Recycling Treated Municipal Wastewater for Industrial Water Use

Section 2
Implementation Consideration s
pricing structure, between $1.50-$2.00 per 1,000 gallons, and surface supplies were in
the $2.50-$3.00 per 1,000 gallon cost range.
Industries requiring additional removal of color or organic compounds, as in the
pulp&paper or textile industry, may use granular activated carbon (GAC) treatment
technology. The cost for GAC treatment equipment (following a standard treatment
process as described for cooling water) ranges from $75,000 for a 0.1 mgd system
($0.75/gpd) to $500,000 for a 1 mgd system ($0.5/gpd), based on cost curves for
smaller GAC systems with a 10 minute empty bed contact time [U.S. EPA, 2005]. This
does not include GAC replacement costs.
The metal finishing and electronics industries require high quality water. In some
instances and for some processing needs potable supplies are adequate. However,
often reverse osmosis technology is used to obtain the water quality required for this
industry. The costs for reverse osmosis system with a capacity in the 1 mgd range
(assuming pretreatment with a microfiltration process) is between $1.80-$2.00 per
gpd, based on cost curves scaled to June 2006 [AWWARF, 1996]. A demonstration
study using reclaimed water at an electronics facility indicated that the costs to treat
reclaimed water were comparable to those treating the municipal supply currently
used. This study focused on the operating costs of a microfiltration followed by
reverse osmosis process train. The costs to treat the reclaimed water were $3.78/1,000
gallons and for the potable supply were $4.50/1,000 gallons [Gagliardo, P. et al, 2002].
2.4 Institutional Considerations
There are several institutional issues that need to be addressed. Laws, policies, rules,
and regulations that affect the planning and implementation of water reuse projects
include – for example – water rights, conflicting laws and regulations, permitting,
local planning ordinances, environmental assessment and impact, public
involvement/education, legal agreements or contracts, agency jurisdictions, fee
structures, etc. Task 2 of this project involves working with key state agencies
(MPCA, MDH, and MDNR) to identify their specific roles as they relate to water reuse
and develop recommendations regarding potential policies and regulations that are in
concert with each other.
2.5 Examples of Reuse in Minnesota and Industrial Reuse
Minnesota Reuse Applications
The first uses of reclaimed water in Minnesota were for agricultural irrigation, mainly
because the wastewater treatment facilities did not have an acceptable receiving
stream. More recent reuse applications involve golf course irrigation in urban and
resort areas, and as toilet flush water for an institutional building. In the majority of
these cases the driver for reuse was to provide a discharge for the wastewater
generated onsite. Table 2.12 provides a list of facilities that are using treated,
municipal wastewater effluent in Minnesota. The one industrial application, use of
cooling water for the Mankato Energy Center, is discussed below.
2-26 Craddock Consulting Engineers
In Association with CDM & James Crook
TM1-Sec2_0707.doc