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Felmra7. 2004 Hayrleu Gu@!~ Tcnanral, ]nt. * Hayden Gxlcb Loar/out - 2003 Aunuat Hydro/agy Report ~ Yage 5
<br />' same location in January 2004- Calcium (227 mg/1), total recoverable copper (0.03 mg/1), total
<br />recoverable molybdenum (0.0071 mg/1) and fluoride (0.5 mg/1) all reported concentrations in January
<br />2004 that were greater than previously reported concentrations. Flow at HGSD] in January 2004 was
<br />visually estimated at 20 gallons per minute (0.045 cubic feet per second). At HGSD3, total iron (0.20
<br />mg/1), potassium (4.2 mg/1), and rota] nitrate (0.34 mg/1) concentrations in June 2003 represented new
<br />minimum concentrations.
<br />' HGTI has compiled a list of water quality standards for livestock. This list is composed primarily of
<br /> Colorado Department of Public Health and Environment (CDPHE) standards, although other
<br /> regulatory agency standards were used if they were more stringent or if CDPHE has no standard for a
<br />' particular constituent. Table 4, Comparison of 2003 Surface WaterQuality to Livestock Standards, provides a
<br /> list of the livestock standards along with a comparison of those standards to 2003 surface water quality
<br /> data. Units of concentration are as listed in Table 4. Laboratory analytical reports generally report
<br /> constituent concentrations as mg/l. The following constituents exceeded their respective standard:
<br /> • sulfate (standard of 500 mg/1):
<br /> HGSD? on 6/25/03 (1,720 mg/1) and 1 /21 /04 (2,040 mg/1)
<br /> HGSD3 on 6/25/03 (2,500 mg/1)
<br />' • total dissolved solids (2,500 mg/1):
<br />HGSDI on 6/25/03 (3,740 mg/1) and 1 /21 /04 (3,500 mg/1)
<br /> HGSD3 on 6/25/03 (4,270 mg/1)
<br />' While these values were greater than their respective criteria, historic values for these constituents at
<br /> both locations typically exceeded the respective criterion. The manganese standard of 0.200 mg/I has
<br /> often been exceeded at the upstream location, HGSDI during previous sampling events. However, no
<br /> manganese exceedances were reported in 2003 a[ HGSD7. Time-[rend plots of manganese, sulfate
<br />' and TDS concentrations versus time are presented in Appendix C.
<br />3.3 GROUNDWATER DATA
<br />Groundwater data for 2003 and historic data are presented in Appendix D, GroundtvaterQuality Data.
<br />Presently, HGTI is only monitoring alluvial groundwater in monitoring well, HGDAL3. In 7993,
<br />HGTI installed HGDAL3 as a new downdip alluvial monitoring well in response to Colorado
<br />Division of Minerals and Geology (CDMG) concerns that the two existing alluvial wells, HGDALI
<br />and HGDAL2, may have been partially completed in the Lewis Shale. Groundwater quality data was
<br />collected from monitoring wells HGDALI and HGDAL2 between 1987 and 1995. Groundwater
<br />monitoring ceased for HGDALI and HGDAL2 in 1995. The location of the groundwater monitoring
<br />wells are shown on Figure 7, Monitoring Site Location Map. HGTI reported in the existing, valid Mining
<br />and Reclamation Permit (revision date of May 1998) that chemistry information obtained in HGDAL3
<br />is similar to the historic chemistry depicted by monitoring wells HGDALI and HGDAL2.
<br />The first semi-annual event occurred on June 25, 2003. The second event did not occur in the fall of
<br />2003. Instead a sampling event occurred on January 21, 2004. In January 2004, HGDAL3 was frozen
<br />in the PVC stand-pipe and, therefore, it was not sampled. In general, the June 2003 groundwater
<br />quality data from HGDAL3 is similar to previously observed values with a few exceptions. Sulfide as
<br />hydrogen sulfide decreased from 3.9 mg/1 in October 2002 to 1.G mg/1 in June 2003. Aluminum,
<br />boron, conductivity, chloride, fluoride, molybdenum, nitrogen as ammonia, pH, potassium, selenium,
<br />sodium, total alkalinity, and total suspended solids (TSS) decreased compared to October 2002
<br />concentrations. However, calcium, hardness, magnesium, manganese, phosphate, orthophosphate
<br />sulfate, and total dissolved solids (TDS) slightly increased from October 2002 to June 2003. No
<br />constituents in 2003 represented new maximums or minimums at HGDAL3. Time trend plots for
<br />common constituents are presented in Appendix D.
<br />A1le'H * 7475 Pine Grove Raatl, Serite 109 * Steanibaat Spnngg CO 80477 * (970J 579-6260
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