How Flow Measurement Technology Can Save Water

Humans consume vast quantities of water and create an increasing amount of wastewater. This places greater emphasis on environmentally responsible water treatment and leveraging reclaimed resources. Flow measurement is a basic and important control parameter for ensuring that clean, high-quality water is available. Applications ranging from water storage and transmission to wastewater treatment, leak detection and pump management cannot be done without flow meter technology.

Growing Demand for Water

Manufacturing and commercial sites rely heavily on water for many of their operations. Used for everything from producing steam to cooling various systems to maintaining overall machinery, water serves as a precious commodity that modern facilities cannot afford to be without. Companies must find ways to deal with new, higher standards for water quality and pollution controls. They are also under pressure to save energy and upgrade aging infrastructure. Facilities see a revenue opportunity in treating wastewater and selling byproducts. Water and wastewater treatment operations require plant-wide process control, integrated measurement, and monitoring capabilities and data reporting. They also need effective solutions to minimize energy usage and reduce risks to assets and the community. Neglected or poorly performing water treatment systems can significantly reduce plant efficiency and reliability, increase chemical and energy costs, and trigger regulatory noncompliance.

Meeting Today’s Demands

With greater awareness that water resources exist in limited quantities, there is an urgent need to save, reuse and recycle water along with developing methodologies to improve resource management and optimize water treatment efficiency. Problems involving water sanitation stem from the rise in urban migration and the growth of manufacturing. Industrial and commercial organizations have long dealt with the problem of residue disposal; their effluents are one of the largest sources of water pollution. Effective water treatment solutions include metering effluents for surcharge reporting and precisely measuring influent water. Industrial sites are striving for cost savings through optimized staffing and increased automation. They seek to reduce raw water consumption, lower energy and chemical costs, minimize toxic waste treatment and discharge, and improve regulatory compliance. Municipalities and industries are facing concerns about the impact of biological contaminants and chemicals in supply water and wastewater along with stringent manufacturing requirements in process water. Regulatory standards established by the U.S. Clean Water Act (CWA), National Pollutant Discharge Elimination System (NPDES), Effluent Limitation Guidelines (ELG) and the National Sanitation Foundation (NSF) dictate effective water usage, treatment and disposal techniques.

Importance of Measuring Flow

Measuring water is vital when it comes to learning how to improve the efficiency of industrial plants. Precise measurements are also important in helping to conserve water that is clean enough to use in everyday life. Water and wastewater treatment facilities have the crucial job of producing a safe supply of high-quality water. Their operations are “pump intensive,” often employing large motors using lots of energy. Reliability is also paramount. Water and wastewater processes involve a wide range of flow measurement tasks and demand the highest meter accuracy and reliability along with long-term stability and a low cost of ownership. Flow meters must be able to measure liquid across all phases, including large volumes of fluid carrying suspended solids, sludge byproducts and other materials. They are also used to monitor methane discharge and reuse. Typical flow measurement applications include:

• water flow monitoring
• dosing of water treatment chemicals
• water consumption monitoring
• leakage detection and reduction
• network load monitoring
• optimization of water usage
• monitoring influent water quantity
• monitoring discharge water quantity
• monitoring of water flow between reservoirs

Flow meters are excellent tools to measure, monitor and control a host of water-related processes. The question is which meter design to use. For example, employing ultrasonic flow meters when recycling greywater reduces both demand on conventional water supplies and pressure on treatment systems. It also supports the objectives of ecological sustainability. There are two types of ultrasonic meters: transit time and Doppler. Both designs will detect and measure bidirectional flow rates without invading the flow stream. They can handle all types of corrosive liquids and gases, and are insensitive to changes in temperature, viscosity, density or pressure. A clamp-on ultrasonic meter is ideal for troubleshooting, diagnostic and leak detection. Recycling techniques even help turn biosolids from wastewater treatment plants into new sources of revenue. Anaerobic digestion with vortex flow meters can be used to stabilize sludge and produce biogas for energy generation. Vortex meters have no moving parts that are subject to wear and do not require regular maintenance. The use of electromagnetic flow meters and control valves to gather and treat discharge can play a vital role in keeping wastewater emissions within limits. Electromagnetic meters can measure virtually any conductive fluid or slurry, including water and wastewater. They provide low pressure drop, high accuracy, large turndown ratio and excellent repeatability. These meters have no moving parts or flow obstructions and are relatively unaffected by viscosity, temperature and pressure. The use of electromagnetic flow meters can also have a favorable impact on pump performance—an important concern for water and wastewater plants seeking to improve overall efficiency. By helping to match pump speed to the flow rate, the meters can help operators save energy through more effective control of the speed of the pump motor. While conservation efforts are key to controlling water costs, the ultimate solution is water submetering. Using advanced meter analytics to allocate water costs directly to departments through measurement of consumption provides an economic incentive to conserve. In a world more focused than ever on safe, sustainable stewardship of water resources, it is critical to improve the ways in which water and wastewater are measured and treated. Increased public awareness drives the need for safe, accurate and reliable flow instrumentation in all areas of water use.