(A) Generally.
(1) Water design shall be in accordance with and shall meet all requirements of the State Administrative Code. It is the responsibility of the design engineer to ensure that these standards are met. In cases where statements herein conflict with such requirements, the more restrictive shall apply. A State Professional Engineer must sign and seal all water main construction plans and revisions submitted for city review.
(2) Water mains and appurtenances in a private road shall be installed and adjusted in the same manner as in publicly maintained streets. The water lines shall be encased in a 30-foot easement dedicated and accepted by the city.
(3) Water mains shall be extended to the end of the development (or across the frontage of the proposed development) to allow for future extensions, as determined by the city.
(4) Easement widths shall be a minimum of 30 feet. Large diameter pipes or deeper installations may require additional easement widths as required by the city.
(5) Water main designs shall consider the possibility of future road widening; projection of future street grades may require increased depth of pipe installation or additional easements.
(6) Water mains shall be extended in such a manner to accommodate future development. Blow-offs or hydrants shall be installed at the end of water mains to allow for flushing.
(B) Water systems design.
(1) Water mains shall be a minimum of eight-inch diameter. Larger mains shall be required at the discretion of the city if necessary to meet current or future demands. Two-inch mains may be used for cul-de-sacs serving a maximum of ten units.
(2) All pipe, except for two-inch mains, shall be ductile iron. All two-inch mains shall be PVC 1120, DR 21.
(3) Water mains will have a minimum of three feet of cover. Minimum cover shall be labeled in profile view.
(4) Fittings, including valves, shall be shown and labeled on the plan view for all water mains and at fire hydrants. Horizontal bends shall be labeled on plan views, and vertical bends shall be labeled on profile views. Maximum allowable deflection of joints shall be three degrees. All valves shall be located by road station.
(5) Hydrants shall be placed a maximum of 500 feet apart and at intersections, and as directed by the City Fire Department. Distance shall be measured along the road centerline. Hydrants may be required on both sides of the street for multi-lane streets, as requested by the City Fire Department. All hydrants shall have integral five-inch Storz connections as shown in the standard details.
(6) Hydrants are to be placed on a lot line and at intersections whenever possible.
(7) Meter box and cleanout placement should be at the center of the lot for which the connection is intended with not more than 30 inches of lateral separation between them (center to center spacing). Meters and cleanouts shall not be placed in sidewalks or driveways. Cleanouts on private property in paved areas shall be traffic-bearing.
(8) All dead-end mains must have a hydrant or a blow-off. No connections shall be made beyond the hydrant or blow-off.
(9) Existing stub-outs shall be shown on plan view with as-built distances.
(10) (a) Reduced pressure backflow preventers are required for all multi-family, industrial, commercial water services and Water Pressure Zones 4 and 5. Double detector checks are required for all nonhazardous fire and sprinkler connections. Hazardous fire and sprinkler connections require a reduced pressure detector assembly. All detector assemblies must be equipped with a Dialog 3G wireless RF as manufactured by Master Meter.
(b) All properties that require irrigation are required to have a reduced pressure backflow preventer installed and tested prior to final approval.
1. Solid hard pipe is required within three feet on both sides of a backflow prevention device. This includes double check valve assembly and reduced pressure valve assembly.
2. Backflow prevention devices that requires atmospheric pressure to function properly need to be installed within the proper manufacture distance above grade.
(11) Concrete blocking per the standard details shall be installed at all horizontal bends and fittings. If restrained pipe is used instead of concrete blocking, pipe shall be designed using Type 2 laying conditions, safety factor of 1.5, and test pressure of 200 psi. Restrained joint pipe shall be used for all vertical bends in lieu of concrete blocking.
(12) There should be at least ten feet of horizontal separation between water and sewer mains.
(13) (a) Vertical separation of lines shall be as follows:
1. Twelve-inch minimum between storm and sanitary;
2. Twelve-inch minimum between storm and water; and
3. Eighteen-inch minimum between water and sanitary (water over sewer).
(b) Material for water and sewer mains shall be ductile iron, ten feet each side of the crossing, if vertical separation cannot be maintained.
(14) Proposed water lines shall be placed four feet behind the back of curb. Valves shall not be located in ditchlines.
(15) Proposed water lines shall be placed a minimum of five feet off edge of pavement of all NCDOT roads and existing ribbon-paved roads. A NCDOT right-of-way encroachment agreement will be required for work within the right-of-way of any state maintained road.
(16) Existing paved roads shall be bored or tunneled to allow for water main and service installation. Restrained joint or mechanical joint pipe shall be required inside encasements (label on plans).
(17) Water mains shall be designed to provide a minimum residual service flow of ten gallons per minute (gpm) at a pressure of 20 pounds per square inch (psi) at any point within the system during periods of combined average daily flow and fire flow.
(18) The minimum average daily demands for residential units shall be established as 120 gallons per day (gpd) per bedroom with each residential unit having a minimum of two bedrooms. Average daily demand for non-residential demand shall be based on the proposed use and fire flows.
(19) Fire flows shall be established in accordance with the latest requirements of the State Insurance Service Office. A minimum fire flow of 1,000 gpm shall be used for residential developments and 1,500 gpm for non-residential. When requested by the city, the engineer of record shall submit the calculations of fire flow requirements and domestic water demands for the project for review and approval.
(20) The water distribution systems and any extensions shall be designed to supply the demands of all customers while maintaining the following minimum pressures and velocity:
(a) Forty psi for maximum daily flow;
(b) Thirty psi for peak hourly flow;
(c) Twenty psi for instantaneous flow plus fire flow; and
(d) Four feet per second (fps) for flushing.
(21) (a) Average daily flow may be estimated at 1,500 gpd per acre. This estimate should be modified as necessary based on specific zoning and land use data.
(b) Maximum daily flow and peak hourly flow shall be determined as follows.
1. Maximum daily flow equals average daily flow times 1.5.
2. Peak hourly flow equals average daily flow times 2.1.
(22) Transmission mains larger than 12 inches shall be designed on the basis of the most recent system wide demand data and hydraulic modeling.
(C) Water system specifications.
(1) Water mains.
(a) Ductile iron pipe shall be marked with the manufacturer’s name or trademark, size, weight, thickness class, the date of manufacture and the word “Ductile”.
(b) Ductile iron pipe (DIP) shall conform to ANSI A21.51 (AWWA C151), grade 60-42-10 for ductile iron pipe centrifugally cast in metal molds or sand-lined molds.
(c) All ductile iron pipe shall conform to ANSI A21.50 (AWWA C150) for thickness design and shall be supplied in 18- or 20-foot nominal lengths. Minimum pressure class shall be 350 for pipe 16 inches and smaller. Pipe larger than 16 inches shall be pressure class 250.
(d) Push-on joints, joint accessories and gasket lubricant shall conform to AWWA C111. The manufacturer shall furnish push-on joints with a single rubber gasket that fits into the bell end of the pipe and the gasket lubricant.
(e) All plugs, caps, tees and bends shall be provided with 3,000 psi concrete thrust blocking.
(f) PVC pipe shall be used for two-inch water mains. Ductile iron pipe is required for all water mains larger than two-inch. Two-inch water main pipe shall be PVC 1120 in accordance with ASTM D2241. Pipe shall have an SDR of 21 or less, and be designed for a working pressure of 200 psi. PVC water main pipe shall be installed with a tracer wire.
(2) Restrained joint pipe. Ductile iron flexible restrained joint pipe shall be installed at the locations shown on the engineer’s drawings. All restrained joint pipe shall have flexible push-on joints designed to deflect a minimum of three degrees per joint. At locations where field cutting of restrained joint pipe is required, a special field cut kit shall be used by the contractor. Field welding will not be allowed. Field cut kits shall provide restraint joint equivalent to factory manufactured restrained joint pipe. Field kits shall be provided by the pipe manufacturer. Field kits shall be used only in instances that it is absolutely necessary to cut restrained joint pipe sections, not in lieu of restrained joint pipe. Restrained joint pipe with a gripping gasket as the only means of providing restraint will not be allowed. Pipe shall be Flex-Ring by American, TR Flex by U.S. Pipe, Snap-Lok by Griffin or Super-Lock by Clow.
(3) Gate valves.
(a) Gate valves shall be used for all pipe 16 inches and smaller. Gate valves shall be resilient wedge type with mechanical joint ends and a non-rising stem. Valves shall meet ANSI/AWWA C509 or C515. Joints shall meet ANSI/AWWA C111. Valves shall open counterclockwise.
(b) Working pressure shall be 250 psi.
(c) Iron body shall have 10 mils of epoxy coating, inside and outside. Epoxy coating shall meet ANSI/AWWA C550. Iron wedge shall be symmetrical and fully encapsulated with molded rubber with no exposed iron.
(d) Valves shall be Mueller A23 60-20, or approved equal.
(4) Valve boxes.
(a) Valve boxes shall be installed for all new valves.
(b) Valve boxes shall be adjustable slip-joint or screw type in three pieces. The lower (base) piece shall be belled at the bottom to fit around the stuffing box gland and rest on the valve bonnet. The upper piece shall flare at the top end to receive the lid. Lids shall be marked “WATER” in raised letters.
(c) Valve boxes shall be centered and plumb over the operating nut and installed so as not to transmit shock or stress to the valve.
(5) Hydrants.
(a) Hydrants shall be Mueller Centurion with National Standard Threads and open left.
(b) Hydrant shall be installed in accordance with fire codes, Fire Department requirements, and at the end of all dead-end lines six inches and larger.
(c) Locate and install hydrants per city standard details. Hydrants may not be located next to walls or other obstructions.
(d) All hydrants shall have a gate valve. Valve stem shall extend to within six inches of the finished grade.
(e) Pump nozzle shall be one-piece design compatible with five-inch Storz hose coupling. Nozzle shall be integral to the fire hydrant. Storz adapters will not be permitted.
(f) Hydrants shall be painted yellow in accordance with Fire Department specifications.
(6) Water services.
(a) Service line shall be copper tubing for water service connections, ASTM B-88 Type K with fittings conforming to AWWA C-800.
(b) Meter setter (meter yoke) shall be of copper and brass of the proper size for the service on which they are installed. The inlet shall be vertical and the outlet horizontal. The setters shall be equipped with an ASSE approved model angle dual check valve and have a lock wing ground key angle meter stop. Suitable adapters for coupling to service pipe shall be provided. Meter setters for three–quarter inch and one-inch services shall be Mueller H1404-2A, or approved equal meeting the same dimensional and performance standards. Meter setters for two-inch services shall be Mueller B-2423.
(c) Corporation Stops shall be of brass, meet AWWA C-800, and have a minimum pressure rating of 150 psi. Inlet threads shall be AWWA standard and the outlet shall have a compression connection. Where dictated by the tapping angle, eighth or quarter bend couplings shall be provided. Suitable brass adapters for coupling to service pipe shall be provided. Corporation stops for three-quarter inch services shall be Mueller Hl5008 (CC x CTS110) or an approved equal meeting the same dimensional and performance standards. Corporation stops for one and one-half inch and two-inch services shall be Mueller B-25008. On PVC pipe, corporation stops shall be installed with a tapping saddle as specified in division (C)(5)(d) below. On ductile iron pipe, services one inch and smaller may be direct tapped; larger sizes, all services shall be installed with a tapping saddle or tee.
(d) Tapping saddles shall be provided for all corporation stops installed on PVC pipe and for services larger than one inch on ductile iron pipe. Saddles for two-inch PVC line must be brass with two-piece hinged construction, Mueller S-13420 or approved equal. Saddles for larger pipe shall be ASTM A536 ductile iron with double straps suitable for CC taps. Straps shall be ASTM A108 carbon steel, electogalvanized with a dichromate seal. The saddle shall have an epoxy coating. Saddles for ductile iron pipe shall be Smith-Blair 313, or approved equal.
(e) Meters shall be Multijet body with Allegro AMI registers as manufactured by Master Meter of Fort Worth, Texas. No substitutions are allowed.
(f) Meter Boxes and covers for three-quarter inch and one-inch services shall be made of plastic, Carson 1015, and conform to the minimum dimensions shown in the city’s Standard Details. Lids shall be of a design appropriate for detection of the radio read meter signal. Lids shall be clearly marked “WATER”. Meter boxes for one and one-half inch and two-inch services shall be Sigma Russell MBX-5A Super Jumbo cast iron meter box. Concrete meter vaults are required for three-inch and larger services, as shown on the standard drawings.
(g) Once the final asphalt surface has been placed, a one-year moratorium shall be in effect for any open cuts within the road.
(7) Water installation.
(a) Taps shall be made perpendicular to the water main and spaced at least 12 inches apart along the length of the main line using materials and methods in conformance with these specifications. Taps must be made on “wet” water mains that have been pressure tested, chlorinated and flushed.
(b) Meters shall be located at the edge of the right-of-way at the center of the lot, but in no case closer than 24 inches to any wall, building or obstruction. The location of each meter shall be verified with the city.
(c) Pipe shall be cut to the required length and properly laid in the service ditch with adequate provisions to protect against expansion and contraction.
(d) Water service lines shall be installed with 20 to 30 inches of cover unless otherwise approved by the city due to unusual circumstances.
(e) 1. Pipe shall be laid with bell ends facing in the direction of laying, unless otherwise approved by the engineer. Every precaution shall be taken to prevent foreign material from entering the pipe while it is being placed. Trench width shall be as shown on the standard drawings.
2. At times when pipe laying is not in progress, the open ends of pipe shall be closed by a water-tight plug or other means approved by the engineer. This provision shall apply during the noon hours as well as overnight. If water is in the trench, the seal shall remain in place until the trench is pumped completely dry.
3. Where the bottom of the trench at subgrade is found to be unstable or to include ashes, cinders, all types of refuse, vegetable or other organic materials, or large pieces of fragments of inorganic material which, in the judgment of the city, should be removed, the contractor shall excavate and remove such unsuitable material to the width and depth ordered by the city. Before the pipe is laid, the subgrade shall be made by backfilling with aggregate base course, #67, in six-inch uncompacted layers. The layers shall be machine tamped, as directed by the city, so as to provide a uniform and continuous bearing and support for the pipe at all points along the pipe length. Suitable backfill material shall be brought in as required and compacted in eight-inch lifts to bring the trench back to the desired grade.
4. Pipe protection cover to a depth of 12 inches above the top of the pipe shall consist of select material free from rocks larger than two inches, and may require hand placement. However, should the material excavated from the trench be completely free of rock larger than two inches, the trench may be machine backfilled. Should the excavated material not be suitable for machine backfill or hand placement, the contractor may, at his or her option, use #67 stone to a depth of six inches above the top of the pipe. The trench may then be backfilled as outlined in divisions (C)(7)(e)5. and (C)(7)(e)6. below.
5. After the pipe protection cover has been placed, the trench excavated areas shall be backfilled with excavated material free from rock larger than 12 inches.
6. All pipeline trench backfill shall be placed in six-inch layers and compacted using a mechanical, hydraulically-powered vibratory trench compactor or other equivalent equipment. All trench backfill shall be compacted to 95% (minimum) of that of the adjacent undisturbed soil.
(f) The contractor shall fill and flush the newly constructed lines and visually check all valves and fire hydrants to assure proper operation.
(g) All pipe shall be tested as set out in AWWA C600, latest revision. Tests will be conducted after the line is completed and backfill made, except those areas around valves and fire hydrants may be left open at the discretion of the contractor.
1. The line shall be tested at 150% of the designed operating pressure or a minimum of 200 psi, whichever is greater. The engineer will assist the contractor in determining test pressure at any given point. The contractor shall provide all pumps or other equipment necessary to maintain the test pressure within five psi at the test point for a period of two hours.
2. The leakage test shall be conducted concurrently with the pressure test. LEAKAGE shall be defined as the quantity of water that must be supplied into the newly laid pipe, or any valved section thereof, to maintain pressure within five psi of the above specified test pressure after the air in the pipeline has been expelled and the pipe has been filled with water. Leakage shall not be measured by a drop in pressure in a test section over a period of time.
3. The contractor shall be responsible for providing all pumps, equipment and appurtenances necessary to maintain the above specified test pressure, and to meter the water supplied to the line in order to maintain the test pressure within the limits specified.
4. Leakage for water pipe shall be within the limits set out in AWWA C600, latest revision. Should any test of pipe laid disclose leakage greater than that specified, the contractor shall, at his or her own expense, locate and repair the defective joints, and retest the line until the leakage is within the specified allowance.
5. a. No pipe installation will be accepted if the leakage is greater than that determined by the following formula.
b. In inch-pound units, L = SDP
133,200
c. Where:
I. L equals allowable leakage, in gallons per hour;
ii. S equals the length of pipe tested, in feet;
iii. D equals the nominal diameter of the pipe, in inches; and
iv. P equals the average test pressure during the leakage test, in pounds per square inch (gauge).
(h) 1. After successful testing, the water main shall be emptied of water. The line shall then be disinfected in accordance with AWWA C651, latest revision, for “Disinfecting Water Mains”, continuous feed method, except that the placing of hypochlorite granules into the main during construction will not be permitted.
2. All water mains installed shall be thoroughly flushed and disinfected before being placed in service. This work shall be done under the direct supervision of the engineer’s inspector. The contractor shall supply all labor, equipment and materials necessary for carrying out this work. After a thorough flushing and cleaning out, sufficient chlorine compounds shall be introduced in the lines to produce a chlorine concentration of at least 100 parts per million. The chlorine solution shall be retained in the lines for at least 24 hours. At the end of this period, the chlorine residual shall be at least ten parts per million. The lines will then be flushed sufficiently to clear them of chlorine exceeding one part per million. Samples of water from the mains will then be taken and analyzed for bacteriological purity. If the mains fail to meet the bacteriological standard for purity, disinfecting and flushing will be repeated until such standards have been met. All analysis for chlorine and bacteriological purity will be by the contractor at state approved laboratories. The city shall be furnished copies of certified lab results.
3. After sterilization is complete, the contractor shall then flush the sterilizing solution from the lines, and the lines will then be placed into service. Chlorinated water shall not be discharged into or near streams or other water bodies.
(D) Construction.
(1) Installation must meet these specifications and the standard drawings.
(2) Water connection location shall be stamped into the curb at the exact location of the crossing (“W” for water). All valves shall be indicated by a “V” stamped in the curb at a point closest to the valve.
(3) Contractors will be responsible for a one-year warranty beginning the date final construction acceptance is given by the city.
(4) (a) The city will not maintain any newly installed infrastructure until final acceptance of the project is granted by City Council.
(b) The one-year warranty period will not begin until final acceptance. The developer may not request final acceptance until all deficiencies have been satisfactorily addressed as determined by the city and a set of as-built drawings certified by the engineer of record have been submitted, reviewed and accepted by the city.
(c) It shall be the responsibility of the developer to request the final acceptance.
(Ord. passed 9-27-2021) Penalty, see § 153.999