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~~ <br />i <br /> <br />Water at this site also occasionally exceeds recommended agricultural <br />standards for manganese of 0.2 mg/7 total manganese. This proposed <br />criterion is recommended for areas in which acidophilic crops are I <br />cultivated (USEPA, 1976). Soils and waters in Routt County are generally <br />alkaline, and thus this standard is inappropriate. The NAS Water Quality <br />Criteria (1974) suggests that multiple decade continuous irrigation with <br />10 mg/1 manganese could reduce productivity, but concentrations <br />discharging from Pond A average 0.27 mg/1 and never exceed 2 mg/1. <br />The aquatic life standard for total iron is 1 mg/1. Background total <br />iron concentrations at Site 14, an undisturbed site, is 1.4 mg/1, forty <br />percent higher than the standard. Between 1979 and 1986, 276 analyses <br />were made at Site 39. Only ten samples exceeded the average total iron <br />concentration at Site 14. Additionally, in 1986, the operator started <br />obtaining analyses of total recoverable iron at this site. (Total <br />recoverable analyses are currently the accepted analytical technique for <br />the Colorado Department of Health. 'Total recoverable' analyses differ <br />from 'total' analyses in that acid digestion is less concentrated.) None <br />of the 16 total recoverable iron analyses exceeded the quality criteria <br />of i mg/1, and they averaged 0.273 mg/1. Therefore, it would appear the <br />iron concentrations discharging from Pond A do not degrade water quality <br />in Foidel Creek. <br />Nitrite concentrations discharging from Site 39 averaged c 0.044 mg/1 <br />from 14 samples taken in 1986. Five samples/ equaled or exceeded the <br />recommended aquatic life standard and the receiving stream standard of <br />0.05 mg/1, This standard is based on 55% mortality of rainbow trout <br />exposed to 0.55 mg/1 for 24 hours. CYCC stocked Pond A with a variety of <br />trout three years ago, and employees are currently catching numerous <br />15"-20" fish. This would suggest that the restrictive standard is <br />inappropriate. <br />The salinity of waters discharging from Pond A averaged 1970 mg/1 total <br />dissolved solids in 1986 and ranged as high as 2480 mg/1, The National <br />Academy of Science and the National Academy of Engineering recommend a <br />maximum concentration of 3000 mg/1 for livestock watering and 2000 mg/1 <br />for irrigation waters. (USDI, OSM, 1982) Using these criteria, the water <br />in Pond A is marginally acceptable for livestock watering and <br />unacceptable for irrigation purposes. <br />(h) The level of water shall be sufficiently stable to <br />support the intended use; <br />In the past three years, water levels have varied 3.6', This has <br />resulted in a change in surface area of the lake of 3.7 acres. In places <br />the shoreline has migrated as much as 200'. Mudflats are occasionally <br />observed at the emergency spillway area and along the east side of the <br />pond. Other areas have developed good stands of vegetation, which <br />provides food and cover for wildlife using the impoundment. <br />