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Newsletter 2005 issue 1 |
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Ingredients: Raw Material, Wastewater...
No product label is likely to list “wastewater” as an ingredient. But, wastewater might be dilute product that can be formulated into the next batch.
A formula for reuse
Although Abby Science Labs, a formulator of skin care products, cleaners and other supplies, stays away from petroleum-based products—focusing on organic solutions—its landlord wanted a letter from the U.S. Environmental Protection Agency (EPA) saying that it is okay to drain its wastewater into the septic system.
“No one appears willing to write that letter so we started testing and putting rinses in a holding tank while we evaluated disposal options,” said Greg Boster, Abby’s president.
Boster called Karl DeWahl, MnTAP chemical engineer, to ask about what is allowed in a septic system.
“When we called Karl, he started a discussion about reusing the solutions,” Boster said. “I thought ‘How simple! Why didn’t we think of that?’ Now, instead of storing all of the rinse solutions together, we store them on a per project basis so we can reuse them.”
Abby tests the stored rinses to ensure that contamination is not a risk.
The Ham Lake company will save $2,000 a year in water and disposal costs. “This gives us peace of mind more than anything. We know for sure that we are not creating an issue in the drain field,“ noted Boster.
Reuse in dairy
Cheese production creates salt whey, a byproduct containing primarily water and salt.
Unable to discharge salt whey into its wastewater treatment ponds because of the high chemical oxygen demand (COD), Bongards Creameries, in Norwood, separated and hauled the waste to St. Paul for treatment. At $2,800 a week, freight and wastewater strength costs were expensive.
Brent Jewett, Bongards’ plant manager, wanted to reuse this byproduct as an ingredient. “Everything in the salt whey already exists in process cheese,” he said. “Fat and salt are dairy ingredients.“
Bongards worked with Lloyd Metzger, assistant professor in the Department of Food Science and Nutrition, at the University of Minnesota. Metzger researched the use of salt whey as an ingredient in process cheese.
Over two years, he gathered samples and ran tests that showed the “waste” whey could effectively and safely be used as an ingredient. The company used those findings to receive approval from the Food and Drug Administration (FDA) to allow reuse.
“Right now, we’re using about half of the salt whey in product,” said Jewett. “Eventually, we hope to be using it all. Then we expect the savings to increase.”
Because the company produces processed cheese in the same facility as its natural cheese, it’s economical to reuse the salt whey. This saves Bongards $144,000 in raw materials and in waste management fees.
More information
Regardless of the product you formulate, evaluating your wastewater discharges for potential reuse opportunities may be a recipe for savings. For assistance with reusing waste streams call MnTAP.
Septic systems are regulated in order to protect underground sources of drinking water from contamination. More information is available in the U.S. EPA fact sheet Underground Injection Control (UIC) Class V Wells.
For regulatory information, call the MPCA Customer Assistance Center at 651/297-2274 or 800/646-6247.
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