SECT-51_PIPE_INSTALLATION_FOR_WATER_MAINS.DOC

SECTION 51 - PIPE INSTALLATION FOR WATER MAINS

SECTION 51 - PIPE INSTALLATION FOR WATER MAINS

Item No. Title

51.1 GENERAL

51.2 PIPE HANDLING

Pipe shall be installed in accordance with the manufacturer's specifications and instructions for the type of pipe used and applicable AWWA standards, such as C600 and C603, unless otherwise stated in these specifications.

51.2 PIPE HANDLING

All types of pipe shall be handled in such manner as will prevent damage to the pipe or coating. Accidental damage to pipe or coating shall be repaired to the satisfaction of the CITY ENGINEER or designee or be removed from the job. When not being handled, the pipe shall be supported on timer cradles or on properly prepared ground, graded to eliminate all rock points and to provide uniform support along the full length. When being transported, the pipe shall be supported at all times in a manner which will not permit distortion or damage to the lining or coating. Any unit of pipe that, in the opinion of the CITY ENGINEER or designee, is damaged beyond repair by the CONTRACTOR shall be removed from the site of the work and replaced with another unit.

Joint gaskets shall be stored in a clean, dark, dry location until immediately before use.

Dirt or other foreign material shall be prevented from entering the pipe or pipe joint during handling or laying operations and any pipe or fitting that has been installed with dirt or foreign material in it shall be removed, cleaned and relayed. At times when pipe laying is not in progress, the open ends of the pipe shall be closed by a watertight plug or by other means approved by the CITY ENGINEER or designee to ensure absolute cleanliness inside the pipe.

51.3 SEPARATION OF WATER MAINS AND SEWERS

51.3.1 GENERAL

Water mains that are laid in the vicinity of pipelines designated to carry raw wastewater or reclaimed water (wastewater effluent) shall meet the horizontal and vertical separations specified below.

51.3.2 HORIZONTAL SEPARATION

NORMAL CONDITIONS: Water mains shall be located at least 10 feet horizontally from pipes carrying raw wastewater, and 3 feet horizontally from pipes carrying reclaimed water. The distance shall be measured from inside edge of pipe to inside edge of pipe.

UNUSUAL CONDITIONS: When local conditions prevent a horizontal separation of 10 feet, a water main may be laid closer to a pipe carrying raw wastewater provided that the bottom of the water main is at least 18 inches above the top of the sewer pipe and water main is laid in a separation trench or on an undisturbed earth shelf. This configuration shall receive approval from the Florida Department of Environmental Protection (FDEP) and the CITY ENGINEER or designee, IN WRITING, prior to initiation in the field.

51.3.3 VERTICAL SEPARATION

NORMAL CONDITIONS: Water mains shall be laid to provide a separation of at least 18 inches between the bottom of the water main and the top of the sewer.

UNUSUAL CONDITIONS: When construction conditions prevent a vertical separation of 18 inches as described hereinabove, the sewer pipe shall be constructed of ductile iron pipe with mechanical joints.

51.3.4 CROSSING OF WATER MAINS AND SEWER MAINS

Water mains shall be above the sewer whenever they cross.

Adequate structural support for both the water main and sewer mains shall be provided to prevent excessive deflection of joints and settling.

If separation is less than required, sewers shall be constructed of ductile iron pipe with mechanical joints and the length of the ductile iron pipe shall be a minimum of 18 feet and centered at the point of crossing so that the joints will be equidistant and as far as possible from the water main.

51.4 TRENCH PREPARATION AND PIPE BEDDING

51.4.1 TRENCH PREPARATION AND PIPE BEDDING

Applicable provisions of Section 32 shall apply. Also refer to STANDARD DRAWINGS.

51.4.2 PIPE PREPARATION AND HANDLING

All pipe and fittings shall be inspected prior to lowering into trench to insure no cracked, broken, or otherwise defective materials are being used.

The CONTRACTOR shall clean ends of pipe thoroughly and remove foreign matter and dirt from inside of pipe and keep clean during and after laying.

The CONTRACTOR shall use proper implements, tools, and facilities for the safe and proper protection of the WORK. The CONTRACTOR shall lower pipe into the trench in such a manner as to avoid any physical damage to the pipe and shall remove all damaged pipe from the job site. Care shall be taken to not drop or dump pipe into trenches under any circumstances.

51.4.3 TRENCH DEWATERING AND DRAINAGE CONTROL

Specifications from Section 32 shall apply. The CONTRACTOR shall prevent water from entering the trench during excavation and pipe laying operations to the extent required to properly grade the bottom of the trench and allow for proper compaction of the backfill. Pipe shall not be laid in water.

51.4.4 SURVEY LINE AND GRADE

Pipe shall be laid to the lines and grades shown on the PLANS, within a tolerance of plus or minus 0.10 feet. The CONTRACTOR shall provide line and grade stakes at a 100 foot locations. The CONTRACTOR shall provide Temporary Bench Marks (TMB'S) at maximum 1,000 foot intervals. The minimum pipe depth shall be three (3) feet below the finished grade surface or three (3) feet below the elevation of the edge of pavement of the road surface whichever is greater.

51.4.5 PIPE LAYING IN TRENCH

The CONTRACTOR shall prevent foreign material from entering the pipe while it is being placed in the trench. The CONTRACTOR shall remove all foreign material from the pipe or joint ring before the next pipe is placed. If the pipe laying crew cannot put the pipe into the trench and in place without getting earth into the pipe, the CITY ENGINEER or designee may require that snugly-fitted, tightly-woven canvas bags be placed over each end before lowering the pipe. The bags shall be left in place until the connection is to be made to the adjacent pipe. During laying operations, the CONTRACTOR shall keep debris, tools, clothing, or other materials out of the pipe.

51.4.6 LAYING PVC PIPE

All PVC pipe shall be installed in accordance with standards set forth in the UNI-BELL "Handbook of PVC Pipe Design and Construction" unless such standards conflict with this ARTICLE in which case this ARTICLE shall apply.

51.4.7 LAYING DUCTILE IRON PIPE

All ductile iron pipe shall be installed in accordance with AWWA C600 unless such standards conflicts with this ARTICLE in which case this ARTICLE shall apply. The CONTRACTOR shall cut pipe only as necessary to comply with alignment shown on the PLANS. Flame cutting of pipe shall not be allowed. The CONTRACTOR shall provide special tools and devices, such as special jacks, chokers, and similar items required for proper installation. Lubricant for the pipe gaskets shall be furnished by the pipe manufacturer, and no substitutes shall be permitted under any circumstances.

LAYING OF PIPES ON CURVES

Long radius curves, either horizontal or vertical, may be laid with standard pipe by deflections at the joints. Maximum deflections at pipe joints and laying radius for the various pipe lengths shall be as recommended by the pipe manufacturer.

51.4.9 PIPE RESTRAINING

Requirements specified in Section 34 shall apply.

51.4.10 BEDDING AND BACKFILL FOR PIPES

Requirements specified in Section 32 shall apply.

51.5 HYDROSTATIC TESTS

51.5.1 GENERAL

Hydrostatic tests shall consist of pressure test and leakage test. Hydrostatic tests shall be conducted on all newly laid pressure pipes, joints and valves, including all service lines to the curb stops. Air testing of pressure pipes will not be permitted under any circumstance. Tests may be made on sections not exceeding 2,000 feet, when this procedure is acceptable to the CITY ENGINEER or designee. The CONTRACTOR shall furnish all necessary equipment and material, including water, make all taps, including cross connects, and furnish all closure pieces in the pipe as required. Equipment to be furnished by the CONTRACTOR shall include graduated containers, pressure gauges, hydraulic force pumps, and suitable hoses and piping. The CITY ENGINEER or designee will monitor the test.

The CONTRACTOR may conduct hydrostatic tests after the trench has been partially backfilled with the joints left exposed for inspection for this informational purposes only. The hydrostatic tests for acceptance shall only be conducted after the trenches have been completely backfilled and compacted as specified.

51.5.2 TESTING CRITERIA

All pipe sections to be pressure tested shall be subjected to a hydrostatic pressure of 150 psi. The duration of each pressure test shall be for a period of two (2) hours. The maximum allowable pressure loss for the two (2) hour test shall be two (2) psig. If during the test, the integrity of the tested line is in question, the CITY ENGINEER or designee may require a second two (2) hour pressure test. The basic provisions of AWWA C-600 shall be applicable.

51.5.3 PROCEDURE FOR PRESSURE TEST

Each section of pipe to be tested shall be slowly filled with water and the specified test pressure shall be applied by means of a pump connected to the pipe in a satisfactory manner. Before applying the specified test pressure, all air shall be expelled from the pipe, and the main shall be flushed and pigged using a City approved swab. To accomplish this, taps shall be made, and appropriate valves installed to ensure bleeding of all air from the main. If defective pipes, fittings, valves, or hydrants are discovered in consequence of this pressure test, all such items shall be removed and replaced by the CONTRACTOR with sound material and the test shall be repeated until satisfactory results are obtained. Provisions of AWWA C600, where applicable, shall apply.

51.5.4 PROCEDURE FOR LEAKAGE TEST

After completion of the pressure test, a leakage test shall be conducted to determine the quantity of water lost by leakage under the specified test pressure. Applicable provisions of AWWA C600 and C602 shall apply.

Allowable leakage in gallons per hour for pipeline shall not be greater than that determined by the formulas:

Ductile Iron Pipe (DIP)

Polyvinyl Chloride (PVC)

Leakage is defined as the quantity of water to be supplied in the newly laid pipe or any valved section under test, which is necessary to maintain the specified leakage test pressure after the pipe has been filled with water and the air expelled. Should any test of pipe laid disclose leakage greater than that allowed, the CONTRACTOR shall locate and replace or repair the defective joints, pipe or valve until the leakage from subsequent testing is within the specified allowance.

51.6 DISINFECTION OF WATER MAINS

51.6.1 GENERAL

Before being placed in service, all new water mains shall be chlorinated in accordance with the specifications below and the procedures outline in AWWA C-651, "Standard Procedure for Disinfecting Water Mains." Disinfection of water mains shall be witnessed by the City Engineer or his designee.

51.6.2 FLUSHING AND PIGGING

Sections of pipe to be disinfected shall first be flushed (full diameter) and pigged to remove any solids or contaminated material that may have become lodged in the pipe. If no hydrant is installed at the end of the main, then a blow-off valve shall be provided large enough to develop a velocity of at least 2.5 feet per second in the main.

All taps required for chlorination or flushing purposes, or for temporary or permanent release of air, shall be provided for by the CONTRACTOR as a part of the construction of water mains. After the disinfection, all such taps shall be sealed to the satisfaction of the CITY ENGINEER or designee.

51.6.3 DISINFECTION CRITERIA

Before being placed into service, new mains and repaired portions of or extensions to existing mains shall be chlorinated by the CONTRACTOR so that the initial chlorine residual is not less than 50 mg/1 and that a chlorine residual of not less than 25 mg/1 remains in the water after standing 24 hours in the pipe.

51.6.4 FORM OF APPLIED CHLORINE

Chlorine may be applied as a liquid chlorine (gas-water mixture), or a mixture of water and high-test calcium hypochlorite. The CONTRACTOR shall assume responsibility for safe handling of chlorine and shall meet requirements of OSHA and other regulatory agencies for safe handling of chlorine.

51.6.5 POINT OF APPLICATION

The preferred point of application of the chlorinating agent is at the beginning of the pipeline extension or any valved section of it, and through a corporation stop inserted in the pipe. The water injector for delivering the chlorine-bearing water into the pipe should be supplied from a tap made on the pressure side of the gate valve controlling the flow into the pipeline extension. Alternate points of applications may be used when approved or directed by the CITY ENGINEER or designee and/or the Florida Department of Environmental Protection (FDEP).

51.6.6 OPERATION OF CITY VALVES

Valves shall be manipulated by or in the presence of duly authorized CITY personnel so that the strong chlorine solution in the line being treated will not flow back into the line supplying the water.

51.6.7 RETENTION PERIOD

Treated water shall be retained in the pipe at least 24 hours or as required by the CITY ENGINEER or designee and/or the Florida Department of Environmental Protection (FDEP).

51.6.8 CHLORINATING VALVES AND HYDRANTS

In the process of chlorinating newly laid pipe, all valves or other appurtenances shall be operated while the pipe line is filled with the chlorinating agent and under normal operating pressure.

51.6.9 FINAL FLUSHING AND TESTING

Following chlorination, all treated water shall be thoroughly flushed from the newly laid pipe at its extremity until the replacement water throughout its lengths shows upon test, a free chlorine residual not in excess of that normally carried in the system.

After flushing, water samples collected on two (2) successive days from the treated piping system, as directed by the Florida Department of Environmental Protection (FDEP), shall show acceptable bacteriological results. All bacteriological sampling shall be performed by a private, state certified laboratory. All bacteriological analysis must be performed by a laboratory certified by the State of Florida. Proper chain of custody procedures must be followed and samples shall only be collected by certified laboratory personnel in the presence of duly authorized CITY personnel. Copies of testing results and all related correspondence with the Florida Department of Environmental Protection (FDEP) shall be submitted to the CITY ENGINEER or designee. Bacteriological sampling and testing procedures shall be paid for by the CONTRACTOR.

51.6.10 REPETITION OF FLUSHING AND TESTING

Should the initial treatment result in an unsatisfactory bacterial test, the original chlorination procedure shall be repeated by the CONTRACTOR until satisfactory results are obtained.

51.7 NOTIFICATION AND CONNECTION TO EXISTING MAINS

Requirements specified in Section 35.3 shall apply.

51.8 WATER SERVICE PIPING AND CONNECTION

Water service piping and connection shall be installed as indicated in the STANDARD DRAWINGS. The location of all service lines shall be as shown on the DRAWINGS and shall be either single or dual service. On curbed streets the existing location for each installed service shall be marked by etching or cutting a "W" in the concrete curb. Where no curb exists, locations shall be adequately marked by a method approved by the CITY ENGINEER or designee.

51.9 LOCATION AND IDENTIFICATION

All water mains shall be installed with a continuous, two (2) inch wide metallic locator tape with the words "CAUTION BURIED WATER LINE BELOW" imprinted at one (1) foot intervals, installed eighteen (18) inches above and centered over the top of the pipe for location purposes. A continuous, solid, 12 CU.UF 1AWG tracer wire with a blue covering shall be attached to the main. All wire splices shall be completed using a splice kit and wire nut. Splice kit shall have a durable plastic housing with water resistant silicone gel. (Ranger Serviseal Closure with Poly-Bee Sealant or approved equal.) See STANDARD DRAWINGS.

All PVC water mains shall be a solid blue color with black lettering. All lettering shall appear legibly on pipe and shall run the entire length of the pipe. Lettering shall read as is acceptable for the intended use.

All ductile water mains shall be marked with a continuous stripe located within the top 90 degrees of the pipe. Said stripe shall be a minimum two (2) inches in width and shall be blue in color. Backfill shall not be placed for 30 minutes following paint application.