PFAS Leachate Removal Pilot Equipment & Testing

2026-11-03

The selected vendor will provide equipment , labor , and materials for an on - site FF pilot study to remove PFAS from the Facility ’ s leachate . The vendor will contract directly with the City under the oversight of Sanborn Head , the City , and the New Hampshire Department of Environmental Services ( NHDES ). The objectives of the pilot study are to 1 ) evaluate PFAS removal in landfill leachate , and 2 ) develop design parameters for a full - scale treatment system that can effectively remove PFAS from landfill leachate . Leachate is currently discharged to the City ’ s sewer system and treated as wastewater at the City ’ s wastewater treatment plant ( WWTP ). The goal is to remove PFAS regulated by the NHDES including the following compounds ( and precursor compounds that could transform into the four regulated compounds ) which have Maximum Contaminant Levels as indicated below following the compound name : • Perfluorooctanoic acid ( PFOA )– 12 ppt • Perfluorooctane sulfonic acid ( PFOS ) – 15 ppt • Perfluorohexane sulfonic acid ( PFHxS ) – 18 ppt • Perfluorononanoic acid ( PFNA ) – 11 ppt The pilot study will consist of three phases , as outlined below . The combined timeframe of the three phases is estimated to be six weeks . The pilot study system should have the capacity to operate at or above the current average flow conditions ( 16 , 400 gpd ). When excess leachate flow is generated , beyond the capacity of the pilot system , the excess leachate will go through a bypass to the WWTP without PFAS treatment . The conceptual layout of the pilot study site is shown in the figure in Attachment B . Sanborn Head will be responsible for analytical sampling and coordinating with analytical labs during the study . Phase I : Concept Confirmation and Efficiency Evaluation The PFAS treatment efficiency will be initially assessed under the most robust ( i . e ., conservative ) treatment conditions for 24 to 48 hours . This assessment will provide a baseline starting point for optimization testing . One set of leachate samples will be collected for PFAS and geochemical analysis . Phase II : Operation Optimization Robust treatment conditions often entail longer treatment residence time , frequent changeout , and / or high energy consumption . During Phase II , variable conditions will be tested by the vendor to evaluate PFAS removal efficiency . The goal of this test is to identify the operating parameters that are the most sensitive to PFAS treatment efficiency . The vendor should consider the most sensitive parameters based on the leachate characteristics included in Attachment A and include an explanation in the proposal . Different combinations of operating parameters will be tested to identify the conditions that can successfully achieve the desired treatment efficiencies and result in the lowest operation costs . Each of the combinations will be tested for 24 to 48 hours , during which one set of leachate samples will be collected for PFAS and geochemical analysis . The PFAS analysis for the system influent ( untreated leachate ) and system effluent ( treated leachate ) will be expedited to allow the on - time evaluation of the results . Phase I and Phase II should be completed in 1 to 1 . 5 weeks . The correlation among operational conditions , treatment efficiency , and waste generation should be evaluated and established during Phase II . Phase III : Long - Term Operation The optimal operating parameters identified during Phase II will be tested for a longer treatment duration up to 3 weeks . Various samples will be collected to confirm the repeatability and consistency of this treatment . The primary goal is to confirm the removal efficiency and system operation metrics including waste generation rates . The secondary goal is to evaluate potential scaling and clogging conditions that can affect system operation . System pressure and flow rate will be closely monitored during this phase .

New Hampshire

2026-04-28