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March 2007 Haykn Gukh LoaAon! - 2006Axnuat Hydrology Re)rort 1 Page 4 Per the requirements of the CDPS permit COG-850008 quazterly Dischazge Monitoring Reports (DMRs) were submitted to the appropriate regulatory agencies under separate cover. For completeness purposes, copies of the 2006 DMRs aze provided in Appendix B, CDPS Discharge Monitoring Repor7s. 3.2.2 Stream Monitoring Two stream monitoring locations were sampled in the vicirtiry of the Loadout along Dry Creek. Permit specified monitoring consists of semi-annual (spring and fall) monitoring for flow and water quality. The upstream surface water monitoring site (HGSDl) is located approximately 0.5 miles upstream of the Loadout permit boundary. This site is located on Dry Creek just downstream of Routt County Road 53. The downstream surface water monitoring site (I-IGSD3) is located on Dry Creek within the rail loop, downstream of the Loadout facility azea. A third location (HGSD2), which is downstream of where the rail spur transitions into the loop and, of HGSD3, was abandoned in 1995 (this site is inactive). The locations of the current and former surface water monitoring stations aze shown on Figure 1, Monitoring Site Z.acatians. The spring runoff monitoring event occurred on May 8, 2006. The fall monitoring event was conducted on October 12, 2006, and both Dry Creek locations were sampled. Surface water quality data for 2006 aze included in Appendix C, Surface [Y/aterQuality Data. A review of the laboratory analyses for samples collected during the May monitoring event shows that the surface water constituents from HGSDl and HGSD3 aze similar to previous yeazs. In general, the potentially dissolved concen[rattons were simdaz to the total recoverable values. Constituents that historically were not detected in the total recoverable form were also generally not detected in the potentially dissolved form. The October sample collected at HGSDl had a new maximum concentration for potassium (9.2 mg/1). This value is only slightly higher than the previous maximum (8.9 mg/1) and does not appeaz to reflect an increasing trend. The October sample collected at HGSD3 had a new maximum concentration for azsenic (0.0021 mg/1). This value is only slightly higher than the previous maximum (0.002 mg/1) and may be nothing more than analytical noise. The October HGSD3 sample also had a new maximum dissolved uon concentration (0.26 mg/1). The Colorado Depaztment of Public Health and Environment has established use classifications and numeric standazds for Dry Creek in Regulation 33, Classification and Numeric Standards for Upper Colorado River Basin (Yampa River Segment 13d). Classified stream uses aze agriculture, recreation la and aquatic life warm 2. The primary water use for Dry Creek is agriculture (both irrigation and livestock watering); however, the CDPHE also determined there is a reasonable chance of primary contact recreation as a water use, and consequently, classified the stream as recreation class la. The aquatic Gfe wazm 2 classification is based on a finding that Dry Creek is not capable of sustaining a wide variety of aquatic life, primarily because of physical habitat limitations -stretches of the creek aze intermittent and water temperatures in the summer frequently approach 30 ~C. Because agriculture is the primary use, HGTI has compiled a list of applicable agriculture water quality criteria. Table 5, Campariron of 2006 Surface Water Quality to Agriculture Standards, summarizes the applicable standards along with a comparison of those standazds to 2005 surface water quality data. The manganese standazd of 0.200 mg/1 was exceeded a[ both surface water sites for both sampling events. However, this has been typical of previous yeazs sampling results. Hydro-Envirotunental Solutions, Inc. P.0. Box 772996 57 10~ Strcef, Sufte B Suamhaat Sp>zngr, CO 80477 (970f 877-6125