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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The well was closed successfully with a cement plug at a depth of 3,474
feet in 1939. In 1963, it was reopened and the water used in the con-
struction of Interstate Highway 80. Sometime thereafter, it was again
plugged by pumping cement from the surface downward into the casing to
a depth of 1,036 feet. The saline flow was stopped for a time, until the
casing rotted away and water began flowing around the cement plug onto
the surface at a rate of 50 gpm.

On September 22, 1978, preparations were begun to clean out the well and
~lug it a third time. A five-inch diameter hole was drilled through the
1,036-foot cement plug. An expandable packing device was positioned at
4,119 feet and mud pumped into the entire well column, stopping the water-
flow. A series of six cement plugs were set in the well at varying depths
to create a permanent barrier (see Figure 4).

The costs to plug the well in 1978 were as follows:

'<
-{

BLM supervision. . . .

. . . . . $

2,600

BLM and contract site preparation
(gravel access road, level drill
site, clean-up site). . . . ,

Drilling and plugging contract. ,

Total

$ 4,700
$ 35,400
$ 42,700

A flow of water at 50 gpm, with a concentration of 9,600 mg/l, would yield
a total of 1,044 tons of salt and 80 ac-ft of water annually. Plugging
of the well, totally stopping the saline flow, resulted in a salinity re-
duction at Imperial Dam of 0.073 mg/l. The annual value of this benefit
would be $25,039. The cost-effectiveness and benefits are computed as
foll ows:

Total Annual Costs
(annualized on a 50-year basis) . . . . . . . . $ 3,774

Cost-Effectiveness:

$ 3,774 per year $
0.073 mg/l reductlon =

51,699 per mg/l per year

Incremental Economic Benefits.

. $ 425,000 per mg/l
per year

Total Annual Benefits:

$ 425,000 x 0.073 mg/l = $ 31,025

The cautions outlined in section VI.B. should be exercised when attempting
to plug saline-flowing wells. Costs can greatly exceed those of the
Bitter Creek Well Project; however, plugging of saline-flowing wells may
be more cost-effective than evaporation ponds.

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