National Pollutant Discharge Elimination System (NPDES) Final Permit – 2022

The Final NPDES Permit (No. NH0100781) defines how the Town of Waterville Valley must manage, treat, and monitor all wastewater discharged from its Advanced Wastewater Treatment Facility into the Mad River, part of the Merrimack River watershed. Issued jointly by the U.S. Environmental Protection Agency (EPA Region 1) and the New Hampshire Department of Environmental Services (NHDES), this permit is the community’s primary regulatory authorization under the federal Clean Water Act.

The permit sets precise numerical limits on the quality of treated effluent—covering parameters such as biochemical oxygen demand (BOD₅), total suspended solids (TSS), nitrogen, phosphorus, pH, and E. coli—to ensure that discharges do not degrade water quality or harm aquatic life. It also introduces new monitoring for PFAS compounds, metals, and toxicity, reflecting the latest federal and state water-quality standards. Compliance requires regular sampling, reporting through EPA’s NetDMR system, and quarterly Whole Effluent Toxicity (WET) testing.

In addition to effluent limits, the permit contains operational mandates: maintaining a qualified operations staff, mapping and maintaining the full sewer collection system, controlling infiltration and inflow, and ensuring standby power for continuous operation. It also outlines schedules for achieving stricter future limits on ammonia and aluminum and specifies how the Town must respond to unauthorized discharges or system upsets.

By codifying these requirements, the NPDES permit protects the Mad River and downstream waters, while giving the Town a clear regulatory framework for planning its major facility upgrade. The standards set here guide every design and construction decision now underway for the new plant, ensuring that Waterville Valley continues to meet the highest environmental benchmarks.