Recycling Treated Municipal Wastewater for Industrial Water Use

TM3: Recycled Wastewater System Components and Costs
Recycling Treated Municipal Wastewater for Industrial Water Use
The majority of costs presented in this study were derived from the cost curves
developed in evaluation of various treatment technologies for potable water supplies
under the Technologies and Costs Document for the Final Long Term 2 Enhanced
Surface Water Treatment Rule and Final Stage 2 Disinfectants and Disinfection
Byproducts Rule (EPA, 2005). The capital cost curves were checked against the cost of
constructed projects if information was available and against manufacturer’s planning
level information. Theses costs include the O&M costs associated with treating the
water and handling the associated waste streams and final products. All cost curve
and vendor supplied information was adjusted using the Engineering News Record
(ENR) Construction Cost Index to September 2006 dollars.
Cost curves were developed for each of the six types of reclaimed water quality for a
range of water demands and transmission distances, as provided for the base system
cost curves shown in Figures 5 and 6. The cost curves and supporting information for
each water type are compiled in Appendix D.
5.6.2 Tertiary 1-Conventional
The California Water Recycling Criteria requires filtration, and possibly a coagulation
process prior to filtration, for industrial uses of reclaimed water that contact humans.
Many industrial water uses require the removal of dissolved solids from WWTP
effluent. It is assumed for this study that coagulation and clarification are required,
recognizing that filtration of advanced secondary effluent without these processes
may suffice for many reuse applications. Tertiary 1 reclaimed water involves the use
of chemicals such as ferric chloride to increase suspended solids and pathogen
removal, and also for phosphorus removal, or the addition of lime if hardness needs
to be reduced. A filtration process following sedimentation removes additional
particulates and pathogens. The Tertiary 1 process train consists of chemical addition
facilities, a flocculation basin, sedimentation, and filtration, as depicted in Figure 8.
Advanced
Secondary
Effluent
Chemical Addition
Flocculation
Clarification
Filtration
Disinfection
Figure 8. Tertiary 1 - Conventional Treatment
The costs presented in this study assume the use of traditional concrete basins for
coagulation, flocculation, and sedimentation. A gravity filtration process with sand
and anthracite is assumed. There are a variety of process enhancements and
fabricated systems available that can be used for removal of particulate and dissolved
solids, as indicated in Section 3.2.2. The costs for these systems will vary with the
36 Craddock Consulting Engineers
In Association with CDM & James Crook
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