Recycling Treated Municipal Wastewater for Industrial Water Use

Section 2: Recycled Wastewater Demand & Supply
Recycling Treated Municipal Wastewater for Industrial Water Use
Table 2.7. Industries Within a 5-Mile Radius of Empire and Rosemount WWTPs
Industry Name
MDNR
Permit
Water
Source*
Annual
Average
Water Use,
mgd
Industry Category
(MDNR Appropriations Permit
Database)
Aggregate Industries-NCR Inc x G & S 1.462
Sand & Gravel Washing; Non-Metallic
Processing
Bituminous Roadways Inc x S 0.004 Sand & Gravel Washing
Cannon Equipment M 0.010 Metal Processing
Cemstone Products x G 0.107 Sand & Gravel Washing
Petroleum or Chemical Processing,
Continental Nitrogen & Resources x G 0.085 Ethanol
CF Industries Inc x G 0.010 Non-Metallic Processing
Flint Hills Resources LP x G 6.531
Petroleum or Chemical Processing,
Ethanol
Greif Bros Corp M 0.038 Industrial Processing
J I T Powder Coating M 0.014 Metal Processing
Kemps LLC M&G 0.256 Agricultural Processing
Marigold Foods Inc x G 0.319 Agricultural Processing
NRG Processing Solutions LLC x G 0 Non-Metallic Processing
Performance Industrial Coating M 0.009 Metal Processing
Spectro Alloys Corp x G 0.006 Metal Processing
Valmont/Lexington M 0.004 Metal Processing
Wayne Transports Inc M&G 0.030 Metal Processing
* M: Municipal; G: Ground Water; M & G: Municipal and Ground Water: S: Surface Water.
2.5 Industry Focus – Ethanol Plant Inventory
The expansion of the ethanol industry in Minnesota has stimulated the exploration of wastewater
recycling for this industry. Ethanol production is a fairly water intensive process, requiring on average 3-6
gallons of water to produce 1 gallon of ethanol (gallons water/gallon ethanol). In Minnesota, the lowest
water use rate in 2005 was 3.6 gallons water/gallon ethanol at the Chippewa Valley Ethanol Company
(Institute for Agriculture and Trade Policy, 2006) and rates were greater than 7 gallons water/gallon
ethanol for some facilities pre-2002. While improved practices have reduced water use in ethanol
production, it still requires a significant allocation of water resources. In addition, most ethanol facilities
are located in areas with limited water supplies. To properly address the water appropriations permitting
and other permitting requirements for the ethanol industry, state agencies have formed teams to work
specifically on the environmental issues of this industry sector. One action developed from these teams is
to investigate the use of recycled wastewater as a water supply for ethanol facilities. State agencies are
exploring funding options for specific application to wastewater recycling projects with ethanol facilities
during the summer 2007 budget process.
Facilities within the state have the capacity to produce over 550 million gallons of ethanol a year from
sixteen locations across the middle and south part of the state (MDA, 2006). Assuming a higher end water
use rate of 5 gallons water/gallon ethanol, the estimated water demand for the state’s ethanol production
capacity is about 7.5 mgd. An inventory of ethanol facilities in conjunction with WWTPs in the state is
shown in Figure 2.17. The facilities and water demands for facilities with their own permitted supply are
listed in Table 2.8.
Metropolitan Council Environmental Services 29