PUB00050 - Laserfiche WebLink

Home Browse Search

ing a database from information contained in these plans that can serve as a baseline to analyze the effectiveness of various water conservation measures. INDUSTRIAL CONSERVATION Industrial and commercial facilities use about 26 percent of urban applied water. according to DWR, about half the amount used by residential users. This group of water users includes manufacturing plants, food processors, office buildings, institutions such as hospitals and schools and public facilities such as parks and golf courses. California is well repre- sented in industries that rank among the heaviest water users - food processing, paper and allied products, and chemicals. Water usage in industrial settings varies widely. from product washing in food processing to cooling towers in commercial and institutional buildings. Surveys by urban water agencies indicate potential water use reductions at industrial sites ranging from 25 percent to 90 percent of previous use. Indeed, DWR statistics document a nearly 50 percent decline in industrial wafer consumption in the 1990s. A survey of 15 industrial sites by the city of San Jose found conservation measures at those sites saved over 1 billion gallons of water per year worth $2 million. Payback periods for investments made in water conservation measures typically were less than one year, according to the survey. DWR recommends a seven-step process for boost- ing water efficiency at industrial and commercial facilities that begins with lining up top management support and resources and doing obvious things first, such as fixing plumbing leaks promptly and eliminating unnecessary uses. Next, a step-by-step water audit is recommended to identify quantities, characteristics and uses of water at the facility. The audit is the basis for identifying water management opportunities such as recirculation, reclamation and displacement of potable water uses where appro- priate. The final three steps are to prepare an action plan, implement the water management measures in it and publicize successes. Opportunities for water conservation in industrial and commercial facilities include capturing steam con- densate in boilers and HVAC (heating, ventilating and air conditioning) systems for reuse, eliminating single-pass cooling in cooling tower operations, using closed-loop systems for water-cooled equip- ment, and installing low-flow plumbing fixtures. Many conservation measures also reduce wastewater discharges. MWD. which supplies 60 percent of the water to 16 million customers in southern California, has per- formed more than 900 surveys of commercial, industrial and institutional water users. Results of the surveys have not been completely analyzed yet, but MWD officials believe opportunities for major water savings exist in management of cooling towers, product rinses and landscaping. Cooling towers under active management can reuse the same water up to five times without adverse effects. Rinse water used to clean products such as integrated circuit boards often can be reused without compromising product quality. Water reuse in cooling towers and installation of water-conserving toilets and faucets are steps that can be taken in both the industrial and commercial settings to reduce water use. Here are some examples of steps taken by businesses that have reduced water use: . A San Jose tomato processing and canning plant reduced water use by a third over a six-year period by recycling water used to flume tomatoes from trucks, using evaporative cooling in place of once-through cooling, and implementing an employee training pro- gram that stresses conservation. Investments in equipment and modifications to achieve the water use reductions were recouped in less than one year. . An Oakland commercial laundry recycles up to half its treated effluent stream back into its hot water system, saving up to 11 million gallons of water per year and reducing its energy bill for hot water. The recycling system also helps the laundry reduce costs for wastewater discharges. Payback on the 537,000 capital investment was just over one year. . An audit of a Ventura soft drink bottler found more than 4.5 million gallons of water per year could be saved by running slurry water through a purifier and reusing the recovered water, recycling wastewater that previously was discharged to the sewer through a flocculating clarifier, and other steps. The conser. vation measures had estimated payback times ranging from one month to 15 months. Many office buildings, restaurants, entertainment venues, and other public facilities have installed automatic water saving devices in public rest rooms. Electric "eyes" that automatically flush urinals and toilets or turn on water for a preset time for hand washing are becoming more common. 1S