Findings > Baseline

  • Baseline or "existing" conditions are determined from the analytical results considered together, that is, across all the seasons for each stream.

  • Baseline metals, ammonia, and nitrate values are the 85th percentile of the measurements.

  • Dissolved oxygen is the 50th and pH is the range between the 15th and 85th percentiles.

  • The baseline condition for E coli is the geometric mean of the measurements.

  • Colorado uses these values in evaluating streams as potential Outstanding Waters.

  • Baseline values, shown below, for all 12 parameters at all 9 of the streams sampled in this study meet the water quality requirements for Outstanding Waters classification.