2012-06-20_PERMIT FILE - C2010089A (10)

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water level measurements demonstrate the rapid recharge of groundwater levels in response to seasonal irrigation. Groundwater migrates through the OB, coal and UB zones downdip to the southwest toward the bedrock outcrop, (see Map 2.04.5 -1). Total migration of groundwater from NHN through the bedrock zones at the rate of only 3.3 gpm would account for the entire remaining 292 ac -ft. From historical data (see New Horizon 1 Area Permit) the annual flow from the backfill and irrigation runoff water in Nygren Draw out of NPDES pond 001 is about 243 ac -ft. Subtracting the flow in Nygren Draw at SW -N06 results in a net annual gain of just 44 ac -ft This equates to a continuous flow rate of about 0.001 cfs or > 0.5gpm. The total flow from NPDES Pond 001 (243 ac -ft) explains some of the gain in the Tuttle Draw flow from SW- N1 to SW -N3. The 1986 to 1987 monitoring data from SW -N1, SW -N3, SW -N6, SW -N7, and NPDES 001 are included in Appendix 2.04.7 -2 of this application. The out of permit flow of Meehan and Glasier Draws into the upper reaches of Coal Creek Canyon is about 811 ac -ft per year or an average of about 1.12 cfs. Down stream users to the 2" Park ditch system use about three times more water than the permit area and up stream users suggesting that annual flow into Coal Creek Canyon as the result of irrigation is on the order of 3,200 ac -ft per year or an average of about 4.4 cfs. The flow in the lower reach of Coal Canyon (site CSS) during March 2011(non- irrigation season) was measured at 1.296 cfs. Surface Water Quality Baseline water samples from the 16 surface water monitoring sites (SW -N06 was destroyed by county road maintenance) were collected quarterly when a site was experiencing flow (see Map 2.04.7 -1). The 2" Park Lateral flowed from April 23, 2009 through October 5, 2009. Out flow monitor sites on (SW -N202, SW -203) Meehan and Glasier Draws flowed throughout the year, while inflow sites on the same two draws showed periods of being dry. This indicates the seepage of irrigation water maintains flow in the lower reaches (within the permit area) of these two draws. Water quality data from the 16 new surface water monitoring sites at NHN area are contained in Appendix 2.04.7 -2 of this permit application. Glasier Draw and Meehan Draw provide about 811 ac -ft of flow to the upper reaches of Coal Canyon this flow has a weighted average quality of about 1320 mg /I TDS. The baseline water quality analyses from the new sites indicate that the water flowing into the permit area is better than the water flowing out of the permit area. This indicates a natural degradation in water quality that is expected. Table 2.04.7 -6 summarizes the water quality flowing into the NHN permit area. Table 2.04.7 -7 is a summary of the surface water quality flowing out of the permit area. The data in Tables 2.04.7 -6 and 2.04.7 -7 only includes the sites that have been monitored since 2008. The Meehan Draw (SW -N202) and Glasier Draw (SW -N203) out -flow quality differs significantly with the in -flow quality of the 2 Park Lateral (SW -N209) irrigation water. The irrigation water quality between SW -N200 and SW -N209 in the 2 Park Lateral is very similar for this 3,700 ft. section of the ditch. The irrigation water is suitable for domestic drinking water although it does have a relatively high (untreated) pH, (see Table 2 CDPHE WQCC Regulation No. 41). The water in the drainages is suitable for livestock and irrigation but unsuitable (high in sulfates >250mg/1) for domestic drinking water (see Table 2, 3 and 4 CDPHE WQCC Regulation No.41). Measurement of water quality in Coal Canyon site CSS (3/11/2011) showed TDS of 2940 mg/1 with sulfate at 1890 mg/l. Section 2.04.7 Page 19 November 2011