[Federal Register Volume 59, Number 78 (Friday, April 22, 1994)] [Unknown Section] [Page 0] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 94-9724] [[Page Unknown]] [Federal Register: April 22, 1994] ----------------------------------------------------------------------- DEPARTMENT OF THE INTERIOR Yellowtail Afterbay Dam Water Quality Study, Yellowtail Unit, Lower Bighorn Division, Pick-Sloan Missouri Basin Program, Montana AGENCY: Bureau of Reclamation, Interior. ACTION: Notice of cancellation of a notice of intent to prepare a draft environmental impact statement. ----------------------------------------------------------------------- SUMMARY: The Bureau of Reclamation (Reclamation) is canceling plans to prepare a draft environmental impact statement (DEIS) for the Yellowtail Afterbay Dam Water Quality Study. A notice of intent was published by Reclamation for the proposed DEIS in the Federal Register, 58 FR 30181, May 26, 1993. The DEIS intended to focus on structural alternatives to correct supersaturated levels of dissolved gases, primarily nitrogen, in the Bighorn River. In the interim, however, experimental operational changes and downstream monitoring were instituted to determine if a simpler solution would alleviate the problem. Subsequent monitoring showed that the operational changes did in fact minimize the supersaturation problem. By continuing to refine operational adjustments and monitoring the resulting changes in saturation levels, Reclamation believes compliance with the Administrative Rules of Montana for Owners and Operators of Water Impoundments can continue to be achieved. FOR FURTHER INFORMATION CONTACT: Kip Gjerde, Acting Chief, Planning Liaison and Special Projects Division, Great Plains Region, Bureau of Reclamation, GP-770, PO Box 36900, Billings MT 59107-6900; telephone: (406) 657-6193. SUPPLEMENTARY INFORMATION: The Bighorn River is a world class fishery with large numbers of rainbow and brown trout. Discharges from Yellowtail Afterbay Dam have been shown to supersaturate the water with atmospheric gases as the water is released downstream. This gas supersaturation problem can cause fish mortality if gas in the water exceeds toxic levels. As owner and operator of Yellowtail Dam and Afterbay, Reclamation was notified of this water quality problem in June 1984 by the Montana Department of Health and Environmental Services (MDHES), and was asked to comply with Sec. 16.20.632 of the Administrative Rules of Montana for Owners and Operators of Water Impoundments. These rules require that owners and operators of water impoundments operating prior to 1971 demonstrate to the satisfaction of MDHES that operations are conducted to minimize harmful effects. Studies on the effects of dissolved gases on the fishery downstream were conducted under a Reclamation contract to help define the overall issues related to the operation of the dam and gas supersaturation problems. In 1991, results were published by Montana State University, in conjunction with the Fish and Wildlife Service and the Montana Department of Fish, Wildlife, and Parks. Water quality data taken upstream and downstream from the afterbay dam identified the structure as the major contributor to elevated dissolved gases downstream. Experimental operational changes along with downstream monitoring were instituted to see if a less drastic solution other than structural modifications could relieve the problem. By making these operational changes, the supersaturation problem was actually minimized without structural modifications to the facility. Further planning for physical modification of the afterbay dam has been suspended pending evaluation of continued operational changes. Improvements in the gas supersaturation problem continue to be documented. Reclamation believes this approach will comply with Montana water quality standards, address the gas supersaturation problem, and satisfy public concern over potential damage to the fishery. Dated: April 15, 1994. Donald R. Glaser, Acting Director, Program Analysis Office. [FR Doc. 94-9724 Filed 4-21-94; 8:45 am] BILLING CODE 4310-94-M