The United States Environmental Protection Agency has issued draft regulations that will set maximum contaminant levels (MCLs) for a series of PFAS compounds. Proposed MCLs for PFOA and PFOS are both set at 4 parts per trillion (ppt) which are quite a bit lower than MassDEP requirements. A hazard index will be used to regulate 4 additional chemicals - PFNA, PFHxS, PFBS and HFPO-DA. Test results for all of these compounds are available at https://www.topsfieldpublicworks.org/apps/watertesting/. The draft regulations also include Maximum Contaminant Level Goals of zero ppt for PFOS and PFOA. Ultimately EPA doesn't want to have any PFOS or PFOA in drinking water but there are limitations that prevent this including testing accuracy, removal effectiveness and economics. These considerations are why the proposed MCL is 4 ppt.
Our water typically contains around 5 ppt of PFOA so if the regulations are adopted as proposed then we will have to build a PFAS removal facility or find a PFAS free water source. EPA will set a deadline as to when it has to happen but the Town can move faster. We have not seen an implementation schedule yet but it usually is staggered where large suppliers must comply first, followed by medium sized suppliers and the last group is small suppliers serving less than 10,000 customers such as Topsfield. We'll know more when EPA publishes the final rule later this year.
We've been tracking the PFAS issue since MassDEP proposed their PFAS6 regulations in January 2019. Thanks to a MassDEP grant, we conducted a PFAS removal pilot test at our plant to evaluate several PFAS removal systems. We know a granular activated carbon filter, the most common treatment alternative, works well with our water and can lower PFAS levels to below today's detectable limits. The question is how much treatment to install with the understanding that the ability to accurately test smaller concentrations will improve in the future and regulations will get stricter given EPA's goal of zero ppt of PFOS and PFOA. We've seen this already when the original PFAS tests conducted in 2014 didn't detect any PFOS or PFOA. Removing PFAS to below today's detectable limits does not guarantee future compliance.
Almost ten years ago now, we looked at a number of alternatives to building a manganese removal plant including connecting the Salem & Beverly and the MWRA. Connecting to the MWRA was considered because it solved two problems - got manganese free water and it came from outside the Ipswich River Basin. It was too expensive at the time but it was decided the Town should work towards a regional MWRA connection so that it could be a more reasonable alternative in the future. To that end, the Town has been actively involved in regional planning efforts and in the North Shore Water Resilience Task Force. This group, spearheaded by Senator Tarr, is looking at ways to make additional water resources available to the North Shore, including sharing water between communities and connecting to the MWRA. The Task Force has been working for a couple of years and the next round of study results should be available later this summer.
MWRA is often seen as a permanent solution to this area's water issues. It is an attractive option since it has the largest capacity in the state and their water complies with EPA's proposed regulations. However, there are some drawbacks. There is a cost to transporting water across the state. Locally sourced and treated water tends to be less expensive. The last estimate to connect Topsfield to the MWRA, from about 5 years ago, was 35-40 million dollars in infrastructure costs.
Also, there is the possibility that MWRA is not immune to PFAS problems. MWRA says their water contains only trace amounts of PFAS. This means that some compounds were found but at levels that are too low to accurately quantify. The levels found are greater than zero but less than the detectable limit of 1.7 ppt. MWRA is one of the only, if not the only, large metropolitan surface water supplier in the nation that doesn't filter their water. Unlike the Cambride Water Department, the MWRA can't simply change their filter media to remove PFAS, they'll have to build a plant from scratch.
The bottom line is we're going to need additional treatment or a new water source. Perhaps a temporary PFAS removal system could be installed until a viable regional soution is developed. Either way, we anticipate lots of PFAS discussions later this year and plan to submit some sizable PFAS related FY2025 capital requests.