CP Implements Solutions to Effectively Reduce the Presence of PFAS in Drinking Water

CP Implements Solutions to Effectively Reduce the Presence of PFAS in Drinking Water

Written by: Matthew Peles, Associate Vice President, and Melissa Caliente, Project Engineer

New PFAS Regulations: What You Need to Know

Earlier this spring, New Jersey’s Department of Environmental Protection (DEP) announced it is in conversations with the federal Environmental Protection Agency (EPA) that will likely dramatically change the landscape of water quality regulation in the state. And while New Jersey has been a leader around PFAS regulation and remediation, we may soon be lagging.

What Are PFAS?

According to the NJ Department of Health, per-and polyfluoroalkyl substances (PFAS) are a “large group of manmade chemicals which repel water and oil and are resistant to heat and chemical reactions.” They are used in a variety of consumer and commercial goods and processes including waterproof and stain-proof coatings, flame-retardant fabrics, fire-fighting foams, leak-proof food packaging, and in the production of non-stick cookware. They are not biodegradable and can stay in the environment and the human body for many years, giving them the moniker “forever chemicals.” The four types of PFAS most often found in human blood samples include:

  • PFOS: perfluorooctane sulfonate
  • PFOA: perfluorooctanoic acid
  • PFNA: perfluorononanoic acid
  • PFHxS: perfluorohexane sulfonate

Why Do PFAS Matter?

PFAS enter drinking water through landfill leaching, sewage treatment plant release, the use of some firefighting foams, and industrial discharge into water, air, or soil. While they have been used in the US since the 1940s, studies now suggest exposure to PFAS can lead to health challenges including high cholesterol, some cancers, decreased antibody response after vaccinations, and low birthweight, increased risk of infection, and developmental problems in young children. PFAS levels in the human body can decrease slowly over time once exposure to the chemicals ends or is reduced.

What Does it Mean for New Jersey?

In 2018, New Jersey became the first state in the country to propose enforceable standards for PFAS chemical levels in drinking water. These standards included a Maximum Contaminant Level (MCL) for PFNA with MCLs for PFOA and PFOS established in 2020. Current MCLs for PFAS in New Jersey include:

  • PFNA 13 ppt (parts per trillion) or ng/L (nanograms per liter)
  • PFOA 14 ppt or ng/L
  • PFOS 13 ppt or ng/L

In an announcement in March of 2023, the US EPA shared its intention to go even further to limit PFAS in drinking water by adopting new standards by the end of the year. These new standards include MCLs of:

  • PFNA 10 ng/L
  • PFOA 4 ng/L
  • PFOS 4 ng/L

Adding:

  • PFBS 2000 ng/L
  • Gen X 10 ng/L
  • PFHxS 9 ng/L

These updates would likely prompt the state to implement these new standards within three years of federal adoption. These changes would mean that drinking water under public or private ownership would be expected to meet the new levels, which may or may not include water systems that have already undergone remediation processes to adhere to the 2018 levels. After the 2018 updates were adopted, 95 individual Public Community Water Systems and Non-transient Non-Community water systems have received at least one PFAS MCL violation as of March 14th, 2023. Sample data on existing PFOA and PFOS suggests that those violations could increase by three or four times under the new standards.

PFAS Remediation Strategies

There are several technologies that have proven effective in reducing the presence of PFAS in drinking water, with new advancements being made constantly. Some of the most effective solutions include:

Granular Activated Carbon (GAC)

GAC is one of the most used measures because it is a tried-and-true method to remove PFAS. It uses activated carbon, a highly porous material made from organic materials, to collect substances like PFAS at the interface between liquid and solid phases. It can be highly effective for larger water demand flows and is also a more accessible option given recent supply chain challenges. GAC is not contaminant specific, and it will remove any contaminant that will absorb to it. The absorption of the additional contaminants will result in more frequent change-outs of the carbon media and oversizing of the GAC vessels. GAC vessels also require periodic backwashing, needing more energy, maintenance, equipment, and space.

Ion Exchange (IX)

Ion exchange is another well tested, high-performing solution to remove PFAS from drinking water. It uses ion exchange resins made up of highly porous, polymeric material that is acid, base, and water insoluble and is effective for removing negatively charged contaminants, like PFAS. It can be more expensive than GAC, but the resins can focus on removing the PFAS, unlike GAC.  It is recommended to backwash the ion exchange media or utilize single-use media, which will need to be replaced frequently. Like GAC, ion exchange uses large tanks.

Reverse Osmosis (RO) and Nanofiltration (NF)

Reverse osmosis and nanofiltration systems use high-pressure membranes to remove PFAS and other impurities from the drinking water.  The process produces clean water but creates a reject stream that contains any contaminants that were in the water stream.  This reject stream must be collected and either treated or discharged, which poses a challenge due to sewage authorities often prohibiting flows with PFAS.  In addition, the membranes will need to be cleaned periodically, which requires space, chemicals, and a second waste stream.  Depending on the level of filtration, consumers may be able to tell a difference in the taste of their water, so some minerals may need to be introduced back into the water prior to entering the distribution system.

CP is working with a technology provider to provide a system for a small lake community in northern New Jersey that will use a nanofiltration system and equipment to treat the reject water from the reverse osmosis/nanofiltration system.  The technology passes the reject water through an aqueous electrostatic concentrator (AEC), which attracts the PFAS chains to the charged surfaces.  The reject water is then free of PFAS contamination and if there are no other contaminants in the reject water, can be mixed with the clean water, allowing for the minerals that were removed earlier to be re-introduced. CP Engineers and the lake community are in the process of obtaining a Temporary Treatment/Pilot Study approval for the system installation.

The filtration membranes and AEC surfaces do need to be cleaned. The cleaning stream is directed to an evaporator and the system discharges a small solid residual, unlike ion exchange, which can create a large amount of waste. Because it doesn’t require the backwashing supply/waste tanks or backwashing pumps needed in GAC, this system can be used in smaller spaces.  The technology works well for this community because space restrictions make it difficult to install the large vessels and backwash equipment needed for other methods.

As these proposed regulations come closer to reality, many organizations throughout the state will be compelled to find the method that is best for their water system. Because the design of each water system is unique, each PFAS remediation approach must be as well. The best solution for your project is one that will be catered to the existing process design and equipment, as well as influent water characteristics.

If you are facing potential challenges with the PFAS levels in your water system, you need expert advice on the best approach. CP Engineers has been transforming challenges into opportunities since 1983, and we have extensive experience working on PFAS removal from wells in northern and central New Jersey. If we can help you navigate the evolving world of PFAS standards, please contact us today.

Sources:

https://www.nj.gov/health/ceohs/documents/pfas_drinking%20water.pdf

https://www.njspotlightnews.org/2023/03/epa-tightens-limits-on-pfas-chemicals-in-water-pfos-pfoa-pfna/

https://dep.nj.gov/pfas/epa-actions/

https://www.epa.gov/sciencematters/reducing-pfas-drinking-water-treatment-technologies