A. WATER LINE MATERIALS
1. Ductile Iron Pipe
a. All ductile iron pipe shall be Class 50, 51, or 52 designed in accordance with AWWA Standard C-150. Design shall be done for external and internal pressures separately, using the larger of the two for the net design thickness. An additional allowance shall be made for corrosion and casting tolerances. The thickness design for external and internal pressures shall use the following conditions:
1. 3' minimum cover and maximum cover as shown on the plans;
2. Laying condition - Type 1
3. A minimum working pressure of 150 psi.
4. A surge pressure of an additional 100 psi.
b. The minimum class thickness shall be Class 50.
c. The ductile iron pipe shall be manufactured in accordance with applicable requirements of AWWA Standard C-151. The ductile iron pipe shall be supplied in nominal lengths of 18 or 20 feet.
d. The ductile iron pipe shall be cement-mortar lined with a seal-coat in accordance with AWWA Standard C-104, and bituminous coated in accordance with AWWA C-151.
e. Pipe joints shall be mechanical or “push-on” manufactured in accordance with AWWA Standard C-111 for “push-On” and AWWA Standard. C-111 for mechanical joints and shall be rated for a minimum 250 psi working pressure.
f. Each joint of ductile iron pipe shall be hydrostatically tested to 500 psi at the point of manufacture before the outside coating and inside lining are applied. Testing may be performed prior to machining bell and spigot. Failure of ductile iron pipe shall be defined as any rupture or leakage of the pipe wall.
g. All materials used in the production of the pipe are to be tested in accordance with AWWA Standard C-151 for their adequacy within the design of the pipe, and certified test results are to be provided to the County upon request. All certified tests, hydrostatic, and material, are to be performed by an independent testing laboratory at the expense of the pipe manufacturer.
h. Push-on and mechanical joint pipe shall be as manufactured by the American Cast Iron Pipe Company, United States Pipe and Foundry Company, Griffin Pipe Products Company, McWane Cast Iron Pipe Company.
i. Restrained joints shall be TR Flex or Lok Tyte as manufactured by U.S. Pipe, Lok-Fast or Lok-Ring as manufactured by American Pipe or Super-Lok as manufactured by Clow. Restrained joints shall be used when the pipe locations excluded the use of thrust blocks for proper support.
2. Ductile Iron or Cast Iron Fittings
a. All fittings shall be manufactured in accordance with AWWA C-110 or C-153 for standard fittings and ductile iron compact fittings, respectively. The fittings shall be tested, and the manufacturer shall provide certified test results when requested by the County. This testing shall include hydrostatic proof testing of the fittings.
b. All fittings shall be of the mechanical joint type. Mechanical joints shall be manufactured in accordance with AWWA Standard C-111. Gaskets shall be plain rubber, of heavy sectionand high durometer, single molded. Lubricant shall be a non-toxic, tasteless, odorless grease that will not support bacteria.
c. All fittings shall be cast iron or ductile iron and shall have a minimum working pressure rating of 250 psi and a minimum iron strength of 25,000 psi.
d. All fitting interiors shall be cement-mortar lined in accordance with AWWA Standard C-104, and the outside shall be bituminous coated.
3. Polyvinyl Chloride Pipe (PVC) and Fittings
a. Polyvinyl Chloride Pipe 4” in Diameter and Larger – PVC pipe in sizes 4” diameter and above, shall meet the requirements of AWWA C900 and C905. The C900 Pipe shall have an SDR of 18; the C905 shall have an SDR of 18 or 25. Each pipe shall be stamped or marked with the NSF-PW certification. Joint shall be the push-on type with rubber ring gaskets conforming to ASTM D3139 and ASTM F477 such as Ring Tite or equal. All Fittings shall be mechanical joint cast iron or ductile iron as specified in Section 2 above.
b. Polyvinyl Chloride Pipe 2” in Diameter and Smaller – PVC pressure pipe 2” in diameter and smaller shall conform to the requirements of ASTM D2241 and D1784. The pipe shall bear the National Sanitation Foundation stamp of approval. The pipe shall have push-on bell and plain-end gasketed type joints. The bell shall consist of an integral wall section with strength equal to that of the pipe. The pipe shall be Class 200 with a SDR of 21.
4. GATE VALVES
a. Gate valves shall be iron body type, resilient seated wedge type, non-rising stem, and shall be designed for 200 psi working pressure. The valves shall conform to the requirements of the AWWA Specifications for “Resilient-Seated Gate Valves” C509, and turn counter-clockwise to open. The valve shall have no metal to metal wedging and the discwedge shall have the same configuration and design on both sides. The valve shall have an unobstructed waterway when fully opened equal in diameter to the nominal valve size.
b All internal and external surfaces shall be coated with epoxy to a minimum thickness of 8 mils. Said coating shall be non-toxic, impart no taste to water and shall conform to AWWA C550. Said coating shall be applied prior to assembly such that all exposed external areas, including end connection bolt holes, body to bonnet bolt holes, etc. shall be coated with epoxy.
c. Valves shall be provided with two O-ring stem seals with one O-ring located above and one O-ring below the stem collar. The stem shall be permanently lubricated. All seals between valve parts such as body and bonnet, bonnet and bonnet cover, shall be O-rings. The stem shall be provided with an external dirt and weather seals independent of the O-ring pressure seal.
d. Valves shall have mechanical joint ends, unless flanged ends are called for in the plans, in which case the flanges shall be faced and drilled to the ANSI, Class 125 Standard.
e. All valves shown to be located in valve boxes shall have 2-inch square operating nuts. The Contractor shall furnish the Owner with two “T” handled operating wrenches for these valves. Where the valves are located above normal reach of the operator, they shall be equipped with chain wheels, chain guides, and operating chains as required, whether so indicated on the Drawings or not. All other valves shall be equipped with hand-wheels, indicating the direction of turn to open or close the valve. The valves shall be as manufactured by Mueller, American Darling, Kennedy, Clow, or approved equal.
5. Air Release Valves
a. Air release valves shall be constructed of cast iron body and cover (ASTM No. A48, Class 30), Bronze trims (ASTM No. B143), Stainless steel floats (ASTM No. A240) with shockproof synthetic seats for 150 psi maximum pressure. The air release valve shall have ¾ inch inlet and 1/8 inch orifice. The piping used for the installation shall be schedule 40 galvanized steel. Air release valves shall be Val-Matic Model No. 25 or approved equal.
6. Service Saddles
a. Service saddles shall be provided on all service connections 2” in size and smaller. The saddle used shall be specifically designed for the type and size main being tapped. The saddle body shall be constructed of high tensile ductile iron (ASTM A5365) or bronze. The strap (s) and nuts shall be constructed of bronze or of 18-88 stainless steel. The saddle shall have a double strap, but shall have a minimum of 2 inches total strap width on the pipe. .
7. Valve Boxes
a. The Contractor shall furnish and install cast iron valve boxes for all buried valves at the locations shown on the drawings. They shall be adjustable telescope sliding action units, suitable for use under heavy traffic. The covers shall be marked “WATER” and bases shall be the round types. All valves deeper than 4 feet shall have valve stem extenders pinned at the valve. All valves shall be capable of being operated by a 48- inch valve wrench. All valve boxes shall be placed so as not to transmit shock or stress to the valve and shall be centered and plumb over the operating nut of the valve.
8. Fire Hydrants
a. Hydrants will be three way compression type with two 2-1/2” hose nozzles and a 4-1/2” pumper nozzle, all with National Standard hose threads and operating nut, and will have 5-1/4” valve opening and a 6” mechanical joint base connection and will be as manufactured by Mueller Company Centurion with bronze bushed shoe, or approved equal. Hydrant shall be of sufficient length to provide a minimum of three feet bury and be of the breakaway impact type. Working pressure of 200 psi and tested to a hydrostatic pressure of twice the working pressure with valve open and closed.
b. Hydrants shall be open-left type and shall have a six-inch hub- end or mechanical joint elbow. Hydrant barrels shall measure 3- 1/2 feet minimum from the ground line to the bottom of the connection pipe and will be equipped with safety flanges and “O” ring seals. Hydrant barrels shall be longer where necessary to obtain proper pumper nozzle height. All cast iron parts below ground line will be hot-dipped in black asphaltum varnish and all parts above ground will be painted the color normally used by Rockingham County. Hydrants will further be in accordance with AWWA Specifications C502.
c. Bronze to bronze threads shall be provided between the hydrant seat or seat ring and the seat attaching assembly. All hydrants must include cast or ductile epoxy lined shoe, rubber drain seals and positive, protective valve stop device.
a. Taps 1" and smaller may be made directly into ductile iron pipe with a corporation cock. For taps 2" diameter or less into PVC and taps greater than 1" but less than 2" in ductile iron, saddles and corporation cocks shall be used.
b. Unless otherwise noted, new service connections shall be ¾”. All service connections 2” and smaller shall be provided with a corporation stop. The corporation used for tapping the water main shall be of brass construction conforming to AWWA C800 and shall have AWWA threads on the inlet. The outlet of the corporation stop shall be designed to accept the type of service pipe being used. When the water line is below 4” in diameter, a tee and globe valve will be used.
c. Taps larger than 2” or greater than one half the diameter of the main line shall be made using the appropriate size tapping sleeve and valve. On a “dry line”, the connection shall be made with a tee and valve.
2. Service Lines
a. Service lines shall be a minimum of 3/4". Lines 3/4"-1" shall be type "K" soft copper. Fittings shall be flared copper type brass fittings. Lines greater than 1" up to 2" in diameter shall be type "K" soft copper. Service lines greater than 2 shall be ductile iron pipe with cast or ductile iron fittings or PVC as specified in 3(a) and 3(b) or
b. Polyethylene service pipe shall be ¾”-inch diameter unless otherwise noted on the plans. Polyethylene pipe shall conform to ASTM 2739 with SDR 9. The pipe shall be rated for 160 psi service and be approved by National Sanitation Foundation for potable water use.
3. Meter setters and Boxes
a. Meter boxes shall be cast iron with a cast iron cover. The box shall be designed to withstand light traffic. The box shall be 18” in length and depth. The cover shall adapt to the box and the lid opening shall be a minimum of 10-3/8” in width (Dewey Bros. MBX-2 Type “C” or equal).
b. Commercial and industrial meters shall be of a size and configuration approved by the County. All meters over 1" shall have a bypass with a lockable valve. If meter by-pass is to be used for purposes other than emergency fire protection, a meter shall be installed.
c. Meters shall be purchased from the County and set by the County at the Owner/Customer’s expense.
d. Copper setters shall be made using lead-free solder and having a dual angle check valve at the meter outlet and padlock wings on the key valve at the meter inlet of the copper setter. The copper setter shall be sized for a 5/8” x ¾” meter and shall be a Ford 70 Series Model No. VHH-72-9WE or equal with flare copper by Double Purpose Coupling.
4. Multiple Meter Assemblies
a. The use of multiple meter assemblies must be approved by the County Engineer. When allowed, meter assemblies shall be as shown in the standard details. All piping shall be provided with unions for easy disassembly. All pipe shall be of the same quality as used for individual meters. Boxes and setters shall be subject to approval by the County. Meters shall be purchased from the County, and set by the County at the Owner/Customer’s expense.
5. Backflow Preventers
a. Meters 3/4" and smaller shall be supplied with integral backflow preventers as specified for copper setters in 3-d.
b. For meter services larger than 3/4" and up through 2", reduced pressure type backflow preventer, Model FRP as manufactured by Beeco, or approved equal, installed in a separate meter box on the customer's side of the meter shall be furnished and installed by the customer.
c. For meter services larger than 2" inches, reduced pressure type backflow preventers, Model 6CM as manufactured by Beeco or approved equal, shall be installed by the customer in a separate vault on the customer's side of the meter.
d. All backflow preventers shall meet approval of the U.S.C. Cross Connection Control Lab.
WATER SYSTEM DESIGN CRITERIA
1. Minimum main line pipe size shall be 6 inches for fire hydrants. Minimum main size shall be 2 inches, with a maximum of 20 residences connected. A 2-inch main shall not exceed 1,000 feet in length.
2. Minimum pressure in system shall be 20 psi at peak demand (fire flow).
3. Minimize dead ends, and where they must occur provide a fire hydrant per standard detail or flushing valve. The fitting required at a dead end line shall be determined by the County Engineer.
4. Minimum cover shall be 3 feet.
5. Install valves as follows: three at a cross; two at a tee; one on a single hydrant branch.
6. Install valves on loops so a maximum of 600 feet can be taken from service without effecting other areas.
7. Water mains shall be installed with a minimum of 10' horizontal separation from sewer lines. Where this is not possible, as determined by the County Engineer, the water line shall be a minimum of 18 inches above the top of the sewer. Crossing of water main over the sewer with less than 18” separation requires ductile iron pipe for both sewer & water for a minimum of 10’ on each side of crossing. Crossing of water main under a sewer main requires ductile iron pipe for both sewer & water for 10’ on each side of crossing.
8. Maximum spacing between fire hydrants shall be 1,000 feet, (500) foot radius.
9. Backflow preventers shall be supplied for every service connection. For services up to 3/4 inch it shall be integral with the meter, for services larger than 3/4 inch up to 2 inch it shall be in a separate meter box and for backflow preventers larger than 2 inches, a vault shall be provided.
10. Vaults shall have aluminum hatch doors with lift assist and shall be capable of withstanding expected traffic loads.
11. All bypasses, other than those with locking valves shall have detector check valves installed.
12. Reduced pressure principle backflow preventers are to be installed on all lines to installations involving wet manufacturing processes, chemical or boosted sprinkler systems, irrigation systems, or any other hazardous locations as determined by the County Engineer.
13. Water line drawings and specifications shall bear the seal of a Registered Professional Engineer licensed to practice in North Carolina and the installation of the system shall be inspected and certified by the Engineer in accordance with N.C.A.C.IOD.0903.
14. Water lines shall have a 30' permanent easement (15’ each side of center line) in the County's name. A 50' temporary construction (25' each side of center line, unless directed otherwise) easement shall be provided.
WATER PLANS CHECKLIST
Water line plans should, at the minimum, show the following information:
1. Locations and dimension of all existing and proposed street and sanitary sewer rights of way.
2. Sanitary sewer and storm drain systems dotted in.
3. Invert of storm drains at crossings, storm drains closely paralleled by water lines.
4. Invert of sanitary sewers at crossings and at upstream and downstream manholes.
5. Size, lengths (or stationing), and type of lines (water, storm, sanitary).
6. All tees, gate valves, fire hydrants and blow offs properly labeled.
7. Legend of symbols.
8. North arrow.
9. Street names.
10. Location(s) of nearest existing valves.
11. Existing pavement, and if applicable, width and length of cut.
12. Include "General Notes on all plans.
13. Registered Engineer's seal and signature.
14. Vicinity map, showing location of lines and a visual plan page index.
15. Location of existing utilities.
E. WATER LINES - GENERAL NOTES
1. Concrete blocking (3000 psi) shall be placed at all bends & tees or as required.
2. Standard depth of cover shall be 3 feet except at valve or hydrant locations or other special situations. Cover is based on ground elevation or as indicated on the plans.
3. Provide concrete pad (30" x 30" X 6") at all valve boxes.
4. Extensions for valve boxes, when required, shall be 5" soil pipe.
5. All pavement cuts, concrete or asphalt shall be replaced according to the standard details of the NC Department of Transportation.
6. Pavement cuts shall be replaced immediately after backfilling initial cut either with permanent replacement or a temporary replacement of 1-1/2" of I-2 or 4" of H-Binder.
7. Repairs to main breaks:
(a) Bell clamps will not be allowed, except in special situations and as directed by the County Engineer.
(b) Solid sleeves shall be used for connecting spigot ends and shall be of the long pattern type.
8. In any instance where it will be necessary to have the water shut off on existing mains in order to make a tie-in, the work shall be done under the direct supervision of the County Engineer and at the time least inconvenient to the water customers involved.
9. When a water main crosses an existing sewer main, the contractor shall replace the sewer pipe spanning the ditch with ductile pipe when the following conditions occur:
(a) Anytime a water main is installed under a sewer main.
(b) When a water main is over a sewer main and the vertical distance between the two mains is 18" or less.
10. Water lines shall be disinfected and hydrostatically tested in accordance with all State and County requirements.