[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]


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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.

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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