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Use Attainability Analysis City of Conrad. Ann Harrie and Bob Bukantis WQS Section, MT DEQ June 28, 2007. The Situation. Conrad WWTP discharges into unnamed tributary Tributary flows into Dry Fork of Marias River (DFMR) Both are classified as B-2, part of Marias Watershed
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Use Attainability Analysis City of Conrad Ann Harrie and Bob Bukantis WQS Section, MT DEQ June 28, 2007
The Situation • Conrad WWTP discharges into unnamed tributary • Tributary flows into Dry Fork of Marias River (DFMR) • Both are classified as B-2, part of Marias Watershed • Suggested reclassification of receiving waters (unnamed tributary) from B-2 to E-2 • Community looking to reduce cost of WWTP upgrade by avoiding unnecessarily stringent effluent limits
Changing Classifications • DFMR changes from B-2 to B-3 less than ½ mile from confluence (1981) • Must show the tributary and receiving waters were originally misclassified (75-5-302,MCA) • Significant differences between B-2 and E-2
Designated Uses for B-2, B-3 and E-2 *Indicates marginal use
Preliminary Site Visit – April 2006 Source: "The Inland Fishes of New York State" by C. Lavett Smith, published by the New York State Department of Environmental Conservation, 1985.
The Study Objectives • Determine whether tributary was ephemeral or perennial • Determine existing & potential use support • Provide quality data
B-3 B-2 Site 1 Site 2 Site 3 Site 5 Site 4 Site 6 Site 1 Above confluence, DFMR Site 2 Downstream of confluence, DFMR # # Site 5 Discharge pipe # Site 3 Unnamed tributary # # Site 4 Unnamed tributary below discharge # Site 6 Above lagoons
Data Collection • Flow • Fish • Temperature • Photos • Water Quality Sampling Study period: June-October, 2006
Site 6 • Flow • Temperature logger • Macroinvertebrates • Water samples
Site 5 • Flow (supplied by Conrad) • Water samples
Site 4 • Flow • Temperature logger • Macroinvertebrates • Fish • Water samples
Site 3 • Flow • Temperature logger • Macroinvertebrates • Fish • Water samples
Site 1 • Flow • Temperature logger • Macroinvertebrates • Fish • Water samples
Site 2 • Flow • Temperature logger • Macroinvertebrates • Fish • Water samples
Brown Trout Lethal Limit (27.2) Rainbow Trout Lethal Limit (24.3)
Fish and Aquatic Life • Fish and aquatic life were found throughout the DFMR and the unnamed tributary • Fishes found: fathead minnow spottail shiner brook stickleback brassy minnow longnose dace lake chub white sucker • NO salmonids
Other Uses • Industry • Agriculture • Recreation – potentially • Drinking water - potentially
Overview of Findings • Original classification suggestion was E-2 • Flow & conductivity data suggest perennial flow • E-2 classification not appropriate • Tolerant fish & other aquatic life • Water temperatures too high for marginal propagation & growth of salmonids • Suggest reclassifying tributary to B-3 • Suggest that cutoff for B-3 be moved upstream to Hwy 91
Options • Reclassify the waterbody to a B-3 to reflect existing conditions - Data supports this (temperature, fish) - Conrad supports this • Retain current B-2 classification
Thoughts/Suggestions? References: Bear, E.A. May 2005. Effects of temperature on survival and growth of westslope cutthroat trout and rainbow trout: implications for conservation and restoration. Thesis for degree in Fish and Wildlife Management, Montana State University. Raleigh, R. F., L. D. Zuckerman, and P. C. Nelson. 1986. Habitat suitability index models and instream flow suitability curves: Brown trout, revised. U.S. Fish Wildl. Serv. Biol. Rep. 82(10.124). 65 pp. [First printed as: FWS/OBS-82/10.71, September 1984-J.