Section 11-62-33.1 - Specific requirements for new and proposed treatment units(a) Septic tank. (1) All wastewater shall discharge into the septic tank. Roof, footing, garage, surface water drainage, cooling water, and graywater disposed of in accordance with section 11-62-31.1(g)(4) shall be excluded.(2) Septic tanks shall meet the International Association of Plumbing and Mechanical Officials (lAPMO) material and property standards for prefabricated septic tanks, lAPMO ANSI ZlOOO-2013. Septic tanks shall be approved and listed by lAPMO.(3) Plans for cast-in-place septic tanks shall be submitted with the application for the individual wastewater system. The plans for the septic tank shall be designed and stamped by a licensed structural engineer and shall meet the lAPMO design specifications.(4) The following schedule shall apply to septic tank sizing: No. of Bedrooms | Minimum Capacity (Gallons) |
4 or less | 1000 |
5 | 1250 |
(5) For wastewater flows greater than 1,000 gallons per day or five bedrooms, the formula: Minimum capacity gallons = 1,000 + (Q-800)x 1.25, where Q=design flow, shall be used.(6) Concrete septic tanks shall be coated to protect the tank from leakage and corrosion by acceptable means. The coating shall cover the entire tank interior.(7) Manholes or removable covers to septic tanks shall be brought to grade. The cover shall be secured to prevent unauthorized entry or opening of the tank.(8) When septic tanks are installed in ground water or in clay soils with an expansive nature, the engineer shall design or provide adequate protection to prevent the tank from floating, moving or crushing.(9) The excavation to receive the tank shall be large enough to permit the proper placement of the tank and backfill. Tanks shall be installed on a solid base that will not settle and shall be level. Where rock or other undesirable protruding obstructions are encountered, the bottom of the hole shall be excavated an additional six inches and backfilled with sand, crushed stone, or gravel to the proper grade. Backfill around and over the septic tank shall be placed in such a manner as to prevent undue strain or damage to the tank or connected pipes.(10) When a septic tank is installed under a driveway, parking lot, in a heavy saturated soil, or other areas subject to heavy loads, the tank shall be capable of withstanding an H-20 wheel load as defined by the American Association of State Highway Officials.(11) Effluent from a septic tank shall be discharged into a soil absorption system, sand filter, subsurface irrigation system as approved by the director, or other treatment unit approved for use by the director.(b) Household aerobic units. (1) All wastewater shall discharge into the household aerobic unit. Roof, footing, garage, surface water drainage, and cooling water shall be excluded.(2) Household aerobic units shall be approved by the director based upon the 'Standard No. 40" for Class I units as set forth by the National Sanitation Foundation. The performance data shall have been obtained by an agency such as a university or an independent research laboratory acceptable to the director or from the National Sanitation Foundation (NSF) Testing Laboratory, Ann Arbor, Michigan.(3) Owners of proposed and existing household aerobic units shall have an active service contract for the proper maintenance of the aerobic unit and its disposal system with a certified operator or factory certified representative, and a copy of an active service contract shall be submitted annually to the department. The contract shall also include pumping service to maintain the household aerobic unit. For proposed household aerobic units, a copy of an executed service contract shall be submitted prior to the final approval of the individual wastewater system.(4) As a minimum, the aerobic treatment unit service contract shall include the term of contract period (start and end dates) and the following requirements:(A) Inspect all aerobic treatment unit equipment to ensure its proper operation at least every six (6) months;(B) Provide regular maintenance of equipment as required by the manufacturer;(C) Verify the aerobic treatment unit is providing adequate mixing and aeration of the microbes;(D) Measure the depth or volume of sludge in the aerobic treatment unit every six months, and assess whether sludge removal by pumping is necessary. Provide sludge pumping, as needed. If pumping is necessary, record the depth of sludge or percentage of sludge volume in the ATU prior to pumping; and(E) Maintain a log of all service provided.(5) Effluent from an aerobic unit shall be discharged into a soil absorption system, sand filter, subsurface irrigation system as approved by the director, or other treatment unit or disposal system approved for use by the director.(6) In areas below (makai of) the Underground Injection Control Line established pursuant to chapter 11-23, where the vertical separation distance from the discharge to the seasonal high groundwater table is less than three feet, a new household aerobic unit may discharge its effluent into an elevated mound to achieve the vertical separation or drip irrigation system or, with a variance approved by the director and if the effluent is disinfected, to a seepage pit. Where water bearing formations are in danger of contamination, the director may require greater vertical separation,(c) Subsurface and recirculating sand filters shall be reviewed on a case-by-case basis by the director.Haw. Code R. § 11-62-33.1
[Eff 8/30/91; am and comp 12/09/2004] (Auth: HRS §§ 321-11, 342D-4, 342D-5) (Imp: HRS §§ 321-11, 322-1 to 322-4, 322-8, 342D-2, 342D-4, 342D-5, 342D-50)