(2) The pit shall have a capacity of not less than 50 cubic feet per seat and be not
less than 4 1/2 feet or more than 6 feet deep, measured from the original ground
surface. Where rock formations or groundwater are encountered at shallower depths, a
mound may be constructed to permit a pit of sufficient depth.
(3) Sills shall be provided to form the support for the outhouse building. Pit
curbings shall extend to the full depth of the pit unless in rock formation, in which case
the lower section of the curbing may be omitted. The curbing should not support the
building or the sills.
(4) Pit mounds shall be of well-tamped earth installed in thin layers, shall extend
outward on the level for a distance of not less than 18 inches in all directions from the
sills, and thence outward to meet the surrounding ground surface with a slope not
greater than 1 vertical to 3 horizontal. Mounds should be covered with sod or
otherwise protected against erosion.
(5) The floor and seat riser shall be built of impervious material or tongue and
groove lumber, and in a manner to exclude insects. The seat riser shall be so
constructed and bonded with the floor as to prevent seepage through the riser onto the
(6) The seat opening shall be covered with a hinged lid.
(7) The pit should be ventilated from the riser to a point outside the building by a
flue or vent having a cross-sectional area of not less than 12 square inches. The joints
shall be tight and the opening screened with 16 mesh screening, preferably of copper.
History: 1944 AC; 1944 ACS 7; 1954 AC; 1979 AC.
R 325.423 Minimum standards for septic tank privy or septic toilet.
Rule 3. (1) The tank should be located at least 50 feet from any well or other source
of groundwater supply and upon ground sloping away from the water supply. No tank
shall be located less than 2 feet from any lot or alley line or less than 25 feet from any
lake or stream.
(2) The tank shall be constructed of an impervious material and be watertight.
The depth below the outlet pipe shall be not less than 30 inches. When constructed of
concrete the side walls, top and bottom shall be of a mixture and thickness which will
insure a dense, watertight structure. Sufficient reinforcement shall be used to prevent
cracking. When constructed of metal, Armco ingot iron or other rust-resisting
material not less than 12 gauge shall be used. All metal surfaces inside and outside shall
be thoroughly coated with a good quality asphalt base material. All tanks shall be
provided with an outside opening, not less than 12 inches in diameter, fitted with a
tight cover, to permit inspection and cleaning. The outlet of all tanks shall be so
constructed as to prevent solid material passing into the discharge pipe. Tanks should be
filled with water before being put into operation and after each cleaning.
(3) A drop tube, securely fastened to the toilet bowl and to the tank, shall extend
into the tank but not more than 2 inches below the water line. A vitreous china toilet
bowl with seat and seat cover securely hinged should be used.
(4) A ventilating pipe connected to the bowl and extending above all parts of the
building shall be installed.