Planning for Water Distribution System Renewal

Association of Construction & Development
September 20, 2013 — 1,383 views  

Old water pipes being in use since the 1970s are an infrastructural challenge. The aging infrastructure in the DC area represents a sustaining problem, if not an immediate threat to the water supply system. Moreover, these pipes are of poor standards and do not meet the current industry standards. In fact everything from water pipes to water mains is in dire need of replacement. 

The Current Issue 

While the aging infrastructure may not be an immediate threat, it could prove to be a disaster in waiting. These pre-stressed concrete water supply pipes, encasing steel bands, which claimed to have a life of 100 years, fail to meet the current benchmark of standardization. Their size varies from 16 to 96 inches (diameter) and the largest among them carry huge a quantum of water from the water mains. If they burst or fail, hundreds of thousands of people could be impacted.

Pipes of diameter 54 inches or more are classified as big pipes. If they fail, it could be catastrophic. A similar failure in Prince George’s County recently impacted nearly two hundred thousand people. Over a period of time the concrete as well as the metal corrode and snap, gushing a huge stream of water and debris. Concrete is a poor choice as far as material for water mains is concerned, but there are several more factors that determine the life span of these pipes. 

What Inspections Suggest

Inspection reveals that water supply pipes and water mains are in dire need of replacement. In fact, it is recommended that the entire aging infrastructure be overhauled with a system that meets the current industry standards.

It is not known, however, how long the old system will last. What is known is that the aging infrastructure is problematic and might cause enormous damage or break down. While sections of concrete pipes could work fine for many years, certain portions might need immediate replacement.    

According to the WSSC spokesman, two percent of the pipes need to be fixed. A smaller percentage of pipes, however, pose the threat of rupturing. In 2011 and 2012, this small percentage actually amounted to several thousand water mains that needed repair. There have been accidents in the past primarily because such aging infrastructure could not sustain the stress of present needs.

Other Problem Areas and Possible Solutions

While the entire aging infrastructure is in need of overhaul, there are specific problem areas that need to be addressed. There are possibly a dozen or so snapping bands detected by cables. There are broken or failing water mains, which would be inspected and detected by WSSC, so that concrete pipes could be replaced with the new steel model.

The biggest issue cited by officials is valves. They were found especially problematic in Prince George’s County, needing immediate repairs. The function of valves is to control the water flow in water supply pipes. The problem of water outage occurs due to frozen valves. Currently, there are some 80,000 valves in the system that require frequent repairs. 

In addition, the WSSC will create more pipelines for smooth functioning of the water supply. The project is likely to continue through the next year, with a $36 million fund allocation.

Association of Construction & Development