§ 7.5-126. Water system construction.

(1)

Generally.

(a)

It shall be expressly understood that these specifications are for installation of all underground water mains and appurtenances.

(b)

All work shall conform to the applicable provisions of the AWWA specifications of latest revision except as otherwise specified herein.

(2)

Trench excavation.

(a)

Trenches shall have a minimum width of twenty-four (24) inches or the diameter of the outside of the bell of the water main plus twelve (12) inches, (whichever is greater), and the depth thereof shall be such that there shall be a minimum of forty-two (42) inches of cover measured below the roadway surface, natural ground, or proposed grade to the top of the pipe. In cases where water lines cross sanitary sewers, there shall be a minimum of two (2) feet vertical separation between the water and sewer mains. In cases where water mains parallel sewer mains there shall be a minimum of ten (10) feet horizontal separation maintained between the mains.

Trenches shall be dug so that the pipe can be laid to the alignment and depth required, and the trench shall be of such width and shall be braced and drained so that the workmen may work therein safely and efficiently. No chocking under the pipe will be permitted. All joints shall be as specified herein. Excavation must be made under the bell of each pipe so that the entire length of the pipe will lie uniformly on the bottom of the trench and the pipe weight shall not rest on the bells. Trenches shall be free of water during the work.

Water lines shall have a minimum cover of forty-two (42) inches. All changes in grade shall be made gradually. At points of interference with storm sewers and cross drains, pipe will be run under the conflicting utility if the minimum cover cannot be maintained by going over the top of the pipe.

In laying pipe across water courses, railroad crossings, or depressions of any kind, the minimum depth here specified shall be maintained at the bottom of the depression.

Where necessary, the line shall be lowered at valves so that the top of the valve stem is approximately one (1) foot below the finished grade. The trench shall be deepened to provide a gradual approach to all low points of the line.

(b)

Wherever rock is encountered in the excavation, it shall be removed by suitable means. If blasting is used for removal of rock, the contractor shall take all proper safety precautions. He shall comply with all rules and regulations for the protection of life and property that may be imposed by any public body having jurisdiction relative to the handling, storing and use of explosives. Before blasting, the contractor shall cover the excavation with heavy timbers and mats in such a manner as to protect the adjacent property owners from damage. All rock encountered shall be removed six (6) inches below the bottom grade of the trench and the trench built back to the correct grade with suitable material tamped into place. Sides of the trench shall be trimmed of projecting rock that will interfere with backfilling operations. The contractor shall be wholly responsible for any damage resulting from blasting. Rock excavation by blasting shall be at least seventy-five (75) feet in advance of pipe laying.

(c)

After the pipe has been laid, backfilling shall be performed in two (2) distinct operations. In general, all backfill beneath, around and to a depth of twenty-four (24) inches above the top of the pipe shall be placed in six-inch layers for the full width of the trench and thoroughly compacted by hand with vibratory equipment. Care shall be taken so that the pipe is not laterally displaced during backfilling operations. The backfill lifts shall be placed by an approved method in accordance with that hereinafter specified. Backfill materials shall be the excavated materials without bricks, stone, foreign matter or corrosive materials, where not otherwise specified or indicated on the plans.

(d)

Backfill under permanent concrete or bituminous pavement and as elsewhere specified or indicated on the plans shall be as shown in the standard detail drawings for trenches in paved areas. Mechanical vibrating equipment shall be used to achieve the required compaction.

(e)

Backfill under gravel or crushed stone surfaced roadways and low-type bituminous surfaced roadways shall be approved suitable excavated material placed in twelve-inch layers and thoroughly compacted for the full depth and width of the trench, conforming to the compaction, density compaction method and materials as specified in subsection (d) above.

(f)

Backfill in unpaved areas shall be compacted with mechanical vibrating equipment to ninety-five (95) percent as determined by the Standard Proctor Test. Trenches shall be compacted so they will not settle. If settlement occurs, trenches are to be refilled, recompacted and regraded. Backfill material from pipe bedding to ground surface shall be excavated earth free from large stones and other debris.

(g)

Contractor shall fully restore and replace all pavement, surface structures, grassing, landscaping, etc., removed or disturbed as part of the work to a condition equal to that before the work began. All pavement removal shall be replaced per standard detail drawings.

(h)

Where sheeting is used in connection with the work, it is in no case to be withdrawn before the trench is sufficiently filled to prevent damage to banks, road surfaces, adjacent pipes, adjacent structures or adjacent property, public or private.

(3)

Laying pipe. All pipe shall be laid straight, true to line and grade. Bell and coupling holes shall be dug in the trench and the pipe shall have a continuous bearing with the trench bottom between bell or coupling holes. No shimming or blocking up of the pipe shall be allowed. When the work is not going on, all pipe openings shall be securely closed by the insertion of the proper size plug and caulking so that dirt and debris will not be washed into the pipe in case of rain.

In making the joints with ductile iron pipe, the spigot end of the pipe and the inside of the bell shall be thoroughly cleaned and the gasket inspected to see that it is properly placed; lubricant shall be applied to the spigot end of the pipe and it shall be inserted into the bell of the adjoining pipe to the stop mark on the pipe.

(4)

Thrust restraint for pressure lines.

(a)

Reaction blocking.

1.

Underground piping laid around curves and at all unsupported changes of direction, all tees, wyes, crosses, plugs and other like fittings shall be solidly and properly blocked with concrete against solid earth to take the reaction of the main pressure and to prevent lateral movement of the pipe or fittings when under pressure. Reaction blocking shall be installed at all locations requiring same and where tie rods and clamps are not called for in the plans. Concrete for reaction blocking shall have a minimum compressive strength of three thousand (3,000) psi at twenty-eight (28) days. The blocking, unless otherwise shown, shall be so placed that the pipe and fitting joints will be accessible for repair. In addition to the concrete blocking specified herein, all mechanical joint fittings shall be installed with Mega-Lug retainer glands.

2.

Reaction blocking shall be constructed as per AWWA Standard C600 Section 3.8, latest revision. It shall be constructed in conformance with the Standard Detail Drawings for Reaction Blocking.

(b)

Retainer glands. Mechanical joint fittings on ductile iron pipe shall be installed with retainer glands. Retainer glands are to be Mega-Lug retainer glands as manufactured by EBBA Iron.

1.

Clean the socket and the plain end. Lubrication and additional cleaning should be provided by brushing both the gasket and the plain end with soapy water or an approved pipe lubricant meeting the requirements of ANSI C111 or AWWA A21.11 just prior to slipping the gland and gasket onto the plain end for joint assembly. Place the gland on the plain end with the lip extension toward the plain end, followed by the gasket.

2.

Insert the pipe into the socket and press the gasket firmly and evenly into the gasket recess. Keep the joint straight during assembly.

3.

Push the gland toward the socket and center it around the pipe with the gland lip against the gasket. Insert bolts and hand tighten nuts. Make deflection after joint assembly but before tightening bolts.

4.

Tighten the bolts to the normal range of bolt torque specified in AWWA C600 while at all times maintaining approximately the same distance between the gland and the face of the flange at all points around the socket.

5.

Tighten the torque limiting twist off nuts in a clock-wise direction until all wedges are in firm contact with the pipe surface. Continue tightening in an alternate manner until all of the nuts have been twisted off.

(5)

Setting fire hydrants. Fire hydrants shall be placed at the locations shown on the plans or as directed by the city. All fire hydrants shall be installed with a resilient seat gate for isolation from the main. Gate valves for fire hydrants shall be connected directly to the main by means of a "Locked Hydrant Tee." Fire hydrants shall be connected to the isolation valve with a locked hydrant adapter. Installations where locked hydrant tees or locked hydrant adapters cannot be utilized, either due to distance from the main or size, shall be restrained with retainers glands and threaded rods. Care shall be exercised that set screws and retainer glands are tightened sufficiently to secure the hydrants before pressure is put on the main. Not less than nine (9) cubic feet of coarse, broken stone shall be placed around the base of the hydrants, as shown in the standard detail drawings, Section 400. Before placing the hydrants, care shall be taken to see that all foreign material is removed from within the body. The stuffing boxes shall be tightened and the hydrant valve opened and closed to see that all parts are in first class working condition. All hydrant openings shall be kept capped, except when hydrant is being worked on. Existing fire hydrants shall not be operated without permission of the city.

When a fire hydrant has been constructed but is not yet in service, the contractor shall provide and attach to the fire hydrant, flags or collars indicating that the fire hydrant is not in service. Said flags or collars shall remain on the fire hydrant until it is put into service.

Whenever an existing fire hydrant is taken out of service, whether temporarily or permanently, it shall be equipped with a flag or collar indicating that it is not in service. The contractor shall provide and install flags or collars as required and shall notify the fire department whenever the operating status of any fire hydrant changes.

Fire hydrants shall not be operated with any tool except a specifically designed fire hydrant wrench. If the contractor observes any other contractor or person operating a fire hydrant with an unapproved fire hydrant wrench, he shall report that fact to the city immediately. It is the contractor's responsibility to insure that all new facilities are maintained in new condition until final completion of the project and acceptance by the city. Fire hydrants with damaged operating nuts shall not be accepted.

(6)

Setting valves and fittings. Valves shall be set plumb, and shall have cast iron valve boxes. The valve boxes shall be placed directly over the valve and set plumb, the top of the box being brought to the surface of the ground. Provide valve extensions on all valves with operating nuts more than three (3) feet in depth. Valve extensions shall bring the operating nut to within eighteen (18) inches of the surface and shall be keyed into the valve nut. After the boxes are in place, earth shall be filled in the trench and thoroughly tamped around the box. After all settlement has taken place, a precast concrete collar shall be installed for each valve box.

Fittings shall be properly restrained to insure that they will not be blown off or broken loose under the greatest possible working pressure (see standard detail drawings). All fittings shall be mechanical joint and shall be installed with Mega-Lug retainer glands and concrete blocking unless specified otherwise. In situations where there is insufficient undisturbed earth to act as a bearing surface or where otherwise directed by the city, fittings shall be restrained by the use of threaded rods or other method acceptable to the city.

Prior to blocking any joint or fitting with concrete, that joint or fitting shall be wrapped with polyethylene film in such a manner that the concrete will not stick directly to the pipe but that the load bearing capacity of the blocking will not be affected. Care shall be taken to prevent the concrete from covering bolts. Polyethylene film shall be installed at other points along the water main where so directed by the city.

(7)

Placing of steel casing pipe. Casing pipe shall be installed at the location shown on the plans. Unless directed otherwise, the installation procedure shall be by the dry bore method. The hole is to be mechanically bored and cased through the soil by a cutting head on a continuous auger mounted inside the casing pipe. The installation of the casing and boring of the hole shall be done simultaneously by jacking. Lengths of pipe are to be adequately welded to the preceding section installed. Excavation material will be removed and placed at the top of the working pit. Backfill material and methods of backfilling and tamping shall be as required under backfilling. Carrier pipe shall be inserted within the casing by use of stainless steel casing spacers. Intervals shall be as detailed in Section 805.24.

(8)

Marking location of valves.

(a)

Each main line water valve shall be marked by cutting a letter "V" in the horizontal surface at the back of the curb. The "V" shall be turned to point toward the valve which may be either in the street or in the grass behind the curb. The letter height shall be four (4) inches to six (6) inches.

(b)

Concrete valve markers shall be set for main line water valves with an even number of feet between the center line of the valve and the center line of the aluminum disc in the top of the marker, and the distance in feet between the valve and marker shall be stamped in the marker at the time of setting.

(9)

Dewatering trenches. The contractor shall do all necessary pumping or bailing, build all drains and do all other work necessary at his own expense to keep the trenches clear of water during the progress of the work.

(10)

Bracing, sheeting, and/or shoring. Whenever the condition of the ground is such that it is necessary to protect the work, the street, the roadway or the workmen, the sides of the trench shall be supported with suitable bracing, sheeting and/or shoring to be furnished by the contractor at his own expense.

(11)

Rock excavation. Drilling and blasting operations shall be conducted with due regard for the safety of persons and property in the vicinity and in strict conformity with requirements of all ordinances, laws and regulations governing blasting and the use of explosives. Rock excavation near existing pipelines or other structures shall be conducted with the utmost care to avoid damage. Injury or damage to other structures and properties shall be promptly repaired by the contractor to the satisfaction of the city and property owner. Rock in trenches shall be excavated over the horizontal limits of excavation and to depths as follows:

Size of Pipeline (in inches)	Depth of Excavation Below Bottom of Pipe (in inches)
6 and Less	6
8 to 18	8
18 to 30	10
Over 30	12

 

The undercut space shall then be brought up to grade by backfilling with size #57 crushed stone material or approved equal.

(12)

Location and protection of existing underground utilities. It is the responsibility of the contractor to locate the underground utilities and to protect same. Utility lines or services damaged by the contractor shall be repaired by the contractor at his own expense. The contractor is to comply with all federal, state and local laws requiring notification of the utilities protection center prior to excavating.

(13)

Connection to the existing city water system.

(a)

Requirements for all connections. All persons desiring to connect a line extension to an existing main must make application at the city at least twenty-one (21) working days prior to the date the connection is to be made. Connection to existing mains will only be allowed for approved projects. All connections must be made with a wet tap using a tapping saddle or tapping sleeve. The contractor has the option of contracting with the city water department to perform the actual tapping of the main or they may contract with an outside private contractor. City approval of private contractor to perform pipe tapping is mandatory. Submit detailed resume and work history with references to establish competency and expertise for performing tap work. A city water department inspector must be present at all times during tapping operations. The contractor shall furnish the following information when making application:

1.

Approved plan for the project.

2.

Copy of street or highway permit if applicable.

3.

Schedule of work to be performed.

4.

Resume, work history and references of proposed tapping contractor for taps installed by a private contractor.

5.

Payment of cost estimate for connections installed by the city.

(b)

City makes connection. The city will charge for work at prevailing department rates and schedule the connection to conform to their work schedule and notify the contractor so that he can complete his preparation.

1.

The contractor shall furnish the following at site:

a.

Tapping sleeve and valve installed on the line and ready for tapping.

b.

Proper traffic control devices and person(s) to direct traffic if required.

c.

Backhoe or lift capable of handling the tapping machine.

d.

Minimum of three (3) men to assist with the work.

2.

The contractor will be billed for making the connection based on material costs and the hourly rates for the city's operator, additional laborers, truck and any other equipment used if made by city forces.

(c)

Private contractor makes connections.

1.

city personnel shall supervise the tap and associated work by private contractor.

2.

All taps shall be made on wet lines under pressure.

3.

All taps to be made with saddles or tapping sleeves meeting city standard specifications.

(14)

Street cuts.

(a)

All paved roads will be bored and cased. A bore must be attempted before consideration will be given to cutting the street. A permit is required for all utility installations in existing city streets as detailed in subsection 7.5-68(6)(c).

(b)

One (1) lane of traffic shall be maintained open at all times.

(c)

Construction work shall be limited to the hours between 9:00 a.m. and 4:00 p.m. Other time constraints may be imposed if deemed necessary by the city.

(d)

The contractor shall furnish traffic control devices and person(s) to direct traffic, if required.

(e)

Compaction and surface replacement to be performed per city standard specifications as detailed in other sections herein.

(15)

Standard drawings. Installation of fire hydrants, water valves, valve boxes, meters, long side services water lines, etc. shall be made in accordance with applicable standard design drawings in these specifications.

(16)

Clean up. Prior to requesting the final inspection, the contractor shall do the following:

(a)

Remove and dispose of in an acceptable manner all shipping timbers, shipping bands, spacers, excess materials, broken material, crates, boxes and any other material brought to the job site.

(b)

Repair or replace any work damaged by the water line construction.

(c)

Regrade and smooth all shoulder areas disturbed by the water line construction.

(d)

Set precast concrete collars around all valve boxes outside paved areas.

(e)

Insure that all fire hydrants are set to grade and that all valves have been located and are fully open.

(17)

Interruption of water supply during construction. Approval of the city water department must be obtained prior to interrupting water service to an occupied building. A minimum of one (1) business day advance notice shall be given to any occupied building served by a water line which is required to be shut off. Occupants shall be informed of the date, time of cutoff and the duration of stoppage by written notice posted on doorways of all buildings affected. Failure to do so will make the contractor liable for any damages reported to the city office.

(Ord. No. 32-98, § 1, 8-27-98; Ord. No. 50-98, § 8, 1-7-99)