Distribution Works

The Distribution Works consists primarily of the piping that carries the water to the customers. This piping ranges in size from 2 inches to 24 inches in diameter. The original mains, most of which are still in use, are made of pit-cast iron. Shortly after the original construction, galvanized iron piping came into use, usually only for 1½-inch to 2-inch lines. Some of these old lines are still in service. In the mid 1950s, cement asbestos was used for water mains. The current material used is ductile iron.
Fire Hydrants
There are over 2,000 fire hydrants connected to our system and of these, over 1,800 are public hydrants under the care of our staff. The hydrant inventory by age is given below:

Age Percentile 
No date, includes unknown date 13.9%
1956-1959 1.46%
1960-1969 19.75%
1970-1979 20.48%
1980-1989 21.12%
1990-1999 23.26%
Fire Hydrant
Hydrant manufacturers did not begin marking the year on the hydrant barrels until the mid 1950s.

City Worker Draining HydrantMaintenance & Flushing of Hydrants
The flushing of the hydrants is usually done once a year. Although this appears to be a hydrant-based activity, the purpose is to flush sedimentation from the water mains. This is normally done by opening all the hydrants at the ends of the mains and usually takes 2 to 3 weeks.

Our staff performs the maintenance and replacement of public hydrants. All of our hydrants have automatic drains, which drain the barrel after use to prevent freezing and the accumulation of stagnant water. Occasionally these do not work and require repair. Because we use a river source, there are great seasonal fluctuations in the water temperature.

Hydrant Replacement
This occasionally causes hydrants to leak. The majority of hydrant replacements are done by our staff. The exceptions are those cases where hydrants are damaged by vehicle collisions. These damaged hydrants are replaced by a contractor at the expense of the driver's insurance company. Most of our hydrants have stainless-steel identification tags, which give the hydrant's inventory number. Our staff also paints the public hydrants as weather permits. Painting is an ongoing operation.

Service Lines
Service lines are the connections from the main to the customer's water meter or fire system. The older lines are galvanized iron tubes. Since the 1940s, copper has been used for the smaller house lines. Fire lines are normally of the same materials being used for water mains.

Maintenance of Service Lines
Our staff repairs or replaces the portion of the service lines between the main and the property line as needed. These are similar to water main repairs. Many of these are not emergencies but are scheduled. When an old galvanized-iron service line corrodes, the inside opening becomes smaller which restricts the flow. Replacing these lines restores capacity. We usually will do this after the homeowner has changed the service line on his or her property to type-K copper.

As other utilities mark out the location of their buried lines when we are digging, we must locate our lines for them. We are not a member of the Dig Safe System, and must be contacted separately by anyone planning to excavate. We also mark out our lines at the planning stage of projects such as sewer-collection-system extensions.

Treatment PlantStandpipes
The two tanks in the center of the plant are called standpipes. They are connected to the Treatment Plant by 16 inch and 24 inch diameter forced mains. These forced mains also diffuse water to the distribution works. The function of the standpipes is to even out the production demand on the treatment plant, maintain pressure, and to have on hand a ready supply of water for emergencies. Each standpipe has only one connection to the distribution system; they float on the system.

When the treatment plant is producing more water than is being consumed the water level in the standpipes rises. When there is more demand than production the water level in the standpipes falls. The water level in the standpipes is normally kept within 15 feet of the overflow. Water pressure at any particular point in town is controlled by the distance that particular point is below the water level in the standpipes.

Main Breaks
Our system averages about 40 main breaks per year. Most of these occur in the winter. Sometimes the pipe is found to have a rock under the pipe or passing through an old sewer trench that has settled. The majority of breaks are unexplained. When a main fails we must isolate (shut-off) the area and call Dig Safe to locate underground utilities.

Beam & Lengthwise Breaks
There are two basic types of main breaks. The first is beam breakage, which results in the pipe splitting around its circumference. We repair this with a wrap-around clamp. The second type of break is lengthwise. This is usually more difficult to repair and can require a larger excavation.

A lengthwise break requires that a section of pipe be cut out and replaced. These cracks can run 9 to 10 feet along the pipe. After the break has been repaired and the excavation has been largely filled in, the water will slowly be turned on to fill the main. Then the area mains will be flushed through the hydrants to rid the main of air and sediment.