WSP07462

• File Number: 8270.100
• Description: Colorado River Basin Water Quality/Salinity -- Misc Water Quality
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1976
• Author: CDH
• Title: Report on the Investigation of the Water Quality of the Colorado River - Dotsero - Colorado to Utah Border
• Water Supply Pro - Doc Type: Report/Study

values ranged from 18 mgll at Grand Valley to 153 .rrqll at De Beque. Dissolved

oxygen measurements varied from zero at Glenwood Springs and West Glenwood

Springs to 4.3 ppm at Grand Valley.

Duri.ng the study period, the WWTP at West Glenwood was being rebuilt and

expanded. A sample collected after the plant was at full operation on August 8,

1974, demonstrated that the facility was in compliance on all counts except

residual chlorine. A sample collected the same day at New Castle indicated

that the facility was well within the d1.scharge standards except for a dissolved

oxygen determination 0.2 ppm below the discharge standard. Comparison of data
gathered upstream and downstream from the wastewater treatment plants. gave no

indication of measurable degradation of the Colorado River by the effluents.

Bacteriological
Results from the fecal coliform tests were tabulated along with physical

and chemical data (see Tables 2 - 10). In only eight instances did counts

exceed 100 organisms per 100 ml samples. At CR-5, downstream from the West

Glenwood treatment plant, 110 o.rganisms Were counted February 1, 1974. Two

hundred and twenty o.rganisms per 100 mls Were counted on September 26, 1973 at

CR-7, 9, 10, 15, and 16 . On January 30, 1974, 640 organisms per 100 ml were

collected at CR-14 below the De Beque WWTP effluent. Three hundred and twenty

organisms per 100 ml were in a sample from the River at Cameo on March 7, 1974.

The remainder of bacterial analyses indicated populations less than 100 organismsl

100 ml sample. State standards for Bl waters require fecal coliform counts to

be less than 1000 organisms per 100 mls.

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