Recycling Treated Municipal Wastewater for Industrial Water Use

Section 3
Inventory of Major WWTPs and Potential Industrial Reuse Demands
Craddock Consulting Engineers 3-5
In Association with CDM & James Crook
WWReuseTM1_Sec 3_final.doc
Wastewater Treatment Plants
The state of Minnesota has nearly 600 municipal WWTPs permitted for discharge to
surface waters, as indicated in Figure 3.5. While the majority of permitted WWTPs
have capacities of less than 1 mgd, the majority of effluent discharged comes from the
11 WWTPs whose capacities exceed 10 mgd. Thus, the greatest potential for
maximizing industrial reuse may lie in the vicinity of these larger plants. In contrast,
numerous reuse systems – perhaps numbering in the hundreds – would be required
to take full advantage of the treated effluent resource.
Permitted Design Combined
Capacity (mgd)
280
240
200
160
120
80
40
0
517
0-1 mgd 1-2 mgd 2-5 mgd 5-10 mgd 10-50 mgd >50 mgd
Figure 3.5. Capacity and Number of Municipal WWTPs in Minnesota
Source: MPCA, 2005
Proximity of Industries to WWTPs
23
28
No. Of Facilities
WWTP Design Capacity (mgd)
While an understanding of the industrial water users throughout the state is helpful
in assessing industrial water demands, these industries must be located near a WWTP
for reclaimed water to be an economically viable supply.
A statewide map of industries, the relative volume of water they use, and the
proximity to larger WWTPs (Figure 3.6) gives a synopsis of potential industrial
opportunities. A more detailed review is provided on an individual watershed basis
in the following subsections. Figure 3.6 presents all the permitted MDNR industrial
water users for the state by category. The power generation industry subcategories
were all grouped under the general heading of power generation, as shown by the
purple color in Figure 3.6. The relative volume of water used by these industries is
depicted by the size of the symbol. Circles represent ground water-using industries
and squares are surface water users.
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