§ 20-120. Construction specifications.

Specifications for construction of a septic tank provided for herein shall be as follows:

(1)

Materials of construction:

a.

Septic tank proper: Reinforced concrete, metal properly treated with a noncorrosive agent, vitrified clay or other impervious material.

b.

Lateral system: One-foot lengths of farm drain tile.

c.

Filter trenches: Gravel, coarse sand or cinders. Gravel or washed rock one-half-inch and three-fourths-inch in size is preferred.

(2)

Construction:

a.

Septic tank: The septic tank shall have a working capacity of not less than three hundred (300) gallons, and where the total number of persons using the same is above six (6), this capacity shall be increased at least fifty (50) gallons for each additional person served, or where the number of fixtures is equal to more than two (2) complete sets, consisting of tubs, water closet and lavatory, an increase in the capacity of the tank above the minimum shall be made according to the following:

1.

Water closet, seventy (70) gallons.

2.

Laundry sink, fifteen (15) gallons.

3.

Kitchen sink, fifteen (15) gallons.

4.

Shower bath, ten (10) gallons.

5.

Bathtub, ten (10) gallons.

6.

Lavatory, five (5) gallons.

If the plant consists of more than one (1) compartment, no compartment used shall have a working capacity of less than one hundred (100) gallons. The septic tank shall be watertight at all times.

If the plant consists of a single chamber concrete tank constructed in place, the following inside dimension shall be considered minimum:

1.

Depth (below water level), three (3) feet and six (6) inches.

2.

Width, two (2) feet and six (6) inches.

3.

Length, five (5) feet.

If at any time it becomes necessary to increase the capacity of this tank because of the requirements set forth above, the length of the tank shall be from one and one-fourth (1 ¼) to two (2) times the width. The width in no case shall be less than that set forth above.

Influent (inlet) and effluent (outlet) pipes shall be so constructed that the sewage influent and effluent is introduced and withdrawn from the tank at a depth of at least six (6) inches below the water level. Baffle walls may be used in lieu of influent and effluent tee's or elbows and such baffle walls must extend from six (6) inches from top of tank to a depth of at least six (6) inches below the water level. Influent and effluent pipes must be built so that the waterline is at least eight (8) inches from the ceiling of the septic tanks. A small hole shall be cut into the effluent (outlet) tee or elbow, above the waterline, to allow for the escape of gases into the soil through the lateral lines. Suitable manholes or removal covers shall be provided for each compartment to allow for cleaning.

b.

Laterals.

1.

From the effluent tee there shall extend not less than eight (8) feet of watertight four-inch tile pipe.

2.

The lateral system shall consist of not less than one hundred fifty (150) feet of four-inch farm drain tile laid with open joints. This is to take care of not to exceed five (5) persons. For each addition person, thirty (30) feet of drainage shall be added, or where the number of fixtures is equal to more than two (2) complete sets, an increase in the lineal feet of drain tile above the minimum shall be made according to the following:

(i)

Water closet, seventy (70) linear feet.

(ii)

Laundry sink, fifteen (15) linear feet.

(iii)

Kitchen sink, fifteen (15) linear feet.

(iv)

Bathtub, ten (10) linear feet.

(v)

Shower bath, ten (10) linear feet.

(vi)

Lavatory, five (5) linear feet.

This lateral system is to be laid at the top of a filter trench filled with coarse sand, gravel or cinders. The filter trench is to be at least sixteen (16) inches wide at the bottom. There is to be six (6) inches of coarse sand, gravel or cinders underneath the farm drain tile and the trench filled five (5) inches over the top of the drain tile with this same material.

Each open joint of tile is to be covered with a strip of tar paper or building paper. On top of the gravel, sand or cinders is to be a two-inch layer of hay or straw, other material suitable as a protective covering for the porous filler around the pipe, and not less than ten (10) to twelve (12) inches of soil. The drainage tile shall have a fall of not exceeding one (1) inch per one hundred (100) feet. The lateral lines shall in no case be less than twelve (12) feet apart.

(3)

Special conditions: If at any time due to special conditions, the requirements set forth in this article are deemed inadequate by the director of public health, he shall set forth the size septic tank, length of lateral or construction of filter trench best suited to the special condition and in accord with the standards set by the state department of health. It shall be unlawful for any person to maintain a septic tank on any premises when such premises are within one hundred (100) feet of an available sewer line. Before any septic tank or drainage system is covered up, the person installing the septic tank shall notify the director of public health, who shall then inspect the tank and drainage system to see that the construction is in compliance with the requirements of this chapter. No septic tank or drainage system shall be covered up until they have been inspected and passed by the director of public health. It shall be unlawful for any building to be erected in an unsewered district until an approval in writing shall have first been secured from the director of public health for the method of excreta disposal to be employed. No person shall permit a septic tank within the city, or a septic tank or other means of sewage disposal located outside the city and within three thousand (3,000) feet of the corporate line of the city to become foul, offensive, nauseous or in any way drain to the surface of the ground so as to become injurious to the public health. Cesspools of any kind are hereby positively prohibited within the city limits.

(Ord. of 1-7-54, § 3)