West Covina Municipal Code § 23-52 Size of main line sewer

All plans required under the provisions of this article for the construction of main line and house connection sewers shall conform to the standards of design prescribed by this division. Plans required for all other sewer construction or installation under the provisions of this article shall conform to the standards of design on file in the office of the city engineer.

(Code 1960, § 5223)

(a) Main line sewer pipe shall have an inside diameter of not less than eight (8) inches and shall have sufficient capacity to carry sewage from the area tributary thereto when computed upon the following basis:

(1) For residential areas, per acre, 0.004 cubic feet per second.

(2) For light industrial areas, per acre, 0.016 cubic feet per second.

(3) For heavy industrial areas, per acre, 0.021 cubic feet per second.

(4) Individual plant capacities shall be the determining factor where they exceed the above coefficients.

(b) The city engineer shall determine the classifications set forth in subparagraphs (1) through (4) of paragraph (a) of this section, and shall approve any modification thereof.

(Code 1960, § 5223.1)

A main line sewer shall be designed to provide a minimum velocity of two (2) feet per second for pipes flowing one-half full, except that the city engineer may approve a gradient that will develop a lower velocity if he finds that a gradient that will develop a velocity of two (2) feet per second is unobtainable.

(Code 1960, § 5223.2)

The slope of the sewer shall be shown on the plans in feet of fall per one hundred (100) feet of horizontal distance expressed as a percentage. Slopes used expressed in percentages shall be divisible, without remainder, by four (4) in the hundredth column. For example, sixteen hundredths (0.16) percent complies with this section.

(Code 1960, § 5223.3)

(a) The standard depth for main line sewers in residential districts shall be six and one-half (6½) feet and in business districts shall be sufficient to provide a house connection depth of ten and one-half (10½) feet. Standard depth for four (4) or six (6) inch house connection shall be six (6) feet in residential districts and ten and one-half (10½) feet in business districts respectively, below the curb grade or grade of center line of street, at the property line. "Depth" is defined as vertical distance to invert of sewer.

(b) Exceptions to the above minima may be made only on approval by the city engineer.

(Code 1960, § 5223.4)

Manhole structures shall be placed in the main line sewer at all changes of alignment and gradient; the maximum distance between structures shall not be more than three hundred fifty (350) feet. All structures shall be designed according to the standard drawings for structures on file in the office of the city engineer.

(Code 1960, § 5223.5)

Main line sewers shall be located within five (5) feet of the center lines of the streets or alleys except on major and secondary highways where separate sewers shall be located in the roadway six (6) feet from either curbline. Exceptions to these standard locations may be made only upon approval by the city engineer.

(Code 1960, § 5223.6)

End structures shall be located not less than ten (10) feet upgrade, unless at end of line, from the downgrade lot line of the last lot served, and/or carried to within five (5) feet of tract boundary when required by the city engineer.

(Code 1960, § 5223.7)

(a) Six (6) inch house connection sewer service shall be provided in the street for each lot and the depth shall be sufficient to provide a connection to the lowest and/or farthest point of the lot with a cover of one (1) foot and a grade of not less than two (2) percent.

(b) Any exception to this requirement may be had only upon approval by the city engineer.

(Code 1960, § 5223.8)

Pipe used for sewers shall be:

(a) Standard strength for sewers not more than ten (10) feet in depth from the surface to invert.

(b) Extra strength for sewers more than ten (10) feet and not more than twenty-five (25) feet in depth.

(c) Reinforced with concrete cradle or concrete encasement for sewers more than twenty-five (25) feet in depth.

(d) Encased in concrete or placed inside of steel pipe backfilled with sand for sewers under railways.

(e) Reinforced as required by the city engineer for sewers under large conduits or other structures.

(Code 1960, § 5223.9; Ord. No. 1487, § 9, 8-25-80)

All substructures which will be encountered in the construction or which will be installed as part of the improvement of main line or house connection sewers shall be shown and designated on the plan. Large substructures which require special treatment in the design of the sewer shall also be shown in the profile.

(Code 1960, § 5223.10)

Soil conditions in areas known to have rock, or filled ground, shall be prospected and the results shown on the profile.

(Code 1960, § 5223.11)

A system of bench marks on U.S.G.S. datum and adequate to construct the work subject to this division shall be shown on the profile.

(Code 1960, § 5223.12)