310 CMR 15.351
System Pumping and Routine Maintenance
(1) 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. Without limiting the foregoing, a septic tank, tight tank, or
cesspool shall be pumped when the owner or operator is required to do so by the Local
Approving Authority or the Department. Whenever a system component including, but not
limited to, a septic tank, tight tank, cesspool, grease trap, pump chamber or distribution box is
pumped, its condition shall be noted by the system pumper on a system pumping form approved
by the Department, and the results shall be submitted by the system pumper to the Approving
Authority within 14 days from the pumping date. Such notation of the system's condition on the
system pumping form shall not constitute a System Inspection Report submitted to the
Approving Authority in accordance with 310 CMR 15.340.
(2) Grease traps shall be inspected monthly by the owner/operator and shall be cleaned by a
licensed septage hauler whenever the level of grease is 25% of the effective depth of the trap, or
at least every three months, whichever is sooner. The owner/operator shall keep all inspection
and pumping records.
(3) Pumps, alarms and other equipment requiring periodic or routine inspection and
maintenance shall be operated, inspected and maintained in accordance with the manufacturer's
and the designer's specifications. In no instance shall inspection be performed less frequently
than once every three months for any system serving a facility with a design flow of 2,000
gallons per day or greater, and annually for any system serving a facility with a design flow of
less than 2,000 gallons per day. The system owner shall submit the results of such inspections
to the Approving Authority annually by January 31st of each year for the previous calendar year.