WSP06813

• File Number: 8273.400
• Description: Colorado River Basin Salinity Control - Federal Agency Reports - BLM
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 2/1/1980
• Title: Control of Salinity from Point Sources Yielding Groundwater Discharge and from Diffuse Surface Runoff in the Upper Colorado River Basin - 1978-79 Status Report
• Water Supply Pro - Doc Type: Report/Study

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VI. TECHNOLOGY OF CONTROLLING SALINITY IN GROUNDWATER

Saline groundwater can be manifest on the surface through a number of
. different kinds of discharge points. These have been studied to better
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Lll understand mechanisms that affect flow of groundwater to the surface, a
~ necessary step before it can be controlled. Some important point source
c() emissions of groundwater are listed below with an explanation of possible
factors affecting their surface discharge.

Flowing well, borehole

Man-caused saline groundwater
discharge by artesian pressure.

Artesian spring

Natural discharge of saline
groundwater under pressure.

Point source saline discharge by
gravity along a fault or outcrop
of porous material.

Gravity discharge of saline
groundwater along a fault or
porous material ending in a stream-
bed. This may be either a point
or diffuse source emission.

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Spring, seep

Effluent stream or
groundwater interface

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A. Springs and Seeps

Saline springs and seeps allow examination of saline aquifers through a
surface discharge. Such discharge points are easier to locate and may
be easier to control than more diffuse inflow directly into channels.
Possible control measures are evaporation ponds, deep well injection,
and plugging. Evaporation requires a means'of collecting all discharge,
a conveyance system, and a suitable disposal site.

A collector system may consist of a concrete or earthen dike with its.
base anchored to an impervious layer (bedrock, tight c1ay}c, located
downslope of the spring. A dike can be relatively short in length when
a spring discharges from one point or may be long when discharge is
emitted from several scattered points or a diffuse area, as in the case
of a seep. The major concern in designing the dike is that it should
completely intercept saline waters, thus preventing salt from entering
perennial streamflow and/orstorm runoff. Care should be taken to
minimize the inflow of overland storm runoff into the collector. A
large volume of runoff water entering the system could cause saline
spills or rupture of the collector dike, Saline water is collected
behind the dike into a pond or sump where it can be diverted into a
conveyance system. Dikes can also be placed across a.channel to inter-
sect and divert subsurface channel flow.

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The conveyance system
to the disposal site.
or a closed pipeline.

transports sal ine water from the source (collector)
It can take the form of an open channel (ditch)
A 1ined~ open channel can function well where it

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