Chapter 19.30
WATER SYSTEM
Sections:
19.30.010 Introduction and applicability.
19.30.010 Introduction and applicability.
A. The items herein contained are the water system standards, conditions, and specifications of the city of Rock Island, and are to be considered in conjunction with other provisions of city plans and/or regulations governing the public water supply system. These are minimums only and may be increased or altered to fit particular site conditions and/or situations. The city by this reference adopts the latest edition of the “Standard Specifications for Road, Bridge and Municipal Construction” (hereinafter referred to as the “Standard Specifications”) as prepared by the Washington State Department of Transportation and the Washington State Chapter of the American Public Works Association to govern all aspects of street improvements including but not limited to materials, labor, equipment for installation, workmanship, testing, etc. Any material, design, standard, or testing not specifically addressed within this document shall be as per the Standard Specifications. The city also by this reference adopts the latest version of the “Standard Plans” (engineering drawings hereinafter referred to as the “Standard Plans”) published by the Washington State Department of Transportation.
B. In addition to the specific standards set forth in this chapter, the city may develop a technical specifications guidebook containing drawings that graphically depict the provisions of this chapter and the Standard Specifications. This guidebook may also specify where the city may choose to add to, remove from, and/or replace (in whole or in part) certain aspects of the Standard Specifications and Standard Plans adopted by reference herein. The guidebook is a technical reference document that may be updated periodically based on changes in engineering standards, whether those be city standards or updated standards in the design and construction documents that are adopted by reference in this chapter.
C. These standards and specifications shall apply to any work that is done to the city’s water system, whether required as a condition of development permit approval or as a result of an individual request for water extension. (Ord. 01-062 § 5).
19.30.020 Design standards.
The design and construction of water system improvements shall be dependent on local site conditions, and shall conform to the following minimum standards:
A. General Requirements.
1. The design and construction of extensions of the water system shall be consistent with the city’s approved comprehensive plans and all other applicable state, county and local agency standard regulations. Obtaining necessary permits issued by an agency or authority other than the city shall be the responsibility of the developer.
2. If future extension of the system are deemed probable by the city, the proposed systems shall be designed and sized to service future customers. Easements shall be provided to facilitate the same. Water lines shall be extended to the boundaries of the property being served, providing access for future service to adjacent properties. Water mains shall be designed and constructed for the ultimate development of the service areas and as may be further established in the city’s water comprehensive plan.
3. Whenever water lines are located outside of public streets or alleys, the easement shall be of sufficient width to allow for future replacement of the facility without damage to permanent adjacent improvements. In general, if the water line is located in the center of an easement, the easement shall be a minimum width of 15 feet. Special circumstances may require additional widths as determined by the city.
4. Detailed plans shall be submitted for the city’s review and approval that provide the location, size, type and direction of flow of the proposed water mains and the connection with existing mains. Horizontal locations and elevation information shall be to a datum acceptable to the city. Computations and other data used for the design of the water system improvements shall be submitted to the city for approval.
5. Construction of new water systems or extension of existing systems will be allowed only if enough water is available to meet fire flow requirements per the city and the Uniform Fire Code.
6. All materials shall be new and undamaged, and the same manufacturer of each item shall be used throughout the work. Material and installation specifications shall contain appropriate requirements that have been established by the industry in its technical publications, such as ASTM, WSDOT, WEF and APWA standards. Requirements shall be set forth in the specifications for the pipe and methods of bedding and backfilling so as not to damage the pipe or its joints, impede cleaning operations and future tapping, nor create excessive side fill pressure or deformation of the pipe, nor seriously impair flow capacity.
7. All main lines must be designed to provide proper circulation of water and fire flow to all lands serviced by the development. All water mains shall be designed to prevent damage from superimposed loads. Proper allowance for loads on the water main due to the width and depth of the trench should be made. When standard strength water pipe is not sufficient, extra strength pipe shall be used, as determined by the city.
8. Prior to final inspection, all pipelines shall be tested, flushed and cleaned and all debris removed and disposed of at a location approved by the city. A pipeline “cleaning ball” of the proper diameter for each size of pipe shall be flushed through all pipelines prior to final inspection. Hydrant meters shall be acquired from the city and utilized by the contractor for all water withdrawn form the city’s system for flushing, construction, cleaning and testing purposes.
9. After all other work is completed and before final acceptance, the entire roadway, including, without limitation, the roadbed, planting, sidewalk areas, shoulders, driveways, alley and side street approaches, slopes, ditches, utility trenches and construction areas shall be neatly finished to the lines, grades and cross sections for a new street consistent with the provisions of this title and the original street section.
10. Water main extension projects shall be conveyed to the city for operation and maintenance upon final project acceptance.
B. Design Elements.
1. Water pipelines shall be laid only in dedicated streets, alleys or easements which have been, or will be prior to final acceptance, exclusively granted to the city.
2. The minimum size water main permitted shall be six-inch diameter when an adequate grid is provided. An adequate grid shall be defined as a piping system that measures no more than 600 feet on one side and the sum of the two sides shall not exceed 900 feet. Hydraulic calculations shall be submitted where required to validate designs involving two or more pressure zones, a booster pump, or a reservoir, as required by the engineer. Where an adequate grid is not established, pipe size shall be eight-inch diameter or larger as required to transport peak daily demand plus fire flow.
3. The water pipelines shall be located such that a minimum of 10-foot horizontal separation from proposed or existing parallel sewer mains and five-foot horizontal separation from all other parallel underground utilities is maintained at all times.
4. Ductile iron pipe shall be Class 52 and conform to AWWA C151 and C104.
5. The allowable cover (finished grade) for DI and PE pipe shall be no less than four feet nor more than 25 feet, as approved by the city engineer. The city reserves the right to require a minimum of four feet of cover unless topography, existing facilities or other future improvements prohibit this minimum cover for installation.
6. Fire hydrants are required approximately every 350 feet in the residential areas and are required every 300 feet in commercial, public and industrial areas. The size, type and location of fire hydrants shall meet the approval of the fire district, and all fire hydrants and installations shall conform to the current edition of the Uniform Fire Code.
7. Pipe runs from main line to standard hydrants less than 50 feet in length must be a minimum of six inches. Pipe runs from main line to standard hydrants more than 50 feet in length must be a minimum of eight inches.
8. One-inch minimum air and vacuum release valves shall be installed at principal high points in the system. High points should be avoided, to the extent possible. Valving shall be installed at all intersections, on each end of easement lines and in line at maximum spacing of 600 feet.
9. Dead end lines are not permitted, except in certain cul-de-sac streets, in which case hydrants must be provided at the end of the main.
10. Service connections shall be installed with pipe saddles for two-inch taps. Double strap saddles are required on 12-inch and larger diameter mains.
11. System valves shall be installed at intervals of no more than 1,200 feet.
12. Blow-off assemblies are required at all dead ends and all low points in the water distribution system, and shall be placed as determined by the city engineer.
13. Pressure reducing systems must be installed when static pressures exceed 80 psi.
14. Meters smaller than two inches shall be furnished and set by the city. Meters shall not be activated prior to payment by water user of all applicable hook-up fees. The city owns and maintains only appurtenances from and including the water meter to the water main.
C. General Construction Practices.
1. Except as otherwise noted herein, all work shall be accomplished as recommended in the current Standard Specifications and according to the recommendations of the manufacturer of the material or equipment used. Contractor shall have a copy of the specifications on the job site at all times. Contractor shall furnish a water-tight plug of the appropriate size which shall be installed in the end of the water main when work is delayed or stopped at the end of the work day.
2. Installation and testing shall be in conformance with the current edition of the Standard Specifications. The city must supervise the owner taking necessary samples for bacteriological tests. The system shall not be placed into service until the city provides written permission.
3. Hydrostatic testing shall be accomplished by the developer on lines before completion of backfilling, with the pipe joints accessible for examination. Sufficient backfill material shall be placed over the pipe barrel between joints to prevent movement.
4. Trenches shall be excavated to the line and depth designated by the approved plans and shall be excavated only to such widths as are necessary for adequate and safe working space. No manned trench width less than 30 inches will be allowed. The trench shall be kept free from water until complete. Surface water shall be diverted so as not to enter the trench. The developer shall maintain sufficient pumping equipment on the job to insure that these provisions are carried out.
5. The developer shall perform all excavation. Boulders, rocks, roots and other obstructions shall be entirely removed or cut out to the width of the trench and to a depth six inches below water main grade. Where material is removed from below subgrade, the trench shall be backfilled to grade with material satisfactory to the city. Unsuitable material below the depth of the proposed pipe shall be removed and replaced with satisfactory materials as determined by the city. The developer shall be responsible for meeting current Labor and Industry Trench and Shoring Protection and Washington State Safety Standards.
6. When trenching operations cut through asphalt/concrete pavement, the pavement shall be removed to a solid edge along the width of the trench as approved by the city engineer. The pavement shall be saw cut on a straight line and shall be beveled so that the cut will be approximately one inch wider at the top than at the bottom.
7. Trenching operations shall not proceed more than 200 feet in advance of pipe laying without written approval of the city.
8. Special treatment may be required at the discretion of the city for pipe laid in filled areas. This treatment may consist of compacting the backfill in six-inch layers, use of select backfill materials, use of mechanical joint ductile iron pipe in short lengths, welded HDPE pipe, or such other reasonable methods or combinations as may be necessary in the opinion of the city based upon topography, soil type and any other unique characteristics of the area.
9. Pipe shall be placed on a prepared subgrade of stable bedding material consisting of clean, granular, unfractured material. Bell holes shall be excavated so the pipe, when laid, will have a uniform bearing under the full length of the pipe. The developer shall be responsible for adequate support and bedding for the pipe. The trench shall be backfilled and compacted to no less than 95 percent of the maximum theoretical density.
10. Whenever the trench is excavated below the depth required for proper bedding, it shall be backfilled with bedding gravel and compacted, as provided above.
11. Backfilling and surface restoration shall closely follow installation and testing of pipe, so that not more than 200 feet of pipe is left exposed without express approval of the city. Selected backfill material shall be placed and compacted around and under the water mains by hand tools to a height of six inches above the top of the water main. The remaining backfill shall be compacted to current WSDOT standards. Where other agencies have jurisdiction over roadways, the backfill and compaction shall be done to the standard of the agency having jurisdiction.
12. Pipe trenches shall not be backfilled until the pipe and bedding installation has been inspected and approved by the city.
13. Final testing shall not be accepted until after the asphalt-treated base or finished paving is accomplished, all other underground utilities have been installed, and the lines have been satisfactorily flushed and cleaned in accordance with the requirements of the State Health Department and in a manner satisfactory to the city.
14. Any material, design, standard or testing not specifically addressed within these standards shall be as per the current edition of the Standard Specifications and the American Water Works Association Standards, which is hereby adopted by this reference.
15. The developer shall give city customers whose service may be disrupted no less than 24 hours’ notice prior to the interruption. (Ord. 01-062 § 5).
19.30.030 Plans and profiles.
A plan and profile of the proposed water system improvements showing the following data shall be submitted to the city for approval prior to any final development approval and construction. The plan shall be prepared and designed by a civil engineer currently licensed to practice in the state of Washington and shall contain the engineer’s stamp and signature certifying the design. It shall be submitted on a sheet size of 24 inches by 36 inches, and shall be drawn at a scale of one inch equals 50 feet. A one-and-one-half-inch margin shall be provided on the left edge, and a one-half-inch margin shall be provided on the other edges of the map. All maps shall be drawn on mylar sheets.
A. Plan. The plan shall contain the following information:
1. Show the locations of existing streets, rights-of-way, adjacent property lines, easements, utilities, driveways and water mains;
2. Show all proposed rights-of-way, easements and or proposed property lines;
3. Site topography shall be shown at a minimum of one-foot intervals, to include a minimum of five-foot internals within adjacent areas;
4. Show a vicinity and site location map;
5. Include all known existing structures, both above and below ground, that might interfere with the proposed construction, particularly sewer lines, gas mains, storm drains overhead and underground power lines, telephone lines and television cables;
6. Show all valves, fire hydrants, fittings and other appurtenances. Each shall be called out and located by stationing along the centerline of the street or baseline of the easement;
7. Show the size, material and length of each water line;
8. Show details as necessary to direct the contractor in making connections to the existing system and to protect existing facilities during construction of the new water line. Details shall be to scale drawings, which clearly show special water pipeline joints, connections, cross sections, water appurtenances and all other items as required by the city to clearly identify construction items, materials and/or methods.
B. Profile. A separate drawing showing the vertical profile of the proposed water system is required. The scale of these drawings shall be one inch equals 50 feet horizontal and one inch equals five feet vertical with horizontal grid of 50 feet and vertical grid of five feet.
1. Show the water line in profile and the existing and proposed ground lines. Identify the size, slope and horizontal length of the water line.
2. Above the ground line, indicate the profile location by street name or other right-of-way designation.
3. Show all crossing utilities and designate special materials or construction procedures that may be required.
4. Provide a legend to clearly illustrate the composition of the profile. (Ord. 01-062 § 5).