Section 096-596-9 - Best Practicable Treatment for Overboard DischargesBest practicable treatment must be determined by the process defined in the Department's Criteria and Standards for Waste Discharge Licenses, 06-096 CMR 524 unless specifically defined in the Effluent Guidelines and Standards, 06-096 CMR 525 or this section.
A.Treatment Requirements for Combined Blackwater and Graywater Discharges. All overboard discharge wastewater must receive best practicable treatment as follows.(1) A non-discharging wastewater disposal system designed and installed in compliance with the Subsurface Rules, 10-144 CMR 241, or connection to a publicly owned sewage collection and treatment system.(2) A holding tank, where Section 9, Paragraph (A)(1), of this chapter is not feasible, and the facility is a seasonal residential overboard discharge located on the mainland or an island connected by vehicle bridge or scheduled car ferry service as long as the discharge's removal, alone or in conjunction with other discharges would result in the opening of a shellfish harvesting area.(3) Where Section 9, Paragraph (A)(1) of this chapter has been demonstrated not feasible and the conditions described in Paragraph 2 and 4 of this subsection are not applicable, a septic tank followed by treatment in a sand filter bed followed by disinfection is deemed best practicable treatment. The sand filter must be of a Department approved design and must be sized to provide a minimum treatment area of one gallon per square foot per day.(4) Where kitchen waste water or similar effluents containing a significant quantity of oil or grease are discharged, or where small property lot sizes will not accommodate the installation of a sand filter, a mechanical treatment system using an aeration and settling process followed by disinfection shall be deemed best practicable treatment. The licensee must maintain a service contract with a person certified pursuant to 06-096 CMR 517 of the Department's Rules.B.Treatment Requirements for Graywater Discharges. Where Section 9, Paragraphs (A)(1) and (2) of this chapter are impracticable, appropriate treatment for graywater is a settling tank followed by disinfection.C. Treatment Requirements for Remote Islands with Intermittent power supplies or primitive water supplies. Where conditions exist that make installation or operation of treatment systems meeting Section 9(A) impracticable, the licensee must submit a plan to provide the highest appropriate level of wastewater treatment to the Department for approval prior to relicensing.06- 096 C.M.R. ch. 596, § 9