Los Angeles County Municipal Code Part 3 Design Standards

New main-line sewers shall conform to the requirements of Part 3 of this chapter unless otherwise specifically excepted.

(Ord. 6130 Part 5 Ch. 6 § 5601, 1952.)

New water pollution control plants and sewage pumping plants shall conform to the requirements of Part 3 of this chapter unless otherwise specifically excepted.

(Ord. 8690 § 3 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5602, 1952.)

New house laterals shall conform to the requirements of Part 3 of this chapter unless otherwise covered by the Plumbing Code, set out at Title 28, of this code, as amended.

(Ord. 6130 Part 5 Ch. 6 § 5603, 1952.)

New condominium developments shall be served with main-line sewers and house lateral sewers such that each building will have a separate and independent connection to a main-line sewer.

(Ord. 11716 § 27, 1978; Ord. 6130 Part 5 Ch. 6 § 5625, 1952.)

Where a lot is of sufficient size that the Zoning Ordinance, as set out at Title 22 of this code, does not prohibit its division into smaller parcels, each of such possible parcels into which such lot legally may be divided, upon which one or more buildings containing plumbing facilities are or may be located, shall be considered as a separate lot. Separate house laterals shall be constructed to the main-line sewer for each of such possible parcels except where the owner has filed an affidavit as provided in Section 1110(d) of Ordinance 2269, the Plumbing Code (see Title 28 of this code). If the main-line sewer does not extend to a point from which such possible parcels can be served in accordance with the requirements of Section 20.32.530, the main-line sewer must be extended in compliance with Section 20.32.530.

(Ord. 10020 § 3 (part), 1970; Ord. 6982 § 9 (part), 1956; Ord. 6130 Part 5 Ch. 6 § 5604, 1952.)

A.

A "letter of participation," prepared on a form provided by the county engineer, shall be submitted before approval of public sewer plans describing all properties which have participated in the cost of the project.

B.

All such properties listed will be exempt from the connection charge only, specified in Section 20.32.130.

C.

The "letter of participation" shall not be revised after the sewers have been accepted for public use by the board.

D.

Exception: The "letter of participation" shall not be revised after a reimbursement agreement authorized under Section 20.28.050 has been approved by the board. Listed participants will be exempt from the reimbursement district connection charges specified in Section 20.32.150 established for that project in which they have participated.

(Ord. 9119 § 2, 1966; Ord. 6130 Part 5 Ch. 6 § 5624, 1952.)

A.

New main-line sewers shall be offered for dedication to the County.

B.

An offer of dedication of main-line sewers for a new subdivision shall be included in any agreement to construct such sewers entered into pursuant to Section 21.32.020 of Title 21 as a condition for the recordation of a final tract map or parcel map.

C.

An offer of dedication of main-line sewers other than as described in subsection B, above, shall be made on forms provided by the County Engineer and shall be signed and acknowledged. The offer of dedication shall be required as a condition precedent to the County Engineer's approval of the plans for the construction of the sewers. The County Engineer is authorized to accept said offer of dedication on behalf of the County.

D.

When the construction of the sewer has been completed and the offer of dedication has been accepted by the County, the sewer becomes a public sewer.

E.

No sewer shall be accepted for dedication by the County of Los Angeles unless such sewer has been constructed in conformity with the requirements of Division 2 of this Title 20.

(Ord. 2010-0038 § 1, 2010; Ord. 83-0020 § 1, 1983; Ord. 9119 § 1 (part), 1966; Ord. 6982 § 9 (part), 1956; Ord. 6130 Part 5 Ch. 6 § 5623, 1952.)

If a literal compliance with any engineering requirement of this Division 2 is impossible or impractical because of peculiar conditions in no way the fault of the person requesting an exception, and the purposes of this Division 2 may be accomplished and public safety secured by an alternate construction or procedure, and the county engineer so finds that such alternate complies with sound engineering practice, he may grant an exception permitting such alternate construction or procedure.

(Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5622, 1952.)

Any plans submitted for approval under the provisions of this Division 2 shall be prepared by or under the direction of and shall be signed by a registered civil engineer of the state of California.

(Ord. 10020 § 21970; Ord. 6130 Part 5 Ch. 6 § 5604.1, 1952.)

A.

Before a sewer construction permit required by section 20.32.010 may be issued, plans for the proposed construction shall be submitted to and approved by the Director of Public Works, unless the Director of Public Works determines that plans are not necessary.

B.

After the fee required by Section 20.32.230 has been paid, the director of public works shall check the submitted plans for compliance with the requirements of this ordinance and other applicable laws and ordinances of the county, state, or other governmental jurisdiction.

C.

If plan corrections and other requirements necessary for plan approval have not been completed within one year after the checked plans are returned by the of public works, it shall constitute abandonment of the work and the director of public works shall so notify the person who has submitted the plans.

D.

Except as provided in subsection F of this section, approval of sewer plans shall expire two years from the date of their approval, unless construction of the involved sewer facilities has commenced.

E.

Resubmission of abandoned and expired plans shall be subject to new plan check fees as specified in Section 20.32.230.

F.

Notwithstanding subsection D of this section, the life of any unexpired approved sewer plan issued in connection with an approved tentative tract or parcel map shall be extended for the 24-month time period provided in California Government Code section 66452.23 to the extent such section applies to the involved tract or parcel map, except that the Director of Public Works may, as a condition of such extension, require modifications to the approved sewer plan to comply with any applicable changes in federal, State, or local law which took effect after the approval of the sewer plan. If after the effective date of the ordinance adding this subsection F, the California legislature amends the Subdivision Map Act to further automatically extend the life of any approved tentative tract or parcel map, the Director of Public Works shall have the discretion to extend the life of any related sewer plan approvals for the periods of time granted by such legislative extensions, and to require the sewer plan modifications he or she deems necessary as described in this subsection F.

(Ord. 2013-0020 § 1, 2013; Ord. 2005-0033 § 9, 2005; Ord. 11716 § 26, 1978; Ord. 10020 § 3 (part), 1970; Ord. 8690 § 10 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5605, 1952.)

A.

A person desiring to construct a sewer in an easement under the provisions of this Division 2 shall present to the county engineer a request for processing, sufficient information to enable the preparation of a written description, and the fee specified in Section 20.32.240.

B.

The location and dimensions of sanitary sewer easements shall be sufficient to provide present and future sewer service to abutting areas and adequate access for maintenance as determined by the county engineer.

C.

Until the required easements have been properly executed and recorded:

No plans shall be approved by the county engineer for sewer facilities to be constructed by any person across the property of others;

No sewer facilities shall be accepted for public use, nor placed in use by any person.

(Ord. 10020 § 3 (part), 1970; Ord. 8690 § 11, 1964; Ord. 6130 Part 5 Ch. 6 § 5605.1, 1952.)

A.

The size of main-line sewer pipe shall be determined by standards of design and the coefficients listed below, but in no case shall it be less than eight inches inside diameter.

* Individual building, commercial or industrial plant capacities shall be the determining factor when they exceed the coefficients shown.

B.

The coefficient to be used for any zoned area not listed will be determined by the county engineer based upon the intended development and use.

C.

The county engineer shall determine which of the coefficients or combination of coefficients shall be used for design, as determined by the established or proposed zoning in the study area. Any modifications to these coefficients due to topography, development or hazard areas shall be approved by the county engineer.

(Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5606, 1952.)

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

(Ord. 6130 Part 5 Ch. 6 § 5607, 1952.)

A system of bench marks on the U.S.C. & G.S. Sea Level Datum of 1929 and adequate to construct the work shall be shown on the profile. The elevation of the sewer at the point where the system is to be discharged shall be shown as determined in the field from the above shown datum.

(Ord. 6982 § 9 (part), 1952; Ord. 6130 Part 5 Ch. 6 § 5617, 1952.)

Soil conditions, particularly in areas known to have high groundwater tables, rock, or filled ground, shall be prospected, and the results shown on the profile, if required by the county engineer.

(Ord. 6130 Part 5 Ch. 6 § 5616, 1952.)

The slope of the sewer shall be shown on the plans in feet of fall per 100 feet of horizontal distance, expressed as a percentage. Slopes used expressed in percentages shall be divisible, without remainder, by four in the hundredth column. For example, 0.36 percent complies with this section.

(Ord. 6130 Part 5 Ch. 6 § 5608, 1952.)

Where design considerations permit, main-line sewers shall have a straight alignment, and shall be located five feet from and on the northerly and easterly sides of the centerlines of streets or alleys, except on major or secondary highways where

separate sewers shall be located in the roadway six feet from each curbline.

(Ord. 10020 § 3 (part), 1970; Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5611, 1952.)

A.

The minimum depth for mainline sewers shall be seven and one-half feet.

B.

Where groundwater is present, the depth for residential main-line sewers may be sufficient to provide for a house lateral with a minimum depth of at least five feet below the curb grade or centerline of street or alley grade at the property line.

C.

Exceptions to the above minimum may be made only as set forth in Section 20.32.400.

(Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5609, 1952.)

A.

For each lot, a six-inch internal diameter house lateral sewer shall be provided in the street, straight in alignment and grade between the main-line sewer and the property line, with minimum depths as required by Section 20.32.520, and at right angles to the mainline sewer whenever possible.

B.

Exception: House laterals constructed in the street under the provisions of the Plumbing Code, (as set out at Title 28 of this code) or house laterals provided in the street for lots restricted to single-family residential use under the provisions of the Zoning Ordinance, set out at Title 22, may have an internal diameter of four inches.

(Ord. 10020 § 3 (part), 1970; Ord. 9119 § 1 (part), 1966; Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5620, 1952.)

A.

The depth of house laterals at the property line shall be sufficient to provide service to the lowest or farthest point to be served on the lot at a minimum grade of two percent, with the top of the pipe not less than one foot below the ground surface at any point.

B.

The minimum depth for house laterals at the property line shall be six feet below the curb grade or the centerline of street or alley grade, except as set forth in Section 20.32.500 for locations where groundwater is present.

C.

Where street-widening lines have been established by the Zoning Ordinance, as set out at Title 22 of this code, the minimum depth shall be measured at such established line. If house laterals are constructed before the existing street is widened, the depth at the property line shall be such that extension at the same straight grade and alignment to the new property line will produce the required depth.

(Ord. 10020 § 3 (part), 1970; Ord. 9119 § 1 (part), 1966; Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch. 6 § 5621, 1952.)

End structures shall be placed at whichever of the following locations is farthest up grade:

A.

Not less than 10 feet upgrade from the downgrade lot line of the last lot being served;

B.

Not more than 40 feet downgrade from the upgrade lot line of the last lot being*served, if there may be a future extension of the main-line sewer;

C.

At a location where the house lateral and building sewer can be constructed in a straight alignment at right angles to the main-line sewer.

(Ord. 10020 § 3 (part), 1970; Ord. 6130 Part 5 Ch. 6 § 5612, 1952.)

Manhole structures shall be placed in the main-line sewer at all changes of alignment and gradient; the maximum distance between structures shall be not more than 350 feet. All structures shall be designed according to the standard drawings for structures on file in the office of the county engineer. Exceptions to the above requirements may be made only on approval of the county engineer.

(Ord. 6130 Part 5 Ch. 6 § 5610, 1952.)

All substructures which will be encountered in the construction or which will be installed as part of the improvement 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. The engineer who has prepared the plans shall submit to the county engineer a statement that he has determined from each utility or other company having substructures in the affected area that the location and size of such structures, as shown on the submitted plans, are the same as shown upon such company's records.

(Ord. 10020 § 3 (part), 1970; Ord. 6130 Part 5 Ch. 6 § 5615, 1952.)

A.

All pipe other than vitrified clay or cast iron shall first have been approved for use by the county engineer and shall be equivalent to vitrified clay or cast iron pipe in strength, effectiveness, durability and safety in accordance with the use intended.

B.

Before approving any pipe, the county engineer may require satisfactory proof that such pipe is suitable for use, including actual tests performed by an independent and approved testing laboratory at no expense to the county.

(Ord. 10020 § 3 (part), 1970; Ord. 8690 § 12 (part), 1964; Ord. 6982 § 9 (part), 1956; Ord. 6130 Part 5 Ch. 6 § 5619, 1952.)

A.

Vitrified clay pipe, main-line and house lateral sewers, shall be constructed of the class designated as extra-strength pipe.

B.

Sewer pipe installed under a railway shall be encased in concrete, or encased in a steel pipe backfilled with sand, or encased by other approved means which will protect the pipe to the same extent.

C.

Sewer pipe installed under a conduit or other structure, or at depths greater than 20 feet or in other locations where the county engineer determines that additional protection is required, shall be reinforced with a concrete cradle, or encased in concrete, or reinforced by other approved means which will protect the pipe to the same extent.

D.

Sewer pipe installed in streets or public easements with the top of the pipe less than four feet below the surface, as determined during construction or indicated on the plans, shall be encased in concrete, or other approved means to protect the pipe.

(Ord. 8690 § 12 (part), 1964; Ord. 6130 Part 5 Ch.6 § 5614, 1952.)