[HISTORY: Adopted by the Board of Health of the Town of Yarmouth 4-7-1989. Amendments noted where applicable.]
This regulation is adopted by the Yarmouth Board of Health under the auspices of MGL c. 111, § 31.
The purpose of this chapter is to protect the groundwater used for drinking water purposes, lake and pond recharge areas and coastal watersheds from contamination which may result from concentrated sewage disposal.
The groundwater underlying this Town is the sole source of its existing and future water supply, including drinking water, and the groundwater aquifer is integrally connected with and flows into the surface waters, lakes, ponds, rivers, streams and coastal estuaries which constitute significant recreational and economic resources of the Town, used for bathing and other water-related recreation, including shellfishing and fishing.
The foregoing conclusion is confirmed by findings set forth in the Town of Yarmouth Water Resources Protection Study (August 1988) prepared by IEP, Inc.
This chapter shall apply to all proposed subsurface disposal systems with a design sewage flow of 2,000 gallons per day or greater.
The applicant(s) must demonstrate by written report to the satisfaction of the Board that drinking water standards [including five milligrams per liter (mg/l) nitrogen] will be met at the downgradient property limit and that surface water standards will be met at downgradient lakes and ponds (0.05 mg/l phosphorus) and estuaries (0.75 mg/l nitrogen), including but not limited to Lewis Bay, Lewis Pond, Parkers River, Swan Pond, Bass River, Chase Garden Creek, Mill Creek, Mill Pond, Short Wharf Creek, Bass Creek, Clays Creek, Dennis Pond, Little Sandy Pond, Hallets Mill Pond and Long Pond.
The written report shall be prepared by a qualified professional who is acceptable to the Board of Health and be based upon the following scope of work:
Water table map (one-foot contour interval) showing groundwater flow directions.
Projections of downgradient concentrations of nitrogen, using the Board of Health Nitrate-Nitrogen Loading Regulation (or other contaminants as requested by the Board of Health). Projections of downgradient water quality will be determined utilizing two-dimensional solute transport models and input variables approved by the Board of Health.
Currently approved input variables include:
Transmissivity to be determined by on-site slug or pump test.
Aquifer thickness to be determined by on-site boring (location of confining layers and estimated plume thickness).
Dispersivity equals 40 feet longitudinal per 30 feet transverse.
Hydraulic gradient as determined by site-specific water table map.
No retardation factor.
Sewage flows as determined by Title 5 design flows.
Applicants who receive permits under this regulation shall install a minimum of three downgradient and one upgradient multilevel wells placed on the property. Groundwater flow direction will be determined from the USGS (1987) Water Table Map and from site-specific observation wells where necessary. Wells will be constructed of two-inch threaded flush joint PVC with locking caps. Groundwater samples will be obtained on a quarterly basis using standard sampling procedures. Water samples will be tested by a state-certified laboratory quarterly for nitrate-nitrogen, ammonia-nitrogen, Kjeldahl nitrogen, total phosphorus, chlorides, and specific conductance and annually for volatile organic compounds (EPA Analytical Procedure 624) for the first three years of operation. The frequency of sampling will then be reevaluated by the Board of Health. Results are to be reported to the Yarmouth Board of Health and shall meet Massachusetts Class I groundwater standards and appropriate advisory levels for organic chemicals at the downgradient property boundary. In the event that water quality standards are violated, the following actions will be undertaken by the property owner(s):
Report results to Yarmouth Board of Health within 48 hours.
Resample wells and retest within five days.
Notify downgradient property owners within 48 hours.
Decrease wastewater flows or increase level of treatment within 45 days.
Initiate remedial cleanup actions as deemed necessary by the Yarmouth Board of Health.
Nothing within this regulation shall prohibit approval by the Board of Health for any applications involving the maintenance and/or repair of an existing subsurface sewage disposal system, provided that said application does not involve a change of use as defined by Board of Health, Planning Board or Board of Appeals regulations. Where a change of use is involved, the applicant must demonstrate compliance with this regulation.
Variance from this regulation may be granted by the Board of Health only if the applicant can demonstrate to the satisfaction of the Board that enforcement thereof would do manifest injustice, and the applicant must also prove to the Board of Health that the installation of an on-site subsurface sewage disposal system or systems will not have a significant adverse effect on public and/or private drinking water resources, lakes, ponds, rivers, streams or any other body of water.
If applying for a variance, the applicant shall be required to submit, but shall not be limited to, the following items/data: geohydrological report (as noted above); direction of the groundwater flow; depth to groundwater; population density; soil conditions; size, shape and slope of the lot existing and known future water supplies; nitrate and phosphorus loading calculations; and other information deemed pertinent by the Board.
A variance review fee may be assessed by the Board of Health to retain the service(s) of an independent registered civil/sanitary engineer and/or environmental consultant to conduct a review of the submitted variance. The fee will be determined by the Board, based on the complexity of the planned project and subsurface system or systems and the time required to adequately review all plans, reports, etc., along with the expected impact to ground and surface waters. The applicant will pay the fee at the time of the variance request. Any unused portion of the fee shall be refunded to the applicant after the review.