Section 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.