In the construction of aerobic digestion systems:
(a) All tanks shall be of watertight construction, constructed of materials resistant to excessive corrosion or decay, properly reinforced and of sufficient thickness to withstand expected earth and hydrostatic pressures when both full and empty, and completed to present a smooth inside finish free of spalls, honeycomb, pits, etc.
(b) The design and installation of aerobic systems shall be such that each unit must be set level and at the correct elevation. The sound level of the unit in operation shall not be such as to constitute a nuisance.
(c) The aeration compartment shall have a minimum holding capacity of 850 gallons. The shape and design of the tank inlet and outlet arrangements, compartmentation, baffling and air application shall be such as to:
(1) Allow for intimate mixing of the applied oxygen;
(2) Prevent excessive short-circuiting of flow;
(3) Prevent the deposit of solids in any portion of the compartment;
(4) Prevent excessive accumulation of foam anywhere in the system; and
(5) Enable the system to operate as a septic tank in case of mechanical or electrical failure.
This would necessitate an opening equivalent to a four-inch pipe between the aeration compartment and the settling compartment.
(d) The treatment system shall be easily accessible as shall each individual unit or compartment. Inspection manholes shall be of a size necessary to visually examine or test the effectiveness of any tank and its mechanical components. Such inspection manholes shall be brought up to or above finished grade and shall be equipped with a safely secured cover. All mechanical components shall be accessible to and easily removed or replaced through such inspection manholes. Each tank compartment shall have an inspection manhole.
(e) Tank walls, baffles and hoppers shall be very smoothly finished and shall be sloped at not less than sixty degrees to the horizontal.
(f) The settling tank shall be equipped with an inspection and access manhole located so as to allow visual examination of the outlet tee (or baffled overflow weir) and tank scum accumulations and so as to allow for removal of accumulated scum.
(Ord. 1973-7. Passed 9-24-73.)