Septic Service in Harwich, MA
Covering Harwich and the surrounding Barnstable County area.
Nitrogen rules and sewer plans in Harwich
Sewer first, septic second
The question that decides your budget in Harwich is not the state rule, it is whether the town sewer reaches your street before the deadline does. A property that gets connected does not need a nitrogen-reducing septic system at all, and the gap between the two outcomes is tens of thousands of dollars.
For Harwich the designation date is July 7, 2023. The requirement to install Best Available Nitrogen Removal Technology (BANRT) began on July 8, 2025, and the upgrade window runs to July 7, 2028.
The designated systems in Harwich
MassDEP designates by estuary system, not by town line. 3 systems are in Harwich are on the list, and a property counts as inside a designated area based on which watershed it drains into.
| Estuary system | Nitrogen TMDL | Designated |
|---|---|---|
| Allen, Wychmere and Saquatucket Harbors Embayment Systems | TMDL Completed, 2016 | July 7, 2023 |
| Herring River Embayment System | TMDL Completed, 2016 | July 7, 2023 |
| Pleasant Bay System | TMDL Completed, 2007 | July 7, 2023 |
- Pleasant Bay System — Pleasant Bay System TMDL For Nitrogen (Total)
- Herring River Embayment System — Herring River Estuarine System TMDL For Nitrogen (Total)
- Allen, Wychmere and Saquatucket Harbors Embayment Systems — Allen, Wychmere and Saquatucket Harbors Embayment Systems TMDLs For Nitrogen (Total)
What the town is building
Harwich has a large sewer construction programme underway alongside the other Pleasant Bay towns.
Harwich is one of the four Pleasant Bay towns.
The Pleasant Bay Watershed Permit, in place since 2018, is the working example the state points to. Four towns share one permit and one nitrogen target rather than each pushing the obligation onto individual owners.
Whether a specific address falls inside a designated area is a question with a definite answer. MassDEP publishes a Natural Resource Nitrogen Sensitive Area map you can check parcel by parcel, and the town is the authority on its own permit status.
MassDEP Nitrogen Sensitive Area map · then confirm the permit position with the Harwich Board of Health.
Local status as of 2026-09-20. Town programmes and permit positions change; the town is the authority on its own.