From:
U. S. Department of Agriculture, Rural Development Programs
http://www.usda.gov/rus/water/ees/englib/pdf/cowrt1.pdf

Water and Environmental Programs
Engineering Success Stories

State: Colorado
Borrower Name: City of Las Animas
Engineering Firm: Gilbert B. Morrill, P.E.
RD Contact: Ron Jackson, (303) 236-2801
Congressional Information: Dan Schaefer
Counties: Bent
Keywords: Reverse osmosis

Reverse Osmosis Treatment Plant

Description of the problem:

Las Animas, Colorado, a rural community with a marginal economy and difficult water problems, recently put its new reverse osmosis plant on line.

Las Animas (population approximately 2,660) lies over the alluvial aquifer of the Arkansas River on the plains of southeastern Colorado. Water quality data in this basin has been evaluated and documented through several US Geological Survey studies. The quality of the water is affected by the extensive use and reuse of the Arkansas River water for irrigation. Evapotranspiration of the irrigation water concentrates the dissolved solids. The degradation of the water is illustrated below, starting at Pueblo.

Town   Miles
  from
Pueblo		 Sodium
 Mg/L		 Sulfate
  Mg/L		 Hardness
Mg/L		 Dissolved
    Solids
    Mg/L
Pueblo 0 24 145 219 326
Avondale 11 47 224 307 535
Fowler 36 57 320 368 651
Las Animas 85 201 938 848 1748
Water pumped from the city's seven wells has even higher concentrations of many of the contaminants listed. Water quality data collected from well samples have indicated sulfate ranging from 1,600 to 3,000 Mg/L. Pinhole leaks in the City's water lines could actually close themselves in the span of a few days through the water's disposition of dissolved solids. The problem had become so severe that many people who work in Las Animas refused to live there due to the hardness of the water.
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