A good water conservation program is an important part of sustainability programs. Water conservation can include reduced use and reuse. Below are some steps that plants can take to implement water conservation.
Water Conservation Program – As a starting point, a cross discipline water conservation team should be established to oversee the water conservation process. Backed by management, the team should meet at regular intervals to review water data, discuss potential conservation measures, and provide updates and recommendations to management. Maintenance, Operations, Sanitation, Engineering, and Environmental departments should all be represented.
Metering – Install proper metering to monitor the total amount of water used daily. Metering for specific operations/equipment where use is significant may be helpful in assessing reduction strategies. Wastewater discharge monitoring may also be helpful in determining how much water is utilized within the facility.
Monitoring - A daily report should be developed and distributed to management and those with responsibility for high water use operations and equipment. This report should trend data and convert water usage to an appropriate cost figure.
Pressure Regulation – often, water pressure may fluctuate in the main water in feed to a facility. Determining the needed water pressure and regulating pressure to the facility as a whole, as well as specific water intensive equipment, will reduce overuse when pressure is higher than necessary.
Dry Clean Up – An emphasis on dry clean up of production areas using brooms and squeegees versus water to collect materials from floors and equipment can result in significant water savings.
High Pressure Pumps – Pumps used to provide high pressure for washdown use should be sized and maintained to deliver adequate, not excessive pressure.
Hose Nozzles – Hose stations and nozzles for washdown should be maintained to provide adequate access and pressure for washdown areas. A 5-gallon bucket and a watch with a second hand can be used to assess flow rates.
Nozzles for Product Cooling/Spraying – Nozzles are often used to provide for a cooling or washing spray for production processes. An adequate flow rate should be determined and then nozzles provided and maintained to achieve that flow rate.
Recycling of Cooling Water – Often the cost of a rooftop water to air cooling tower can be paid back quickly in terms of water/wastewater cost savings. These units are particularly cost effective when located and sized to support a bank of equipment like vacuum pumps or packaging equipment. Cooling water is cycled to the roof for cooling, then returned to the equipment for reuse. Make up water is added to address evaporation/losses.
Reuse of Cooling Water – In situations where cooling water cannot be recycled, the higher temperature water can be used to feed equipment like boilers that benefit from the heat already imparted to the water. The cost to heat water, even a few degrees can be significant, and these savings can offset the cost of addition piping/pumping for reuse.
Water Efficient Fixtures – Faucets and toilets used in locker rooms and administrative areas can be significant water users. Use of water efficient fixtures can be cost effective, especially if added when fixtures are due for replacement.
Leak Repairs – establishing a program where production workers are asked to report leaks and drips immediately, with timely implementation of repairs can be very cost effective in reducing overall use. Personnel responsible for pre- and post-operations duties in a specific area can be assigned the responsibility for identifying leaks, as well as being sure all water flows are turned off when not needed.
Water Reuse – The nature of the food industry requires that applications for water reuse be considered carefully. The potential for product contamination is an important consideration in where and when reuse can be applied, especially where the source is treated plant wastewater. Sanitary wastewater streams (from locker rooms, etc. ) should be completely segregated from the reuse source. Often, focusing on a specific application, like brine for chilling cooked product, provides the best opportunity for water reuse. Filtration and disinfection technologies can be employed that provide for both product safety as well as water use reductions.
Depending on the quality of treated wastewater at the plant, use as once through cooling water for refrigeration equipment or similar applications may be viable.
More widespread use for initial wash down of similar operations may require a separate piping system to prevent any cross contamination issues. Training and mechanical lock out to prevent misuse would also be required. Water quality should be carefully assessed to be sure that no product or equipment impacts result.
Sustainability in Action!
Low Flow Nozzles – Sara Lee and Hormel Foods have installed low-flow water hose nozzles and shower-heads.
Armour Eckrich in Junction City, Kansas installed a plate water chiller to chill the city water used in the blending process form 60 to 70 degrees F. down to 35 degrees F. This change reduced the plant’s reliance on CO2 as a chiller by 33 percent.
Eliminate Water-cooled Compressors - Sara Lee’s Commerce City, Colorado, bakery reduced water usage 59 percent by eliminating water-cooled compressors and making their sanitation practices more water efficient.
Ultra-violet Brine Recycling Treatment – Seaboard Foods has installed this treatment system that reduced the total amount of spent brine discharged into the municipal wastewater system.