In January 2014, Governor Jerry Brown declared a drought emergency for the State of California. Today, more than a year later, the drought has only gotten worse. According to California’s Bi-Weekly Drought Brief, January 2015 finished as one of the driest Januaries on record. Statewide, the snowpack is at 22% of what is considered normal for this time of year. Reservoir levels are at all time lows. The State Water Board recently issued warnings of widespread water curtailment mandates if dry conditions persist.
On the positive side, Californians have made progress to save water, partially as a result of an awareness campaign called ”Save Our Water” launched by the State in 2014. The statewide appeal to reduce water consumption was particularly effective in Sacramento region where water usage was cut by nearly 20% in 2014.
Organizations such as American Water Works Association and Water Environment Federation have also placed significant focus on conservation and sustainability as well as educating their constituents about best water management practices.
Reducing consumption is obviously the best approach and the right thing to do, but there are other options that could be implemented by water companies that can have immediate and significant reduction results without relying on the actions of individual customers and businesses.
One such approach is pressure management in waterworks distribution systems. In fact, pressure management has proven to be one of the key parameters that allow water distribution systems to proactively reduce water loss while operating in a way that doesn’t impact the system’s ability to serve the needs of the community. Too little pressure renders a system incapable of supplying the needs of customers and compromises water quality. In the worst-case scenario, not having enough pressure severely hampers the ability to deliver adequate flow for fire fighting (fire flow).
Conversely, having too much pressure leaves a system vulnerable to pipe breaks and background leakage. In fact, small, undetected leaks often represent a higher proportion of water loss than larger reported leaks or pipe breaks. Many systems experience between 10 -20% of water loss through leakage. According to pipe industry research, “All told, leaking pipes lose some 2.6 trillion gallons of drinking water every year, or 17% of all water pumped in the United States. This also represents $4.1 billion in wasted electricity annually”.
Stories of leaking pipelines are rarely talked about in mainstream news stories but catastrophic water main breaks make the headlines every time they occur and there is strong evidence that the age of piping is a significant contributor those pipe failures. In one Utah University Study: Water Main Break Rates in the USA and Canada: A Comprehensive Study by Steven Folkman, PhD, P.E.:
“Our water infrastructure is now in decline after decades of service. The signs of distress surface daily as water mains break, creating floods and sinkholes. The loss of water service is more than an inconvenience, since it causes significant social and economic disruptions and jeopardizes public health”.
Everyone can agree that water loss through pipe breaks and insidious leakage is highly undesirable. It hurts people, damages property and becomes even more detrimental when coupled with drought conditions like those California is experiencing.
Water loss is also very expensive. In a report published by the United States Environmental Protection Agency: Control and Mitigation of Drinking Water Losses In Distribution Systems, one Eastern US water utility’s value of water losses in one year topped $32 million. Other water companies throughout the US also reported value losses in the millions of dollars.
All things considered, older pipelines are prime candidates for the implementation of active pressure management measures that can significantly reduce water losses caused pipe breaks and background leakage.
Using Pressure Reducing Valves for Active Pressure Management
Basic Hydraulic Pressure Reducing Valves (PRVs) are the workhorses of any water distribution system but they do not actively manage pressure. There are, however, enhanced pressure reducing valves available that can perform the functions of a traditional PRVs, as well as adjust pressure up or down based on actual demand.
1. Advanced Hydraulic Pressure Reducing Valves
Advanced Hydraulic Pressure Reducing Valves reduce a higher inlet pressure to a usable outlet pressure based on flow utilizing a dual-stage pilot control with two pressure set points. As the demand decreases, the valve senses the decrease and reduces the pressure to the level necessary for current requirements, as opposed to continuing to maintain a pressure set point that is higher than what is actually needed and may ultimately cause leaks or pipe breaks. When demand returns to normal levels, pressure is increased to meet the heightened requirement. This “pressure on demand” or “active pressure management” capability keeps the system from being over-pressurized, while still ensuring adequate pressure for fire flow.
3. Electronic Pressure Reducing Valves
In some cases, it is desirable to use an electronic control valve to handle pressure reducing requirements in a water distribution system. Electronic Pressure Reducing Valves have the capability of reducing the pressure in a system based on a flow/pressure profile that is loaded into an electronic controller, which in turn, monitors flow and pressure; adjusting the valve according to a set of rules established by the system operator. An Electronic Pressure Reducing Valve can be easily incorporated into water company SCADA control systems to allow remote adjustments to pipeline pressure levels to actively manage pressure.
Proven Pressure Management Solutions Provided by Cla-Val
Throughout the waterworks industry, Cla-Val is known for its development of system optimization strategies using automatic control valves. For the past 30 years, Cla-Val has also provided an array of solutions to help reduce water consumption and loss through the use of control valve technology. Because of this, Cla-Val is the ideal partner for water companies seeking proactive means to conserve water and its pressure management products, the best means to bring water saving goals to fruition.
Active Pressure Management is an obvious and simple way to prevent or minimize water loss. It has been successfully used in the United Kingdom, France and Australia for decades. Pressure Management is also quickly gaining acceptance through successful implementation across Latin America. Perhaps the time has come to use existing technology that is economical and easily accessible to do more to protect our dwindling water resources while we continue to deal with the drought that is plaguing the State of California.
For a comprehensive overview of Cla-Val’s Pressure Management capabilities and water saving valves, visit http://www.cla-val.com/waterworks-pressure-management-c-1_5-l-en.html.