Desalination Concentrate Management Policy Analysis for the Arid West
Project: 11-09
Year Released: 2015
Type: White Paper
Program: Principal
Funding Partner: Water Research Foundation
Total Investment: $463,812 (Cash: $195,000, In-Kind cash and service: $268,812)
Principal Investigator: Edmund G. Archuleta, El Paso Water Utilities
Background
Brackish water desalination (desal) is becoming increasingly important in many regions of the United States because traditional freshwater supplies are highly limited and have already been tapped at their sustainable capacity. Inland desalting offers a viable and reliable (e.g., climate-insensitive) option in many areas in need of additional water, especially in the arid Southwest region of the United States.
Brackish water resources are an important future source of water supply. Developing these resources in inland areas requires advanced water treatment and concentrate management (CM). Due to its potential advantages, brackish water desal is increasingly being utilized in the United States, especially in inland (non-coastal) regions where mid-sized and larger-scale applications would be suitable for water supply utilities.
Goals and Objectives
To further explore the regulatory and policy barriers associated within inland desal CM, EPWU—in coordination with CHIWAWA, Stratus Consulting, Mike Mickley, Bill Dugat, and other researchers—developed a tailored collaboration research effort, which is funded in part by the WRRF, the Water Environment Research Foundation (WERF), and the Water Research Foundation (WaterRF). The objectives of this research include:
- Identifying key CM barriers for community water systems considering inland desal as a source of municipal water supply, with a focus on CM options available in the arid Southwest region of the United States.
- Recommending potential policy solutions that protect both public health and the environment, while enabling broader development of brackish water desal in the United States, and particularly in the arid Southwest.
Research Approach
- A multidisciplinary approach was used to review and analyze regulatory and policy barriers to CM involving several sources of technical, legal, economic and policy expertise. Policies and regulations currently in effect were examined for several western States, as well as Florida. Findings from these efforts were developed into a series of white papers highlighting key issues. These white papers have been incorporated into this report.
- Case studies of desal facilities and CM practices in the United States were conducted to identify policies and regulations that inhibit and/or facilitate the development and use of brackish water desal in practice. Information from various U.S. utilities with regard to permitting processes was compiled and investigated to compare environmental issues, consistency, relative/approximate costs, sustainability, and time lines for development.
- A workshop of more than 50 experts was held in October 2012 to help identify potential solutions and recommendations related to inland CM policies and regulations.
Findings and Conclusions
- Based on the case studies, a few general observations may be made regarding CM:
- In the arid Southwest (and even in coastal Florida), discharge to surface water or sewer is not likely to be a sustainably feasible option unless the system is operating at a very small scale (e.g., 0.03 mgd, which is roughly enough water for less than 40 households).
- Evaporation ponds may be a feasible alternative for CM in some locations, but the combination of sizing and associated land requirements, and other expenses (including double-lining) make this option economically prohibitive and often technically infeasible, except for very small–scale desalting operations.
- DWI may often be the only viable option for CM, but UIC permit requirements may create significant challenges in terms of time and expense required to obtain full approvals, uncertainty about whether permits will be issued, and challenges associated with operating under permit conditions. The new General Permit provision in Texas under Class I of the UIC Program, may serve as a model for a more streamlined approach to DWI permitting.
- Challenges associated with DWI vary significantly by location based on local geology and permitting requirements. For example, EPWU experienced significant challenges in obtaining an AE, even though the water in the receiving aquifer did not meet primary drinking water standards. At the same time, SAWS experienced relatively few difficulties and obtained a permit much faster than EPWU because of the recent General Permit established in Texas for municipal desal concentrate.
- Costs also range significantly depending on permit requirements, depth of the well, and other miscellaneous expenses. For example, EPWU reports that the utility spent about $715,000 on permitting-related costs and an additional $1 million on the AE effort. ECCV, on the other hand, estimates that permitting costs amounted to about $100,000 (however, pressure testing associated with the permit cost an additional $225,000). In terms of capital construction, the capital costs associated with construction of one well range from $2.6 million for Alamogordo to $8.9 million for a second well in ECCV.
- Many of the municipalities evaluated in this report described no significant challenges in obtaining the DWI permit; however, in most cases costs associated with DWI were reported as significant.
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