DERR-2024-012090

Memorandum

6440 South Millrock Drive
Suite 300
Holladay, UT 84121
United States
www.jacobs.com

1

Subject 2023 Annual Cofferdam and Soil Cover Inspection Report
Attention Ken Wangerud/USEPA
Mazie Cox/UDEQ
Justin Anderson/Ogden City
From Terence Mares/Jacobs
Date October 26, 2023
Copies to Becky Rewey/UPRR

This document presents the findings from the annual inspection of the Union Pacific Railroad (UPRR)
Ogden Railyard, Operable Unit 1 cofferdam and soil cover, that occurred on September 14, 2023. This
inspection was conducted to comply with section 5.f.ii of the Environmental Covenant. The inspection was
completed by Terence Mares (Jacobs) on UPRR’s behalf. Mazie Cox (UDEQ) and Ryan Parent (Ogden City
Area Maintenance Supervisor) were in attendance for the annual inspection. A completed cofferdam and
soil cover inspection form (Attachment 1) and representative photo log (Attachment 2) are attached.
Summary of Inspection
Each component of the cofferdam structure was inspected. Observations on the appearance and
condition of each component have been documented in the attached table and photographs are
presented in the attached photo log.
The rip-rap section was intact but has vegetation is coming up through the rip-rap (Photos 1 and 2). The
limited vegetation shown in Photo 2 was cut down by Ogden City on September 27, 2023 (Photo 3). The
soil cover east of the rip-rap also had vegetation coming up. Ogden City continues to handle the
vegetation coming up through the rip-rap by mechanically cutting the vegetation. The soil cover was
moist. (Note: The remedial design was for this soil cover to be submerged, but Ogden City has given
permission to the water ski company using the pond to maintain a lower water elevation and therefore
leaving the soil cover exposed and dry.) There was no evidence of subsidence or cracking of the soil cover.
The drainage slope continues to be to the west toward the pond as it has historically been.
The inlet control structure was blocked by a tarp (Photo 4) which was installed by Goode Ski Group (they
use the pond for testing water ski equipment). Ogden City has contacted the company and is working with
them to remove the tarp. The inlet piping had flow into the pond and was not blocked and in good
condition (Photo 6).
The north and south manhole access covers over the drain line vaults were in place and secure (Photo 5).
A dual phase water level probe was used to tag the bottom of each the sump and no hydrocarbon DNAPL
was visually detected, on the probe, in either vault.
2023 Annual Cofferdam and Soil Cover Inspection Report
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The Restricted Access signs and posts located in the cofferdam area were upright and in good condition
(Photo 7). The cable holding the buoys and signage across the pond was intact and facing in the correct
direction (Photo 8).
The perimeter fencing was in good condition and was not compromised. All gates around the soil cover
and cofferdam were intact and locked (Photo 9).

Attachment 1
Cofferdam and Soil Cover Inspection Form
Cofferdam and Soil Cover Inspection 21st Street Pond, Ogden, Utah
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Item Inspection Criteria Observation Recommended Action Corrective Action Taken
1.Inlet Structure
Inlet Control Structure Functional and clear of debris?
Structure inlet plugged with
debris?
Functional – No
Clear of debris – No
Yes; Plastic tarp placed over
Inlet.
Remove plastic trap placed over inlet
Remove plastic trap placed over inlet
Ogden City has contacted
Goode Ski Group and are
working with them to have it
removed.
Ogden City has contacted
Goode Ski Group and are
working with them to have it
removed.
2.Rip Rap
Rip Rap Rip rap in place and intact, even
across west face of cofferdam?
Rip rap missing?
YES - Vegetation coming up
through rip-rap.
No
Continue mechanical removal of
vegetation
NO ACTION
Ogden City cut down remaining
vegetation
3. Cover Integrity East of Cofferdam
Soil Cover – Moist Is soil cover submerged? No NO ACTION
Inspection Date: September 14, 2023
Inspector: Terence Mares Signature:
Cofferdam and Soil Cover Inspection 21st Street Pond, Ogden, Utah
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Item Inspection Criteria Observation Recommended Action Corrective Action Taken
4.Manholes
Manhole Access Covers Access covers in place and
secure?
Access covers loose and/or
unsecured?
YES
NO
NO ACTION
NO ACTION
Manholes Gauged For
Presence of DNAPL
DNAPL in North manhole?
DNAPL in South manhole?
NO
NO
NO ACTION
NO ACTION
5. Cover Integrity East of Cofferdam
Soil Cover – Moist Evidence of subsidence and
ponding?
Drainage slope not maintained
and/or not sloping to west?
Desiccation cracking?
Burrow holes?
NO
Based on visual inspection the
slope is to the west.
NO
NO
NO ACTION
NO ACTION
NO ACTION
NO ACTION
Soil Cover – Moist –
Cover Vegetation
Coverage uniform across soil
cover?
Bare areas or dead vegetation?
YES - Vegetation coming up
through rip-rap.
NO
Continue mechanical removal of
vegetation
NO ACTION
Ogden City cut down remaining
vegetation
Cofferdam and Soil Cover Inspection 21st Street Pond, Ogden, Utah
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Item Inspection Criteria Observation Recommended Action Corrective Action Taken
6.Discharge Piping
Groundwater Discharge
Pipes
Pipe ends intact and
undamaged?
Pipes damaged?
Discharge from pipes flowing
freely?
Pipes plugged?
YES
NO
YES
NO
NO ACTION
NO ACTION
NO ACTION
NO ACTION
7.Soil Cover and Cofferdam Security
Perimeter Fence and
Signage
Fence intact and secure?
Fence fabric broken or cut?
Fence posts upright and firmly
anchored?
Posts loose and/or tilted?
Signs intact?
Sign(s) missing or damaged?
YES
YES
NO
YES
NO
YES
NO
NO ACTION
NO ACTION
NO ACTION
NO ACTION
NO ACTION
NO ACTION
NO ACTION
Gates and Locks Gates/locks intact and operable?
Gates inoperable?
Locks inoperable?
YES
NO
NO
NO ACTION
NO ACTION
NO ACTION

Attachment 2
Photograph Log

Photograph Log

Jacobs Engineering Group Inc.
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Project Title 2023 Annual Cofferdam and Soil Cover Inspection Report
Location Ogden, Utah
Date October 26, 2023

Photo 1: Overview of the cofferdam and vegetation coming up through rip-rap.

Photo 2: Trees coming up near rip-rap to be removed.

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Photo 3: Current condition of the cofferdam rip-rap with remaining vegetation and trees mechanically
cut down.

Photo 4: Inlet to pond from the Ogden River blocked by tarp installed by Goode Ski Group.

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Photo 5: View of the northern vault. Both the north and south manhole covers are intact and vaults
have no presence of DNAPL.

Photo 6: Inlet into the pond. Free of debris.

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Photo 7: Typical restricted area sign attached to T-Post inside fenced area.

Photo 8: Overview buoys and signage across the pond.

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Photo 9: North access gate secured and operable. All gates were locked and operable.