Omaha Public Power District (OPPD) Cass County Station Units 1-5

NOTICE OF PERMIT ISSUANCE

The Nebraska Department of Water, Energy, and Environment (DWEE) proposes to modify the National Pollutant Discharge Elimination System permit (NPDES) to the Omaha Public Power District (OPPD), 444 S. 16th Street Mall, Omaha, NE d/b/a OPPD Cass County Station Units 1-5, 3520 Mill Road, Plattsmouth, NE. (NPDES# NE0133205; SIC 4911). The current Cass County Station consists of two natural gas-fired simple cycle turbines and three dual-fuel single-cycle combustion generators that provide energy during intermittent peak electrical power demand. Non-process wastewater is discharged through Outfall 001 to Fourmile Creek, Segment LP1-10300 in the Lower Platte River Basin. OPPD Cass County Station plans to expand to include three new dual-fuel single-cycle combustion generators, bringing the total number of units on the site to five. The units will be able to operate on natural gas or fuel oil. OPPD is installing a larger water plant which will utilize reverse osmosis to treat groundwater to support the operation of the three new units. This water plant is expanding its discharge in the proposed permit modification, and the permit is modifying requirements for the discharge. The modification will not change the expiration date of the permit and will continue to restrict pollutant discharges to comply with the requirements of Department regulations. The draft permit, fact sheet, and other public information are available for review and copying at DWEE’s Lincoln Office, 245 Fallbrook Boulevard, Suite 100, Lincoln, Nebraska 68521 between 8:00 a.m. and 5:00 p.m. (CT), weekdays, excluding holidays. To request copies of the draft permit and other information, call 402-471-3557. Individuals requiring special accommodations or alternate formats of materials should notify the Department by calling 402-471-2186. TDD users should call 800-833-7352 and ask the relay operator to call the Department at 402-471-2186. Written comments, objections, and/or hearing requests concerning permit issuance may be submitted to NPDES and State Permits Section, Nebraska Department of Water, Energy, and Environment, 245 Fallbrook Boulevard, Suite 100, Lincoln, NE 68521; before the comment period ending date of September 20, 2026. A determination to hold a hearing will be based upon factual environmental or regulatory consideration. The Nebraska DWEE does not discriminate on the basis of race, color, national origin, disability, age, or sex in administration of its programs or activities, and DWEE does not intimidate or retaliate against any individual or group because they have exercised their rights to participate in or oppose actions protected/prohibited by 40 C.F.R. Parts 5 and 7, or for the purpose of interfering with such rights.