Recycling Treated Municipal Wastewater for Industrial Water Use

Section 3
Inventory of Major WWTPs and Potential Industrial Reuse Demands
Craddock Consulting Engineers 3-11
In Association with CDM & James Crook
WWReuseTM1_Sec 3_final.doc
The Agra Resources Coop is within 2 miles of the Albert Lea WWTP. The Austin
Utilities power facility location is within 5 miles of the WWTP and could be closer
depending on its proximity to the permitted wells.
Factors Influencing Potential for Industrial Reuse
The majority of the Cedar River watershed is in Ground Water Area 2 of the state,
which has a good bedrock aquifer supply and limited water bearing surficial sands
and moderate availability of water in the buried sand aquifers. The southern edge of
the watershed is part of the karst area of Ground Water Area 3, where ground water
supplies are strongly linked to surface supplies. Contamination susceptibility varies
over the watershed with a higher potential in the eastern sections and areas of lower
susceptibility interspersed with areas rated with highest susceptibility in the mid- and
western regions of the watershed. Occasional well interferences have been noted, but
the public water supplies have had no problems. The agricultural practices of the area
have led to nitrate contamination which could affect the Prairie du Chien-Jordan
aquifer as well as surficial aquifers. Agricultural drainage wells have polluted deeper
ground water.
Des Moines River
Industrial Water Use
There is little permitted water used for industrial purposes in the Des Moines River
watershed. Of the 0.66 mgd used in 2004, the majority was for agricultural processing
industries, specifically PM Windom, Worthington Rendering, and the City of Heron
Lake. Sand and gravel operations collectively withdrew 0.1 mgd from surface waters
in 2004. Table 3.9a and Figure 3.9a summarize the industrial water use for the Des
Moines River watershed. There were no water withdrawals related to power
generator facilities.
In Heron Lake, located southwest of Windom, a 50 million gallon capacity ethanol
plant is under construction and scheduled for completion by April 2007. A
wastewater treatment plant expansion has also been bid for construction.
WWTPs
There are two municipal WWTPs in this watershed with design capacities greater
than 1 mgd: Windom WWTP and Worthington WWTP. Table 3.9b summarizes the
design capacity and historic flows for the plants. These WWTPs, with a design
capacity total of 5.8 mgd, discharged over 3 mgd in 2005. WWTPs in this watershed
with design capacities less than 1 mgd have a combined design capacity of 3.1 mgd.
As with Heron Lake discussed previously and below, smaller WWTPs in proximity to
an industry may be a potential supplier of reclaimed water. With over 30% of the
watershed’s wastewater treatment system capacity in facilities less than 1 mgd, and
the agricultural industry potential in this area, smaller WWTPs should be evaluated
more closely in Task 2.