UAA/revised standards for West Division Main Canal

DETP/19/5411

''Monday, July 08, 2019 at 2:27:48 PM (GMT+07:00) Goldstein, Meyer:'' Rule Caption: Water Quality Standards Revision for the West Division Main Canal (Umatilla basin) near Hermiston, Oregon. Adm. Order No.: DEQ 3-2012 Filed with Sec. of State: 5-21-2012 Certified to be Effective: 5-21-12 Notice Publication Date: 10-1-2011 Rules Amended: 340-041-0002, 340-041-0310, 340-041-0315 Subject: The rule revises water quality standards for the West Division Main Canal located near the City of Hermiston in the Umatilla basin. The rule revises the designated beneficial uses for the West Division Main Canal and establishes site-specific water quality criteria (numeric and narrative) for the canal that protect those uses. The canal is primarily a man-made, concrete lined irrigation water conveyance that is screened at both ends to prevent fish from entering the canal. The current beneficial uses were designated broadly for all streams in the Umatilla subbasin, including the canal. The rule removes uses that do not exist and are not feasibly attainable in the canal, including aquatic life, public and private domestic water supply and fishing. The rule establishes water quality standards based on the actual or possible uses of the canal: irrigation, livestock watering, water contact and modified aquatic habitat in the lower segment. The revised criteria are less stringent than the previous criteria. The new criteria will make discharge to the canal a feasible alternative for the City of Hermiston (indirect effect of rule). DEQ does not expect that the revisions to the water quality standards will result in a degradation of water quality within the canal; rather, the proposed revisions are intended to protect existing uses and water quality.