WSP11096

• File Number: 8273.100
• Description: Colorado River Basin Salinity Control - Federal Agency Reports - BOR
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 6/1/1998
• Title: Salinity Management Study - Final Report - DRAFT - June 1998 - Part 1 of 2 - Title Page through
• Water Supply Pro - Doc Type: Report/Study

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USBR/MWD SALINITY MANAGEMENT STUDY
FINAL REPORT

o Distillation

To treat different types of water supplies (reclaimed, brackish, seawater, potable, and
industrial), the desalination technologies which would be most applicable to each are shown in
Table 2-6.

T hi 26M' D r t' T t

tOt'

a e - a.lor esa ma Ion rea men Jpuons
Snpply RO Nanofiltration EDR Distillation
Reclaimed Water X X
---
Brackish Ground Water X X
Seawater X X
-"_.--~-----_.- -
Potable Water X X
------~- -
Industrial Supply Water X X

Desalination usually separates the source water into two components:
I. Low-salinity production water to be used by the intended customer, and
2. A high-salinity waste brine that must be disposed.

Brine, which may constitute up to 25 percent of the treated source water volume, is usually
disposed of through non-reclaimable brine lines which discharge to the ocean. In some
locations, brine is evaporated or injected deep into geologic zones of non-potable water.
Inland projects requiring lengthy brine lines usually cost more than projects conveniently
located near the coast or existing ocean outfalls.

DESALINATION COSTS
The use of desalination in the past has been limited by cost and environmental constraints on
brine disposal. For those reasons, water supply and sanitation agencies have tended to
consider desalination as an action of last resort. However, technological advances and the
need to better manage groundwater basins are making desalination of brackish groundwater
and recycled water more common.

In this study, the cost of desalination is considered as an economic impact to water recycling
and groundwater basins when salinity exceeds certain thresholds for each subarea in the
region. Those thresholds were 900 mg/L for recycled water, and the basin plan objective set
by the Regional Water Quality Control Boards for groundwater basins. Higher desalination
costs were assigned to inland areas because of the extra facilities needed for brine disposal.

BOOKMAN-EDMONSTON Section 2
ENGINEERING, INC. 2-25 Salinity Problems, Impacts, & Technology
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