RIVER STAGE MONITORING
Page 1 of 6
Former Frenchtown Mill
Observer: J. Peterson
Project 350.0065.001
Date / Time: 5/10/18 1340-1520
Clark Fork River Berm
Weather: Cloudy, 61 degrees F
Clark Fork Discharge at USGS Gage 12353000 (cfs): 45,200 - 42,700
.. | M C W F l l C i S
GENERAL COMMENTS/OBSERVATIONS
Site observations today are similar to those documented by D. Hoffman on 8 May 2018. The mill caretaker is on site 3-4 days per week and is keeping an eye on the river stage at the site. NewFields will continue to monitor the berm throughout the spring runoff period. Photo point and staff gage locations are shown on Figure 1.
The Clark Fork River (CFR) is currently above bankfull and inundating floodplain areas. Floodwaters have reached the bottom of CFR berm along the site in many locations between Photo Point 1 and Photo Point 9.
Flow velocities along CFR berm are relatively low except in Photo Point 8 area where the river has not reached berm and in Photo Point 9/CFR-2 area where velocities are moderate.
No evidence of CFR Berm erosion was observed on either the 'dry' (mill)or 'wet' (river) side of berm.
Soil investigation locations (completed in Dec 2017) along CFR Berm were checked and no evidence of erosion was observed.
Outfalls 1, 2 and 3 were observed and photographed. No issues noted.
No cracks observed along the CFR berm, or other indications of geotechnical issues resulting from high water conditions.
CFR water surface elevations were 6 feet or more below top of CFR Berm elevation over entire length of the Berm. In most locations the berm had more than 6 feet of freeboard.
Clear, pooled water was observed at several locations along the 'dry' side of the berm; however, no observations of sand boils noted along the toe of berm which would indicate internal erosion/piping processes due to through- or under-seepage. The storage ponds on the mill side of the berm are largely dry. Less than 12-inches of water was present in the pooled areas.
Sierra Club v. EPA 18cv3472 NDCA
Tier 10
ED 002061 00090265-00001
RIVER STAGE MONITORING
Page 2 of 6
Site: Photo Point 1 Date/Time: 5/10/18 14:20 Staff Gage (ft): N/A Location: N 46.95066 W 114.20983 Comments: Looking northwest. Southwest corner of HP2.
PHOTO LOG
SMewFields
Site: Photo Point 2 Date/Time: 5/10/18 14:25 Staff Gage (ft): N/A Location: N 46.951097 W 114.213278 Comments: Looking east. South of HP2.
Sierra Club v. EPA 18cv3472 NDCA
Tier 10
ED 002061 00090265-00002
RIVER STAGE MONITORING
Page 3 of 6
Site: Photo Point 3 Date/Time: 5/10/18 14:25 Staff Gage (ft): 1.65 Location: N 46.95146 W 114.21378 Comments: Looking northwest. West side of HP2, second staff gage. River is turbid.
SMewFields
Site: Photo Point 4 Date/Time: 5/10/18 14:35 Staff Gage (ft): N/A Location: N 46.95341 W 114.21720 Comments: Looking north. West side of HP2.
Sierra Club v. EPA 18cv3472 NDCA
Tier 10
ED 002061 00090265-00003
RIVER STAGE MONITORING
Page 4 of 6
Site: Photo Point 5 Date/Tme: 5/10/18 14:40 Staff Gage (ft): Below gage Location: N 46.95862 W 114.21883 Comments: Looking south. Located at outfall 1, west side of HP2/HP7. Gage installed on concrete structure on 7/27/17.
PHOTO LOG
SMewFields
Site: Photo Point 6 Date/Time: 5/10/18 14:42 Staff Gage (ft): N/A Location: N 46.96022 W 114.21975 Comments: Looking north. Southwest side of HP11.
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Sierra Club v. EPA 18cv3472 NDCA
wmmmi Tier 10
ED 002061 00090265-00004
RIVER STAGE MONITORING
Page 5 of 6
Site: Photo Point 7 Date/Time: 5/10/18 14:45 Staff Gage (ft): N/A Location: N 46.96448 W 114.22173 Comments: Looking north. West side of H P ll.
PHOTO LOG
SMewFields
Site: Photo Point 8 Date/Time: 5/10/18 14:50 Staff Gage (ft): Below gage Location: N 46.97270 W 114.22433 Comments: Looking north. West side of HP12.
Sierra Club v. EPA 18cv3472 NDCA
Tier 10
ED 002061 00090265-00005
RIVER STAGE MONITORING
Page 6 of 6
Site: Photo Point 9/CFR-2 Date/Time: 5/10/2018 15:00 Staff Gage (ft): above gage Location: N 46.97682 W 114.22689 Comments: Looking north. West side of HP13a. River gage submerged. A transducer is present at this gage site and stage data will be collected when the gage becomes accessible.
PHOTO LOG
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Sierra Club v. EPA 18cv3472 NDCA
Tier 10
ED 002061 00090265-00006
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LEGEND
C I P hoto Point Photo Point with Staff Gage
Staff Gage with Transducer M! Site Boundary 100-Year Floodplain*
Aerial Photo Source: N AIF 201 ! and Newfields 2016 (W ithin Site Boundary)
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SNewFields
^Floodplain Source: As defined by the Federal Emergency Management Agency (FEMA) 2013 Digital Flood Insurance Rate Map (DFIRM). (N FIP 20 I3 )
Notes
AG - Agricultural Land AB - Aeration Stabilization Basin CFR - Clark Fork River C L - Clarifier FP - Rood plain HP - Holding or Storage Pond IB - Rapid Infiltration Basin NPP - N orth Polishing Pond
P - Settling Pond SB - Spoils Basin SPP - South Polishing Pond SW B - Solid Waste Basin W R - W est of River
Sierra Club v. EPA 18cv3472 NDCA
Tier 10
Clark Fork River Stage Monitoring Sites Former Frenchtown Mill Site Missoula County, Montana FIGURE 1
ED 002061 00090265-00007