Recycling Treated Municipal Wastewater for Industrial Water Use

Section 2: Recycled Wastewater Demand & Supply
Recycling Treated Municipal Wastewater for Industrial Water Use
2.6 Summary
Demand vs. Supply
The statewide and Twin Cities metro area demand and supply analysis, summarized in Table 2.10,
determined that the recycled wastewater supply can fulfill 95% of the industrial water demand and that
there is ample recycled wastewater in the Twin Cities metro area to provide industries a water supply.
However, as the spatial analysis showed,
the proximity of a WWTP to an industry is
not always optimum.
The average flow for larger WWTPs
totaled 425 mgd (2005) and industrial
demand totaled 2,760 mgd (2004). If the
power plants using surface water supplies
are not considered a customer for recycled
wastewater, then the industrial demand is
445 mgd. Of this demand, the majority is
for the mining and pulp and paper
Table 2.10. Annual Average Demand and Supply Summary
Industry
Water Demand*
(mgd)
Recycled
Wastewater
Supply
( mgd)
State 445 425
Twin Cities Metro Area 75 255
*Excludes surface water supplies for power facilities
Source: MDNR, 2004; MPCA, 2005
industries in northern Minnesota. Demand for ground water supplies in 2004 was 60 mgd. Table 2.11
summarizes the demand and supply by watershed for ground and surface water supplies and includes
totals with and without the power generation industry sector. Figure 2.18 excludes the larger surface
Figure 2.18. Comparison of Treated Wastewater Supply to Industrial Demands by
Watershed
Cedar River
Des Moines River
Lower Mississippi River
Minnesota River
Mississippi Headwaters
Missouri River
Rainy River
Red River of the North
St. Croix River
Western Lake Superior
Wastewater Supply
Ground Water Demand
Surface Water Demand*
*Excludes surface water for
power generation
0 10 20 30 40 50 60 70 80 90 100
Annual Average Supply or Demand, mgd
water demands of
the power facilities
and provides a more
appropriate scale to
compare recycled
wastewater supply
to industrial water
demands that could
be met with this
alternative water
supply.
The comparison of
historic ground
water use by
industries and
WWTP effluent
discharge flows
indicates that each
watershed currently
processes enough
wastewater to supply the industrial ground water demand, but the industries are not always in proximity
to WWTPs. The larger surface water demands of the existing power generation, mining, and pulp and
paper industries cannot be met by the state’s recycled wastewater supply. New power facilities that will
likely use recirculating cooling systems and partial needs of other high water demand industries could be
supplied by recycled wastewater. The proximity of some of these facilities to WWTPs will make recycled
wastewater a more favorable water supply option.
32 Metropolitan Council Environmental Services
234
mgd
304
mgd