Section 15.260 - Tight Tanks(1) Approval of a tight tank may be granted only to eliminate a failed on-site system when no other feasible alternative to upgrade the system in accordance with 310 CMR 15.201 through 15.293 exists, except as provided in 310 CMR 15.260(8). Tight tanks shall not be approved for new construction or for increased flow to existing systems except as approved by the Approving Authority for: (a) boat waste pump-out facilities where no other feasible alternative exists; or(b) to serve buildings necessary for the operation of a public water supply where it is not feasible to connect to a sewer or to construct a system in compliance with 310 CMR 15.000.(c) to serve publicly owned and operated seasonal structures where it is not feasible to connect to a sewer or to construct a system in compliance with 310 CMR 15.000.(2) The design of a tight tank shall conform to the following criteria:(a) The tight tank shall be sized at a minimum of 500% of the system sewage design flow established by 310 CMR 15.203, but in no case less than 2,000 gallons;(b) plans for the tank shall be prepared, stamped and signed by a Massachusetts Registered Professional Engineer or Registered Sanitarian and submitted to the Department by the applicant for approval;(c) audio and visual alarms shall be set to activate at 3/5 tank capacity in a suitably convenient location. Transmission of the alarm signal to a locus manned 24 hours per day may be required;(d) the application for approval shall indicate the method and frequency of removal of the contents;(e) the specific location and method of disposal of the contents shall be indicated and be in accordance with 310 CMR 15.501 through 15.505;(f) the tight tank shall have at least one 24-inch diameter cast iron frame and cover at finished grade constructed so as to eliminate entrance of surface waters. Permanent suction piping may also be required;(g) the tight tank shall be located so as to provide year round access for pumping; (h) a permit to install the tank shall be obtained from the Approving Authority;(i) an operation and maintenance plan, acceptable to the Approving Authority, shall be implemented which requires monitoring of the system to ensure proper operation and maintenance;(j) the tight tank shall be waterproof and watertight and shall not be located below the water table without extensive testing to prove the integrity of the tank and design against uplift;(k) aeration or other method of odor control may be required; and(l) the tight tank shall be designed in compliance with the requirements for the construction of septic tanks in 310 CMR 15.226(1) through (4).(3) The Approving Authority may require the submission of monthly or less frequent reports concerning operation and maintenance of the tank.(4) No tight tank shall be utilized until written certification by a Massachusetts Registered Professional Engineer or Registered Sanitarian that the tight tank has been constructed and installed in accordance with the approved plan has been submitted to the Approving Authority.(5) When a sewer system becomes available, any person owning a tight tank shall connect to the sewer within 30 days and the tight tank system shall be abandoned in accordance with 310 CMR 15.354.(6) Prior to the issuance of the Disposal System Construction permit for a tight tank, the facility owner shall record or register in the chain of title for the property served by the tight tank at the Registry of Deeds or the Land Registration Office, as applicable, a copy of the Approving Authority's written approval.(7) No tight tank shall be constructed in a velocity zone on a coastal beach, barrier beach, or dune, or in a regulatory floodway, unless it replaces a tank in existence on the site as of March 31, 1995, that has been damaged or destroyed, and placement of the tank outside of the velocity zone or regulatory floodway, either horizontally or vertically, is not feasible.(8) The Approving Authority may allow the use of a tight tank at an existing, seasonal-use residential facility as remedial upgrade of the failed system serving such facility. For the purposes of 310 CMR 15.260(8), a seasonal-use residential facility means a residential facility that is used six months or less during the calendar year. This approval may be renewed upon transfer of the property. The tight tank must comply with the provisions of 310 CMR 15.260. Prior to the issuance of the Certificate of Compliance by the Approving Authority the facility owner shall record or register in the chain of title for the property served by the tight tank at the Registry of Deeds or the Land Registration Office, as applicable, a deed restriction limiting the facility to seasonal residential use and to the approved design flow.