Recycling Treated Municipal Wastewater for Industrial Water Use

Section 3
Inventory of Major WWTPs and Potential Industrial Reuse Demands
Table 3.17a. Industrial Water Use in the Western Lake Superior Watershed
2004 Water Use, mgd
Ground
Industry Category
Water Surface Water Total
Mine Processing 0.01 296.51 296.52
Non-metallic Processing 0.01 0.00 0.01
Petroleum - Chemical Processing, ethanol 0.00 0.43 0.43
Pulp and Paper Processing 0.00 6.78 6.78
Sand and Gravel Washing 0.01 0.30 0.31
Steam Power Cooling - Once through 0.00 182.35 182.35
Steam Power Cooling - Wet Tower 0.12 0.00 0.12
Total
Source: MDNR, 2004
0.15 486.37 486.52
WWTPs
The six major WWTPs in the Western Lake Superior watershed discharged 45 mgd of
treated wastewater in 2005, as summarized in Table 3.17b. Approximately 85% of this
wastewater was processed at the Western Lake Superior Sanitary District (WLSSD)
near downtown Duluth. The other WWTPs have capacities between 1 and 5 mgd. It is
estimated that the capacity for the smaller wastewater treatment systems, less than 1
mgd, is about 7 mgd.
Table 3.17b. WWTPs in the Western Lake Superior Watershed
2005 Ann Avg
Flow, mgd
Flow as % of
Design
Capacity
Facility Name
Design
Capacity, mgd
Eveleth WWTP
Hibbing WWTP North
1.000 0.645 64.5%
Plant
Hibbing WWTP South
3.200 0.000 0.0%
Plant 2.000 2.573 128.7%
Two Harbors WWTP 1.600 0.701 43.8%
Virginia WWTP 4.300 2.182 50.7%
WLSSD WWTP 48.800 38.797 79.5%
Total
Source: MPCA, 2005
60.900 44.898 73.7%
Industries and Proximity to WWTPs
The WWTP and industry combinations in this watershed have some favorable reuse
options. Communities on the iron range are within 10 miles of several industries as
listed in Table 3.17c. The Western Lake Superior Sanitary District (WLSSD) also has
several industries within 10 miles including mine processing, sand and gravel
3-38 Craddock Consulting Engineers
In Association with CDM & James Crook
WWReuseTM1_Sec 3_final.doc