[Adopted 9-14-1999; amended in its entirety 8-16-2022]
A. 
The Town of Lexington has implemented a program to make the sewer system available to all building lots currently within the Town;
B. 
Rapid residential and industrial growth may affect groundwater that reaches drinking water supplies;
C. 
The boundaries of the Town include productive aquifers, surface waters used as a drinking water supply and extensive wetlands that feed into the drinking water supplies of other towns (DEP-designated Zone II areas);
D. 
The Town of Lexington includes many homes which are connected to cesspools or older, inefficient subsurface disposal systems;
E. 
Inadequate treatment of sewage by septic systems may contribute to increased levels of nitrates, bacteria and viruses or hazardous chemicals that can contaminate water supplies; and
F. 
The Town of Lexington, according to Massachusetts Geographic Information Services studies, exhibits high groundwater levels and sandy soils that limit the filtration capabilities of subsurface disposal systems.
All buildings where municipal sewer is available will be connected to the sewer system upon determination of subsurface disposal system failure by a licensed system inspector or by order of the Lexington Board of Health or its agent.
Exemptions to § 155-84 may be allowed under the following conditions:
A. 
The municipal sewer system is not available to the residence. Availability of the sewer system will be based on consideration of the following criteria, including but not limited to: access to the municipal sewer system, proximity to wetlands, geological characteristics of the area and easement requirements. If the pipe serving the building will have to extend more than 30 feet beyond the property line, or if costs for the sewer line exceed 10% of the assessed value of the property, the Board of Health will consider alternative proposals for on-site wastewater disposal for the site.
B. 
There is no increase in design flow to the system involved, or the owner can demonstrate that the public health is protected equally by a new or alternative system with increased design flows, compared with an older system at previous design flows.
C. 
The owner can demonstrate manifest injustice caused by connection to the municipal sewer system compared to the use of a standard subsurface disposal system or alternative system.
D. 
Placement of a sewer line conflicts with the state and Town wetland protection laws or other regulation.
A. 
General requirements. All new on-site sewage disposal systems allowed by the Board of Health shall meet, at a minimum, the standards set forth in Title Five of the State Environmental Code, 310 CMR 15.000, and all additional conditions required by the Board of Health to protect the public health.
B. 
Soil evaluations and percolation tests. Prior to the installation of all disposal systems, complete soil evaluations and percolation tests, as required by 310 CMR 15.000, shall be carried out. The Board of Health or its agent must witness, approve and sign the soil evaluation, and a copy of the study must be submitted to the Board of Health.
C. 
Garbage grinders. Garbage grinders may not be connected to a subsurface disposal system.
D. 
Private wells.
(1) 
Private wells for irrigation or drinking water must meet the following setback limitations from subsurface disposal systems:
(a) 
Septic tank: 75 feet.
(b) 
Soil absorption system: 150 feet.
(c) 
Distribution box: 75 feet.
(d) 
Building sewer: 50 feet.
(2) 
Where, in the opinion of the Board of Health, hazardous conditions exist, the above distances may be increased.
E. 
Subdivided lots. Subdivided lots must be connected to the sewer system.
For all inspections of subsurface disposal systems, a state-licensed inspector shall use the methods noted in 310 CMR 15.00 for seasonal high groundwater determinations. The Board of Health may, at its discretion, require additional tests to determine seasonal high groundwater levels.
A. 
No installation of an on-site sewage disposal system may be carried out without prior plan review and approval by the Board of Health.
B. 
System installers must be licensed by the Town of Lexington through the Board of Health. Licenses will be issued on an annual basis.
C. 
The Board of Health must approve all plans for on-site disposal system designs prior to system installation. Following completion of the system, and prior to issuance of a certificate of compliance, the installer must provide an as-built plan to the Board of Health for approval, to be kept on file for a minimum of three years.
D. 
Alternative systems. The Board of Health may consider alternative on-site disposal system designs to those described under Title Five of the Environmental Code. The Board of Health will approve only those alternative designs accepted by the Department of Environmental Protection.
E. 
The Board of Health may establish any special conditions necessary to ensure adequate protection of public health and safety and the environment and to ensure appropriate evaluation, inspection, maintenance, repairs and replacements. Such conditions may include, without limitation, flow limitations, monitoring, inspections, maintenance, testing and reporting requirements, a requirement that a certified operator operate the system and financial assurance mechanisms.
F. 
The Board of Health may also require additional information and studies to be performed at the site, or adjacent to the site, such as:
(1) 
Hydrological studies and calculations for the mean annual, 10-year and 100-year storm incidents. High water determinations and the corresponding hydrological calculations for these events must be submitted.
(2) 
Water quality studies and analyses.
(3) 
Other studies and analyses related to the design and performance of the proposed system.
G. 
New construction. The Board of Health will not approve alternative systems for new construction unless the lot involved can also support a system that is fully compliant with Title Five of the State Environmental Code, without variance. The area on the lot where a standard septic system might be placed must not be built upon or covered with an impermeable surface.
A. 
Site and plan evaluations. The Board of Health shall assess fees for witnessing of soil evaluations and percolation tests, for system inspections and for outside expert review of preliminary and as-built plans. The owner of the lot, contractor or other agent required to comply with this regulation will be responsible for these costs.
B. 
System installers. The Lexington Board of Health will set fees for licenses that the Board will issue to system installers on a yearly basis.
C. 
Expert review. Upon request of the Board of Health, applicants seeking a permit to construct a new sewage disposal system shall deposit a sum specified by the Board of Health in a special account as described under Article VII, Establishment of Special Accounts, of this chapter. Fees and other expenses for the hiring of consultants, groundwater determinations, review of proposed designs, site evaluations and any other evaluations required by the Board of Health for review of the system design will be deducted from this account. Upon completion of the project, any remaining money will be returned to the applicant.
Every septic tank, tight tank, or cesspool shall be pumped whenever necessary to ensure proper functioning of the system. Pumping is required whenever the top of the sludge or solids layer is within 12 inches or less of the bottom of the outlet tee, or the top of the scum layer is within two inches of the top of the outlet tee, or the bottom of the scum layer is within two inches of the bottom of the outlet tee. Pumping frequency is a function of use, although pumping is typically necessary at least once every three years, and is recommended annually for a system with a domestic garbage grinder. All cesspools must be pumped yearly. The septage hauler must submit to the Board of Health a report of the maintenance service, including the address at which the service was given, name of system owner, date and a description of the maintenance services provided.
A. 
System failure.
(1) 
The Board of Health will find a system to be failing following an inspection by a state-licensed inspector and a determination that one or more conditions described in 310 CMR 15.303 or 15.304 of Title Five of the Massachusetts Environmental Code exists, or the Board of Health or its agent identifies one of the conditions described below.
(a) 
The system is in an environmentally sensitive area as defined in the Town's septic management plan, or in a protected wetlands resources area as defined in the Wetlands Protection Act, MGL c. 131, § 40, and Chapter 130, Wetland Protection, of the General Bylaws.
(b) 
Placement of system within a 100-year flood zone, based on the available flood profile data prepared by the Federal Emergency Management Agency (FEMA).
(c) 
The system was pumped out more than two times in a 90-day period.
(d) 
Any other condition deemed by the Board of Health to require an upgrade, repair or replacement of the subsurface disposal system as allowed under 310 CMR 15.025.
(2) 
Minor repairs (e.g., replacement of cap or inlet tees) may be carried out with approval of the Board of Health.
B. 
Correction of failing systems. If the Board of Health determines that a system fails to protect the public health, the owner must repair, upgrade or connect the system to the sewer within a period designated by the Board of Health or within two years. Failure to comply with an order to correct a failing system may result in fines in accordance with MGL c. 111, § 31, 105 CMR 15.026(4) and Chapter 130, Wetland Protection, of the General Bylaws. Failure to comply with such an order may also result in the declaration of the property as uninhabitable, as defined under 105 CMR 410.750 and 410.831, Minimum Standards of Fitness for Human Habitation (State Sanitary Code, Chapter 11).
C. 
Inspection reports.
(1) 
Licensed system inspectors must submit inspection reports to the Board of Health within 10 working days after completion of the inspection.
(2) 
System inspectors must notify the Lexington Board of Health at least two business days prior to carrying out an inspection on a subsurface disposal system in the Town.
(3) 
Failure to have an inspection carried out on a property as required by 310 CMR 15.300 may result in fines against the property owner under the provision of 310 CMR 15.026(4).
A. 
After connection of a home to the municipal sewer system, or if the Board of Health permits replacement of a system, the owner must abandon the original system. The homeowner must have the septic system or cesspool disconnected from the building it served in accordance with the State Plumbing Code and have the cesspool or septic tank destroyed or made unusable by filling in the tank. Metal tanks must be removed from the ground and disposed of by the homeowner or his or her representative. Building owners will be held responsible for final abandonment of the original subsurface disposal system.
B. 
At the time of system abandonment, both property owner and contractor must sign a Board of Health approved form attesting to completion of the system abandonment.
The Board of Health may allow a variance to any provisions of these regulations when, in its opinion, the enforcement thereof would do manifest injustice and the applicant has proved that the same degree of environmental protection required by these regulations can be achieved without strict application of the particular provision.
As used in this article, the following terms shall have the meanings indicated:
ALTERNATIVE SYSTEMS
Systems designed to provide or enhance on-site sewage disposal systems which either do not contain all of the components of an on-site disposal system constructed in accordance with 310 CMR 15.000 or which contain components in addition to those specified in 310 CMR 15.000 and which are proposed to the local approving authority and/or the Department of Environmental Protection for remedial, pilot, provisional or general use approval pursuant to 310 CMR 15.280 through 15.289.
BUILDING SEWER
A pipe that begins outside the inner face of a building wall and extends to an on-site system or municipal or private sewer.
CESSPOOL
A pit with open-jointed linings or holes in the bottom and/or side walls into which raw sewage is discharged, the liquid portion of the sewage being disposed of by seeping or leaching into the surrounding soils, and the solids or sludge being retained in the pit. Cesspools are nonconforming systems.
DEEP OBSERVATION HOLE
An open pit dug to permit examination of the soils and to obtain data relative to the mean annual high groundwater elevation.
DISPOSAL SYSTEM INSTALLER
A person, licensed in accordance with 310 CMR 15.019, who constructs, repairs or replaces an on-site subsurface sewage disposal system.
DISTRIBUTION BOX
A level, watertight structure that receives septic tank effluent and distributes it in substantially equal portions to distribution lines in a soil absorption system.
FAILED SUBSURFACE SEWAGE DISPOSAL SYSTEM or FAILED SYSTEM
A system that fails to protect public health and safety or the environment, as set forth in 310 CMR 15.303 or 15.304.
GROUNDWATER
Water found in cracks, fissures and pore spaces in the saturated zone below the ground surface, including but not limited to perched groundwater.
HIGH GROUNDWATER ELEVATION
As determined in accordance with 310 CMR 15.103, 15.104 and 15.107. For inland areas, the elevation above which, in eight out of 10 consecutive years, the groundwater table does not rise. This elevation is commonly, but not invariably, reached during the months of December through April.
MAINTENANCE
All activities required to assure the effective and continuous operation and performance of an on-site system, including but not limited to solids and scum removal from the septic tank, re-leveling the distribution box and the upgrade of one or more of the system components, all as more fully described in 310 CMR 15.201 through 15.422.
NEW CONSTRUCTION
The construction of a new building for which an occupancy permit is required or an increase in the actual or design flow to any nonconforming system or to any other system above the existing approved capacity. New construction shall not include replacement or repair of an existing building totally or partially destroyed or demolished if there is no increase in flow or no increase in flow above the existing approved capacity for any system.
ON-SITE SEWAGE DISPOSAL SYSTEM or SUBSURFACE DISPOSAL SYSTEM
A system or series of systems for the treatment and disposal of sanitary sewage below the ground surface on a facility. The standard components of a system are: a building sewer; a septic tank to retain solids and scum; a distribution box; a soil absorption system containing effluent distribution lines to distribute and treat septic tank effluent prior to discharge to appropriate subsurface soils; and a reserve area. These terms also include tight tanks, shared systems and alternative systems. Unless the text of 310 CMR 15.000 indicates otherwise, these terms also include nonconforming systems.
RESERVE AREA
An area of land with demonstrated capacity for subsurface sewage disposal on which no permanent structure shall be constructed and which is intended for siting of a replacement of the principal system should it fail.
SEPTAGE HAULER
A person licensed by the Lexington Board of Health to remove septage from on-site sewage disposal systems and transport it to an approved disposal location in accordance with 310 CMR 15.500.
SEPTIC TANK
A watertight receptacle to receive sewage from a building sewer which is designed and constructed to permit sufficient retention of wastewater to allow for the separation of scum and sludge and the partial digestion of organic matter before discharge of the liquid portion to a soil absorption system.
SOIL ABSORPTION SYSTEM
A system of trenches, galleries, chambers, pits, fields or beds together with effluent distribution lines and aggregate which is installed in appropriate soils to receive effluent from a septic tank and transmit it to the soil interface for treatment in a biological mat and disposal to the underlying soils.
WETLAND
Any land area or surface area so defined by the Massachusetts Wetlands Protection Act, MGL c. 131, § 40, and regulations promulgated pursuant thereto at 310 CMR 10.00 or pursuant to § 404 of the Federal Water Pollution Control Act, 33 U.S.C. § 1341, or as defined in the local bylaw.[1]
ZONE II
That area of an aquifer which contributes water to a well under the most severe pumping and recharge conditions that can realistically be anticipated, as defined in Massachusetts drinking water regulations, 310 CMR 22.02.
[1]
Editor's Note: See Ch. 130, Wetland Protection.