The Small System Challenge
The EPA defines small water systems as those serving fewer than 10,000 people. Of the approximately 66,000 U.S. public water systems required to comply with PFAS MCLs, the majority are small systems — many of which have limited financial resources, technical expertise, and operator capacity. Small systems that detect PFAS above MCLs may face treatment costs that represent a large fraction of their annual operating budgets.
Rural small systems serving agricultural communities face particular challenges: they may draw from groundwater contaminated by biosolids application or from surface water affected by agricultural runoff, and their customers — often with lower incomes than suburban utility customers — may have limited capacity to absorb rate increases needed to fund treatment.
Right-Sized Treatment Technologies
Granular activated carbon (GAC) systems are well-suited for small systems because they can be sized modularly, are well-understood by utility operators, and are maintainable with standard water treatment expertise. Pre-engineered GAC skid systems are available in configurations from 20 to 200 gallons per minute, appropriate for systems serving a few hundred to several thousand connections.
Point-of-entry household filters — provided by utilities to customers as an alternative to centralized treatment — are being used by some small systems as a cost-effective interim measure. Utilities provide certified RO or carbon block filters to each household and fund filter replacement, distributing treatment cost and avoiding centralized infrastructure investment.
Financial Assistance Programs
State revolving fund programs under SDWA provide low-interest loans to small systems for infrastructure improvements including PFAS treatment. Emergency funding through EPA’s Drinking Water State Revolving Fund Emerging Contaminant set-asides provides grants (not loans) to small and disadvantaged systems for PFAS compliance.
Rural water associations — cooperative organizations that assist small rural systems — are developing technical assistance programs for PFAS treatment selection, procurement, and operation. Federal rural water programs through USDA Rural Development provide additional financing for small rural water system infrastructure improvements. Combining multiple funding sources can make PFAS treatment financially feasible for systems that could not otherwise afford compliance.