Agenda Item
viii. Ratification ~ Emergency Purchase ~ K.E.G. Plumbing and Mechanical, Inc. ~ Emergency Sinkhole Repair (Not to Exceed $992,000)
Summary: Presented By: Mr. Erick Hofstetter, Chief Operating Officer, Division of Operations
Request: It is requested that the DeKalb County Board of Education approve the ratification of the emergency spend amount to K.E.G. Plumbing & Mechanical, Inc. for emergency repair of the sinkhole at the Administrative Instructional Complex (AIC) at an amount not to exceed $992,000.
Why: This request is to acknowledge the ratification of an emergency purchase/repair by K.E.G. Plumbing & Mechanical, Inc for the sinkhole at AIC.
Details: On Tuesday, June 10, 2025, a sinkhole began to form at AIC. K.E.G. Plumbing & Mechanical, Inc., an awarded vendor under ITB No. 20-752-037, began work to repair the damage. This was declared an Emergency Repair.
The work was completed in four (4) phases:
Phase 1 Emergency Response and Site Access Scope: Reopening of the site entrance - Completed: Week of June 30, 2025.
Phase 2. Transmission Vault Installation Activity: Delivery and installation of the new engineered transmission vault - Completed: July 18, 2025.
Phase 3. Surface Restoration and Site Finishing - Start Date: August 1, 2025.
Scope: Asphalt capping. Installation of curb, gutter, and sidewalks Final grading and landscaping. General site restoration and cleanup.
Phase 4. Pond Rehabilitation and Fence Replacement Timeline: August 2025 through September 2025. Scope: Restoration of the pond area and replacement of all impacted fencing. Final Project Completion Date: September 2025.
Financial impact: The total contract amount for these services in the amount not to exceed $992,000 will be allocated from the General Fund Budget, Deferred Maintenance
(100.2600.543013.00011.7520.9990.8013.040.0000).
Contact: Mr. Erick Hofstetter, Chief Operating Officer, Division of Operations, 678.975.5924
Mr. Bobby Moncrief, Director of Facilities, Division of Operations, 678.676.1478
Effective: Upon Board Approval
Status: Approved by the Office of Legal Affairs
K.E.G. Plumbing & Mechanical, Inc.
“Keeping Everything Going”
63 Duncan Circle – Hiram, GA 30141
Phone: 770-445-2224 Fax: 678-383-3882
E-mail: service@kegplumbing.com
AIC – Initial Findings
1701 Mountain Industrial Boulevard – Stone Mountain, GA
Summary of Observations (as of June 18, 2025)
Primary Issue
• A 72” corrugated metal pipe (CMP) has separated from the structure at the storm drain basin
near entrance.
• This separation is located near the curb inlet and has led to underground soil
loss and subsidence.
Contributing Factors
1. Pipe Deterioration:
• The bottom of the 72” CMP is rusted and deteriorated, likely due to age and prolonged
exposure to moisture.
2. Silt Accumulation:
• The retention pond is over capacity with silt, reducing its ability to manage stormwater
effectively.
3. Flood Gate Failure:
• The emergency flood gate is broken and stuck shut, causing the underground system to
act as an overflow during heavy rain.
4. Hydraulic Overload:
• During storms, water follows the path of least resistance, exacerbating erosion and
structural failure.
Additional Findings
• The retention pond outlet leads to a vertical drop within 30’ of the collapsed CMP.
• An existing structure drops approximately 20’ into an underground transmission vault, which sits
atop an older vault (pre-dating Dekalb County records).
• This system continues another 20’ down into a stone and cement aqueduct, suggesting a historic
or legacy drainage system.
Resolution
1. Install Cofferdam due to heavy downpours and upcoming periods of rainfall, during this
installation we had multiple affected utilities re-located out of the affected work area. These
utilities included phone and fiberoptic. (Complete)
2. Replace existing piping as needed, possibly all of piping under entrance and connect to upstream
catch basin and curb inlet. (Complete)
3. Bridge entire affected area with erosion matting after being properly shored and all areas exposed
as applicable. (Complete)
4. Install No. 57 stone to establish a settlement base. (Complete)
5. Continue installing temporary piping through cofferdam and re-connecting drainage system to
retention pond. (Complete)
6. Backfill and compact in 12” lifts with suitable soils including clean red clay in the dam area.
(Complete)
7. Open existing flood gate to allow maximum flow during heavy rainfall. (Complete)
8. Investigate the cause of underground failures in depth. (Complete)
9. Re-bridge areas as they are sinking and stabilize the affected area to minimize additional erosion.
(Complete)
10. Create an erosion and maintenance plan for long term duration of project. (In-Progress)
Inspection of vertical outlet and downstream outlet
1. Completed inspection June 16, 2025, of vertical outlet and downstream outlet.
2. As captured images show the two vaults were not joined or sealed together, the upper-level vault
was set over atop of the existing structure and there is a 12” gap from the exterior point to the
interior point of the structures that will need to be sealed and caulked.
3. The outlet pipe of the retention pond penetrates the vault that we will be sealing and caulking as
well. By doing so this will convey the water to the interior portion to the lower-level system.
4. Before we entered the lower-level system, the images show that the upstream portion of the
legacy drainage system had been condemned and caved in. We believe this occurred when the
retention pond was created and the surrounding land parcels were re-developed. The means in
which they capped, bridged and sealed the upstream portion of this vault has failed.
5. We will be entering the lower-level basin and forming and casting a permanent concrete cap or
plug that shall be 12” thick re-enforced with rebar to stop any further erosion or soils entering this
system. Our inspection of this structure to the horizontal downstream appears to be in good
condition given its age. We will conduct another inspection with the robotic camera later this
week to determine where it terminates and the impact on the termination area.
We have ordered the new catch basin and are working with our supplier to expedite manufacturing
this structure. We are expecting this structure to be completed and delivered within two weeks.
Our current goal is to have the road re-opened with sidewalk, curb and gutter poured back no later
than the second week in July, if we do not encounter any unforeseeable hazards. We will then start
the rehabilitation of the retention pond.
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Tuesday 6/10/2025 – 9:00am
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Tuesday 6/10/2025 – Afternoon after rainstorm
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Tuesday 6/10/2025 – Afternoon after rainstorm
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Wednesday – 6/11/2025 - Cofferdam Installation
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Wednesday – 6/11/2025
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Wednesday – 6/11/2025 – Removal of collapsed structure, street, and 72” CMP & Installing
containment fencing.
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Wednesday – 6/11/2025 – First inspection of remaining 72” CMP. Stabilized area so crews could
safely enter.
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Wednesday – 6/11/2025 – 1’:2’ egress slope created for entry.
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Wednesday – 6/11/2025 – Downstream riser to existing aqueduct system.
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Thursday – 6/12/2025 – Morning – Found road separated after rainstorms throughout the night it has
eroded away and must be removed.
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Thursday – 6/12/2025 – Installation of new 60” CMP under entire entrance to stop any more erosion
below roadway and connected to immediate upstream basin.
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Friday – 6/13/2025 – Installation of bridging matting and connection to retention pond. Removed
cofferdam.
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Friday – 6/13/2025 – Replacing retention pond dam and bedding in new 60” CMP.
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Friday – 6/13/2025 – Image of progress on Friday.
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Friday – 6/13/2025 – Continuation of work progress.
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Friday - 6/13/2025 – First time entering sub-level basin.
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Monday – 6/16/2025 – Safety check for confined space entry.
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Monday – 6/16/2025 – Inlet side of lower-level vault was not properly capped or plugged.
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Monday – 6/16/2025 – Downstream outlet of lower-level vault. Upon this inspection the system was
found to be in good working condition.
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Tuesday – 6/17/2025 – Erosion Control
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