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<br />001758 <br /> <br />Fecal coliform samples exceeded the standard at the sites above the Highway 44 bridge in <br />Bloomfield and at the USGS gage in Farmington below the confluence of the San Juan and <br />Animas Rivers. Fecal coliform is noted in the New Mexico State's 303(d) listing as being out of <br />compliance in stream segment 20.6.4.401. Total maximum daily loads (TMDL) studies will <br />begin in 2002 for fecal coliform and bottom sediments. <br /> <br />Projection of Potential Long-Term Impacts <br /> <br />General Impacts - Some parameters could exceed the state standards between Navajo Dam and <br />the confluence of the Animas River with long-term 250 cfs flows during the irrigation season. If <br />a parameter exceeds the standard more than once in three years, then the New Mexico <br />Environment Department would place the parameter on the 303(d) list of impaired streams, The <br />state would then perform a TMDL study on the parameter in the stream segment. <br /> <br />River segments 20,6.4.401 and 20.6.4.405 have several parameters that are exceeded at the <br />present time and would continue to be exceeded at low flows. Segment 20.6.4.401 is out of <br />compliance with fecal coliform and bottom sediments. TMDLs are planned to be developed by <br />the end of 2004 for both of these parameters. Segment 20,6.4.405 is out of compliance with <br />turbidity and bottom sediments and TMDLs are also planned to be developed by the end of 2004, <br /> <br />Table D shows the results from the low flow samples and compares them to the historical data at <br />250 cfs and 500 cfs for the sample site at the USGS gage at Archuleta, Colorado in river segment <br />20,6.4.405. <br /> <br />TABLED <br />Comparison of Water Quality data at USGS gage at Archuleta, Colorado <br /> <br />Parameters Archuleta - low Archuleta - Archuleta - Archuleta - <br /> flow test July 9- historical winter historical data for historical <br /> 15,2001 low flow tests average 500 cfs maximin data for <br /> (winter 1996- flows (range from 500 cfs flows <br /> 97) 450 to 551 cfs) <br />average stream flow 264 280 (n=ll) 503 (n=45) 551/450 <br />( cfs) <br />Conductivity 306 252 (n=ll) 279 (n=43) 480/199 <br />(umhos!cm) <br />water temp degrees 12.8 4.6 (n=l1) 7.3 (n=45) 14/2 <br />Cent, <br />turbidity 1.4 6.3 (n=8) 4 (n=34) 10/1 <br />dissolved oxygen 8.45 10.9 (n=ll) 1O.9(n=9) 14.13/9.43 <br />pH 8.0 8.0 (n=ll) 8.2 (n=43) 8.9/7 .2 <br />HC03 ion (mglL) 103 75.5 (n=8) 96 (n=23) 112/67 <br />N03-N diss (mglL) No Data 0.1 (n=4) 0.085 (n=8) 1.01/0.04 <br /> <br />Page 10 of 15 <br />