Not knowing what the current physical condition of the existing plant is, I wonder if it is necessary to abandon the current system for a completely new plant. If the existing system is providing effective treatment, could it be maintained to fulfill the needs for irrigation and possible future snowmaking, depending on the permit requirements. If discharge to the Gallatin is desired at some point in the future, will it be necessary to treat all of the effluent to the higher limits, or just that portion that will be discharged. If this is the case, it may be prudent to investigate a tertiary treatment process that takes a portion of the current effluent volume and further treats it for discharge. Could the existing ponds be used to isolate just that volume that is intended for discharge?
See Response to Comment 57. Also, any reuse water must be filtered. Costs for expansion using the District’s existing treatment processes has been provided and will be included in the Final Report. However, the effluent from that process would not comply with any effluent reuse requiring Class A-1 effluent (e.g., subsurface discharge).