Harwich gets updated wastewater plan from consultant; Pleasant Bay near compliance, town focuses next on recharge and phasing

Jeff S. of GHD presented the town's updated Comprehensive Wastewater Management Plan (CWMP) Monday evening in a joint meeting of the Harwich Select Board and the Board of Water & Wastewater Commissioners.

The presentation outlined the plan's regulatory context: a 2023 state watershed-permit program that expects towns to attain at least 75% of nitrogen removal targets and work toward 100% compliance within a 20-year permit. GHD said Harwich is about 37% toward overall TMDL compliance, a figure the consultant attributed largely to near‑completion of Pleasant Bay work — which GHD said is essentially on track for near‑100% removal when connections are made and systems operate.

Why it matters: the CWMP update sets the town's priorities and cost estimates for additional sewer phases and for identifying locations to treat and recharge treated effluent. Those choices will determine which neighborhoods are sewered first, what residents will pay to connect, and how Harwich meets state permitting deadlines.

What GHD proposed and why: the consultant reviewed a phased approach targeting Herring River, Allen's Harbor and Sacatucket/Sacotucket watersheds in later phases. GHD said centralized sewer collection remains the baseline recommendation because, in its analysis, widespread IA (innovative/alternative) systems would: require substantial per‑property costs, be variable in performance, and impose large monitoring burdens. The presentation also emphasized that a workable strategy depends on identifying recharge sites and securing intermunicipal agreements (for example with Chatham or Dennis) to treat and/or recharge effluent.

Costs and a key leverage point: GHD presented planning‑level cost estimates based on 2025 dollars that include a wide range of possibilities for treatment and recharge. The consultant and administrators stressed that a deal with nearby Dennis for treatment/recharge could dramatically lower Harwich's capital needs (staff used a $75 million placeholder in some materials as a comparative figure versus a notional $132 million standalone treatment plant).

Board and public reaction: select board members, commissioners and residents asked for more detailed review. Concerns included reliance on older baseline water‑use data (GHD noted its figures use 2004'007 and were updated toward 2021/2025), large shifts in phasing maps versus the 2016 plan, the technical and permitting challenge of finding recharge sites (must avoid Zone II drinking‑water protections and satisfy distance/separation requirements), and whether the plan sufficiently modeled summer peak flows and short‑term population surges.

Residents urged alternatives and equity: public commenters pressed the town to model non‑sewer alternatives more aggressively. One resident argued the current approach disproportionately targets higher‑density, lower‑income neighborhoods for sewering while waterfront and large‑lot properties that contribute substantial nitrogen would not be sewered because of cost or distance; he recommended measures such as townwide fertilizer restrictions, urine‑diversion pilots or town‑run collection programs to generate nitrogen credits and share costs more equitably.

PFAS and recharge safeguards: board members insisted any return of treated effluent to Harwich would need PFAS testing and, where necessary, post‑treatment before recharge. GHD and staff said post‑treatment provisions would be required if recharge discharges would affect drinking‑water areas.

Next steps: GHD recommended the town complete the CWMP update, identify and test candidate recharge sites (desktop GIS work followed by borings and load tests), and prepare a watershed‑permit application by the 2030 deadline. Administrators said they are drafting a policy on selling sewer capacity to ensure the town does not commit flow it does not actually have, and several board members requested four separate review sessions dedicated to: growth and flow data, IA system alternatives, phasing, and financing.

The presentation materials and look‑aheads were posted with the meeting packet; staff said they will adjust phasing and cost assumptions as new data or public comment require and will bring revised recommendations back to the board for formal authorization before submission to the state.