment Deficiencies

This article was first published in the Summer 2012 issue of Spigot News, the Ohio EPA's drinking water program newsletter. Many thanks for allowing us to republish it! You may also be interested in the article Common Source Water Deficiencies.

Ohio EPA conducts sanitary surveys at least once every three years at community public water systems (PWS) and once every five years at non-community PWSs. The purpose of a sanitary survey is to evaluate and document the capability of a water system’s source, treatment, storage, distribution, operation and maintenance, and management. Each of these may favorably or adversely impact the ability of the system to reliably produce and distribute water that meets drinking water standards. 

This article is the second installment in a series of articles to help small water systems identify the most common problems found during a sanitary survey or other investigatory site visit conducted by Ohio EPA staff. The first article focused on source water (well) deficiencies. This article will focus on some of the more common treatment equipment deficiencies which are found during inspections of small water systems.  Future articles in this series will cover distribution deficiencies and other topics. 

Backwash discharge lines: If you have a softener or a pressure filter, you backwash your equipment to clean and replenish the media. The waste that is produced when you backwash discharges into a floor drain or another pipe, which carries the waste to where it will be treated.  If the pipe carrying the backwash wastewater from your treatment equipment is too close to, or even inserted into, the drain or pipe that carries the waste to treatment (see Figure 1), you could end up with back-siphonage.

This could occur if the pipe carrying the waste to treatment backs up and the wastewater is siphoned back into your drinking water treatment equipment, contaminating your treatment equipment with whatever waste the pipe is carrying. Solution: Ensure there is a sufficient air gap between the backwash waste pipe and the floor drain or the pipe conveying the waste to treatment to prevent backsiphonage (see Figure 2). 

Softener tanks, cover, and salt: Softener brine tanks should be kept in sanitary condition. The brine solution should be kept free of dirt and insects. Solution: The best way to accomplish this is to completely cover the brine tanks with an appropriately fitting lid. The lid should not be over- or under-sized and should be kept in place on top of the tank. Also, the brine tank should not be overfilled such that the lid does not fit snug on the tank (see Figure 3).

All substances, including salt, added to the drinking water in a public water system must conform to standards of the “American National Standards Institute/National Sanitation Foundation” (ANSI/NSF).  This is to ensure it is a quality product that will not introduce contaminants into the drinking water. Solution: Ensure the ANSI or NSF symbol can be located on the bags of salt you use or ensure your salt supplier can provide you with documentation from the salt manufacturer that it is ANSI or NSF certified. 

Cartridge filters: Over time, cartridge filters will become clogged with iron or other minerals from your source water. When clogged, the filters become a breeding ground for bacteria. Solution: Ensure filters are replaced in accordance with the manufacturers’ specifications or even more often, depending on the quality of your source water.

General maintenance: Water treatment equipment should be accessible and cleaning solutions and other non-drinking water chemicals and materials should be kept away from the equipment. If treatment equipment is not accessible for Ohio EPA staff to inspect during a sanitary survey, it will not be accessible to the water treatment operator for routine maintenance or during an emergency. Likewise, non-drinking water chemicals stored in close proximity to treatment equipment can be an invitation for a mix-up or, even worse, intentional vandalism (see Figure 4). Solution: Keep clutter and non-drinking water chemicals and equipment away from drinking water treatment equipment. Preferably, these items should be stored in a different room.