Comment

If more robust treatment works capable of producing higher quality effluent is built, the District could use that effluent in a variety of ways including purple pipe projects, rapid groundwater infiltration, snowmaking, or indirect potable re-use via deep aquifer recharge safely and with certainty

Response

Please define “more robust treatment works”. The report documents that MBR is very capable of providing an effluent that meets Montana DEQ Class A-1 effluent, suitable for irrigation reuse (purple pipe), subsurface (groundwater) disposal, and is the preferred base treatment for indirect potable reuse in the United States, as evidenced by California’s use of MBR in Full Advanced Treatment regulations for potable reuse projects. And without detailed hydrogeologic information on the “deep aquifer”, there is nothing certain about injecting effluent into the formation, technically or regulatory, as DEQ currently has no IPR permitting framework.