DWQ-2024-004212

June 1, 2024DIVISION OF WATER QUALITYUTAH DEPARTMENT OF ENVIRONMENTAL QUALITYPUBLIC NOTICE TO RENEW A UPDES PERMITPURPOSE OF PUBLIC NOTICE
THE PURPOSE OF THIS PUBLIC NOTICE IS TO DECLARE THE STATE OF UTAH'S INTENTION TO RENEW A UTAH POLLUTANT DISCHARGE ELIMINATION SYSTEM (UPDES) PERMIT UNDER AUTHORITY OF THE UTAH WATER
POLLUTION CONTROL ACT, SECTION 19-5-104(9) AND 107(2), UTAH CODE ANNOTATED 1953, AS AMENDED. SAID “PERMIT” REFERS TO THE UPDES PERMIT AND THE FACT SHEET STATEMENT OF BASIS.PERMIT INFORMATION:
PERMITTEE NAME:PacifiCorpFACILITY NAME:PacifiCorp Gadsby Power Plant, (Gadsby Plant)MAILING ADDRESS:1359 West North Temple, Salt Lake City, Utah 84116 TELEPHONE:[phone]FACILITY
ADDRESS:1359 West North TempleUPDES PERMIT NO.:UT0000116PERMITTED OUTFALLS:004, 007OUTFALL LOCATION:004, Latitude 40° 46' 7.90" and longitude 111° 55' 50.02"RECEIVING WATER:004, Salt
Lake Abatement Canal to the City Drain Canal to Salt Lake Sewage Canal (North West Oil Drain/Canal) to the Farmington Bay Bird RefugeOUTFALL LOCATION:007, Latitude 40° 46' 6.88’ and
longitude 111° 55' 35.01RECEIVING WATER:007, Jordan River
COOLING WATER INTAKE STRUCTURECWIS LOCATION:Latitude 40° 46' 6.88’ and longitude 111° 55' 35.01 (007)INTAKE WATER:Jordan RiverBACKGROUND
The Gadsby Plant is a steam electric power generating facility consisting of six generation units rated at 66 megawatts (MW), 75 MW, and 100 MW, and three 40 MW Combustion Turbines yielding
a capacity of 361 MW. A CO2 injection system is used at Outfall 004 to control elevated pH readings that may result from biological growth in the settling ponds. The plant is currently
configured for operating all units on natural gas and has a Standard Industrial Classification (SIC) code 4911, for electric power generation. The design flow of this facility is 3.7
million gallons per day (MGD). A flow diagram of the system is appended in Attachment 1. Based on information obtained from facility representatives, there is no once-through cooling
water used at this facility (when used, cooling water is recirculated through the cooling tower until blowdown is required), and there is no discharge of metal cleaning wastes or chemical
metal cleaning wastes.
The Gadsby Plant currently consists of two discharge points, Outfalls 004 and 007.Outfall 004 discharges waste water from treatment ponds into the Salt Lake Abatement Canal. Outfall
007 discharges backwash water from the intake screento the Jordan River.
Cooling Water Intake Structure
This facility has a single cooling water intake structure (CWIS) that is subject to section 316(b) of the Clean Water Act.PacifiCorp has determined that the Gadsby Plant will operate
a closed-cycle recirculating system (CCRS) to reduce impingement and entrainment. Operating this system is consistent with the Clean Water Act section 316(b) rule’s approach to impingement
BTA standards (40 CFR 125.94(c)(1)). Operating a CCRS is one of the best technology available (BTA) alternatives for reducing impingement (40 CFR 125.94(b)&(c)). The Utah Division of
Water Quality (DWQ) has determined that additional monitoring for entrainment and impingement mortality (40 CFR 125.96(b) and (c)(2)) is not required.PUBLIC COMMENTSDuring the public
comment period provided under Utah Administrative Code (UAC) R317-8-6.5, any interested person may submit written comments on the draft permit and may request a public hearing if no
hearing has already been scheduled. A request for a public hearing shall be in writing and shall state the nature of the issues proposed to be raised in the hearing. All comments will
be considered in making the final decision and shall be answered as provided in UAC R317-8-6.12. Public comments are invited any time prior to the deadline of the close of business on
MONTHXX, 202X. Written public comments can be submitted to: Daniel Griffin, UPDES Individual Permits Section, Utah Division of Water Quality, PO Box 144870, Salt Lake City, Utah 84114-4870
or by email at:[e-mail] considering public comments, the DWQ may execute the permit issuance, revise it, or abandon it. The permit is available for public review under
“Public Participation” at www.waterquality.utah.gov/. If internet access is not available, a copy may be obtained by calling Daniel Griffin at [phone].
DWQ-2024-004
Check Permit.FSSOB for these words/terms and replace with
Department – Division or DWQ
closed- cycle recirculating system – CCRS