WSP03388

• File Number: 8041
• Description: 208 Clean Water Grant
• State: CO
• Date: 3/4/1982
• Author: CWCB
• Title: Quarterly Reports on the 208 Clean Water Grant for the Water Quality Control Division of the Coloradio Dept of Health
• Water Supply Pro - Doc Type: Publication

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3708

Dan Law
November 30, 1981
Page two

Assuming that 10,000 tons of salt would have to be removed from the river
system in order to reduce the TD5 concentration of Imperial Dam by 1 mg/L, the
best case achievement of zero salt discharge for all 18 permits considered would
only reduce the concentration at Imperial Dam by 1.7 mg/L. Relative to point
source salinity control proposals presented by the Bureau of Reclamation the
potential for significantly improving the water quality of the Colorado River by
controlling industrial discharges appears low. This observation is supported by
the relatively small amount of salt (tons) contributed by industrial discharges
as well as the relatively low salt concentrations (mg/L) associated with most
industrial discharges. AS a general rule, the cost-effectiveness of removing
salt from water with TD5 levels similar to those discussed above is much less
atttractive than removing salts from waters associated with natural point source
discharges, such as those investigated by the Bureau of Reclamation.

Annual salt discharged and average TD5 concentration associated with Union
Carbide's permit (ico 0000515) deviate considerably from the other 17 permits
analyzed. In a IINo Salt Return Study" submitted February 4, 1980, Union Carbide
identified several alternatives which would reduce or eliminate salt discharges
from the facility. Costs ranged from $121 to $175/tons of salt removed. It was
determined by the Division of Water Quality that none of the possible
alternatives are economically feasible. The Division is currently in the
process of determining the Best Available Technology (BAT) for dealing with the
Uravan Mill discharge. One possibility is that Union Carbide will be required
to convert the mill to a non-discharging facility.

Although this analysis does not consider all sources of industrial
discharge to the Basin, it does look at a good cross section of discharges that
could be expected to contribute to the salt load in the river. The analysis
should serve well to contrast the significance of industrial point source
discarges with other natural and man-made contributors to Colorado River
salinity_

D5/91

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