How much does septic replacement cost on Cape Cod?

The short answer

There is no official price list for septic replacement on Cape Cod, and MassDEP does not regulate what contractors charge. We are a referral service, not a contractor, so we do not quote prices. What we can do is show you the published, sourced figures that exist and what drives them.

• Nitrogen-reducing (I/A) retrofit of an existing Title 5 system: $40,000–$45,000 "all-in" for a home up to 4 bedrooms, per one contractor quoted in a Town of Falmouth task force presentation (Oct. 7, 2026).
• New system with an I/A tank and leach field: $60,000–$70,000 "all-in", same source and home size.
• Two nitrogen-removal technologies, installed: $17,000–$36,000, as reported in MassDEP's 2023 FAQ, which also mentions a homeowner reporting full-system quotes of $60,000–$90,000.

These are reported figures from specific sources and dates, not quotes for your house. Falmouth's own task force notes it received cost data from only two contractors.

Sources: Town of Falmouth task force presentation (10/7/2026); MassDEP FAQ (6/16/23).

Before you pay for a replacement in Harwich

1. Check whether it must be an I/A system. Under the 2023 Cape nitrogen rules the I/A requirement is suspended in watersheds where the town has filed with MassDEP; see Harwich's watershed-by-watershed status. The Board of Health decides what a replacement must meet.
2. Check whether sewer is coming. Harwich's Board of Health has a waiver form for properties in areas to be sewered: the parties agree to connect to sewer once it's available instead of upgrading the septic system (the form lists a $125 filing fee, and an upgrade is still required if the system becomes a threat to public health). See the Harwich sewer connection guide.
3. Find out if a repair is enough. A cracked tank, broken pipe, uneven D-box or bad pump chamber can get a Title 5 conditional pass and be repaired; leach fields and cesspools cannot. See septic repair.
4. Line up financing early. AquiFund loans, the state septic tax credit and MassHousing loans are explained in how Cape homeowners pay for the fix.
5. Get more than one written quote and a written contract with the work plan, cost and payment terms, as Mass.gov's consumer tips recommend.

Request a call back from a local septic provider

Tell us your town and what is going on. We work on matching your request with an independent septic provider serving your area, who must hold the required town permit and contacts you directly. There is no charge to you for the referral.

Harwich Septic Help is a free referral service. We are not a septic company and do not pump, inspect, or repair systems. When you call or send a request, we work on matching you with an independent local septic provider, who must hold the required town permit and may pay us a referral fee. Prices, licensing, scheduling and work are between you and that provider.

Call-recording notice: Calls to our number may be recorded to route your request and for quality. A recorded greeting tells every caller this before the call is connected.

For a sewage backup, call instead of using the form: (508) 593-9460.