Chapter 13.32
SEWER SYSTEM EXTENSION DESIGN STANDARDS
Sections:
13.32.020 Standard specifications.
13.32.030 Plans and specifications.
13.32.050 Rights-of-way and monuments.
13.32.010 Generally.
All extensions to the sewer system must conform to the design standards of the City. The system must be capable of future expansion in accordance with the Comprehensive Plan of the City. The items set forth in this chapter are necessary to meet such conditions. (Ord. 566, 1978)
13.32.020 Standard specifications.
Standard specifications for the agreement set forth in Chapter 13.28 FMC are contained in Standard Specifications for Municipal Public Works Construction, 1977 Edition, prepared by the Washington State Chapter of the American Public Works Association. The owner’s attention is called to the fact that the Standard Specifications contain general conditions as well as construction details. The responsibility for supplying himself with these Standard Specifications shall rest with the owner. (Ord. 566, 1978)
13.32.030 Plans and specifications.
The installation of sewer extensions shall be made in accordance with these conditions and standards. The scale shall be one inch equals 50 feet on 24-inch-by-36-inch mylar. The plans shall be sealed by a licensed professional engineer. The construction plans shall be reviewed or prepared by the City’s Engineers. (Ord. 566, 1978)
13.32.040 Design standards.
A. Unless otherwise called for by the City’s Engineer on the specifications and plans, gravity sewers shall be concrete, clay, asbestos cement or plastic pipe:
1. Concrete, ASTM C-14 class 2;
2. Clay, ASTM C700;
3. Asbestos-cement, class 2400 C248 or C644;
4. Plastic-PVC, ASTM D3034.
B. Manholes shall be precast, shall be 48 inches in diameter in accordance with Detail No. 1 of the Standard Specifications, and shall generally conform to ASTM Specifications for equivalent size reinforced concrete sewer pipe. Manhole covers shall be locking type in accordance with Detail No. 11 of the Standard Details in the Standard Specifications and shall be supplied with stainless steel socket head cap screws.
C. Pressure mains shall be ductile iron.
D. All joints for sewers or pressure mains shall be of the rubber gasket type.
E. The pipe sizes shall be selected as is indicated by good practice and shall conform to the overall sewerage plan.
F. Minimum grade shall be in accordance with “Ten States Standards.”
G. Manholes shall be placed at each grade and direction change. Distances between manholes shall not exceed 400 feet. Manholes shall be used at the termination of each sewer unless specified otherwise by the City’s Engineer.
H. The sewer grade for six-inch side sewer stubs shall be a minimum of two percent.
I. A tight line bypass shall be required to separate existing flows from the new connection, until final acceptance of the sewer extension. (Ord. 566, 1978)
13.32.050 Rights-of-way and monuments.
All rights-of-way in which the sewer extension is to be made shall be improved prior to preparation of construction plans and installation of the sewers. Permanent private easements shall be not less than 20 feet in width, and shall be cleared and grubbed to the entire width. Public rights-of-way shall be cleared, grubbed and graded in accordance with the requirements of the City. Monuments disturbed or destroyed shall be replaced at the owner’s expense. (Ord. 566, 1978)