DWQ-2025-004878

M E M O R A N D U M
TO:Lonnie Schull, Permit Writer
FROM: Suzan Tahir, Wasteload Analyst
DATE: March 12, 2025
SUBJECT: Antidegradation Review for the Morton Salt UPDES Permit UT0000523 Outfall 001
Receiving Waters and Designated Uses
The discharge is to Great Salt Lake. The receiving water the effluent discharges to is classified as 5E Transitional Waters and then to 5A (Gilbert Bay, Great Salt Lake) according to
Utah Administrative Code (UAC) R317-2-6.5.a. Both the Transitional Waters and Gilbert Bay are protected for waterfowl, shore birds, and other water-oriented wildlife including their
necessary food chain. The Transitional Waters are also protected for infrequent primary and secondary contact recreation. Gilbert Bay is protected for frequent primary and secondary
contact recreation.
Level I Antidegradation Review
The Level I antidegradation review requirements are that existing uses will be protected (UAC R317-2-3.1). For the affected receiving waters, existing uses are the same as the designated
uses. The bitterns flow via unnamed ditch to U.S. Magnesium for further processing. Water quality-based effluent limits are not required based on the effluent quality (bitterns: concentrated
salts from Great Salt Lake) and the limited aquatic life habitat supported by the drainage ditch.
Level II Antidegradation Review
In accordance with UAC R317-2-3.5. b.1. (b), a Level II antidegradation review is not required because there is no change to effluent concentrations or loading compared to the previous
permit. The renewed permit should include the design flow for the facility to support future determinations if a Level II antidegradation review is required.