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<br />HI', Leo" ^, WUI'I <br />Page Two <br /> <br />UOlu86 <br /> <br />Fish Bloassays to Determine Toxicity Levels of Ammonia (IUH) Cadmium, Copper, <br />Silver and Zinc in Waters from Five Sites on the Cache La Poudre River by <br />S. H. Horrison, G. Post and D. Erickson, June 1979. <br /> <br />Aquatic Life - Water Qual ity Recommendations for Heavy Hetal and Other Inorganic <br />Toxicants in Fresh Water by P. H. Davies and John P. Goettl, Jr., July 1976. <br /> <br />State of Colorado, Stream Classification Survey Forms for Boulder Creek and <br />Coal Creek. <br /> <br />Table A-43, Bottom Animals, Boulder Creek from Boulder, Colorado, Downstream <br />to St. Vrain Creek, August 1966 from the report Effects of Pollution on <br />Aquatic Life Resources of the S. Platte River Basin in Colorado, Vol. 11- <br />Technical Appendix, December 1967. <br /> <br />Storet (computer printouts) for ammonia and various other parameters along <br />Boulder Creek and Coal Creek. <br /> <br />Hy initial reaction to the above is that the information is particularly scanty for <br />the conclusions reached (not only in the area of stream classifications but also in <br />the proposed NPDES Permit No. CO-0023078 under which the City of Louisvi lie operates <br />its wastewater treatn-ent plant). I would like to enumerate my areas of concern. <br /> <br />I. Stream Flows <br /> <br />Coal Creek drains an area of some 15. I square miles above the Plainview Gauge <br />(Figure I) ranging in elevation from 6540' to 8800' U.S.G_S. Datum. This type <br />of front range drainage displays none of the long term runoff characteristics <br />of high mountain water sheds. Table I records the Coal Creek flows at the <br />Plainview Gauge for the period 1960-1976. These records are shown in Attachment <br />"A" and they indicate that historically 45 percent of Coal Creek's flow occur <br />in one month, Hay. Thereafter, flows gradually dwindle and in the words of the <br />U.S.G.S. Surface Water Records "no flow for many days in most years" are noted <br />as minimum flows. In fact, for the water years 1960 through 1976, the following <br />minimum flows have been recorded: <br /> <br />Total Days of <br />Zero F]ows <br /> <br />1960 - August 4-8, 11-31; September 1-30 <br />1961 - Oc to be I' I -I 3 <br />1962 - August 5-3]; September 1-30 <br />1963 - October 1-22; June 6-8; July 23-31; August 1-]1 <br />1964 - July 22-25; August 5, 10-31; September 1-30 <br />1965 - October 1-20, 25-31; November 1-16 <br />1966 - July 17-31; August 1-12, 19-31; September I, 5-14,23-25 <br />1967 - October 1-31; November 1-3 <br />1968 - September 10-21, 23-28 <br />1969 - October 1 (wettest year of record) <br />1970 .05 CFS minimum flow September 20 <br />1971 .04 CFS minimum flow AU9ust 16-19 <br />1972 .06 CFS minimum flow July 18, 19, 26-30; August I <br />1973 - .05 CFS minimum flow September 3-8, 10 <br />1974 .01 CFS minimum flow September 10 <br />1975 - .03 CFS minimum flow September 6-10, 13-16 <br />1976 .04 CFS minimum flow September 5. 6 <br /> <br />TOTAL <br />Average for 17 years <br /> <br />55 <br />13 <br />57 <br />45 <br />57 <br />43 <br />54 <br />34 <br />18 <br />I <br />o <br />o <br />o <br />o <br />o <br />o <br />o <br /> <br />377 days <br />22 . 2 day 5 <br />