Section IV – Water Distribution System
PART 1 – GENERAL
1.01 WORK INCLUDED
A. The work under this Section includes providing a complete system of water distribution pressure piping and appurtenant items.
1.02 RELATED WORK
A. Section I – Trenching, Backfilling and Compacting for Utility Systems
B. Section III – Concrete
1.03 QUALITY ASSURANCE
A. Design Requirements
1. Water mains and services shall be laid with a minimum cover of 30-inches and a maximum cover of 48 inches below finished grade, unless other wise indicated.
2. Water mains shall be a minimum of three (3) inches in diameter and shall be constructed of the materials as set forth herein.
B. Pipe Inspection: The Contractor shall obtain from the pipe manufacturers a certificate of inspection to the effect that the pipe and fittings supplied for this Contract have been inspected at the plant and that they meet the requirements of these specifications. All pipe and fittings shall be subjected to visual inspection at time of delivery by rail or truck, also just before they are lowered into the trench to be laid, and joints or fittings that do not conform to these specifications will be rejected and must be removed immediately by the Contractor. The entire product of any plant may be rejected when, in the opinion of the Owner, the methods of manufacture fail to secure uniform results or where the materials used are such as to produce inferior pipe or fittings.
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C. Prevention of Electrolysis:
1. Where deemed necessary, electrolytic action through the contact of dissimilar metals, shall be prevented by either:
a. The separation of one material from the other by means of an insulating or dielec tric coupling, or
b. The use of alternative materials, as directed by the Engineer.
1.04 SUBMITTALS
A. Shop Drawings:
1. In general, 6 copies of the following shop drawings shall be submitted to the Engineer for approval prior to construction:
a. Mill test certificates or certified test reports on pipe
b. Details of restrained and flexible joints
c. Hydrants
d. Meter vault and boxes
e. Valves and valve boxes
f. Service connection assemblies
2. A copy of the approved shop drawings shall be sent to the Owner prior to delivery of materials.
B. Record Information:
Record drawings shall be prepared and submitted to Gulf Shores Utilities. These record drawings shall specifically locate via discrete, manual measurements each and every component of the installed system, including: main line alignment and depth, transitions in main line pipe material, main line fittings, valves, fire hydrants, blow-offs, and any other such items or project elements as may be required.
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Location by triangulation measurements will be strictly enforced. Stationing of features from a remote initiation point will not be acceptable. Use of intangible features (e.g. Survey Lines, Property Lines, etc.) as a reference point will not be acceptable.
1.05 JOB CONDITIONS
A. Water in Excavation: Water shall not be allowed in the trenches while the pipes are being laid and/or tested. The Contractor shall not open more trench than the available pumping facilities are able to dewater to the satisfaction of the Engineer. The Contractor shall assume responsibility for disposing of all water so as not to injure or interfere with the normal drainage of the territory in which he is working. In no case shall the pipelines being installed be used as drains for such water, and the ends of the pipe shall be kept properly and adequately blocked during construction by the use of approved stoppers and not by improvised equipment. All necessary precautions shall be taken to prevent the entrance of mud, sand, or other obstructing matter into the pipelines. If on completion of the work any such material has entered the pipelines, it must be cleaned as directed by the Engineer so that the entire system will be left clean and unobstructed.
PART 2 – WATER MAINS
EFFECTIVE JANUARY 1, 2014, ALL MATERIALS SHALL MEET NSF/ANSI 61 STANDARDS (LEAD FREE MATERIALS)
A. APPROVED PRODUCT
PVC PIPE: SDR 21 CLASS 200
DUCTILE IRON PIPE: CLASS 51 FITTINGS: CLASS 350 D.I.
JOINT RESTRAINTS: M.J. RETAINER GLANDS, FIELD LOCK GASKET W/SJ, 1100 & 1200 series by EBBA Iron, SSLD & SSLCE by Sigma, TTLD & TTLP by Tyler-Union or SIP
GATE VALVES: RESILIENT SEAT, M.J. W/2″ OPERATING NUT, MUELLER,CLOW or M&H
FIRE HYDRANTS: SECURITY LOCK TO BE INSTALLED ON OPERATING NUT, MUELLER A-423, M&H, CLOW, AMERICAN DARLING OR CENTURION 3-WAY
TAPPING SLEEVE(PVC): STAINLESS STEEL JCM 452, JCM 459, JCM 462 or Smith-Blair 665. TAPPING SLEEVE(DI): MECHANICAL JOINT IRON, TYLER, M&H, JCM OR MUELLER
TRACING WIRE: 12 GAUGE, COATED BLUE I.D. TAPE: NON METALLIC BLUE, LABELED “WATER LINE”
VALVE BOXES: CAST IRON VALVE MARKERS: FIBERGLASS/PLASTIC “WATER VALVE” (66″ IN LENGTH)
PIPELINE MARKERS: FIBERGLASS/PLASTIC “WATER LINE” (66″ IN LENGTH)
CURB STAMPING: WATER SERVICES SHALL BE IDENTIFIED WITH A “W” PLACED IN THE CONCRETE CURBING IDENTIFYING THE WATER SERVICE VALVES SHALL BE IDENTIFIED WITH A “V” PLACED IN THE CONCRETE CURBING IDENTIFYING THE VALVE
PRESET WATER SERVICE/PRODUCT LINES
All residential lots must be provided with potable and irrigation water service. Common areas where irrigation services will be requested of the water purveyor(Gulf Shores Utilities) for such development must be equipped with pre-set water service. Water service installations must have independent service tap connections from the distribution main. Residential and irrigation water service pre-set installations must consist of the following.
1″ Potable Residential & Irrigation Water Service
Service saddle: ex: JCM #406-IP, Smith-Blair 317-IP or Ford FC202-IP. Epoxy coated w/double stainless steel bale’s & hardware. All service saddles are to be equipped with a 1″ AWWA(IP) outlet thread. Water Service connections established on ductile Iron Piping are to direct tapped utilizing a 1″ AWWA(IP) drill tap & installing a 1″ ground key corporation stop style valve.
1″ ground key corporation stop: Mueller H-15026 or Ford F1100-4Q
1″ Curb Ball Stop 5/8″x3/4″x1″(180 degree w/lock wing): Mueller B-2435 Or Ford B43-342WQ(One inch CTS compression inlet x meter swivel nut)
1″K Copper Tubing Service Line(s)
Meter Vault(PVC) 12201133 Carson Brooks Model 1220B Series w/bolt down feature. Carson Brooks Jumbo CB 1220-12B(base) Color: Black CB 1220-6B(lid) Color: Black w/C.I. Reader attached via steel roll pin
Security Locks: Highfield Firomatic #6 barrel lock & cap. Stainless steel w/dust cap #6 Firomatic Lock #93180128/Dust cap #93110116 IV – 3a
B. Ductile Iron Pipe And Fittings:
1. Ductile Iron Pipe: Ductile iron pipe shall conform to the requirements of ANSI Standard A21.51, Class 51 for all sizes, unless other wise specified. Pipe interior shall have a bituminous seal coat over a cement mortar lining conforming to ANSI Standard A21.4. Exterior of pipe shall have a bituminous coating.
2. Fittings:
a. All iron fittings shall be Class 350 ductile iron, mechanical joint with a minimum pressure rating of 150 psi and shall conform to the requirements of ANSI Standard A21.10.
b. All fittings shall be cement lined, seal coated and outside coated as specified above for ductile iron pipe.
3. Joints: Mechanical joints consisting of bell, socket, gland, gasket, bolts and nuts shall conform to ANSI Standard A21.11. Bolts shall be high strength, annealed, cast iron, or high strength low allow steel, T-head type having hexagonal nuts. Bolts and nuts shall be machined true and nuts shall be tapped at right angles to a smooth bearing surface. Single seal gasket push on type joints shall conform to the requirements of ANSI A21.11 and shall be “Tyton”, “Fastite”, “Super Bell Tite”, “Altite”, or approved equal.
4. Restrained Joints: Joint restraints shall be Series 1100 Megalug ductile iron retainer glands by EBAA iron, SSLD by Sigma, TTLD by Tyler-Union or SIP.
5. Gaskets: Gaskets shall be of vulcanized crude rubber or polyvinyl chloride plastisol. Gaskets shall have plain tips unless otherwise specified.
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C. Polyvinyl Chloride Pipe And Fittings:
1. Pipe:
a. Polyvinyl chloride (PVC) pipe shall conform to the requirements of ASTM designation D 2241, Class 1120 or 1220, SDR 21 for a minimum pressure rating of 200 psi at 73.4-1/4F. All PVC pipe shall bear the approval seal of the National Sanitation Foundation (NSF) for potable water pipe.
b. All polyvinylchloride (PVC) pipe shall be laid with 12 AWG THHN solid wire, blue in color, buried 6″ above and parallel to the pipe. The locator tape shall be at least two inches wide and shall be lettered, “CAUTION: WATER LINE BURIED BELOW”, to be laid two feet above and parallel to the pipe. Where transitions from PVC to DI DI to PVC occur, provision must be made to ensure continuity of locator tape/wire. Care should be taken to ensure continuity at fittings and valves. Locating wire shall be installed at least 6″ directly above the water main with ends termination in appropriate valve boxes. Care should be taken during backfilling to ensure that wire remains centered on the pipe.
2. Fittings:
Fittings for PVC pipe shall be ductile iron fittings with transition gaskets. Ductile iron fittings shall be as specified in Section 2.01.A. above.
3. Joints:
PVC pipe shall have provision for expansion and contraction provided in the joints. All joints shall be designed for push on make up connection. A push on joint shall be a coupling manufactured as an integral part of the pipe barrel consisting of a thickened section with an expanded bell with a groove to retain a rubber sealing ring of uniform cross section. Joints shall conform to the requirements of ASTM Designation D 3139 and provide for the pressure rating of the pipe.
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4. Restrained Joints: Joint restraints between DI & PVC shall be Series 1200 PVC megalug retainer glands as manufactured by EBBA Iron, SSLCE by Sigma, TTLP by Tyler Union or SIP.
D. Gate Valves:
1. Gate valves three (3) inches in diameter and larger shall be iron body, nonrising stem, bronze mounted resilient type gate valves me chanical joint conforming to requirement of the AWWA Standard C509 and shall be provided with a 2-inch square operating nut. Valves be such as to permit replacing the O-ring seals while in service without undue leakage. All valves shall be Mueller, Clow or M&H.
2. Valve Stem Extension: All valves in which the operating nut is greater than 2 feet below finish grade shall be provided with extension stems to bring the operating nut to within two feet of the finished grade. The extension stem shall be provided with a 2-inch square operating nut on top and a coupling to connect the extension to the operating nut of the valve. A stem guide shall be provided to keep the valve stem extensions concentric with the valve box. Extension stems shall be of the same diameter as the valve stem unless otherwise specified.
E. Butterfly Valves:
1. General: All butterfly valves shall be of the tight-closing, rubber-seat type with rubber seats that are securely fastened to the valve body or disc. No metal-to-metal seating surfaces will be permitted. Valves shall be bubble-tight at rated pressures with flow in either direction, and shall be satisfactory for applications involving frequent operation and for applications involving valve operation after long periods of inactivity and for buried installation. Valve discs shall rotate 90 degrees from the full open position to the tight shut position. Valves shall meet the full requirements of AWWA Standard C504 for Class 150B. All valves shall be Mueller or Clow.
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2. Valve Body: Valve bodies shall be constructed of cast iron ASTM A 126 Class B. Ends shall be mechanical joint. Two trunnions for shaft bearings shall be integral with each valve body. When the disc has the rubber seat, the valve body shall have a 18-8 Type 304 stainless steel body seat.
3. Valve Discs: Valve discs shall be constructed either of alloy cast iron ASTM A 436 Type 1 Ni-Resist), ductile iron ASTM A 536, or cast iron ASTM A 48 each with Type 316 stainless steel seating edge or the entire disc may be construction of cast 316 stainless steel. The stainless steel seating edge is not applicable to rubber-seat disc type valves.
4. Valve Seats: Valve seats shall be of a synthetic or natural rubber compound and may be mounted on the disc or valve body.
5. Valve Bearings: Valves shall be fitted with sleeve-type bearings. Bearings shall be corrosion resistant and self-lubricating.
6. Buried Operators: Buried service operators shall be permanently lubricated, sealed for submersion in water for pressures of 20 feet and equipped with a two inch square AWWA operating nut which shall indicate the direction to open. The operator shall be con structed such that the valve will open when the nut is turned to the left (counter clockwise) to open.
F. Check Valves:
1. Swing check valves three (3) inches and larger shall be Mueller or Clow and shall have a cast iron or cast steel body with a bronze or stain less steel seat ring, a noncorrosive shaft for attachment of weight and lever and a 300 psi hydrostatic test pressure rating. Check valves shall absolutely prevent the return of water back through the valve when the inlet pressure decreases below the delivery pressure.
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2. The valve must be full opening, tight seating and its seat ring shall be renewable and must be securely held in place by a threaded joint; the valve disc shall be of cast iron or cast steel and shall be suspended from a non-corrosive shaft which will pass through a stuffing box.
G. Valve Boxes: Cast iron valve boxes shall be provided for all valves installed underground. The valve boxes shall be adjustable to fit the depth of earth cover over the valve and shall be designed so as to prevent the transmission of surface loads directly to the valve or piping. Valve boxes shall have an interior diameter of not less than 5-inches. The valve boxes shall be provided with covers marked “WATER” which shall be so constructed as to prevent tipping or rattling. Boxes shall be constructed of cast iron material. Extension sections shall be cast iron only. Each box shall have an at-grade 2′ diameter by 4″ thick protective ring constructed of Class B concrete (See Section III).
H. Valve Vaults: Valve vaults shall be of precast concrete of the type shown on the Drawings and shall conform to the applicable requirements of Section III. The cover for the nontraffic bearing vault shall be constructed of 3/16-inch steel floor plate with reinforcement or 1/4 inch aluminum diamond plate 150 psi. After fabrication, the steel covers shall be galvanized by the hot dip method in conformance with the requirements of ASTM Designation A 123.
I. Hydrants: Fire hydrants shall be of the compression type with break away upper sections capable of ready replacement without water loss in the event of traffic damage. They shall be designed for a working pressure of 150 pound per square inch and shall conform to AWWA Standard C502 “Dry Barrel Fire Hydrants”.
Each hydrant shall have a 6-inch bottom inlet connection and valve opening at least 5 1/4-inches in diameter. Hydrants shall turn to the left (counterclockwise) to open. Each hydrant shall be fitted with one 4 1/2-inch pumper connection, and two 2 1/2-inch hose connections, both having threads that conform to the Fire Division Standard for the area. Hose caps shall be chained to the hydrant barrel and fitted with nuts similar to the hydrant operating nuts. Each hydrant shall have a barrel of sufficient length to bring the bottom of the 6-inch pipe connection 30-inches below the surface of the finished ground. Each hydrant shall be made in at least two sections bolted together. All interior working parts of the hydrant shall be removable from the top of the hydrant to allow repairs without removing the hydrant barrel after it has been installed. Hydrants shall have renewable O-ring stem seals and shall be Break-A-Way Type. Hydrant barrels shall be painted red with finish paint coat field-applied after final installation. Fire hydrants shall be Mueller A-423 Centurion or F-2545, Clow Medalion, M&H or American Darling. Security locks shall be installed on operating nut.
J. Hydrant Guard Posts: If required, guard posts for hydrants shall conform to the requirements of ASTM Designation A 53, galvanized steel pipe Schedule 40 and shall be painted red.
K. Flushing Assembly: The flushing assembly shall include three (3) inch pipe and fittings, three (3) inch valve, cast iron valve box with lid and concrete for thrust blocking and valve box collar (as previously specified) and painted red. L. Concrete: Concrete shall conform to the requirements of Section III.
M. Tie Rods: Steel for tie rods and tie bolts shall conform to the requirements of ASTM Designation A 242, and rods shall be galvanized in conformance with requirements of ASTM Designation A 123. Tie rods and tie bolts shall be Super Star Tierod Figure No. SS12 and Tiebolt Figure No. SS77 respectively as manufactured by Star National Products.
N. Tapping Sleeves:
1. Ductile Iron Pipe – Tapping sleeves for ductile iron pipe shall have full encirclement end gaskets and shall completely encapsulate the tap zone. Tap sleeves for ductile iron pipe shall be constructed of cast or ductile iron as manufactured by Mueller, Clow or Tyler.
2. PVC Pipe – Tapping sleeves for use on PVC pipe shall have full encirclement end gaskets and shall completely encapsulate the tap zone. Tapping sleeves for use on PVC pipe shall be stainless steel JCM 452, 459 or 462. Ductile iron sized tapping sleeves shall not be accept able for use on PVC pipe. As an alternate, a ductile iron tee may be cut into the PVC main with one full joint of class 51 ductile iron pipe and a long pattern ductile iron solid sleeve on each side of the tee. The ductile iron assembly must be properly disinfected and pressure tested prior to cutting the PVC main. This method will be acceptable only with written GSU permission.
O. Additional Work: Additional items of construction, necessary for the complete installation of the systems, shall conform to specific details shown on the Drawings and shall be constructed of first-class materials conforming to the applicable portions of these specifications.
P. Pipeline And Valve Markers
1. Pipeline Markers – shall be installed on the pipe-line alignment at a maximum of five hundred (500) foot intervals. Specs shall be:
Fiberglass/Plastic Stake(Blue)66″ in length w/verbiage Caution: Water Pipeline and Inscription:”Gulf Shores Utilities 968-6323
2. Valve Markers – shall be installed adjacent to all Valves. Specs shall be:
Fiberglass/Plastic(White) 66″ in length with Verbiage Caution: Water Valve and inscription: Gulf Shores Utilities 968-6323
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PART 3 – EXECUTION
3.01 PREPARATION
A. Bedding:
1. Pipe Cradle: Upon satisfactory installation of the pipe bedding material as specified in Section III, a continuous trough for the pipe barrel and recesses for the pipe bells or couplings shall be excavated by hand digging. When the pipe is laid in the prepared trench, true to line and grade, the pipe barrel shall receive continuous, uniform support and no pressure will be exerted on the pipe joints from the trench bottom.
2. Cleanliness: The interior of the pipes shall be thoroughly cleaned of all foreign matter before being gently lowered into the trench and shall be kept clean during laying opera tions by means of plugs or other approved methods. During suspension of work for any reason at any time, a suitable stopper shall be placed in the end of the pipe last laid to prevent mud or other foreign material from entering the pipe.
3.02 INSTALLATION
A. Pipe:
1. Gradient:Lines shall be laid straight, and depth of cover shall be maintained uniform with respect to finish grade. Water mains shall be installed as generally located on the plans. All fittings and valve assemblies shall be restrained to at least one full joint of ductile iron pipe in each direction. Additional joint restraints may be required in poor soil conditions. Water mains shall be installed with a minimum of 30″ of cover unless ground water is encountered. In no case shall the water main be installed with less than 24″ of cover. In areas subject to vehicular traffic, ductile iron pipe may be required.
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2. Pipe Joint Deflection: Pipe shall not be “bent” between joints to attain desired alignment. Deflection is allowable only at joints and in amounts in accordance with pipe manufacturer’s recommendations. Required deflection shall be achieved by use of appropriate fittings.
3. Rejects: Any pipe found defective shall be immediately removed and replaced with sound pipe at the Contractor’s expense
4. Joint Compounds: No sulphur base joint com pound shall be used. Joint compound must be approved for potable water lines.
5. Anchors: Concrete thrust blocks shall be placed at all bends, tees, plugs and other fittings to provide lateral support, except when restrained joints are specified. Thrust blocks shall conform to the details shown on the Drawings and shall be of 3000 pound mix concrete. (See Section III).
B. Pipe Joints:
1. Type: The joints of all pipelines shall be made absolutely tight. The particular joint used shall be approved by the Owner prior to installation. Where shown on the Drawings or where, in the opinion of the Owner, settle ment or vibration is likely to occur, all pipe joints shall be bolted.
2. Mechanical Joints: All types of mechanical joint pipes shall be laid and jointed in full conformance with manufacturer’s recommendations, which shall be submitted to the Engineer for review and approval before work is begun.
3. Push On Joints: Push on joints shall be made in strict, complete compliance with the manufacturer’s recommendations. Lu bricant, if required, shall be an inert, nontoxic, water soluble compound incapable of harboring, supporting, or culturing bacterial life. Manufacturer’s recommen dations shall be submitted to the Engineer for review and approval before work is begun.
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C. Installing Valves And Boxes:
1. Valves: Valves shall be carefully inspected, opened wide and then tightly closed and the various nuts and bolts shall be tested for tightness. Special care shall be taken to prevent any foreign matter from becoming lodged in the valve seat. Gate valves, un less shown otherwise, shall be set with their stems vertically above the center line of the pipe. Butterfly valves shall have the disc shaft installed horizontally. Any valve that does not operate correctly shall be removed and replaced.
2. Valve Boxes: Valve boxes shall be carefully centered over the operating nuts of the valves so as to permit a valve key to be fitted easily to the operating nut. Valve boxes shall be set to conform to the level of the finished surface and held in position by a ring of concrete placed under the support flange as shown on the Drawings or pre-cast valve collars may be used. The valve box shall not transmit surface loads to the pipe or valve. Care shall be taken to prevent earth and other material from entering the valve box. Any valve box which is out of alignment or whose top does not conform to the finished ground surface shall be dug out and re set. Before final acceptance of the work all valve boxes shall be adjusted to finish grade.
D. Installing Hydrants: Hydrants shall be set plumb and in true alignment with mains. They shall be restrained joints main to hydrant using D.I. pipe. Care shall be taken to insure the free draining of the hydrant barrel and, to this end, coarse material shall be placed around the drain outlet. Backfilling around hydrants shall be carefully done so as not to disturb the hydrant and shall be thoroughly compacted so as to support the hydrant securely.
E. Installation Within Encasement:
Any pipeline installed within or surrounded by encasement of any type or kind shall be of ductile iron pipe or continuous Polyethelene HDPE pipe with cradles. Pipe joints within the encased area shall be acceptably restrained or approved carrier pipe restraint provided at each end of the encasement.
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F. Flush Out Connections: Flush out connections shall be installed at the locations and in accordance with the details shown on the Drawings.
G. Location In Relation To Sanitary Sewers (Including gravity sewers, force main and low pressure sewer lines):
1. The water line shall not make physical contact with the sewer line or appurtenances under any circumstances.
2. The water line shall be located a minimum of five (5) feet horizontally from any existing or proposed sanitary sewer lines or appurte nance.
3. Where water main crosses a sewer main, the following special requirements shall be satisfied:
a. The water main must cross above the sewer main with a minimum of eighteen (18) inches vertical separation. The required vertical separation shall be maintained for a minimum of five (5) feet on either side of the sewer main. Said measurement shall be made normal to the centerline of the sewer main. Minimum line cover for the water main as called for elsewhere shall be maintained.
b. Should circumstances preclude installation as called for in paragraph “a” above, a continuous section of steel casing pipe shall be installed around the sewer main or the water main. The steel casing shall, at a minimum, extend to a point ten (10) feet on either side of the point of crossing. Said measurement shall be made normal to the centerlines of the involved pipe lines.
4. The water line shall not be installed in, placed through, or allowed to come in contact with any soil or soils that have or are suspected to have been contaminated with sewage or septic field leachate.
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H. Backfilling:
1. After pipe has been laid, inspected, and found satisfactory, sufficient backfill shall be placed along the pipe barrel to hold the pipe securely in place during the conduction of the preliminary hydrostatic test. Backfill material shall be dry and free from materials that may damage pipe(stumps, rocks, etc.) In wet conditions, select fill materials may be required. No backfill shall be placed over joints until the preliminary test is satisfactorily completed, leaving them exposed to view for the detection of visible leaks.
2. Upon satisfactory completion of the preliminary hydrostatic test, backfilling of the trench shall be completed. (See Section II)
I. Concrete Protective Slabs: Where waterways, canals ditches or other cuts are crossed, protective concrete slabs shall be installed across and to 10 feet each side of the bottom. Approved utility crossing signs shall be placed on the pipe alignment at each side of the canal, waterway, etc.
3.03 FIELD QUALITY CONTROL
A. Flushing: All water mains shall be flushed to remove all sand and other foreign matter. The velocity of the flushing water shall be at least 4-feet per second. Flushing shall be terminated at the direction of the Engineer. The Contractor shall dispose of the flushing water without causing a nuisance or property damage. No line flushing will be performed without prior notice to and approval from Gulf Shores Utilities (GSU).
B. Cleaning: Prior to pressure and leakage testing, the interior of each main shall be cleaned of accumulation of sand and other foreign matter by pressure or hand methods. Hand cleaning methods may consist of shoveling the material and pressure cleaning with a water hose. Care shall be exercised in cleaning to prevent damage to the pipe lining.
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C. Hydrostatic Tests:
1. All components of the water distribution system, including fittings, hydrants, connections and valves of the water distribution system shall remain uncovered until tested and accepted; provided, however, that pipe trenches under traveled streets or roads or in unstable soil conditions may be back filled with the permission of the Engineer. No hydrostatic testing shall be allowed without twenty-four (24) hours prior notice to GSU and GSU personnel must observe testing.
No testing shall be done until all concrete thrust blocks are in place and set. If high-early strength concrete is used, testing may be conducted 48 hours after the concrete is placed; otherwise, thrust block concrete must cure 5 days before pressure testing commences.
In testing, the part of the system under test shall be filled with water and subjected to a sustained pressure of 150 pounds per square inch. The piping may be tested in sections, thereby testing each valve for secure closure. While the system is being filled, air shall be carefully and completely exhausted. If perma nent air vents are not located at all high points, the Contractor shall install corpora tion stops or fittings and valves at such points so the air can be expelled as the pipe system is slowly filled with water. Testing of an undis infected line section shall not be allowed against a valve on a water line in service. Either disinfect prior to testing or physically isolate test section from active system.
2. Test pressure shall be maintained by pumping for at least 6 hours and until all sections under test have been checked for evidence of leakage. Rate of loss shall not exceed that specified hereinafter. Visible leaks shall be corrected regardless of total leakage shown by test.
3. The system as a whole, or any part, shall be retested after completion of backfilling. Such retest will be required for final acceptance.
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4. All pumps, gauges and measuring devices shall be furnished, installed and operated by the Contractor and all such equipment and devices shall be specifically designed and intended for use in pipeline pressure testing and their installation shall be approved by the Engineer. All pressure and leakage testing shall be done in the presence of a representative of the Owner. Contractor shall provide recording pressure gage with minimum twelve inch (12″) diameter chart and certification of calibration of same. Measuring device to be located on pump suction. The last step of hydrostatic testing shall be a pump-up to test pressure to demonstrate integrity of the results.
5. Water for testing and flushing shall be potable water provided by the Contractor from a source approved by the Engineer.
6. Preliminary pressure testing may be waived by the Engineer for pipe 24-inches in diameter and larger.
C. Allowable Limits For Leakage:
1. The hydrostatic pressure tests shall be per formed as hereinabove specified and no instal lation, or section thereof, will be acceptable until the leakage is less than the number of gallons per hour as determined by the formula:
SD % P L = 133200
in which,
L = Allowable leakage, in gallons per hour S = Length of pipe being tested in feet D = Nominal pipe diameter; in inches P = Average test pressure during the test, in psi gauge. Pressure must be maintained +/- 5 psi of 150 by pump-ups. Last step in test will be to add water to verify the final pressure of 150 psi
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2. For a 1000-foot segment of main with an average test pressure of 150 psi the following table may be used.
Pipe Allowable Pipe Allowable
Diameter (D) Leakage (L) Diameter(D) Leakage (L)
Inches Gal/Hr. Inches Gal/Hr.
3 0.28 14 1.29
4 0.37 16 1.47
6 0.55 18 1.66
8 0.74 20 1.84
10 0.92 24 2.21
12 1.10 30 2.76
3. Water shall be supplied to the main during the test period as required to maintain the test pressure as specified. The quantity used, which shall be compared to the above allowable quantity, shall be measured by pumping from a calibrated container. A 5/8-inch meter installed on the suction side of the pump may be used to measure the leakage for large mains when approved by the Engineer.
D. Correction Of Work: Where leakage exceeds the allowable limit, as specified herein before, the defective pipe or joints shall be located and repaired. If the defective portions cannot be located, the Contractor shall remove and reconstruct as much of the work as is necessary in order to conform to the specified limits.
Any visible leaks or any defective pipe or joint shall be repaired or replaced as directed by the Engineer even though the total leakage is within the specified allowable limits. No additional payment will be made for the correction of defective work, or to damage to other parts of the work resulting from such corrective work.
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E. Disinfection:
1. Before any portion of water distribution system is to be placed in service it shall be disinfected in accordance with the requirements of AWWA Standard C601; and its disinfection shall be demonstrated by bacteriological test conducted in accordance with “Standard Methods for Examination of Water and Wastewater” for the coli-aerogenes group, by an approved laboratory, acceptable to the Engineer and the Alabama Department of Environmental Management. Prior to disinfection all lines shall be flushed in accordance with Paragraph 3.03A.
2. G.S.U. shall observe sample collection.
3. Contractor or Developer shall deliver sample to an ADEM approved lab.
4. Contractor or Developer shall produce lab results.
5. Contractor/Developer shall pay lab fees.
6. The disinfecting agent shall be free chlorine in aqueous solution, with sustained concentra tion for 24 hours or more of not less than 50 parts per million. Chlorine may be derived from chlorine gas, or 70 percent (high test) calcium hypochlorite (HTH or equal). Admin istration may be by any of the several methods described in AWWA Standard C601 as proposed by the Contractor and approved by the Engineer. Proposals as to method must be made prior to commencement of the disinfection process.
7. Following contact with chlorine solution, the system shall be thoroughly flushed out. No flushing without G.S.U. approval. Samples shall then be taken using sterile containers obtained from an ADEM certified laboratory. 8. If samples do not demonstrate satisfactory results, the disinfection procedure shall be repeated until two series of satisfactory samples are obtained, the period between such series of samples to be a minimum of twenty-four hours. (See Section 3.03 B.1.).
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3.04 MISCELLANEOUS
A. Connection To Existing System:
1. All connections to existing mains shall be made after complete disinfection of the proposed system and shall be made under the direction of Gulf Shores Utilities (GSU). Valves separating the mains being installed from existing mains shall be operated by or under the direction of GSU representative. The cost of the work in making the connections shall be paid for by the Contractor.
2. In the event the proposed main is to be connected to a main which has one or more active services between the point of connection and the first existing line valve, a temporary plug or cap shall be installed on the new main until the pressure tests and disinfecting are completed. Upon satisfactory completion, the cap or plug shall be removed from both mains and the connection made with pipe which has been swabbed out with a solution of chlorine and water. The connection shall be made as swiftly as possible and any water in the ditch shall be kept below the level of the pipe. The pipeline shall then be placed in service by GSU personnel.
3. In the event any existing users will be without water while a connection is being made, the Contractor shall notify GSU of when the water will be turned off and when he estimates service will be resumed. In some instances, these connections may have to be made at night. No user shall be without water service for more than two hours. In some cases, GSU may require the Contractor to provide temporary water service to these affected customers.
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B. Pipe Closures
1. Closure section shall not exceed ten feet (10′).
2. Closure shall be by DI pipe.
3. Closure pipe shall be swabbed with HTH solution prior to installation.
4. Care shall be taken while performing closure to ensure that no water, trash, dirt, debris, etc. is allowed to enter pipe during closure operation.
5. Closure shall be accomplished with solid sleeves. No “bucking” of pipe shall be allowed.
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