HYDRO28488 - Laserfiche WebLink

Home Browse Search

Snowcap Coal Co. Inc WWTF Water Quality Assessment CO-0027146 During assessment of the facility, neazby facilities, and receiving stream water quality, no additional pazameters were identified as pollutants of concern. Snowcaa WWTF: The Snowcap WWTF is located in the SE 1/4, Section 34, T10S, R98W; latitude 39° 08' 30", longitude 108° 18' 45' ; at the Cameo Exit, Exit 46, of Interstate 70; in Mesa County. The current design capacity of the facility is 0.59 MGD (0.91 cfs). This represents the combined daily average flow for Outfalls 001, 002 and 016. Wastewater treatment is accomplished using non- aeratedlagoons. The technical analyses that follow include assessments of the assimilative capacity based on this design capacity. Nearby Sources An assessment of neazby facilities based on EPA's Permit Compliance System (PCS) database found 43 dischazgers in the Mesa County azea. Several of the facilities were discharging to another watershed. More than one-half of the facilities conducted construction-related operations (e.g., sand and gravel) and thus had no pollutants of concern in common with Snowcap W WTF. Other facilities were located more than twenty miles from the Snowcap W WTF and thus were not considered. The neazest dischazgers were: • Public Service Company of Colorado-Cameo Station, CO-0000027, dischazges to Coal Canyon Creek and the Government Highline Canal. Coal Canyon Creek is tributary to the Colorado River in the vicinity of the Snowcap WWTF. However, because the Cameo Station facility limitations will be dictated lazgely by the small dilution available in Coal Canyon Creek and due to the large dilution in the Colorado River, no impact from this facility is expected. • Town of Palisade W WTF, COG-584004, dischazges to the Colorado River approximately 3 miles downstream of the Snowcap WWTF. This facility is a minor domestic WWTF that shazes no pollutants in common. The ambient water quality background concentrations used in the mass-balance equation account for pollutants of concern contributed by upstream sources, and thus it was not necessary to model upstream dischazgers together with the Snowcap W WTF when determining the available assimilative capacities in the Colorado River. Due to the distance traveled, the significant dilution of the receiving stream, and the changes in the chazacteristics of the receiving stream, modeling downstream facilities in conjunction with Snowcap WWTF was not necessary. Based on available information, there is no indication that non-point sources were a significant source of pollutants of concern. Thus, non-point sources were not considered in this assessment. Metals: Metals may occur naturally in rock around coal seams. Earth disturbances, such as mining operations, expose rock to air and water creating a potential for these elements to be present in elevated concentrations. Although ongoing mining activities do not occur at this facility, a complete metals analysis has not been recently performed. Thus, azsenic, cadmium, copper, chromium, iron, lead, manganese, mercury, nickel, selenium, silver and zinc, which have been identified as pollutants potentially present in mine water discharges aze pollutants evaluated in this assessment. According J to the Agency for Toxic Substances and Disease Registry, chromium in the trivalent form occurs naturally in the environrnent whereas hexavalent chromium is produced by industrial processes. Appendix A Page 9 of 12 Last Revised 9/15/2003