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.