[HISTORY: Adopted by the Board of Health of the Town of Nantucket 5-21-2026.[1] Amendments noted where applicable.]
[1]
Editor's Note: This enactment also superseded former Ch. 382, adopted 6-29-1995, and provided an effective date of 7-1-2026.
A. 
To preserve, protect, and manage the quality and supply of fresh water in Nantucket's sole source aquifer, and to protect the health and welfare of the inhabitants of the Town of Nantucket, the following regulations are hereby adopted by the Board of Health of the Town of Nantucket pursuant to the authority granted under MGL c. 111, § 31.
These regulations shall be applicable in that part of the Town of Nantucket known as the area constituting the Wellhead Protection District as delineated on a map entitled "Wellhead Protection District," on Town of Nantucket GIS Maps or as amended by MassDEP. GIS Maps are available for review on-line at https://www.nantucket-ma.gov/151/GIS-Maps.
A. 
As used in this regulation, the following terms shall have the meanings indicated:
ACRE
A unit of land measure equal to 40,000 square feet which is considered a building acre in accordance with standard real estate practices.
CONVENTIONAL SEPTIC SYSTEM
On-site wastewater treatment consisting of septic tank and a leach pit, trench or bed subsurface soil absorption system, which relies on gravity to distribute effluent, and is not a tight tank or innovative alternative system.
INNOVATIVE/ALTERNATIVE (I/A) SYSTEM
Any on-site wastewater disposal system or part of one that differs from the design or construction of a conventional or standard septic system and/or tight tank. A conventional, or standard, system has a septic tank, distribution box or dosing mechanism, a soil absorption system (SAS), and a reserve area.
NITROGEN REDUCING TECHNOLOGY
A MassDEP approved I/A treatment system capable of reducing nitrogen in wastewater to a minimum of 19 mg/liter from an average influent concentration of 40 mg/liter.
SOIL ABSORPTION SYSTEM (SAS)
Part of an on-site system: the area of ground and system of subsurface pipes, leach pit, drip dispersal system, or chambers into which partially treated wastewater from the septic tank or I/A system is discharged for final treatment and absorption by soil. Also called "leach field," "drainfield" or "absorption field."
B. 
All other terms used in this regulation shall be as defined in Chapter 223, Board of Health Administration, Article III.
A. 
All properties currently existing or created which are served by in-ground septic systems and located within the Wellhead Protection District Protection District as defined within these regulations shall not be constructed or reconstructed to receive design flows over 110 gallons per day of effluent for every 10,000 square feet of lot area. Incorporation of a MassDEP approved nitrogen-reducing technology wastewater disposal system shall not increase design flows above 110 gallons per day of effluent for every 10,000 square feet of lot area. The use of area within abutting roads and rights-of-way next to a property shall not be included in calculating the permissible effluent flows for the subject property.
B. 
Existing developed properties shall be allowed to maintain existing design flows permitted under prior state and/or local codes when performing any upgrades or maintenance as required hereunder or as otherwise required by the Board.
C. 
The addition of an accessory dwelling unit (ADU) to a property should use the guidance from MA DEP: Guidance on Title 5 (310 CMR 15.000) Compliance for Accessory Dwelling Units, April 7, 2025, to determine how to comply with Title 5 regulations and to determine if there is a need for a variance from the strict application of these local protection district regulations.
D. 
Properties located within the Wellhead Protection District Protection District and connected to a municipal water service shall not be exempted from compliance with Subsection A of this section.
All soil absorption systems for conventional systems must have a separation distance of at least six feet to groundwater. Nitrogen-reducing technology wastewater disposal systems must have a separation distance of at least five feet of separation to groundwater.
A. 
The owner of any property located within the Wellhead Protection District served by a conventional system shall cause the system to be inspected by a licensed Title 5 Inspector every five years from the date of July 1, 2026, unless the system was inspected within five years prior to the effective date of this regulation in which case, the first inspection following adoption of these Regulations shall be five years after the last inspection was performed. The inspection is to be witnessed by the Board of Health or its agent and inspection report(s) shall be filed with the Nantucket Health Department within 30 days of the inspection.
B. 
Notwithstanding the provisions of Subsection A hereof, all systems shall be inspected as required by Title 5, including:
(1) 
At the time of property transfer;
(2) 
Upon new construction or increase in design flow of the facility served by the system;
(3) 
Upon evidence of breakout or other signs of hydraulic failure; or
(4) 
Upon order of the Board of Health.
A. 
The owner of any property located within the Wellhead Protection District served by a conventional system shall either abandon the system and connect to the municipal sewer system in accordance with Chapter 332, Sewage Disposal and Treatment, Article II; or
B. 
Cause the system to be abandoned and replaced with a MassDEP approved nitrogen-reducing technology wastewater disposal system designed and operated such that the effluent flow does not exceed 110 gallons per day of effluent for every 10,000 square feet of lot area, upon occurrence of any of the following events:
•
System Failure: In the event of system failure documented by a Title 5 Inspection Report and Town of Nantucket Septic System Inspection Report, the entire on-site sewage disposal system shall be brought into full compliance with all applicable State and Local Regulations;
•
New Construction or Structural Alteration or System Expansion: Any proposal for new construction, as defined in Board of Health Regulation Chapter 223, Article III, § 223-13, Terms Defined, on a property with a conventional system. Any property that does not meet current nitrogen loading limitations shall upgrade to the maximum extent feasible; and/or
•
Property Transfer: For property transfers, as defined in Title 5, for properties located within the Wellhead Protection District.
Nitrogen loading credits for greater effluent flows will not be permitted.
*Existing developed properties shall be allowed to maintain existing design flows as described in § 382-3B, above.
A. 
Notwithstanding the provisions of § 382-5.1, the owner of any property located within the Wellhead Protection District served by a conventional system shall cause the system to be abandoned and replaced with a MassDEP approved nitrogen-reducing technology wastewater disposal system designed and operated such that the effluent flow does not exceed 110 gallons per day per 10,000 square feet of lot area of design flow within six months of a system inspection showing that the system is exhibiting hydraulic failure.
B. 
Notwithstanding the provisions of § 382-5.1, the owner of any property located within the Wellhead Protection District served by a conventional system shall cause the system to be abandoned and replaced with a MassDEP approved nitrogen-reducing technology wastewater disposal system designed and operated such that the effluent flow does not exceed 110 gallons per day per 10,000 square feet of lot area of design flow within 12 months of a system inspection showing that the system has groundwater separation distances less than six feet.
C. 
Nothing herein is intended to limit the authority of the Board of Health to require repair or replacement of any system at any time when the Board deems it necessary for the protection of public health, safety and the environment in accordance with Title 5 and/or any other local regulation.
A. 
No certificate of compliance for on-site subsurface sewage disposal systems with one or more nitrogen-reducing technology wastewater disposal system components shall be issued without proof of the following filed with the Nantucket Health Department:
(1) 
Active operation and maintenance (O&M) agreement detailing the following:
(a) 
Service and monitoring of proper system operation;
(b) 
Laboratory testing of effluent at least two times per year;
(2) 
Deed notification of the presence of an innovative/alternative system; and
(3) 
As-built plan stamped by a professional land surveyor, if no changes were made from the approved plan. If changes were made from the approved plan, then a stamp of a professional engineer or registered sanitarian responsible for designing the system is required.
The Board of Health, in its sole discretion, may issue a variance from the strict application of these regulations in accordance with the criteria set forth in Chapter 223, Board of Health Administration, Article I and § 223-9. The Board may, in its discretion, grant a requested variance if necessary to avoid undue hardship for properties that meet the qualifying criteria for affordable, attainable, or year-around housing, as set forth by the Town of Nantucket Housing Department.
Without limiting any other available remedies or penalties, the Board of Health and/or its agent may enforce this regulation as set forth in Chapter 223, Board of Health Administration, Article II.
In the event that any provision of these regulations is declared invalid or unenforceable for any reason, all other provisions will be unaffected and shall remain in full force and effect.