Recycling Treated Municipal Wastewater for Industrial Water Use

TM3: Recycled Wastewater System Components and Costs
Recycling Treated Municipal Wastewater for Industrial Water Use
reclaimed water and some also treat an incoming water supply to meet Tertiary 1-3
water quality levels. A comparison of reclaimed water system costs to an industry’s
existing water supply cost must include any onsite treatment costs currently incurred
by the industry.
The cost analysis indicates that for a 1 mgd supply transmitted 5 miles, the costs for
lower levels of treatment can compete with potable water supplies. Most industries
with a water demand of 1 mgd or less are more likely to use a potable source,
depending on their water quality requirements. For these industries, reclaimed water
could provide an alternative to a potable source.
As the demand increases to 2 mgd, the total system cost for a base water quality is
under $1.00/1000 gallon – similar to potable supplies provided by utilities using
ground water supplies with minimal treatment. While industries with their own
water supply system typically have water supply costs less than a $1.00/1000 gallons,
these costs reflect areas with high quality, abundant sources close to the industry. For
areas with water supply limitations, where ground water sources are a considerable
distance or only a surface water source is available (which could also be a significant
distance from the industry and require more treatment costs) reclaimed water could
be a more economical water supply.
Another consideration in comparing reclaimed supplies to potable water supply
systems is the infrastructure capacity of the potable water system and the impact on
capital expenditures. Increased domestic demand can be met without expansions if a
portion of the industrial sector uses reclaimed water and the total demand for the
potable water system is kept constant.
The economic viability of water reuse in Minnesota will depend on the specific match
of WWTP effluent quality to a customer’s water quality requirements and the
availability of traditional water supplies in the area. The most significant reclaimed
water quality issue for Minnesota appears to be hardness and high salts. While data
across the state is lacking, given the general water supply characteristics, it is expected
that many WWTPs will have effluent water quality that is not suitable for a significant
portion of industrial water uses without treatment for dissolved solids. The
evaluation of site-specific applications with more refined cost estimating will narrow
the range of costs for supplying reclaimed water to select industries in Minnesota.
6.0 References
CDM, 2006. Metro Wastewater Reclamation District, City of Aurora, Sand Creek Basin
Wastewater Master Plan – PAR 1005. Technical Memorandum No. 8.
CDM, 2004. Durham County Reuse Wastewater Facilities Project Preliminary
Engineering Report.
CDM, 2003. Wastewater Reclamation District, City of Aurora Wastewater Utility Plan.
42 Craddock Consulting Engineers
In Association with CDM & James Crook
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