823 - Water Mains
GENERAL
Water mains are a conduit or pipe that is constructed to convey treated water for consumption or to provide water for emergency services such as Fire Departments. The pipes, which are typically cast iron, are run under pressure to provide a continuous supply of water when performing such tasks as washing dishes.
Water mains are typically maintained by local municipalities and in some instances, regional entities.
MATERIALS
Pipe
Pipe material is per Section 923 of the Standard Specifications for Construction. Pipe material is typically bituminous and cement lined cast iron material with male and female ends. The bituminous lining, which is applied to the outside of the pipe helps to mitigated corrosion of the cast iron pipe as well as the cement lining which is applied to the inside of the pipe. Each section of pipe can either come with push-on joints or be bolted mechanically. Note that there may be additional material requirements as specified by the maintaining agency for the water main.
The Inspector should verify the material is acceptable for incorporation into the project by comparison to approved Material Source Lists and delivery tickets.
Figure 1Example of mechanical joint restraint
Figure 2 Pipe with flange pipe fitting
Water Services
Water service material is per Section 923 of the Standard Specifications for Construction. Water services are a smaller diameter water line, usually made of copper, that feeds off the main water main line to a house or businesses.
Gate Wells
Gate wells material is per Section 909 of the Standard Specifications for Construction. Gate wells are typically precast concrete structures that provide access to gate valves. Refer to special details associated with the water main work as maintaining agencies have different requirements for gate wells.
Gate Valves
Gate valves material is per Section 923 of the Standard Specifications for Construction. Gate Valves are installed along water main runs and are intended to provide isolation points to full open or fully close a run of water main. Gates valves are operated by turning the stem to open or close the valve as you would with a household spigot. Refer to special details associated with the water main work as maintaining agencies have different requirements for gate valves.
Tapping Valves
Tapping valves material is per Section 923 of the Standard Specifications for Construction. Tapping Valves are installed along a water main that is in in place and can be installed if the pipeline service cannot be suspended. Refer to special details associated with the water main work as maintaining agencies have different requirements for tapping valves.
Valve Boxes and Curb Boxes
Valve and Curb Boxes must meet the material requirements per Section 923 of the Standard Specifications for Construction. The boxes, made of cast iron, are installed over gate valves that are used for service shut offs or hydrants. Refer to special details associated with the water main work as maintaining agencies have different requirement.
Figure 3Valve Box
Corporation Stop and Curb Stop
Corporation stop and curb stop must meet the material requirements per Section 923 of the Standard Specifications for Construction. Corporation stop’s screw into the municple water main and a curb stop is what is used to shot of water to residence. Refer to special details associated with the water main work as maintaining agencies have different requirements.
Figure 4 Corporation stop with double strap saddle
Service Saddle
Service Saddles must meet the material requirements per Section 923 of the Standard Specifications for Construction. Service Saddles are intended to secure a service lead to the water main, see Figure 2 for a picture of a service saddle. Refer to special details associated with the water main work as maintaining agencies have different requirements.
Hydrants
Hydrants must meet the material requirements per Section 923 of the Standard Specifications for Construction. Hydrants serve as discharge points so that water can be delivered from the distribution system. Hydrants serve as an important means of assisting emergency services. Refer to special details associated with the water main work as maintaining agencies have different requirements.
Figure 5 Hydrant installation, with gate valve
Backfill material
Granular material will be used as per Section 902 of the Standard Specifications for Construction and as noted in applicable standards associated with the water main work.
The Inspector should verify the granular material is acceptable for incorporation into the project by comparison to approved Material Source Lists and delivery tickets.
Polyethylene Encasement
Polyethylene Encasement, also commonly called Polywrap, will be used as per Section 923 of the Standard Specifications for Construction and as noted in applicable standards associated with the water main work. Polywrap is common method used to protect ductile iron pipe from corrosion in certain types of soil The material works by depleting oxygen in the water trapped under the wrap and thereby reducing corrosion.
EQUIPMENT
The following list of equipment can be used for water main work:
- Excavators
- Backhoes
- Front end loaders
- Occasionally bulldozers and riding vibratory rollers for aggregate compaction
- Plate compactors
- Ho-Pac attachments
- Gas powered rammer tamping machines
- Air powered pogo thumper hammers
- Sand/stone boxes
- Portable cement mixers
- Cement/mortar mixing tubs
- Portable generators
- Electric submersible pumps
- Trash pumps
- Pipe lasers
- Transit or laser levels
- Leveling/grade poles
- Electric impact wrenches
- Pipe/spud bars
- Small hand tools (shovels, levels, pipe “chop” saws, etc.)
- Direct tap machine for water main taps
CONSTRUCTION
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MEASUREMENT AND PAYMENT
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