(A) Materials handling and storage.
(1) The contractor shall be responsible for the safe handling and storage of all materials furnished by them and shall replace, at their expense, all such materials found defective in manufacture or damaged in transportation, handling, or storage.
(2) Pipe, fittings, and accessories shall be loaded and unloaded by lifting with hoists or skidding to avoid shock or damage. Under no circumstance shall such materials be dropped. All material shall be stored in a neat and orderly manner. Pipe shall be stored, to the greatest extent possible, in unit packages or bundles, and shall be handled to prevent stress to bell joints and prevent damage to bevel ends. In addition, materials shall be handled and stored in accordance with manufacturer’s recommendations.
(3) If, in the opinion of the engineer, damage or defects in the factory-applied external coatings on steel or ductile iron pipe and fittings (including fire hydrants) can be repaired, then the contractor shall make said repairs as follows.
(a) If approved by the engineer, the contractor may make repairs when damage or defects occur in the factory-applied external epoxy or MegaBond coatings supplied on steel or ductile iron pipe and fittings (including fire hydrant risers and joint restraint devices). Coating repairs shall be made using a high build, low temperature applicable, fast cure, liquid epoxy coating. This epoxy coating material shall be DENSO Protal 7125 Repair Cartridge in packaged two component tubes with dispensing gun.
(b) When high ambient temperatures (greater than 85 degrees Fahrenheit) occur or when metal surface skin temperatures are high (greater than 100 degrees Fahrenheit) such that use of the DENSO Protal 7125 Repair Cartridge may be difficult due to the very short handling time of the material, an alternate modified amine cured epoxy coating may be used. This alternate coating shall be Tapecoat TC 7010 FS-Gray Fast Setting epoxy coating.
(B) Alignment and grade. Pipe shall be laid true to the line and grade established on the drawings. Where the drawings indicate that the finished ground surface elevations are to be modified from the existing elevations by this or future construction, the contractor shall exercise care to ensure that pipe, fittings, hydrants, valves and valve boxes are placed to the elevations indicated on the plans.
(C) Underground obstructions. The contractor shall expose existing underground obstructions shown on the plans or located in the field and shall determine their elevations far enough in advance of pipe laying that the proposed water main can be installed without the use of fittings at or near the points of crossing. Wherever obstructions not shown on the plans are encountered during the progress of the work and interfere with the proposed horizontal or vertical alignment of the pipeline, the engineer will change the plans and order a deviation in the line and/or grade, or may arrange for the removal or relocation of the obstructions. The contractor shall not deviate from plan line or grade without the engineer’s approval.
(D) Water main and sewer main/storm sewer separation.
(1) Vertical separation at crossings.
(a) Water mains may cross above sanitary and storm sewers with a minimum vertical distance of 18 inches between the invert of the water main and the top of the sewer. In these cases where the water main is above the sewer and there is at least 18 inches of separation, then at the crossings one full 20 foot length of water pipe shall be centered on the crossing.
(b) A water main may cross above a sewer main with a vertical separation of less than 18 inches, or below the sewer main if either the water or sewer main is encased in PVC, ductile iron, or six inches of concrete for at least ten feet each side of the crossing. If PVC or ductile iron is utilized as encasement material, the ends shall be sealed with six inches of concrete.
(c) Water mains crossing under vitrified clay sewer pipes or concrete sewer pipes shall be encased in six inches of concrete extending ten feet either side of the crossing.
(d) The ten feet either side shall be measured from the outside wall of the sewer to the end of the encasement and is not measured from the centerline of the sewer main.
(2) Water main and sewer main/storm sewer horizontal separation.
(a) Water mains shall be constructed with ten feet of horizontal separation from any existing sanitary or storm sewer or proposed sanitary or storm sewer. The ten feet horizontal separation shall be the clear distance (water pipe sidewall to sewer pipe sidewall) and not the centerline distance between the utilities.
(b) The following installation requires engineer approval and is appropriate for installations where the ten feet separation physically is not possible.
1. A water main may be constructed closer than ten feet to a sanitary or storm sewer if it is laid in a separate trench or it is laid in the same trench and the water main is located on the opposite side on a bench of undisturbed earth. In both cases, the elevation of the crown of the sewer has to be at least 18 inches below the invert of the water main. The sewer main shall be constructed of water main pipe (pressure class pipe) meeting the requirements of § 50.41, and pressure tested for water tightness in accordance with AWWA standards for leakage testing.
2. As an alternative to constructing the sewer with water main pipe (pressure class pipe) and pressure testing the sewer, it would also be acceptable to either encase the water or sewer main with six inches of concrete or to encase either the water or sewer within a PVC or cast iron casing.
(3) Sanitary sewer manholes and storm sewers.
(a) Sanitary sewer manholes and storm sewer pipes and inlets are considered to be sewers in regards to the above separation requirements.
(b) A water main can be constructed within the ten foot horizontal separation from a storm sewer pipe or storm sewer inlet provided that the storm sewer pipe is constructed with sealed joints. The pressure test shall be maintained for a minimum of 30 minutes.
(E) Installation.
(1) (a) Minimum cover depth from top of pipe to finished grade shall be as follows.
Size of pipe (inches) | Minimum cover (feet) |
12 or less | 6 |
14 to 18 | 5 1/2 |
20 or larger | 5 |
(b) In the event adequate cover cannot be achieved, then, if approved by the engineer, the water pipe may be insulated. Insulation may also be required if adequate separation between a storm sewer or culvert and the water pipe cannot be achieved.
(2) Cleaning shall be done as necessary so that the interior of all water pipe and fittings is free from all dirt, cement, or other foreign material before installation. Contact surfaces shall be wire brushed immediately prior to jointing.
(3) Pipe cutting shall be done without damage to the pipe with saw or abrasive wheel and shall be smooth, straight, and at right angles to the pipe axis. Ends of pipe shall be dressed and beveled to remove roughness and sharp corners.
(4) (a) Laying and joining of PVC pipe shall be in accordance with AWWA C900, AWWA C905, and AWWA C605, and with the pipe manufacturer’s instructions.
(b) Pipe shall be laid with bell ends facing in the direction of laying. Each pipe length shall be inspected for defects prior to being lowered into the trench. All pipe and fittings shall be carefully lowered into the trench piece by piece by means of pipe slings to prevent damage to the pipe and/or coating. Full lengths of pipe shall be installed except where connecting to appurtenances and fittings. The contractor shall leave an appurtenance or fitting with a full length of pipe whenever possible.
(c) Water main pipe shall not be installed in frozen ground or in water, and no water shall be allowed to run into or through the pipe.
(d) During the course of construction, a suitable stopper shall be kept in the end of the pipe so as to prevent any dirt and/or water from entering during the progress of the work at all times. Any dirt, loose material, or cement mortar which may accumulate in the pipe shall be removed as the work progresses.
(e) Push-on joints. The spigot end of field cut piping shall be cut square and then beveled. Joint surfaces shall be cleaned and lubricated immediately before completing the joint.
(f) Mechanical joints. Joints shall not be over-tightened. If an effective seal is not obtained the joint shall be disassembled, cleaned thoroughly, and reassembled. Where joint restraint devices are used with a mechanical joint, the holes shall be carefully aligned to permit installation of harness bolts. At mechanical joints, a beveled PVC spigot may not be used. Rather, a non-beveled spigot shall be used for insertion into mechanical joint.
(5) Protection of the work. Once in place, the pipe shall have its open end plugged to prevent soil, water, or other matter from entering the pipe.
(6) Pipe deflection. Deflection of the pipe or pipe joint shall not be permitted except as approved by the engineer. Changes in horizontal and vertical direction shall be achieved using standard fittings, fabricated fittings, and/or high deflection pipe couplings specifically designed and approved for use in joint deflection. The engineer may approve deflection of the pipe or pipe joint if the engineer of record specifically designed for the deflection and the deflection is approved by the pipe manufacturer.
(7) Fittings. Bends and tees shall be placed on a stable foundation, which may require the use of concrete pads of equal size or larger than specified for valves. Fittings shall be provided with thrust blocks, joint restraining devices, and polyethylene encasement (where fittings which are not epoxy coated) as specified herein.
(8) Couplings. Couplings shall be placed on a stable foundation and shall be wrapped in polyethylene encasement as specified herein. Couplings shall be approved by the pipe manufacturer for the use with the pipe and shall be installed according to the coupling manufacturer’s recommendations.
(9) Thrust restraint.
(a) Thrust restraints in the form of concrete thrust blocks shall be provided at tees, crosses, horizontal bends, plugs, caps, valves, fire hydrants, and similar locations whether specifically indicated on the drawings or not. Refer to subdivision (10) below regarding joint restraining device installations for situations and fittings that require the use of joint restraints in lieu of thrust blocks.
(b) Concrete thrust blocks shall have a thickness at the fitting equal to at least half the diameter of the pipe being installed, but shall not be less than six inches thick under any circumstances. They shall extend from the fitting to the undisturbed wall of the excavation. The contractor shall ensure that the concrete does not cover or render inoperable nuts or bolts on the fittings. All metal fittings, valves, or appurtenances shall be wrapped in polyethylene prior to pouring thrust blocks.
(c) Concrete thrust blocks shall be allowed to cure for 48 hours prior to activating the water main. If the water main needs to be activated prior to the concrete curing, then the water main shall be restrained using joint restraining devices. Prior to backfilling, thrust blocks shall cure for a minimum of four hours.
(d) Thrust blocks shall be installed as shown on the drawings and shall meet or exceed the minimum volume or bearing area requirements as specified on the drawings or specifications for the water pressures and soil conditions.
(e) In muck, peat, or similar weak soils, thrust loads shall be resisted by using joint restraining devices or by removal of the soil and replacement with a material of sufficient stability to resist thrust loads as determined by the engineer.
(f) Where prior approval of the engineer is obtained, the contractor may substitute acceptable joint restraining devices for concrete thrust blocking.
(10) Joint restraining device installations. Joint restraining devices are required for the following installations.
(a) All valves 12 inches and larger, and pipe joints within their corresponding L lengths shall be restrained;
(b) All high pressure valves (working pressures greater than 110 psi) and pipe joints within their corresponding L lengths shall be restrained;
(c) Valves ten inches and smaller placed on dead end mains with less than 71 feet of pipe downstream of the valve shall be restrained using the appropriate joint restraining devices for a dead end. Both the upstream and downstream pipe joints within their corresponding L lengths shall be restrained;
(d) All reducers/increasers and their corresponding L lengths shall be restrained;
(e) All vertical bends and pipe joints within their corresponding L lengths shall be restrained;
(f) All water main lowering and pipe joints shall be restrained. Water main lowering restraint shall include restraining all joints within the filling’s corresponding L length, plus restraining all pipe joints which lie between the start of the lowering and the end of the lowering, regardless whether or not the pipe joint is located within the fitting’s L length;
(g) All joint restraint devices shall be double poly wrapped and taped per city specifications for polyethylene encasement. If cathodic protection anodes are used, double poly wrap shall not be required. The polyethylene encasement ends shall be taped around the entire pipe diameter;
(h) Joint restraining devices shall be installed per the manufacturer’s recommendations and for the appropriate water pressures and soil conditions as shown on the drawings or specifications.
(11) Tracer wire. Tracer wire shall be installed along with all water pipes as described below.
(a) The tracer wire shall be extended along with the water main. The wire shall be installed along the top of the pipe and shall be securely anchored to the pipe every four feet horizontally with an adhesive tape. The tracer wire shall be extended along all water main branches and hydrant leads as well. At fire hydrant leads, two tracer wires (the upstream tracer wire and the downstream tracer wire) shall be brought along the lead and brought to the surface at the fire hydrant. The upstream and downstream tracer wire at fire hydrants shall not be tied together, as this is intended to allow independent tracing of the downstream and upstream main.
(b) Tracer wire shall not be installed with copper water service lines.
(c) Tracer wire shall be installed with PVC water services. Tracer wire installed with PVC service lines shall be installed in accordance with water main requirements except that the tracer wire shall be brought to the surface at a service line valve location. Do not connect the water service tracer wire to the tracer wire on the main. Tracer wire installed along service lines shall be independent of the tracer wire installed along the main. This allows for only tracing the service line.
(d) At locations where the PVC water service is not being replaced entirely, the contractor shall splice the new tracer wire to the existing tracer wire at the point of re-connection. In instances where a PVC water service is not being replaced entirely and an existing tracer wire is not encountered, the contractor shall coil approximately five feet of wire at the re-connection location(s) to facilitate a future splice.
(e) All tracer wire connections shall be accomplished through the use of pig-tails. All splices and pig-tails shall be accomplished by stripping the wires to be connected, twisting the wires together, securing the connection by using an appropriately sized wire nut, and then preserving the splice or pig-tail wire nut with silicone.
(f) The main line tracer wire shall run continuous along the main(s) from fire hydrant auxiliary valves to fire hydrant auxiliary valve but shall not be continuous at fire hydrant auxiliary valves. At fire hydrant auxiliary valves, two tracer wires shall be installed. One wire is the main line wire from downstream of the fire hydrant, and the second wire is the main line wire going upstream of the fire hydrant. The tracer wire shall be extended at least three feet above the auxiliary valve, the wires folded, connected with wire nuts, wire nuts made waterproof with silicone and inserted into the auxiliary valve box for storage. The wire shall be easily retrievable for connection to and subsequent testing. The main line tracer wire shall not be interconnected at the fire hydrant auxiliary valve or at the main. This is intended to allow independent tracing of the downstream main from the upstream main and vice versa. Service line tracer wire shall not be connected to the main line tracer wire.
(g) The Public Works Department shall be able to successfully electronically trace all newly installed tracer wire/water mains. Personnel should be able to connect to tracing wires at every fire hydrant auxiliary valve location and energize all water mains between that fire hydrant auxiliary valve and the surrounding fire hydrants auxiliary valve. The contractor is responsible for coordinating conductivity testing with public works personnel prior to finish surfacing activities. If the tracer wire does not function as intended, the contractor shall repair the system to the satisfaction of the engineer.
(h) The Public Works Department shall inspect all underground splices and pig tails prior to backfilling.
(12) Insulation. Insulation shall be placed where noted on the plans. Insulation board shall be placed on a smooth and level cushion, minimum of two inches, of fine concrete aggregate (sand) and shall be covered with a minimum of two inches of the same material before placing bedding or backfill material on the insulation. The build-up of insulation sheeting shall be done by staggering the joints. An acceptable adhesive may be used to retain the individual sheets in the final specified dimensions.
(13) Fire hydrants and auxiliary valves.
(a) Fire hydrants shall stand plumb and shall have their nozzles parallel with or at right angles to the street, with the pumper nozzle facing the street. At intersections, the pumper nozzle shall face the higher classification street. Hydrants shall be set with the bottom of the breaker flange two inches above the finished ground elevation as shown on the standard details, resulting in the centerline of the lowest nozzle being at least 18 inches above finished grade. In no case shall hydrants be set closer than four feet from curb or edge of pavement, measured from outside of hydrant barrel to back of curb or edge of pavement.
(b) The contractor shall set each fire hydrant on an eight inch by 12 inch precast concrete pad with a four inch thickness and shall place a minimum of one-third cubic yards of Type 2 Foundation Material around the lower part of the hydrant to at least six inches above the drain port to provide a drainage area for the hydrant barrel. The contractor shall ensure that the drain port at the base of the hydrant is open to allow for the hydrant to drain properly when closed. Cast in place concrete may be used in lieu of the pre-cast pad if the hydrant lead is not charged for at least 48 hours and the drainage ports are maintained.
(c) The hydrant barrel shall be poly wrapped to the ground surface and the poly wrap shall not cover up the weep holes.
(d) An appropriately sized thrust block shall be installed between the hydrant valve chamber and the undisturbed trench wall. The thrust block shall meet the thrust block specifications herein.
(e) An auxiliary valve matching the size of the fire hydrant lead and a valve box shall be installed on the fire hydrant lead. Auxiliary valves shall be installed as detailed on the standard plate and shall be placed on a precast concrete block, or shall be fitted with a joint restraining device as approved by the engineer. Cast in place concrete may be used in lieu of the pre-cast pad if the hydrant and hydrant lead are not charged for 48 hours, and four hours cure time is allowed before backfilling. If the auxiliary valve needs to be moved away from the fire hydrant to avoid a conflict, it may be moved up to five feet away from the hydrant.
(f) Tracer wire conduit shall be attached to the fire hydrant auxiliary valve prior to backfill. Refer to subdivision (11) above for tracer wire installation requirements.
(g) Fire hydrant lead shall mean that portion of the hydrant branch line from the main to the auxiliary valve.
(14) Valves.
(a) Valve interiors and adjacent piping shall be cleaned of foreign material prior to making valve to pipe connection. Pipe/valve joints shall be straight and without deflection. All valves shall be encased in polyethylene per AWWA standard C105 and as specified herein, and shall be placed on a precast concrete anchor block and centered on the valve. Valves shall be backfilled with Type 1 bedding material to one foot above the valve. The contractor shall check all operating mechanisms for proper functioning. Valves which do not operate easily or are otherwise defective shall be replaced at the contractor’s expense.
(b) Valves placed on dead-ends of mains with less than the required L length of pipe extending beyond the valve shall be restrained using the appropriate joint restraining devices.
(c) All valves which are not epoxy coated shall be poly wrapped.
(15) Valve boxes.
(a) Valve boxes shall be installed straight and plumb directly over the valve stem and shall not be placed in direct contact with the valve. The top of the valve box shall be placed flush to one-fourth inches below flush with the surfacing in paved or graveled areas and one to two inches above finished grade in grass surfaced areas. Where the drawings indicate that the future grade at the valve location will be higher or lower than the existing grade at the time of valve installation, the contractor shall provide the correct combination of extension pieces so that the valve box can be adjusted to the future finished grade without replacing the valve box.
(b) A valve box adaptor shall be installed on the valve bonnet prior to installing the valve box.
(c) Tracer wire shall be secured to the valve box section prior to backfill.
(16) Tapping tees for taps four inches and larger.
(a) Where new four inch or larger service lines or mains are to be connected to a main, the contractor shall furnish all material necessary for connection to the water main, as specified herein. The tapping tee shall be assembled in accordance with the manufacturer’s instructions. Tapping sleeves shall be supported independently from the pipe prior to tapping and shall be provided with thrust restraint as specified for other fittings. All tapping tees which are not epoxy coated or non-corrosive material shall be poly wrapped.
(b) The Public Works Department will coordinate all taps, and the contractor shall schedule all taps between 7:30 a.m. and 12:30 p.m. Monday through Friday, or as alternately scheduled by the Public Works Department.
(c) The contractor shall obtain and pay for all applicable permits and tapping fees.
(17) Polyethylene fitting encasement. All fittings and accessories, which are not epoxy coated or made of non-corrosive material, shall be encased in eight millimeter thickness sheet polyethylene per AWWA standard C105. The polyethylene sheet shall be installed per AWWA C105 and taped. The polyethylene shall fully encase the fitting and appurtenances. Excess material shall be neatly trimmed away and all seams shall be tapped. The transition between the polyethylene sheet and PVC pipe or the DI poly tube shall be accomplished by sealing the ends of the sheet and taping the material fully around the circumference of the pipe. Cost of the encasement shall be incidental to the bid price of the fitting.
(F) Disinfection.
(1) General. Disinfection shall comply with the requirements of AWWA standards C651, C605, and C600. All new water mains and appurtenances shall be disinfected before they are placed in service. All water mains taken out of service for inspecting, repairing, or other activity that might lead to contamination shall be disinfected before they are returned to service.
(2) Preventative methods.
(a) The tablet method specified below may be used only if the pipes and appurtenances are kept clean and dry during construction. Therefore, the contractor shall take precautions to protect the interiors of pipes, fittings, and valves against contamination. Pipe delivered for construction shall be strung so as to minimize the entrance of foreign material.
(b) If dirt enters the pipe, it shall be removed and the interior of the pipe surface swabbed with a 1-5% hypochlorite disinfecting solution. If, in the opinion of the engineer, the dirt remaining in the pipe will not be removed by flushing, the contractor shall clean the interior of the pipe by mechanical means, such as a hydraulically propelled foam pig. Following mechanical cleaning the contractor shall flush the line achieving minimum flushing velocities of at least 30 feet per second, and shall then disinfect the pipe using either the continuous feed or the slug method. Flushing a completed main will not be allowed as a method of cleaning sediment allowed to enter the pipe during construction.
(c) All openings in the pipeline shall be closed with watertight plugs when pipe laying is stopped at the close of the day’s work or for other reasons, such as rest breaks or meal periods. If water accumulates in the trench, the plugs shall remain in place until the trench is dry. If, for any reason, the water main is flooded during construction, it shall be cleared of the floodwater by draining and flushing with potable water until the main is clean. The section exposed to floodwater shall then be filled with a chlorinated potable water that, at the end of a 24 hour holding period, will have a free chlorine residual of not less than 25 milligrams per liter. The chlorinated water shall then be flushed from the main and after construction is completed, the main shall be disinfected using the continuous feed or slug method.
(3) Disinfectant.
(a) Unless specified otherwise in the detailed specifications or on the drawings, or required by other provisions of this specification, disinfection shall be accomplished by the tablet method. The contractor shall obtain the engineer’s approval prior to using a method other than the tablet method.
(b) This method requires that the pipes and appurtenances be kept clean and dry. This method may not be used if the pipes and appurtenances are not kept clean and dry. In the event this happens, the engineer must be contacted.
(c) Tablets shall be five gram calcium hypochlorite tablets conforming to AWWA standard B300 and shall contain between 65-70% available chlorine. Tablets shall be fresh and shall be stored in a cool, dry, and dark environment to prevent loss of strength, which occurs upon exposure to the atmosphere.
(d) Do not use calcium hypochlorite intended for swimming pool disinfection, as this material has been sequestered and is extremely difficult to eliminate from the pipe after the desired contact time has been achieved.
(4) Dosage. Unless otherwise specified, the contractor shall place hypochlorite tablets in each section of water pipe installed, including the hydrant branch, according to the table below.
Number of five gram calcium hypochlorite tablets required | |||||||
Length of pipe section (feet) | Diameter of pipe (inches) | ||||||
Number of five gram calcium hypochlorite tablets required | |||||||
Length of pipe section (feet) | Diameter of pipe (inches) | ||||||
4 | 6 | 8 | 10 | 12 | 14 | 16 | |
13 or less | 1 | 2 | 2 | 3 | 5 | 6 | 8 |
13-18 | 1 | 2 | 3 | 5 | 6 | 8 | 11 |
18-20 | 1 | 2 | 3 | 5 | 7 | 9 | 12 |
4 | 6 | 8 | 10 | 12 | 14 | 16 | |
20-30 | 2 | 3 | 5 | 7 | 10 | 14 | 18 |
30-40 | 2 | 4 | 6 | 9 | 14 | 18 | 24 |
1 For pipes 18 inches and larger, refer to drawings or detailed specifications for disinfection requirements. | |||||||
(5) Placing tablets. Tablets shall be adhered to the inside top section of each pipe length using a food-grade adhesive, such as Permatex Form-a-Gasket No. 2 or Loctite Corporation Permatex Clear RTV Silicone Adhesive Sealant. There shall be no adhesive on the tablet except on the broad side attached to the surface of the pipe. If the tablets are attached before the pipe section is placed in the trench, their position shall be marked on the pipe section to indicate the pipe has been installed with the tablets at the top.
(6) Filling and contact. The water main shall be filled slowly so that the water velocity is no greater than one foot per second. Precautions shall be taken to assure that air pockets are eliminated. The water shall be allowed to stand in the pipe for at least 24 hours. Valves shall be positioned so that the strong chlorine solution in the treated main will not flow into water mains in active service. The chlorinated water shall remain in the pipe for at least 24 hours. The contractor shall notify the engineer at the end of the 24 hour retention period prior to flushing to allow the engineer to check the chlorine residual in the pipe. If the chlorine residual is less than 25 milligrams per liter, the contractor shall, at his or her expense, disinfect the water main again by the continuous feed method or the slug method, as approved by the engineer.
(7) Flushing.
(a) Within 48 hours of the end of the 24 hour retention period, the contractor shall flush the heavily-chlorinated water from the main until the chlorine concentration in the water leaving the main is no higher than that prevailing in the system or is less than one ppm as determined by the engineer. In addition to the above requirements, a minimum flushing velocity of three feet per second and flushing duration of one minute per 100 feet of pipe being flushed shall be achieved per the table below.
(b) Flushing shall be done in accordance with AWWA C651. Flushing shall be accomplished through use of hydrants or temporary fittings installed for the purpose. Flushing through corporations and/or water service lines is prohibited. The contractor shall obtain the engineer’s approval prior to installing special fittings for flushing.
(c) Flushing shall be conducted in such a way as to prevent contamination of existing water mains and/or water service lines and to minimize traffic and pedestrian hazards and nuisance conditions. When possible, flushing shall be to the nearest storm sewer or drainage way. Flushing to the sanitary sewer is prohibited.
(d) The contractor will be responsible for any damage to fish and/or aquatic life caused by the chlorine residual. If chlorine reaches or is detected in a stream, river, or other waterway the contractor will be in violation for that discharge.
(e) A velocity in the main of at least three feet per second shall be attained during flushing. The flushing shall proceed until the chlorine concentration in the water leaving the main is no higher than that prevailing in the system, or is less than one ppm as determined by the engineer. The table below shows the rates of flow required to produce a velocity of three feet per second in pipes of various sizes, and the minimum flushing duration per 100 feet of pipe length. In no case shall the flushing duration be less than that indicated in the table below.
Required flow and minimum flow duration to flush pipelines | ||||
Pipe diameter (inches) | Flow required to produce 3 feet per second velocity in main2 (gpm) | Fire hydrants | Minimum flushing duration (minutes per 100 feet of pipe) | |
Number of fire hydrants | Outlet size (inches) | |||
Required flow and minimum flow duration to flush pipelines | ||||
Pipe diameter (inches) | Flow required to produce 3 feet per second velocity in main2 (gpm) | Fire hydrants | Minimum flushing duration (minutes per 100 feet of pipe) | |
Number of fire hydrants | Outlet size (inches) | |||
4 | 120 | 1 | 2.5 | 1 |
6 | 280 | 1 | 2.5 | 1 |
8 | 480 | 1 | 2.5 | 1 |
10 | 740 | 1 | 2.5 | 1 |
12 | 1,100 | 2 | 2.5 | 13 |
14 | 1,450 | 2 | 2.5 | 13 |
16 | 1,950 | 3 | 2.5 | 13 |
1 For pipes 18 inches and larger, refer to drawings or detailed specifications for flushing requirements 2 Requires a minimum 40 psi pressure in the main and the hydrant flowing to atmosphere 3 Assumes that the corresponding flow rate is being met | ||||
(f) Per AWWA C651, the contractor shall sample for coliform bacteria contamination. After the water lines have been flushed, the contractor shall sample the lines. Two consecutive samples of water from the end of the disinfected/flushed line must be collected at least 24 hours apart. These samples must be submitted to the state health laboratory, or other laboratory acceptable to the state Department of Environment and Natural Resources and the engineer. The samples must show the absence of coliform bacteria contamination before any taps may be made to the main or the main is activated and placed into service. Copies of all sample results shall be submitted to the engineer within 48 hours of receipt thereof.
(g) Because of the high risk of contamination during sampling, the contractor shall use certified lab personnel or a trained sampler to collect all samples submitted for testing.
(8) Disposal of chlorinated water. When, in the opinion of the engineer or contractor, the potential exists for chlorinated water to reach a stream, river, or waterway, the contractor shall apply a neutralizing chemical to the water to be wasted to neutralize thoroughly the chlorine residual remaining in the water as listed in appendix B of AWWA standard C651. The contractor will be responsible for any damage to fish and/or aquatic life caused by the chlorine residual. If chlorine reaches or is detected in a stream, river, or other waterway the contractor will be in violation for that discharge.
(G) Pressure and leakage test for mains and service lines four inches or larger.
(1) General. Pressure and leakage tests shall be performed on all newly installed water mains. The simultaneous pressure and leakage tests will be used unless otherwise specified. The testing methods specified in this division are specific for water pressure testing only. Air pressure testing is prohibited due to the catastrophic nature of failure should failure occur.
(2) Test restrictions.
(a) The pressure shall be 150% of the working pressure at the point of test, but not less than 125% of normal working pressure at the highest elevation, whichever is greater. Test pressure shall not exceed pipe, valve, or thrust restraint design pressures, and shall not vary by more than five psi (plus or minus) for the duration of the test. The duration of the hydrostatic test shall be a minimum of two hours.
(b) The contractor shall anticipate the need to conduct multiple tests in areas of varying topography and shall conduct testing in such a manner and sequence that the pressure requirements indicated above are achieved.
(3) Pressurization. Before applying the specified test pressure, each valved section of pipe to be tested shall be slowly filled with potable water and all air expelled from the pipe, valves, fittings, and hydrants. Where town water is not available, the contractor shall furnish sufficient potable water to fill and test the pipe. The specified test pressure, based on the elevation of the lowest point of the section under test and corrected to the elevation of the test gauge, shall then be applied by means of a suitable pump connected to the pipe in a manner satisfactory to the engineer and shall be sustained for the specified time. The test pump shall be equipped with two accurate pressure gauges, between the pump shut-off valve and water main being tested, both to show the line pressure reading during testing. When hydrants are in the test section, the test shall be made against closed hydrant valves.
(4) 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 specified test pressure after the pipe has been filled with water and the air has been expelled. Leakage shall not be measured by the drop in pressure for a test section over a period of time.
(5) Allowable leakage for PVC pipe. The PVC pipe shall be pressure and leakage tested in accordance with AWWA C605. No pipe installation will be accepted if the leakage is greater than that indicated in the table below.
Allowable leakage in gallons per hour per 1,000 feet of pipe (gph) | ||||||
Average test pressure (psi) | ||||||
Pipe diameter (inches) | 50 psi (gph) | 100 psi (gph) | 150 psi (gph) | 200 psi (gph) | 250 psi (gph) | 300 psi (gph) |
Allowable leakage in gallons per hour per 1,000 feet of pipe (gph) | ||||||
Average test pressure (psi) | ||||||
Pipe diameter (inches) | 50 psi (gph) | 100 psi (gph) | 150 psi (gph) | 200 psi (gph) | 250 psi (gph) | 300 psi (gph) |
4 | 0.19 | 0.27 | 0.33 | 0.38 | 0.43 | 0.47 |
6 | 0.29 | 0.41 | 0.50 | 0.57 | 0.64 | 0.70 |
8 | 0.38 | 0.54 | 0.66 | 0.76 | 0.85 | 0.94 |
10 | 0.48 | 0.68 | 0.83 | 0.96 | 1.07 | 1.17 |
12 | 0.57 | 0.81 | 0.99 | 1.15 | 1.28 | 1.40 |
14 | 0.67 | 0.95 | 1.16 | 1.34 | 1.50 | 1.64 |
16 | 0.76 | 1.08 | 1.32 | 1.53 | 1.71 | 1.87 |
18 | 0.86 | 1.22 | 1.49 | 1.72 | 1.92 | 2.11 |
20 | 0.96 | 1.35 | 1.66 | 1.91 | 2.14 | 2.34 |
24 | 1.15 | 1.62 | 1.99 | 2.29 | 2.56 | 2.81 |
30 | 1.43 | 2.03 | 2.48 | 2.87 | 3.21 | 3.51 |
36 | 1.72 | 2.43 | 2.98 | 3.44 | 3.85 | 4.21 |
(6) (a) Acceptance shall be determined on the basis of allowable leakage. If any test of installed pipe discloses leakage greater than that specified in the table above, the contractor shall, at his or her own expense, locate and make approved repairs as necessary until the leakage is within the specified allowance. All visible leaks shall be repaired, regardless of the amount of leakage.
(b) Any damaged or defective pipe, fittings, valves, hydrants, or joints discovered following the pressure test shall be repaired or replaced with approved material at the contractor’s expense, and the test shall be repeated until it is within the specified allowance.
(H) Pressure and leakage test for service lines less than four inches. Pressure and leakage tests shall be performed on all newly installed copper water service lines if the service line has one or more couplings installed between the corporation and the curb stop, and/or one or more couplings installed between the curb stop and the property water distributing system. The testing method shall be as specified in the National Standard Plumbing Code with the exception that air pressure testing is prohibited.
(I) Water main closures and temporary service.
(1) Water main closures shall be scheduled to minimize the inconvenience to the public. Consequently, water main closures shall be scheduled between 8:00 a.m. and 4:00 p.m. Monday through Friday, when possible. Water main closures scheduled to begin prior to or continue beyond those times listed above will require approval from the engineer. In any case, water main closures will not be allowed until the engineer gives his or her approval.
(2) The contractor shall notify the Public Works Department of all proposed closures at least 48 hours prior to closure of any water main, unless a shorter time of notice is approved by the engineer. The Public Works Department will issue closure notification to affected landowners.
(3) Operation of valves. Only public works personnel shall operate valves on existing water mains. The contractor may operate valves on newly installed water mains that are under his or her control, until such time as they are accepted by the city for operation and maintenance.
(4) Temporary water service for private residences affected shall be provided by the contractor when the water main closure will exceed eight hours. The contractor shall provide temporary water service for businesses upon request, regardless of the length of closure. When temporary service is to be provided to businesses, the contractor shall obtain the name and phone number of a responsible contact person at each affected business and submit the information to the engineer at least 48 hours prior to closure.
(J) Abandonment and/or salvage of water main and appurtenances.
(1) Water mains. The contractor shall seal all open ends of water mains to be abandoned with a concrete plug having a length equal to the diameter of the pipe being plugged.
(2) Fire hydrants. Fire hydrants and auxiliary valves are to be removed and salvaged, unless indicated otherwise on the drawings or detailed specifications, and shall be delivered by the contractor to the Public Works Department in good working condition. Any damage to the hydrant and/or appurtenances as a result of removing, salvaging, and delivering, shall be repaired by the contractor at no cost to the city.
(3) Valves. Unless indicated otherwise on the drawings or detailed specifications, valves are to be removed, salvaged, and delivered by the contractor to the Public Works Department in good working condition. Any damage to the valve as a result of removing, salvaging, and delivering, shall be repaired by the contractor at no cost to the town.
(4) Valve boxes. The contractor shall close the valve, remove and salvage the top sections of those water main valve boxes marked on the plans to be abandoned and shall deliver them to the Public Works Department. The resulting holes shall be backfilled and compacted to meet the requirements of these specifications and shall be resurfaced with the appropriate material: i.e. seed, sod, asphalt, concrete, etc.
(5) Others. When the drawings indicate items are to be removed or salvaged, the contractor shall deliver the items to the Public Works Department in good working condition. Any damage to the items as a result of removing, salvaging, and delivering, shall be repaired by the contractor at no cost to the town. Unless an item is indicated as salvaged, the item will be considered a contractor obligation to remove and dispose of.
(K) Service lines and fittings.
(1) Permits, obtainable from the Public Works Department, will be required for all connections to the town water system.
(2) Service pipe. Copper pipe shall be laid with sufficient waving as to prevent rupture in settlement. A goose-neck shape shall be constructed in the copper pipe leading from the corporation stop. Copper splicing couplings shall be as described in this specification. PVC or Class 200 psi black poly service pipe shall be laid as specified herein for water mains. Minimum cover depth for water service lines shall be six feet. A ten foot horizontal separation shall be maintained between water service and sewer service lines. Tracer wire shall be installed along with all PVC service lines, as described in the specification section relating to tracer wire. Tracer wire shall not be installed with copper service lines.
(3) Service saddles shall be installed for all connections to water mains. Unless specified otherwise on the drawings or detailed specifications, the contractor shall furnish and install all service saddles.
(4) Corporation stops shall be provided by the contractor, and inspected by the Public Works Department.
(5) Service lines larger than two inches diameter shall be connected to the main with either an appropriately sized tapping sleeve and valve or an epoxy coated ductile iron tee as specified for water main fittings elsewhere in these specifications.
(6) Curb stops and boxes shall be installed on all service lines and shall be located entirely within the public right-of-way. The curb stop and box shall be located between one and seven feet from the property line, unless otherwise approved by the engineer. If any curb box is closer to the property line than 0.9 feet or farther from the property line than 7.1 feet, measured to the center of the box, then the box shall be reset to within the allowable tolerance.
(7) Water service new connections.
(a) Where new service lines are to be installed for undeveloped property or future buildings or additional services added to an existing building, the contractor shall furnish all materials necessary for connection of new service lines to the water main as specified herein, and shall obtain and pay permits and tapping fees as established by ordinance.
(b) Where the new service line is terminated, the service line shall be capped and plugged water tight to prevent leakage if the curb stop is inadvertently opened. New service connections shall have curb stops left turned off at the time of installation and the termination point shall be marked with a minimum three foot long steel fence post. The steel post shall be buried below the surface at least eight inches. The post needs to be steel to facilitate location by magnetic locators.
(c) The contractor shall schedule all service taps between 7:30 a.m. to 4:00 p.m. Monday through Friday, and the Public Works Department shall inspect.
(d) Water service new connections for service lines four inches or larger shall be made as described in division (E)(16) of this section.
(8) Water service reconnections.
(a) The contractor shall furnish all materials necessary for reconnecting service lines existing prior to reconstruction of a water main. On town projects, all permits and tapping fees will be waived. However, the contractor shall obtain a no charge permit to work in the right-of-way from the Public Works Department.
(b) On non-town projects, the new account set-up/inspection permit (tap permit), the right-to-work permit, and tapping fees are applicable and will be secured prior to beginning work.
(c) The contractor shall schedule all service taps between 7:30 a.m. to 4:00 p.m. Monday through Friday, with the Public Works Department to inspect.
(9) Inspection. All water service installations, regardless of whether or not the service is located on private property or in public right-of-way, shall be inspected by the Public Works Department prior to the contractor backfilling the trench. The contractor shall notify the Public Works Department Supervisor a minimum of four hours prior to the time he or she needs the inspection. Any trench backfilled without being inspected and approved by authorized town personnel shall be re-excavated by the contractor to expose the work for the required inspection. Discrepancies shall be corrected by the contractor and re-inspected by town personnel. Any re-inspection fees will be charged to the contractor.
(L) Acceptance of curb stops and main valves. As a condition for project acceptance, all curb stops and water main valves within the project boundaries shall be in proper operating condition. Town personnel will inspect and operate each curb stop and water main valve as part of the final inspection. The contractor shall correct any deficiencies discovered during the inspection.
(Ord. passed 3- -2006)