A sewer assessment is a charge to a property owner for a specific benefit received (a public sewer). It can be up to 100% of the property owner’s proportional cost share of the project’s cost. It can also be subsidized so that the charge is less than 100% of the proportional cost share or capped at a maximum dollar amount. Extending sewer service is necessary to meet federal clean water standards in our estuaries. All residents benefit when the Town’s water resources are protected. Therefore, a shared cost approach is used to equitably fund the costs of building infrastructure to provide sewer service. Under the shared cost approach, a portion of the cost is paid by the sewer assessment charged only to new sewer users; another portion of the cost will be provided by state and federal grants (in the form of subsidized low interest loans and principal subsidies on loans); visitors to the Town will contribute by paying the local room occupancy taxes (including the Cape Cod and Islands Water Protection Fund Excise), and local meals tax; and the remaining portion of the cost will be paid out of the Town’s General Fund. This shared cost approach mirrors the method used to fund previous infrastructure projects. The Sewer Assessment Ordinance is intended to charge property owners who will be connected to new sewer service, as outlined in the Comprehensive Wastewater Management Plan, a fair share of the cost of the infrastructure needed to provide that service. Property owners connecting to sewer service will have the convenience and reliability of modern sewer service without the costs of maintaining and ultimately replacing a Title 5 septic system. Properties connected to sewer service may experience a 6-13% increase in home value1, and an increase in the marketability of the property. In addition, roadways where sewer mains are installed will be repaved. Based on recent studies performed for Mt. Pleasant Township, PA and Old Lyme, CT. Studies are available on the Town’s website at: Revised April 6, 2021

The Sewer Assessment is a charge that will be applied to the owners of properties that have one or more residential or commercial sewer units that are eligible to be newly connected to sewer service under the sewer expansion plan.

A residential sewer unit is defined as the number of dwelling units on a residential lot.
For example, a two (2) family dwelling unit on a residential lot will be assessed two (2) sewer assessments. A commercial sewer unit is defined by the amount of sewer flow on the property based on Title 5 of the State Environmental Code, 310 CMR 15.203, system sewage flow design criteria; whereby every 330 gallons per day of flow equals one (1) sewer unit. A property owner will be charged the same number of sewer assessments as there are residential or commercial sewer units on the property.

The Sewer Assessment does not apply to existing sewer customers in Town, or to any properties that are already eligible to connect to live sewer service, even if they are not yet connected as the sewer system is already available.

The Sewer Assessment represents the allocated cost of the sewer infrastructure that will be serving an owner’s residential or commercial property, as defined in #2 above.

Allocated cost is the sum of (a) 100% of the cost of general benefit facilities (i.e., main trunk lines, pumping stations) divided by the number of properties served by those facilities; and (b) 100% of the cost of special benefits facilities (i.e., adjacent sewer main tied into the main trunk line), divided by the number of properties served by those facilities. The combined cost allocated for the general and special benefit facilities will be capped at $10,000 at the beginning of the program and possibly adjusted for the inflation in construction cost annually thereafter.

The Sewer Assessment represents the lesser of (a) $10,000 or (b) the allocated cost of the general benefits infrastructure and special benefits infrastructure (see #3 above).
The Sewer Assessment does not include the cost of connecting a property to the sewer service located in the street. It also does not include the cost of decommissioning the current on-site system.

However the Sewer Assessment does cover the cost of the first grinder pump per sewer unit on the property, if needed to connect to the sewer system located in the street.

In addition to the Sewer Assessment, a property owner is responsible for the cost to connect their property to the public sewer system located in the street. Connection costs will vary based on property characteristics. It is recommended that property owners obtain at least three bids from a qualified sewer installe

Once sewer service is connected, property owners will be charged a sewer service user fee based on their water usage. The current typical residential sewer usage bill averages around $435 annualy and may vary based on water usage. If the property has irrigation, a property owner can install a deduct meter which will enable the property owner to realize a savings for water that does not enter the sanitary sewage system.

Finally, if the cost of expanding the public sewer system is not assessed 100% to the property owners scheduled to be connected to the system, a General Fund contribution will be required to fund a portion of the program. This results in a portion of a property owner’s property taxes being used to fund the program.

A property owner will be charged the Sewer Assessment when the sewer system serving their respective property becomes live. The Sewer Assessment will be issued at that time whether or not the property is immediately connected to the sewer system.


A property owner can opt to pay the Sewer Assessment all at once when due, or may opt to finance the Sewer Assessment and pay quarterly installments on their property tax bill over thirty years. In accordance with current policy, the Sewer Assessment under the thirty-year payback option would be amortized at an interest rate equivalent to 2% above the rate of borrowing, unless otherwise determined by the Town Council.

If the sewer assessment is added to future tax bills, a lien will be recorded on the property at the Registry of Deeds.

The lien for the sewer assessment may either be transferred to the new owner of the property or paid off at the time of transfer. If financing is involved with the property transfer, this will depend upon the financial institution.

The Board of Health has the authority to require property owners to connect to the public system when it becomes live. The Board of Health also has the authority to allow property owners to delay connecting depending upon their unique circumstances.

If you have a question or circumstance that you believe may necessitate a delay in connecting to sewer service, please call the Town of Barnstable Health Division at 508-862-4644 or email

All properties within the Phase 1 sewer area will be required to connect to sewer service and pay the sewer assessment.

The Board of Health and Department of Public Works are working closely with property owners to avoid situations where new Title 5 systems are installed in areas that will be receiving sewer service. If you have a question about your property, please call the Town of Barnstable Department of Public Works at 508-790-6400 or email

The de-commissioning and/or removal or filling of septic systems will be determined on a property- by-property basis.

This determination will be made at the time the property is being connected to the sewer system.

Connection costs may vary based on property characteristics. See Question #5 above.

Any property owner may opt to pay the Sewer Assessment in quarterly installments and have it added to their property tax bill over thirty years. The property owner may also opt to have the town connect their property to sewer service in the road, in which case the costs of connection also may be paid in quarterly installments over thirty years. See Question #5 above. An abatement process will be available if a property owner believes they were incorrectly charged for a sewer assessment or if the sewer assessment charge is incorrect.

The Town is also exploring the possibility of allowing qualifying homeowners the option to defer their sewer assessment if they meet certain income and asset limits. This would carry an interest charge and the sewer assessment would be paid at the time of a transfer in ownership or refinancing of the property.

If you are already eligible to connect to live sewer service you will not be charged a Sewer Assessment, even if you have not yet connected to sewer service.

The sewer assessments are determined using either a fixed uniform rate or a rate based upon a uniform unit method.

A fixed uniform rate shall be based upon the estimated average cost of all the sewers therein, according to the frontage of such land on any way in which a sewer is constructed, or according to the area of such land within a fixed depth from such way, or according to both such frontage and area. This method is better utilized when building out undeveloped land.

A uniform unit method shall be based upon sewerage construction costs divided among the total number of existing and potential sewer units to be served, after having proportioned the cost of special and general benefit facilities. Each sewer unit shall be equal to a single-family residence. This approach allows the Town to establish a cap on sewer assessments at the beginning of the program resulting in more predictability as to the financial impact to property owners.

The Town of Barnstable received the final Watershed Permit Regulations (314 CMR 21.00), and Title 5 Natural Resource Nitrogen Sensitive Area Regulations (“NSA”) (310 CMR 15.214 and 15.215), on Thursday, June 22, 2023, and is in the process of completing a comprehensive review. Our initial understanding is that the Town’s state-approved Comprehensive Wastewater Management Plan (CWMP) will comply with the requirements of a Watershed Management Plan (WMP) and can be used as the basis for a Watershed Permit. The Town has already reached out to MassDEP and requested a Watershed Permit application form and will apply for a Watershed Permit covering the entire Town of Barnstable, as quickly as we can. We will continue to advise our community  as we advance through the application process and further implementation of the CWMP.