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
Designated Use B-2 B-3 E-2
Aquatic Life *
Fishes (salmonid) *
Fishes (non-salmonid)
Agriculture
Industry
Drinking Water
Wildlife
Recreation
*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
Site 1
Site 2
Site 3
Site 4
Site 5
Site 6
##
#
# #
#
Site 1 Above confluence, DFMR
Site 3
Unnamed tributary
Site 4
Unnamed tributary below discharge
Site 5
Discharge pipe
Site 6
Above lagoons
Site 2
Downstream of confluence, DFMR
B-2
B-3
Data Collection
Flow Fish Temperature Photos Water Quality Sampling
Study period: June-October, 2006
Site 6
• Flow
• Temperature logger
• Macroinvertebrates
• Water samples
Around the Lagoons
Site 5
•Flow (supplied by Conrad)
•Water samples
After the Pipe
Conrad Sand & Gravel
Site 4
• Flow
• Temperature logger
• Macroinvertebrates
• Fish
• Water samples
Site 3
• Flow
• Temperature logger
• Macroinvertebrates
• Fish
• Water samples
The Confluence
Confluence Continued
Site 1
• Flow
• Temperature logger
• Macroinvertebrates
• Fish
• Water samples
Site 2
• Flow
• Temperature logger
• Macroinvertebrates
• Fish
• Water samples
Electrical Conductivity Results
0
500
1000
1500
2000
2500
3000
3500
4000
EC
(um
ho/c
m)
July
August
September
October
Above Lagoons Discharge Pipe Below Lagoons
Tributary Below Spring
Downstream Confluence (DFMR)
Upstream Confluence
JuneJuly
AugustSeptember
October0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Flo
w (
cubi
c ft
/sec
)
Flow for the Unnamed Tributary
Above Lagoons Discharge Pipe
Below Lagoons
Tributary Below Spring
Site Temperatures
38.2
3230.6
27.5 27.5
9.5
4.9
1.2
4.8 4.8
16.5 17.1
13.7
17.1 17.2
0
5
10
15
20
25
30
35
40
45
Tem
pera
ture
(˚C
)
High
Low
Average
Above Lagoons Below Lagoons Tributary Below Spring
Downstream Confluence
Upstream Confluence
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 shinerbrook stickleback brassy minnowlongnose dace lake chubwhite 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.