Laserfiche WebLink
<br /> <br />oon5S' <br /> <br />Blue River - Page 3 <br /> <br />that both the phosphate and nitrogen concentrations are high enough <br /> <br /> <br />to cause eutrophication at least in the upper reaches of the reservoir. <br /> <br /> <br />These studies also indicate the concentration of orthophosphate in the <br /> <br /> <br />Big Blue River varies from 0.3 ppn to 2.9 ppm. The modal concentration <br /> <br />1s 1.2 ppm at Barnston. Sawyer2 has stated that concentrations in <br /> <br />2Sawyer, C. N" 1952 <br />Lake Fertilization. <br /> <br />Some New Aspects of Phosphates in Relation to <br />Sewage and Industrial Wastes, vol. 24, pp. 768-776. <br /> <br />excess of 0.01 mg/l of inorganic phosphorus can be expected to produce <br /> <br /> <br />algae blooms of such density as to cause nuisance. All of the orthophate <br /> <br /> <br />analysis to date at the Barnston station have exceeded this level. <br /> <br />Table 1 shows the chemical water quality of the Big Blue River at <br /> <br /> <br />Crete and Barnston based upon a large series of analysis by the <br /> <br /> <br />Nebraska State Department of Health. For each analysisJ the maximumJ <br /> <br />minnum and modal concentrations are given. The mode has been used in <br /> <br />the interpretation of the analysis rather than the arithmetic mean because <br /> <br />the standard deviation of the arithmetic mean was so great that there <br /> <br /> <br />was little reliability. ThereforeJ the mode which is the value that <br /> <br />occurs most frequently was used as it appeared to represent the most <br /> <br />reliable value. A study of the data in Table 1 shows that there is very <br /> <br /> <br />little change in the concentrations of chemical ions 1n the Big Blue River <br /> <br />between Crete and Barnston. <br />