System Sewage Flow Design Criteria

(1) Each component of an on-site subsurface sewage disposal system shall be designed to treat sanitary sewage discharged from all buildings to be served by the system using the System Sewage Flow Design flows set forth at 310 CMR 15.203(2) through (5), except as provided in 310 CMR 15.203(6). Actual water meter data shall not be substituted for the design flow criteria for the activities listed in 310 CMR 15.203(2) through (5) unless pursuant to 310 CMR 15.416. Design flow is equivalent to estimated generated flow for the proposed use plus a factor representing flow variations. MINIMUM ALLOWABLE GPD FOR GALLONS SYSTEM TYPE OF ESTABLISHMENT UNIT PER DAY DESIGN (2) RESIDENTIAL Bed & Breakfast per bedroom Bed & Breakfast per bedroom with restaurant open per seat to public add Camp, resident, mess hall, per person* washroom and toilets Camp, day, washroom per person and toilets Camp, day, mess hall, per person washroom and toilets Campground, showers and toilets per site Family Dwelling, Single per bedroom 330** including, but not limited to, single family condominiums & cooperatives Family Dwelling, Multiple per bedroom *** Family Mobile Home Park per mobile home Motel, Hotel, Boarding per bedroom House Retirement Mobile Home Park per site Housing for the Elderly per two bedroom unit 150**** Work or Construction Camp per person * Person in the context of 310 CMR 15.203 means an individual. ** A system may be designed for flows of not less than 220 gpd, if a deed restriction essentially identical to the model Grant of Title 5 Bedroom Count Deed Restriction developed by the Department, is provided that limits the dwelling to two bed rooms as the term "bedroom" is defined in 310 CMR 15.002. A home office or home retail business whose only employees reside in the home, where no additional wastewater is generated other than toilet and hand washing waste, is not considered a change in the type of establishment and does not require the addition of flow for the purpose of designing the system. *** The number of bedrooms in a condominium shall be as specified in the Master Deed. Establish- ment of bedrooms in excess of the specified number shall be considered an increase in design flow. A home office or home retail business whose only employees reside in the home, where no additional wastewater is generated other than toilet and hand washing waste, is not considered a change in the type of establishment and does not require the addition of flow for the purpose of designing the system. **** One bedroom unit Housing for the Elderly, and units with more than two bedrooms shall be designed based on 110 gallons per day per bedroom. (3) COMMERCIAL Airport per passenger Barber Shop/Beauty Salon per chair Bowling Alley per alley Country Club, dining room per seat Country Club, snack bar or lunch room per seat Country Club, lockers and showers per locker Doctor Office per doctor Dentist Office per dentist MINIMUM ALLOWABLE GPD FOR GALLONS SYSTEM TYPE OF ESTABLISHMENT UNIT PER DAY DESIGN (3) COMMERCIAL (continued) Factory, Industrial Plant, per person Warehouse or Dry Storage Space without cafeteria Factory, Industrial Plant, Warehouse or Dry Storage Space with cafeteria per person Gasoline Station per island***** with service bays per bay ***** Plus flows for bays, if any Kennel/Veterinary Office per kennel Lounge, Tavern per seat Marina per slip Movie Theater per seat Non-single family/ per washing automatic clothes washer machine Office building per 1000 sq.ft. Retail Store (except supermarkets) per 1000 sq.ft. Restaurant per seat Restaurant, thruway per seat service area Restaurant, Fast Food per seat Restaurant, kitchen flow per seat [for sizing of grease trap only] Service Station per bay [no gas] Skating Rink per seat Supermarkets per 1000 sq.ft. Swimming Pool per person Tennis Club per court Theater, Auditorium per seat Trailer, dump station per trailer (4) INSTITUTIONAL Place of worship without kitchen per seat with kitchen per seat Correctional Facility per bed Function Hall per seat Gymnasium per participant Gymnasium per spectator Hospital per bed Nursing Home/Rest Home per bed Assisted Living Facilities per bed Public Park, toilet per person waste only MINIMUM ALLOWABLE GPD FOR GALLONS SYSTEM TYPE OF ESTABLISHMENT UNIT PER DAY DESIGN (4) INSTITUTIONAL (continued) Public Park, bathhouse, per person showers and flush toilets Day Care Facility per person (5) SCHOOLS****** Elementary School, without cafeteria, gymnasium or showers per person Elementary School, with cafeteria but no gymnasium with showers per person Elementary School, with cafeteria, gymnasium and showers per person Secondary/Middle School, without cafeteria, gymnasium or showers per person Secondary/Middle School, with cafeteria but no gymnasium or showers per person Secondary/Middle School, with cafeteria, gymnasium and showers per person Boarding Schools, Colleges per person ****** All schools to be served by an alternative technology approved pursuant to 310 CMR 15.280 through 15.288 shall have an equalization basin as part of the system design and have it installed prior to the treatment device. (6) Facilities other than those listed in 310 CMR 15.203(2) through (5), and nonresidential facilities with unique design features that result in significantly different design flows than those listed above may apply to the Department for a determination of design flow using actual meter readings of established flows from existing or similar installations without the need for a variance pursuant to 310 CMR 15.410 or 15.416. Prior to making a determination the Department will consult with the local Approving Authority. For state and federal facilities, the Department may also establish system design flows other than those listed above using actual meter readings of established flows from existing or similar installations. Any design flow established by the Department pursuant to 310 CMR 15.203(6), shall be based on 200% of average water meter readings in order to assimilate maximum daily flows or on other methods determined to be appropriate by the Department. (7) In schools, flows generated from sinks or other drains receiving wastes from science laboratories, graphics arts classrooms, or vocational school activities, including, but not limited to, automotive repair painting, or metal fabrication are classified industrial wastes and shall be directed pursuant to an appropriate permit, to a sewer, if a sewer connection is feasible and, if not, then to an industrial waste holding tank in accordance with 314 CMR 18.000: Industrial Wastewater Holding Tank and Container Construction, Operation, and Record Keeping Requirements or an approved hazardous waste collection receptacle.