§ 13.08.530. Standards of quality of materials and methods of construction.

A.

General. All materials used and all joints made in, or entering into, the construction of sewer systems or parts thereof shall be water-tight and free from defects. The materials and joints specified in this code are the minimum approved standards that shall be used. Building sewer joints shall be of such design as will permit sealing and placement without appreciable irregularities in flow lines.

The provisions of this code are not intended to prevent the use of any material not specifically prescribed by this code; provided, however, that such substitute material shall be first approved by the Director of Public Works.

B.

Materials. Pipe for building sewers shall be vitrified clay, cast iron, polyvinyl chloride plastic pipe or any other material approved by the Director of Public Works.

Vitrified clay pipe and fittings shall conform to ASTM Standard Specifications for "Extra Strength Unglazed Clay Pipe," Serial Designation C-700 as amended.

Cast iron soil pipe and fittings shall conform to ASTM Standard Specifications for "Cast Iron Soil Pipe and Fittings," ASTM Designation A 74, as amended, or by the United States Department of Commerce standard for service weight "Cast Iron Soil Pipe and Fittings," Designation Commercial Standard CS 188-59, as amended.

Polyvinyl Chloride plastic pipe shall conform to all of the standards set forth in Section 207-17, POLYVINYL CHLORIDE PLASTIC PIPE, as that particular section appears in the "Standard Specifications for Public Works Construction", as adopted by the city of Oakland.

C.

Size of Pipe for Building Sewers.

1.

Pipe Sizes, General. Pipe sizes mentioned within this chapter refer to the interior diameters of the pipes. The sizes of any building sewer shall be at least as large as the size of the sanitary building drain to which it will connect, but in no case less than four inches. Where more than one building drain connects to the building sewer, the size of the building sewer shall be determined by the Director of Public Works.

2.

Pipe Sizes, Replacement of Existing Five-Inch Diameter Building Sewer. Where any premises is served by an existing five-inch diameter building sewer, the five-inch diameter sewer may be reduced to four-inch diameter pipe when building sewer replacement occurs and a new connection is made to the sanitary sewer main. A two-way cleanout shall be required in accordance with Section 13.08.390, two-way cleanout required—reduction in size of building sewer, when the downstream size of the pipe is reduced.

D.

Excavation, Backfilling, and the Protection of Building Sewer Trenches. Unless otherwise provided, the excavation, backfilling, and protection of building sewer trenches in public streets, sidewalks, alleys, or other public places shall be made in compliance with all the applicable requirements of this title.

All building sewers, other than metallic pipe, in private property shall be installed so that there will be at least twelve (12) inches of cover over the top of the pipe.

Tunneling of building sewer trenches, other than under concrete curb and gutter, will not be allowed without the prior approval of the Director of Public Works.

E.

Construction of Building Sewers and Their Connections, Bends Prohibited, Cleanouts, Passage Through or Under Walls, Corrosive Materials. All building sewers shall be laid in a straight line with no horizontal or vertical bends. The horizontal alignment of the portion of any building sewer within a street area shall be perpendicular or radial to the centerline of the street right-of-way. Bends authorized or directed by the Director of Public Works shall be constructed as hereinafter described.

Sewer cleanouts shall be required at the connection of the building drain to the building sewer, grade changes, horizontal changes in direction in excess of twenty-two and one-half (22-1/2) degrees, and at intervals not to exceed one hundred (100) feet in straight runs. The minimum size of cleanouts shall be four inches and they shall be so placed as to be accessible at all times.

All building sewers passing through or under walls shall be protected from breakage in a manner approved by the Director of Public Works.

All building sewer pipes passing through corrosive materials shall be protected from external corrosion in a manner approved by the Director of Public Works.

Any cleanouts or other appurtenances required by this section are in addition to the two-way cleanouts required by another section in this code.

F.

Protection of Piping. No building sewer piping other than cast iron or an approved equal shall be installed within two feet of any bearing or foundation wall. All building sewers installed below the footing of any building and paralleling the footing must be encased in concrete unless located outside the range of excessive footing pressure.

G.

Construction of Building Sewers and Their Connection, Joints, Slope, Laying in Filled Ground, Depth at Curb. Vitrified clay or asbestos-cement pipe for building sewers shall be connected by flexible compression type joints or an approved equal.

Cast iron pipe for building sewers shall be connected only in the manner permitted for connections of case iron pipe under buildings.

The minimum slope of any building sewer shall be one-fourth inch per foot toward the public sewer or point of disposal; provided that where it is impractical due to the depth of the street sewer or to the structural features or to the arrangement of any building or structure, to obtain a slope of one-fourth of an inch per foot, any such building sewer may have a slope of not less than one-eighth of an inch per foot when approved by the Director of Public Works.

Where laid in filled ground with less than ninety (90) percent relative compaction, the building sewer shall be of cast iron or asbestos-cement; however, pipe may be of vitrified clay if approved flexible joints are used or if laid on a bed of approved material.

At the curbline, the outside top of the building sewer pipe shall be at least thirty-six (36) inches below the existing or proposed top of curb grade, whichever grade shall be lower.

(Prior code §§ 6-6.340—6-6.346)