343 SECTION 724
724.01 Description
This work consists of furnishing and installing water, lines, sewer lines, and appurtenances.
724.02 Equipment
Reserved.
724.03 Materials
Item Section Reinforced Concrete Sewer Pipe 830.01 A Ductile Iron Sewer Pipe 830.02 A Plastic Pipe 830.03 Copper Pipe ASTM B 88 Type K Rubber Gaskets ASTM C 443 Gate Valves AWWA C 500 Butterfly Valves AWWA C 504 Concrete – Class AE 802 Use SDR-18, Class 150 PVC pipe that meets the requirements of AWWA C 900. Use joints and fittings that meet the requirements of AWWA. Construct copper services with flared or compression fittings Use gate valves with: − Non-rising stems; − O-ring seals; and − 2 inch operating nuts that open counter -clockwise. Use granular material with 100 percent passing a 2 inch sieve and no more than 35 percent passing a No. 200 sieve for bedding and encasement.
724.04 Construction Requirements
A.General. Comply with the requirements of the North Dakota Plumbing Installation Standards, the NDDEQ , and city ordinances. Do not construct water mains in the same excavated trench as sanitary sewer pipes. Provide at least 10 feet of horizontal clearance between water mains and sewer pipes. If it is not possible to maintain the 10 feet of horizontal clearance or if it is necessary for the water main and sewer pipe cross, provide a minimum vertical separation of 18 inches.
B.Excavation and Trenching. Exca vate trenches to a minimum width of 30 inches or a width of 24 inches wider than the outside diameter of the pipe, whichever is greater. Provide sheathing and bracing to support the trench.
1.Excavation. Remove rock, shale, or hard pan to a depth 1 foot below the bedding elevation and replace with bedding material. The Department will pay for excavation required in excess of 1 foot below the specified bedding elevation as “Common Excavation.”
2.Bedding and Encasement. Tamp the bedding to provide uniform bearing along the entire length of the pipe. Shape the bedding material so that after placing the pipe, the bedding extends up the sides of the pipe a distance of 1/3 the pipe diameter. T amp the encasement without displacement of the pipe.
3.Backfilling. Backfill above the encasement with suitable material excavated from the trench. Place backfill in lifts not exceeding 6 inches of loose material. Compact the material as specified in Section 203.04 G .2.a, “ND T 180” .
C.Water Main.
1.Temporary Services. Coordinate with the utility owner for service interruptions in advance of the actual scheduled interruptions occurring. Provide temporary service to properties whose services will be interrupted for more than 8 hours. If the service will be interrupted for less than 8 hours and if performing the work without providing temporary services, notify all affected property occupants, in writing, at least 24 hours in advance of the service interruption. Include the following infor mation in the notice:
a.Contractor contact information;
b.Engineer contact information;
c.When the service will be interrupted;
d.Approximately when the service will be restored; and
e.A general description of the work being performed. Before distribution, provide the notice to the Engineer for approval of the form and language of the notice. At the same time the property occupants are notified, provide a copy of the final version to the Engineer. If service is interrupted for more than 8 hour s and temporary service has not been provided, provide all necessary temporary services before continuing any other work.
2.Placement. Clean the interior of each joint or fixture before lowering into the trench. Prevent deleterious material from entering the pipe during installation. Drain or pump water encountered during laying operations so no water enters the pipe. Join pipe according to manufacturer’s recommended practices. 345 Where connections to existing lines are required, notify the line owners at least 24 hours in advance, so arrangements for temporary service can be made, or agreement reached regarding when the service can be interrupted.
3.Testing and Disinfecting Lines. After the pipe trench has been partially backfilled, perform a h ydrostatic pressure test on all new pipe or valve sections. The city will provide the necessary taps without charge. Furnish all other equipment and material necessary to make the pressure test. Fill the test section with water and gradually increase the pressure. Conduct the final hydrostatic pressure test at 150 psi and hold for one hour. If defects are found, repair the defects and repeat the hydrostatic pressure test. After the hydrostatic pressure test is successfully completed, disinfect water lines by completely filling lines with a water solution containing a residual chlorine level of at least 100 parts per million. Allow the solution to stand for a minimum of one hour. After the disinfecting period, drain or flush the solution from the line.
4.Thrust Blocks. Use a cast-in -place concrete thrust block to brace fixtures that could separate from the line under pressure. Cast the block between the fixture and the undisturbed vertical trench wall with a minimum bearing surface of 2 square feet again st the vertical wall.
5.Marking Tape. During backfilling, install marking tape 2 feet above the water main. Use non-detectable tape with a minimum width of 5 inches. Use blue tape with the words “CAUTION, WATER LINE BELOW” imprinted on the tape in black capital letters.
D.Water Service Lines.
1.General. Make all connections to water mains with a corporation stop.
2.Placing Water Line. Lay copper pipe in a wavy line in the trench. From the corporation stop to the curb stop, install a length of copper pipe a minimum 2 feet longer than the measured distance between the stops. Place the pipe at least 7.5 feet below the grade of the finished street. Bench the water service and offset on solid ground and take precautions to ensure stability. Loop the water service line at a 45 degree angle at the main into a gooseneck. Support the gooseneck to prevent displacement, settlement, and strain on the corporation or connection.
3.Testing. Test water line and connections in place using normal operating water pressure as soon as the water connection is completed and before placing backfill, open the corporation stop and examine the connection for defects. Repair defects and repeat the pressure test.
E.Sanitary Sewer Pipe. Lay the sewer pipe from the lower end with the spigot ends pointing in the direction of flow. Place the lower segment of the pipe in contact with the shaped bedding throughout its full 346 length and check for line and grade before placing the next segment. Remove all deleterious material from the pipe and bell before placing the pipe. Make joints tight and secure. Completely seat sewer pipe with pre-molded gaskets and check the gasket for proper positioning. Where connections to existing lines are required, notify the line owners at least 24 hours in advance.
724.05 Method of Measurement
The Engineer will measure completed and in place as specified in Section 109.01, “Measurement of Quantities” and as follows:
A.Water Mains. Water main installed length will be measured from center of connected pipe to center of connected pipe or end cap.
B.Sewer Lines. Sewer line installed length will be measured through fittings and from centerline of pipe to centerline of pipe and with no deduction for lengths through manholes. Where two different sizes enter or leave a manhole, the Engineer will measure each size to the center of the manhole.
C.Water Service Lines. Water service lines will be measured horizontally from the centerline of the water main to the end of the service.
724.06 Basis of Payment
Pay Item Pay Unit Butterfly Valve & Box __ IN Each Butterfly Valve __IN Each Fittings – Ductile Iron Pounds Remove Gate Valve & Box Each Gate Valve & Box __IN Each Sleeve __IN Each Water Service Line __IN Linear Foot Temporary Service Lump Sum Watermain __IN Linear Foot __ IN Watermain Linear Foot __ IN Sanitary Sewer Pipe Linear Foot Such payment is full compensation for furnishing all materials, equipment, labor, and incidentals to complete the work as specified. Section 744 347 SECTION 744 POLYSTYRENE INSULATION BOARD
744.01 Description
This work consists of furnishing and installing extruded expanded polystyrene insulation board.
744.02 Equipment
Equipment Section Self-Propelled Pneumatic -Tired Rollers 151.01 C
744.03 Materials
Use polystyrene insulation board that meets the requirements of AASHTO M 230.
744.04 Construction Requirements
A.Base Preparation. Compact and level the base material. Place the board on base that is smooth and level and without point loadings. Do not operate construction equipment on the insulation board. The Engineer will allow placing a layer of sand as a base.
B.Installation. Stagger the insulation boards so the transverse joints are not continuous and are at least 4 feet apart. If multiple layers of insulation are used, place vertical joints in a successive layer a minimum of 6 inches from the joint in the preceding layer. Place boards so that the gap between two boards is less than 1/4 inch. Take any necessary steps to prevent the boards from moving during backfill placement.
C.Cover Material. Place a first lift of 12 inches of loose material on the insulation board. Compact the cover material with pneumatic -tired rollers or hand operated mechanical tamper. Do not drive equipment, other than the compaction equipment, over the insulation board until the first lift of material has been placed and compacted.
744.05 Method of Measurement
The Engineer will measure completed and in place as specified in Section 109.01, “Measurement of Quantities.”
744.06 Basis of Payment
Pay Item Pay Unit Insulation Board Cubic Foot
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 378–381 of 550.