Did You Know?
Pennsylvania's manufacturing sector is made up of more than 15,000 individual companies that employ about 800,000 workers
Pennsylvania's industrial manufacturers withdraw nearly 800 million gallons of water every day from ground and surface water sources. In addition, they use approximately 200 million gallons per day from Pennsylvania's public supply systems.
The fabricated metal products industry makes up about 20 percent of all Pennsylvania manufacturers, and these facilities traditionally operate highly water intensive processes—such as milling, parts washing, and metal finishing.
Pennsylvania is also home to more than 1,200 food product manufactures. Water plays a significant role in formulating food products, cleaning and transporting ingredients, and cleaning process equipment, as well as in meeting regulatory standards.
Although there isn't a one-size-fits-all water-saving opportunity that all manufacturers can implement, nearly all facilities can find opportunities unique to their processes by examining their current water use and scrutinizing their current practices. Saving water in manufacturing settings usually involves approaching a time-tested process in a new and unproven way.
What Can You Do?
- Install water-efficient plumbing fixtures with auto-sensors in employee bathrooms.
- Monitor water meters during work stoppages to identify leaks.
- Minimize blowdown in cooling towers.
- Reuse process water or harvest rainwater for use in cooling tower make-up water.
- Eliminate use of "once-through" cooling.
- Replace water-cooled equipment with air-cooled models.
- Maximize condensate return in boiler units.
- Reduce water temperature to minimize evaporative loss where possible.
- Install water-efficient kitchen equipment in cafeterias.
- Eliminate or minimize use of water for shop floor and equipment cleanup.
- Reuse and recycle process water to maximize its effectiveness.
- Minimize need for landscape irrigation outside offices and facilities.
Fabricated Metal Part Manufacturing
- Reduce or eliminate water used in machining. Dry machining, for example, eliminates the use of water and wastewater treatment. Use of water jet type machining is highly water intensive.
- Install flow restrictors to prevent water in supply pipes from exceeding a predetermined flow rate. A flow restrictor provides a constant water flow and is therefore best suited for rinsing processes.
- Install conductivity controllers, which measure the total dissolved solids in rinse water, to regulate the flow of fresh rinse water into the system.
- Install rinse timers, which are generally preferred for intermittent rinses because they eliminate operator error. Rinse timers in¬stalled in conjunction with flow restrictors can provide precise control when the incoming water pressure may rise and fall.
- Use counter-current cascade rinsing to reuse water from one rinsing operation in another, less critical rinsing operation before being discharged to the sewer.
- Employ spray rinsing, which uses considerably less water than immersion rinsing.
- Spray rinse parts over catch tanks allow for water recycling or reuse.
- Use high-pressure, low-volume spray or fog nozzles, which use much less water than conventional spray systems.
- Use air blowers to remove dust or rags to wipe down parts. This can reduce the frequency of refreshing washing baths.
Food Product Manufacturing
- Recover and reuse process water throughout your facility.
- Decrease water volume use in peeling and pitting operations
- Install rubber-disc scrubbing units instead of cleaning and peeling units, which use high volumes of water.
- Separate waste process streams at their sources to eliminate unnecessary flushing and cleaning of downstream product lines.
- Install low-volume, high-pressure cleanup systems.
- Use steam rather than water baths to blanch or pasteurize product.
- Use air rather than ice baths to cool product after blanching.
- Use flumes with parabolic cross-sections to move product rather than flat bottom troughs.
- Install evaporative coolers rather than water-cooled systems.
- Establish optimum depth of product in cleaning equipment to maximize cleaning effectiveness and minimize water use.
The Green Suppliers Network works with manufacturers of all sizes by providing low-cost technical reviews that try to identify the root cause of waste—including wasted water. Green Suppliers Network partners EPA with NIST Manufacturing Extension Partnerships. Using Lean manufacturing practices, the program identifies strategies for improving manufacturing process lines and ways to use resources more efficiently.
The Pollution Prevention Resource Exchange (P2Rx) is a partnership of eight regional pollution prevention information centers that offer networking opportunities and other services to states, local governments, and technical assistance providers in their region. P2Rx also provides industry-specific topic hubs containing pollution prevention information including water use resources. Topic hubs range from aerospace to wood furniture manufacturing and all sectors in between.
The Alliance for Water Efficiency promotes the efficient and sustainable use of water in manufacturing, serves as an advocate for water efficient products and programs, and provides information and assistance on water conservation efforts.
Pennsylvania State University's Center for the Management of Technological and Organizational Change hosts an annual Advanced Manufacturing Forum that provides manufacturers with a setting in which to share experiences and ideas that allow Pennsylvania manufacturers to implement advanced technologies.
North Carolina Department of Environmental and Natural Resources published a guidance document titled Water Efficiency Manual for Commercial, Industrial and Institutional Facilities (PDF).
The California Department of Water Resources published a fact sheet for the Food Industry titled Water Use Efficiency Ideas (PDF).
The Metal Cleaning Hub at the Waste Reduction Resource Center
provides a list of links to the best resources for reducing water use in metal cleaning.
The Precision Cleaning Web provides information on the core principals of parts cleaning, strengths and limitations of alternatives, and criteria on how to select technologies.
The Practical Machinist is a forum for metal products manufacturers to exchange ideas and practices, pose questions, and browse technical trade information.