PERMFILE131397 - Laserfiche WebLink

Home Browse Search

I• Blue Mountain Energy, Inc. WWTP Water Quality Assessment CO-0038024 Table A-8 Chronic Assimilative Capacities for Total Recoverable Iron, Dissolved Iron, and Dissolved Man anese Fe, Dis (u 1 208 1.2 r 209.2 34 300 46,407 Fe, Trec u 1 208 1.2 209.2 735 1000 46,933 1 Mn, Dis ug/l 208 1.2 209.2 11 50 6,810 INott l: No a,rrrnt or historical ambient 6ackgound data were available for total recoverable Fe. However, total iron data were available and I thus were used as the 6eck~ound concrnha4on. J Ammonia: Ammonia is present in the aqueous environment in both ionized and tm-ionized forms. It is the un-ionized form which is toxic and which is addressed by water quality standards. The proportion of total ammonia present in un-ionized form in the receiving stream is a function of the combined upstream and effluent ammonia concentrations, and thepH and temperature ofthe effluent and receiving stream, combined. The Colorado Ammonia Model (CAM) is a softwaze program designed to project the downstream • effects of ammonia and the ammonia assimilative capacities available to each dischazger based on upstream water quality and effluent dischazges. To develop data for the CAM, an in-stream water qualitystudy must be conducted of the upstream receiving water conditions, particulazlythe pH and corresponding temperature, over a period of at least one yeaz. There were no data available for the White River near [he Blue Mountain Energy, Inc. W WTP that could be used as adequate input data for the CAM. Therefore, the WQCD standazd procedure is to rely on default values for the allowable chronic concentrations ofin-stream total ammonia, which aze provided in the Colorado Total Maximum Daily Load and Wasteload Allocation Guidance and the CDPS Summary afRationale General Permit for Domestic Wastewater Treatment Facilities that Discharge to Receiving Waters with a Chronic Low Flow: Design Flow Ratio of 100:1 or Greater. Note that acute values aze not provided in these sources and thus aze not evaluated as part of this assessment. Segment 13a has no ammonia standazds. In lieu of such standards, total ammonia assimilative capacities aze calculated based on the segment 12 standards and low flows. Additionally, because total residual chlorine is a pollutant of concern unique to Outfa11004, only the design flow ofOutfal] 004 will be used in the analysis. Using the mass-balance equation provided in the beginning of Section N, the chronic low flows for Stream Segment COLCWRI2 set out in Section III, the mean ammonia background concentration shown in Section II, and [he in-stream standazds found in the Colorado Total Maximum DuilyLoad and Wasteload Allocatiot Guidance and the CDPS Summary of Rationale Genera! Permit for Domestic Wastewater Treatment Facilities that Discharge to Receiving Waters with a Chronic Low Flow: Design Flow Ratio of 100:1 or Greater for M3, assimilative capacities for chronic total • Appendix A Page 13 of 15