(a) Capacity. A septic tank shall have a minimum capacity in accordance with the following table:
Minimum Capacities for Septic Tanks | ||||||||||
Serving Individual Dwellings | ||||||||||
Maximum | Nominal | |||||||||
Number of | Liquid | |||||||||
Number of | Persons | Capacity | Liquid | Total | ||||||
Bedrooms |
Served
|
of Tank
|
Length
| Width | Depth | Depth | ||||
(gals.) | (ft.) | (in.) | (ft.) | (in.) | (ft.) | (in.) | (ft.) | (in.) | ||
2 or less | 4 | 500 | 6 | 0 | 3 | 0 | 4 | 0 | 5 | 0 |
3 or 4 | 6 to 8 | 750 | 7 | 6 | 3 | 6 | 4 | 0 | 5 | 0 |
5 or 6 | 10 to 12 | 1000 | 8 | 6 | 4 | 0 | 4 | 6 | 5 | 6 |
7 or 8 | 14 to 16 | 1500 | 10 | 0 | 4 | 6 | 4 | 6 | 5 | 6 |
Note: Liquid capacity is based on the number of bedrooms in the dwelling.
Total volume of cubic feet includes air space above liquid level.
(b) Multiple Compartments. In a septic tank of more than one compartment, the inlet compartment shall have a capacity of not less than two-thirds of the total tank capacity.
(c) Garbage Disposal Units. Where domestic garbage disposal units are installed or contemplated, the capacity of the septic tank shall be at least fifty percent greater than the requirements given in subsection (a) hereof.
(d) Construction. Septic tanks shall be constructed of corrosion-resistant materials and shall be of permanent construction. The cover of the tank shall be designed for a dead load of not less than 150 pounds per square foot and, if constructed of concrete, should be reinforced and not less than four inches thick.
(e) Manholes. The inlet compartment of a septic tank must be provided with one manhole. Other compartments may be provided with a manhole. Manholes shall be at least twenty inches square or twenty-four inches in diameter and provided with covers which can be sealed watertight. Manholes should be extended to grade. Where removable slab covers are provided, manholes are not required.
(f) Baffles. If inlet and outlet baffles are used, they shall extend the full width of the septic tank and be located twelve inches from the end walls. Such baffles shall extend at least six inches above the flow line. Inlet baffles shall extend twelve inches, and outlet baffles fifteen to eighteen inches, below the flow line.
(g) Pipe Inlets and Outlets. In lieu of baffles, submerged pipe inlets and outlets may be installed to the required depth as indicated in subsection (f) hereof.
(h) Inverts. The invert of the inlet pipe shall be located at least three inches above the invert of the outlet pipe.
(i) Dosing Chambers. Dosing chambers are not required in the case of individual disposal systems.
(Ord. 1967-29. Passed 9-6-67.)