The U.S. Environmental Protection Agency’s (EPA) Water Infrastructure Resiliency and Finance Center, in collaboration with the...
ADM Milling Co./Nokomis Mill is a grain milling company that produces flour for regional bread manufacturers. Located in Minneapolis, ASM produces 10,000 cwt., or one million pounds of flour a day. Their use of chlorinated water results in the treatment of 1.2 to 3.5 gallons of water per minute.
ADM Milling relies on chlorinated water in the tempering process of grain milling production. In short, the tempering process cleans the wheat to rid it of dirt and debris, toughens the outer layer of the wheat kernal, and softens the inside - or the part ADM harvests and turns into flour. According to ADM Plant Supervisor Mike Schuele, it's necessary to use chlorine to reduce microbial growth during the wet process. Moisture, of course, not only breeds microorganisms, but mold and other allergens. And because the wheat is used in food products, federal, state and local authorities have strict guidelines on such bacteria.
Until ADM implemented the PPG calcium hypochlorite chlorinating system in February, 1996, the company used liquid sodium hypochlorite, which dripped into the water at a set rate. The problem, however, was one of expense and safety, according to Schuele. Because the sodium hypochlorite was in concentrated form, company officials feared that a line break or leak could pose safety hazards to employees. And the $2.65/gallon cost of purchasing the solution was an expense company officials were trying to reduce.
Since installing the PPG system, ADM officials report success. Their goal of reducing costs immediately was realized. The cost of using chlorine tablets in the PPG system was nearly half the cost of sodium hypochlorite. Overall, they save $300 each month.
Safety has improved as well and requires less training and personal protective gear than previously needed. Yet, according to Schuele, another unexpected benefit of the PPG system was its ease of use. In fact, he says he spends more time training employees in other areas of their jobs than he does in the operation of the PPG system.