Recycling Treated Municipal Wastewater for Industrial Water Use

1.5 Summary
Section 1: Introduction
Recycling Treated Municipal Wastewater for Industrial Water Use
Interest in wastewater recycling is growing in Minnesota. Implementation of several projects over the past
few years demonstrates that some non-drinking water supply needs in Minnesota can be met by
municipally treated wastewater. These applications were driven by either a limitation in the water supply
quantity available or the receiving stream discharge options of an area. Limitations on water supply and
wastewater discharges are expected to increase with future growth across the state. Recycled wastewater
is an alternative water supply to potable water sources and, if the water use is consumptive, can reduce
discharges to receiving waters. Of particular interest to this study are the wastewater recycling
opportunities available for the industrial sector of Minnesota – looking to meet the needs of industry
while also conserving Minnesota’s water resources.
Minnesota’s industries, represented by all power generation and industrial processing facilities, are the
largest water users in the state – using about 75% of the 1,370 billion gallons of water withdrawn in 2004,
or an equivalent 3,750 mgd. Over 60% of this supply is surface water used by power generation facilities
for once-through cooling and is nearly all returned to the same surface water source in proximity to the
withdrawal. Because little water is consumed in once-through cooling processes, replacing surface water
sources with recycled wastewater does little to conserve water or reduce discharge loadings to state
waterways. When power generation facilities using surface water are excluded, the industrial demand for
water in 2004 was 445 mgd. Of this amount, 60 mgd was supplied by ground water. Coupling this 60
mgd with a conservative estimate of the amount of industrial water supply provided by a water utility, it is
estimated that the total industrial water demand for ground water in the state in 2004 was 100 mgd.
1.6 References
California State Water Resources Control Board. 2002. 2002 Statewide Recycled Water Survey.
California State Water Resources Control Board, Office of Water Recycling, Sacramento, California.
Available from http://www.swrcb.ca.gov/recycling/munirec.html.
Crook, J. 2001. National Research Council Report on Potable Reuse. In: Proceedings of the 2001 Annual
WateReuse Research Conference, June 4-5, 2001, Monterey, California.
Florida Department of Environmental Protection. 2002. 2001 Reuse Inventory. Florida Department of
Environmental Protection. Tallahassee, Florida.
Minnesota Department of Natural Resources (MDNR). 2004. Minnesota Water Appropriations Permit
Program, State Water Use Data System. Data summarized through 2004 were obtained from the MDNR
website in March 2006.
Solley, Wayne B., R. R. Pierce, H. and A. Perlman. 1988. U.S. Geological Survey Circular 1200:
Estimated Use of Water in the United States in 1995. Denver, Colorado.
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