Comment

Total Phosphorus discharges would have to come down to 0.03 mg/L to meet all discharge requirements.

Response

False. Class A-1 effluent requirements do not regulate phosphorus at all. 0.03 mg/L of TP is the criterion for the Gallatin River, but only during the nutrient season (July 1st – September 30th), and dilution credits can be claimed to meet this criterion at the end of a mixing zone.

Comment

In fact, it appears that community feedback – including that made by key ratepayers within the District – favoring innovative wastewater treatment and disposal alternatives that protect and improve the local environment condition without resorting to a direct-discharge to the Gallatin, was never a meaningful consideration underpinning the draft Report’s foci.

Response

The District has evaluated “innovative” wastewater treatment and disposal alternatives, these are described in the Report. And the selection of MBR for construction does “protect and improve the local environment condition without resorting to a direct-discharge to the Gallatin. The only wastewater treatment process proposed by a ratepayer was Integrated Fixed-Film Activated Sludge, which as explained and shown in the November 27th presentation, produces a worse-quality effluent than MBR, with a larger footprint and higher cost. It does not make sense given the site constraints at the existing WRF.

Comment

The conservation letter references “disposal of at least 160 mgy” (million gallons per year).

Response

As stated on multiple occasions and in the CDR, There is no intent to dispose of 160 mgy annually to the Gallatin. This is an approximate, proposed discharge permitting goal, to cover potential emergency discharges in the event of a reuse pipeline or large reservoir failure. The estimated need for disposal to the Gallatin River, if needed and at full build-out of the District, is 70 mgy (See Figure 2 of the Executive Summary).