In general, because of the pipe’s deteriorating structural condition, water, air, ground temperature fluctuations and soil conditions. As WSSC enters 90 years of service, we are faced with aging (deteriorating) pipes and valves. 1,380 miles of water mains – out of nearly 5,500 miles we maintain – are more than 50 years-old. Nearly 1,979 miles of mains are between 30 and 50 years-old. 450 miles of pipe are 25-30 years old; the remaining 1,690 miles of pipe was installed in the last 25 years. The older pipes (installed before 1931 and up to 1975) are either cast iron or asbestos cement, and have reached their natural life span (see chart). The aging process is driven by corrosion of the metallic pipes by the soil and by water in cases of internally unlined pipes.

What is the expected lifespan of the ductile iron pipe?

Ductile pipe has mostly been installed since 1977. Ductile pipe installed after 2000 with polyethylene encasement has a lifespan of up to 100 years. WSSC has approx 2,300 miles of ductile iron pipe.

How does WSSC determine the order in which old water mains are replaced?

Several factors are considered: maintenance history, pipe material, unlined pipe interior, soil conditions, the year the pipe was manufactured (being old is not necessarily a prime criterion as some pipes have poorer maintenance records than others).

How often are the lines inspected?

The small diameter (16 inches and smaller) water mains are not physically inspected. However, every time a pipe breaks or leaks and is repaired we have an opportunity to see the condition of the pipes in the trench. Severely deteriorating conditions are reported to our engineers for further investigation. We carry out a continuous review and analysis of “events” that have occurred along the pipelines. Examples of these events are breaks, leaks, discolored water occurrences, etc. We combine the frequency of these events with the pipe’s age, material, diameter, etc. to determine if the pipe should be replaced. We are in the process of developing a plan to inspect the large diameter mains.

What are the main types of breaks?

Circle breaks and split breaks. A circle break occurs around the circumference of the pipe. The split break occurs along the length of the pipe. Circle breaks usually occur in pipelines 10-inch and smaller in diameter. Circular breaks occur because of the presence of cracks in the pipe wall. The cracks develop under corrosion activity or are present in the pipe wall because of defects originating from the manufacturing process. A change in water temperature can result in crack growth and cause a circular break failure. With split breaks, corrosion/ deterioration on the outside of the pipe advances and the pipe could begin to split. The larger diameter pipes are thicker and tend to break by splits first.

How may breaks did you have last year?

WSSC serviced 2,129 water main breaks and leaks in 2007.

Why weren't old pipes replaced sooner?

Aging pipes are a nationwide problem; WSSC has always known that infrastructure deteriorates over time. We have had a plan to replace pipes, but the problem has exponentially outpaced our plan. We are budgeted for replacement of 27 miles of water lines in FY08.

What is WSSC doing to handle the long-term problem of aging pipes?

WSSC developed a 30-year infrastructure plan to replace defective pipes. Working with officials from Prince George’s and Montgomery counties, we are also developing a 10-year fiscal plan to finance the needed work.

What is WSSC doing to get ready for winter weather main breaks?

A “24/7” rapid response center handles emergency calls and quickly dispatches crews. Crews that work to replace water mains and replace and line sewer pipes in warmer months are diverted to repair breaks during the winter months. More than 200 personnel are trained to quickly respond to and repair water main breaks; teams are strategically placed in both counties to respond to weekend and overnight emergencies. For water or sewer emergencies, please call (301) 206-4002. WSSC also has a pool of emergency contractors who can quickly mobilize for larger jobs

Is my water safe to drink following a water main break?

Although there may be some discoloration, the water is safe for drinking.

How long will it take to repair the break?

On average, four to six hours. It depends on the type of break and where it occurs.

Who do I contact regarding any damages sustained to my property?

A WSSC customer claim representative (301) 206-7095. If you are experiencing a water or sewer emergency, call our 24 hour emergency line at (301) 206-4002.

Will someone from claims be coming out to inspect?

Yes, someone from our claims service team will be out to inspect the property.

If there is a delay in replacing the water main, how will residents get safe drinking water?

After six hours, WSSC will supply residents with bottled drinking water in one-gallon jugs, as necessary.