What’s Going On with
Sewers on Cape Cod?

  • Cape Cod is facing a severe nutrient pollution crisis driven by the fact that an estimated 80% of nitrogen loading and 60% of phosphorus loading stems from traditional backyard septic systems, which aren't designed to remove them. Those nutrients flow straight from backyards into the Cape's groundwater, and from there into our ponds, bays, and estuaries, fueling toxic algal blooms that hurt our recreation, environment, and economy.

    Massachusetts finalized a landmark watershed permitting framework requiring all 15 Cape towns to commit to long-term nitrogen reduction plans, meaning cleanup is no longer optional: every town is now bound by a state-approved remediation timeline.

    Cape Cod towns have begun installing municipal sewers near dense village centers and sensitive areas. Depending on the town, properties in less dense or less sensitive areas may either be reached by sewers over time, required to install an “Innovative/Alternative” (I/A) septic system (a large underground installation that uses biological treatment to remove nitrogen on-site), or allowed to keep their Title 5 septic systems.

  • Wastewater management project costs vary widely across the Cape, depending on town populations, development patterns, and watershed pollution.

    Estimated costs range from Truro’s $23.6 million, 20-year recommended plan, to Barnstable’s $1.4 billion, 30-year sewer buildout plan. These estimates do not include costs incurred by individual property owners.

    Cape-wide costs are expected to run into the tens of billions.

  • It depends, and varies by town. There are a few general scenarios:

    Homeowner A: not in a sewer or sensitive area, pays:

    • Any property tax increase levied by the town to fund loans for sewer infrastructure and water treatment

    Homeowner B: in a gravity-line sewered area, pays:

    • What Homeowner A pays, plus:

    • The cost of connection engineering/design/installation

    • The cost of destroying their existing septic system

    • The cost of any plumbing work that must be done to accommodate the sewer hookup

    • The cost of any landscaping work that must be done/redone to accommodate sewer installation

    • The increased water bill

    Homeowner C: in a sewered area requiring a pressured line, pays:‍ ‍

    • What Homeowner B pays, plus:

    • The costs of a grinder pump, which moves wastewater against gravity to the sewer main

    • The potential cost to upgrade their electric system to power the grinder pump

    • The potential cost of a backup generator to power the grinder pumps in the event of a power outage

    Homeowner D: in an area where I/A is required, pays:

    • What Homeowner A pays, plus:

    • The cost of I/A engineering/design/installation (usually runs in the tens of thousands of dollars)

    • The cost of any landscaping work that must be done/redone to accommodate the I/A system.

  • Regulations vary by town, but generally under current regulations, no— and in many places you can face steep fines for noncompliance.

    For financial assistance, the Cape Cod Aquifund is a Barnstable County program offering no-interest and low-interest loans to help residents pay for septic upgrades and sewer connections with up to 20-year repayment terms.

  • There is a category of wastewater management called source separation, which, unlike conventional systems that aim to remove nutrients from wastewater, is simply about preventing most or all of those nutrients from entering wastewater in the first place— with the side benefit of capturing the nutrients for the potential to turn them into fertilizer.

    These solutions are a promising and proven complement or alternative to conventional sewer and septic systems, usually at a fraction of the cost. You may have heard of some types of source separation, like urine diversion or composting toilets.

    Not just for hippies, such systems are common in other parts of the world, but many are currently in regulatory limbo in Massachusetts. We’ll soon add a page here where you can learn more.

Current Wastewater Plans by Town:

  • Bourne's Comprehensive Wastewater Management Plan (CWMP), currently in regulatory review following a draft recommended plan issued in April 2024, takes a hybrid approach to nitrogen reduction across five impaired coastal watersheds. For most of the town — including Megansett-Squeteague Harbor, Phinney's Harbor, Pocasset Harbor, and Pocasset River — the plan calls for widespread installation of Innovative/Alternative (I/A) nitrogen-reducing septic systems, phased in over 20 years and prioritized by proximity to water. Buttermilk Bay is the exception, designated as a Core Sewer Area to be connected to the existing Buzzards Bay Wastewater Treatment Facility once capacity can be expanded, potentially through a regional partnership with Wareham and neighboring towns; I/A systems are proposed as a bridge measure in the interim. Total cost estimates have not been finalized in the official plan documents. The town has not yet filed for a watershed permit, which would determine whether homeowners face a 5-year or 20-year upgrade timeline.

    Further Resources:

  • Further Reading:

  • Sandwich's 2017 Comprehensive Water Resources Management Plan (CWRMP) is structured as a 60-year, three-phase adaptive management program. It takes a hybrid approach, combining a municipal sewer system serving approximately 1,880 parcels with mandatory I/A denitrifying systems for properties in nitrogen-sensitive watersheds outside the sewer area (installed at property owners' expense). Sewered flows will be treated at two new wastewater treatment facilities, one near the Sandwich Industrial Park and one near the Canal Marina, with effluent recharged to groundwater. Phase 1 (infrastructure) is estimated at approximately $86 million (2017 dollars), with non-traditional measures like fertilizer controls adding roughly $580,000 annually in operating costs. Subsequent phases would potentially include a connection to the Joint Base Cape Cod wastewater treatment facility.

    Implementation is underway. The most visible activity currently involves upgrades to the Town's school-based on-site facilities, with the High School/Middle School facility permitted in 2025 and Forestdale and Oak Ridge decommissioning expected in Spring 2026, while the broader municipal sewer program remains in earlier planning stages.

    Further Reading:

  • Further Resources:

  • Barnstable's 2020 Comprehensive Wastewater Management Plan (CWMP) is a 30-year, three-phase sewer expansion plan targeting impaired watersheds across town, with Phase 1 alone adding approximately 90 miles of new sewer infrastructure serving an estimated 4,590 properties. The plan also pursues Innovative/Alternative septic systems, inlet dredging, and cranberry bog conversions. Total estimated cost is approximately $1.4 billion over the full 30-year period, funded through a mix of lodging and meals taxes, sewer user rates, a $10,000 per-property sewer assessment, and potential debt exclusion overrides. Phase 1 is currently underway, with the first two sewer projects completed and the first residential connections made in May 2024; additional Phase 1 projects are actively in construction or design.

    Further Resources:

  • Yarmouth's Comprehensive Wastewater Management Plan is an 8-phase, 40-year project to build a centralized wastewater treatment facility and roughly 174 miles of sewer mains. Phase 1 — focused on the Route 28 corridor and South Shore Drive — was approved by voters at $207 million and is currently under active construction, with the treatment plant expected to be online in early 2027; the total cost across all 8 phases has not been publicly fixed given the long timeline and inflation variables. The project is funded through low-interest state loans, grants, a wastewater enterprise fund, betterment fees, and commercial growth financing, with the stated goal of avoiding a direct hit to residential tax bills.

    Further Reading:

  • Dennis's Comprehensive Wastewater Management Plan calls for an 8-phase, 40-year sewer project serving the Route 28 corridor, Bass River, and Route 134 areas, with wastewater treated at a new treatment facility in South Dennis. Phase 1 is currently under active construction, with three contractors simultaneously installing sewer lines along Routes 28 and 134 and the treatment plant under way.

    Further Reading:

  • Further Reading:

  • Harwich's 2016 Comprehensive Wastewater Management Plan (CWMP) calls for an 8-phase, 40-year sewer project covering approximately 4,950 properties and 74 miles of new pipe, with wastewater treated at a new facility at the Harwich landfill site (HR-12) and, for the Pleasant Bay area, at the regional Chatham treatment plant. The CWMP estimates total capital cost at $226 million (2013 dollars), funded through town bonds repaid via property taxes. Phases 1 and 2 are complete; Phase 3 construction is currently underway. Harwich's CWMP is currently undergoing amendments to reflect updated priorities, funding opportunities, and environmental data.

    Connecting to the sewer system is mandatory within two years for properties along sewer lines, and must be completed at the property owner’s expense. The Board of Selectmen and Board of Health have the authority to enforce the regulations through fines of up to $5,000 per day.

    Further Reading:

  • Chatham's 2009 Comprehensive Wastewater Management Plan calls for a two-phase town-wide sewer expansion and upgrade of the existing Wastewater Treatment Facility. The plan is divided into two phases: Phase 1 (2010–2030) covering the areas with the most critical needs at an estimated cost of roughly $210 million (about $40M for the treatment plant upgrade and $170M for collection system expansion, in 2007 dollars), and Phase 2 (2030–2040) extending sewers to the remaining portions of town. Construction has been actively ongoing, with the town having spent around $118 million so far and additional phases still planned into the late 2020s.

    Connecting to the sewer is mandatory within one year of availability for properties along sewer lines, with limited deferral exceptions, and must be completed at the property owner’s expense. This may be enforced by fines of up to $200 per day.

    Further Reading:

  • Orleans' 2023 Amended Comprehensive Wastewater Management Plan (ACWMP) calls for a 16-phase sewer project covering approximately 60% of homes and businesses over several decades. Phase 1 (Downtown Area) is complete, and Phase 2 (Meetinghouse Pond Area) began construction in July 2023, approved at a total cost of roughly $32.9 million before grants and subsidies from sources including the Cape & Islands Water Protection Fund and the State Revolving Fund. The full buildout timeline extends well into the coming decades across the remaining phases.

    Connecting to the sewer is mandatory for all properties within a sewer service area within one year of receiving a notice to connect, with no exceptions. All connection costs are the property owner's responsibility, estimated at $10,000–$37,000, plus a betterment assessment spread over 30 years on the property tax bill.

    Further Reading:

  • Eastham's Targeted Watershed Management Plan (TWMP) calls for a two-phase sewer project focused on the Nauset Estuary watershed, with Phase 1 serving the Salt Pond and Route 6 corridor and Phase 2 — depending on the feasibility of alternative approaches such as innovative/alternative (I/A) septic systems and a potential regional partnership with Orleans — extending to the Town Cove and Nauset Stream areas; wastewater will be treated at a new facility at the town's Transfer Station/DPW site. Phase 1 estimated capital costs are approximately $131 million (2023 dollars), with Phase 2 adding an additional $140 million if full sewering is required. Town Meeting approved funding for construction on June 23, 2025, with work expected to begin in 2026 and continue for up to three years for Phase 1.

    Further Reading:

  • Wellfleet's 2025 Targeted Watershed Management Plan (TWMP) recommends a hybrid, multi-phase 40-year project, combining a downtown sewer district serving approximately 695 properties with a town-wide program requiring properties outside the sewer zone to upgrade to nitrogen-reducing Innovative & Alternative (I&A) septic systems. Total estimated costs range from $210.2 million (hybrid) to $313.5 million (conventional). The downtown sewer collection system and new water resource processing facility would be sited at the Wellfleet Transfer Station. The TWMP has been submitted to MEPA for environmental review. The town is currently evaluating three alternative sewer district layouts and determining whether to pursue State Revolving Fund financing.

    Further Reading:

  • Truro's 2025 draft Comprehensive Watershed Management Plan (CWMP) is a 20-year, 4-phase plan focusing on the Pamet River, Wellfleet Harbor, and East Harbor watersheds. The Recommended Plan calls for a combination of I/A (Innovative/Alternative) septic systems, cluster systems, and other site and stormwater enhancements, with an estimated capital cost of $23.6 million. Sewering is not part of the Recommended Plan; the more conventional Contingency Plan, which would apply if pilot technologies underperform, does include sewering and carries an estimated capital cost of about $59.9 million. The draft CWMP was published in October 2025 and is currently undergoing public and regulatory review.

    Further Reading:

  • Provincetown's municipal sewer system, built starting in 2000, currently serves approximately half of the town's 2,135 properties. A 2022 Town Meeting vote authorized a Final Sewer Expansion Plan for an estimated cost of $75 million — the largest capital project in town history. The expansion includes a 50% increase in treatment and disposal capacity (adding a third treatment reactor and a satellite facility at the Route 6 soccer field, with effluent disposal relocated to Motta Field), plus sewer system extensions to all currently unserved neighborhoods. Construction is currently underway, with completion targeted by 2030.

    Properties that abut a new sewer main are assessed a betterment, currently estimated at approximately $7,000 per bedroom, and depending on the age of their septic system will generally be required to connect when sewer becomes available.

    Further Resources: