REV_Inspection_Report_Erlanger,_KY_2024R032_Tank_3_-_MLMDSS.pdf

LEVEL 2

TANK INSPECTION REPORT

CVG AIRPORT/PRIME ENGINEERING

CINCINNATI/NORTHERN KENTUCKY AIRPORT

2,000,000-GALLON SPENT DEICING FLUID SYSTEM TANK NO. 3

ERLANGER, KENTUCKY

CCR Job No. 2024R032 CROM Job No. 2001M042

Inspection Performed on July 1, 2024

1. Level 2 Inspection Report Sheets 1 - 14

This item has been electronically signed and sealed by Mike Miller, PE on September 30, 2024 using a

Digital Signature. Printed copies of this document are not considered signed and sealed and the signature must be verified on any electronic copies.

Michael L. Miller, P.E.

Senior Engineer IV

Kentucky License Number: 29604

CROM, LLC

250 SW 36th Terrace Gainesville, Florida 32607

2024R032, 2.0MG Spent Deicing Fluid System Tank 3, CVG Airport July 1, 2024 Level 2 Inspection Report 2 Erlanger, Kentucky

TANK NO. 3 INSPECTION REPORT

1.0 Introduction

CROM, LLC (“CROM”), conducted an inspection of the 2.0 MG Spent Deicing Fluid Storage Tank No. 3 in Erlanger, Kentucky on July 1, 2024. The purpose of the inspection was to evaluate the condition of the tank and its structural integrity. The goal was to determine what measures, if any, would be necessary to extend the useful life of the tank and modernize the safety appurtenances. This report fulfills the inspection requirement in accordance with AWWA D110 and ACI 350.

Chris Barton, Project Manager, performed the inspection and prepared this report under the review of Michael L. Miller, PE.

The Level Two inspection performed by CROM consisted of a comprehensive visual inspection of the tank interior and exterior, including accessories, to evaluate their structural integrity in accordance with all applicable codes and standards and to meet the requirements of AWWA D110 and ACI 350.

2.0 Scope of Work

The investigation included the interior walls of the tank, the dome, floor, and tank accessories. The inspection was a visual survey of the structure with five selective demolition coupons on the interior core wall, two coupons on the exterior wall, and 4 dome cores taken for further engineering analysis.

The tank was inspected in accordance with AWWA D110 and ACI 350 to evaluate the present condition of the tank structure.

The inspection was performed on the following tank:

2.0 MG Spent Deicing Fluid Storage Tank No. 3

115-0” ID x 26-9” SWD (CROM Job. No. 2001-M-042 Completed October 2001)

The tank was drained and cleaned by a CVG subcontractor prior to the interior inspection or CROM personnel entering the tank. CROM used an ambient air monitor to test the quality of air within the tank prior to entry.

The inspector was provided access to the dome roof. The concrete dome was inspected for any deterioration, cracking, efflorescence, spalled concrete, signs of corrosion, or other indicators of existing problems. Tank accessories were examined to determine the extent of the weathering of the material and the condition of the bolts, fasteners, and the screens. All penetrations were checked for signs of leakage into the tank.

The interior wall was observed, where possible due to an existing CIM coating system installed by others, for any deterioration, cracking, efflorescence, spalled concrete, signs of corrosion or other indicators of existing problems. Piping and internal accessories were checked for corrosion along with the condition of their supports, bolts, and anchors.

The entire tank structure was visually evaluated, in areas that are accessible and not coated with CIM, and a record was made of all observations. Photographs were taken as an additional record of the inspection.

Level 2 Inspection Report 3

3.0 Conclusions and Recommendations

The inspection of the prestressed composite tank did not reveal any apparent problems that would cause concern for the structural integrity of the tank itself. However, there are items that should be addressed in order to minimize the potential of future problems. Please refer to those items categorized as “Fair” or “Poor” below.

The report utilizes subjective terminology to rate the condition of various elements of the structure:

• Excellent - indicates like new condition, no remedial action required.

• Good - indicates minor defects, still operable.

• Fair - indicates an element or accessory requiring remedial action before the next scheduled 5-year inspection.

• Poor - indicates immediate action required.

Tank ID Plate

Photo

Foundation

Condition Rating Unknown

Assessment Unable to visually inspect the foundation due to existing backfill.

Recommendation No apparent remedial action required at this time.

Photos

Level 2 Inspection Report 4

Wall Manhole

Condition Rating Good

Assessment No defects noted on wall manhole.

Recommendation No remedial action required at this time.

Exterior Wall

Condition Rating Fair

Assessment Hollow (red circle), shrinkage cracks (red arrow), and corrosion on bottom of dome band noted on exterior wall. CROM performed a destructive investigation of the exterior wall while onsite where cracks were noted. The destructive investigation was performed to determine the integrity of the exterior wall. The destructive investigation was performed in accordance with standards specified in AWWA D110-13, Section

6.4.7. Shrinkage cracks noted on exterior wall with no sign of corrosion, thru-cracks only due to shrinkage/curing. Exterior wall found to be in fair condition.

Recommendation • Clean and seal cracks to prevent further water infiltration.

• Remove the hollow in the wall and dome band area and patch back with an appropriate coating system according to manufacturer's recommendation.

Level 2 Inspection Report 5

Dome Access Hatch

Assessment The tank is not equipped with a self-closing gate at the exterior ladder dome landing or a safety handrail system at the unprotected edges on the dome. Loss of protective coating system, bio-growth, and corrosion at lift lugs noted on access hatch cover.

Level 2 Inspection Report 6

Recommendation • Prepare the surface to remove bio-growth and corrosion stains and recoat the hatch cover with gelcoat.

• Replace the corroded lift lugs with stainless steel equivalent.

• Install a localized dome safety rail system equipped with a self-closing gate, around the dome access hatch to comply with OSHA standards.

Dome Probe

Assessment Cracks noted on dome probe curb. No other defects noted on dome probe.

Recommendation Clean and seal cracks to stop further infiltration of water.

Level 2 Inspection Report 7

Exterior Tank Dome Coating System

Assessment Exterior tank dome coating system found to be in good condition. Minor shrinkage cracking was observed.

Recommendation Clean and seal cracks to prevent further water infiltration.

Tank Dome

Condition Rating Poor

Assessment Due to known deterioration on the interior of the dome, four dome cores were taken about 10 feet above each emergency overflow for further engineering analysis. The core holes were cleaned and formed during a destructive investigation of the exterior dome while CROM was onsite where cracks were noted. The destructive investigation was performed to determine the integrity of the exterior tank dome. The destructive investigation was performed in accordance with standards specified in

AWWA D110-13, Section 6.4.7. Shrinkage cracks noted on exterior tank dome with no sign of corrosion, thru-cracks only due to shrinkage/curing.. Dome core results show pH average 6.33 and the average compressive strength result was 7,823 psi.

Interior Surface Deterioration (see attached comprehensive report):

The cement paste in the near-surface concrete is very absorptive and weak, with little inherent strength. The poor-quality cement paste contains gypsum deposits at depths ranging from 0.5 to 1.5 mm. The surface deterioration is related to acid attack, although exposure to glycol solutions is not directly deleterious. However, propylene glycol can degrade in the presence of oxygen, forming acids like glycolic, formic, acetic, and oxalic acid.

The petrographic examination displayed symptoms of possible sulfuric acid attack and Microbiologically Influenced Corrosion (MIC). However, the chemical analysis of the cores did not confirm sulfuric acid as the cause of the deterioration. It did confirm that an acid attack is occurring, but the exact type of acid remains unknown.

In Core #3 and the tank's near-surface concrete, gypsum deposits suggest a connection to sulfuric acid, potentially due to MIC. The leaching of calcium and sulfate during the acid attack formed gypsum, which can further lead to sulfate attack. While

Level 2 Inspection Report 8 bacterial growth likely contributed to sulfuric acid formation, the exact type of acid causing the distress remains undetermined.

Recommendation Crom recommends removing the low pH surface of concrete and installation of an appropriate interior coating system on the interior of the dome, according to the manufacturer’s recommendation.

Emergency Overflow Openings

Assessment Cracks noted on precast overflow housing. No other defects noted on emergency overflow openings.

Recommendation Clean and seal cracks to prevent further water infiltration.

Level 2 Inspection Report 9

Lightning Protection Equipment

Assessment No defects noted on lightning protection system.

Exterior Ladder

Assessment Absent exterior ladder safety system noted.

Recommendation Install new aluminum ladder system equipped with an OSHA-compliant ladder safety system.

Level 2 Inspection Report 10

Interior Ladder

Assessment Absent interior ladder safety system noted.

Recommendation Install new stainless steel ladder system equipped with an OSHA-compliant ladder safety system. Coat stainless steel ladder with the same coating system that was used on the wall manhole on the interior of the tank.

Tank Floor

Assessment Floor coated by others appeared to be installed over exposed aggregate, which suggests that concrete loss and possible section loss had occurred before coating installation. Previously repaired areas to CIM noted on tank floor. No other defects noted on tank floor.

Recommendation No remedial action required at this time, monitor condition at next scheduled inspection.

Level 2 Inspection Report 11

Floor Wall Connection

Assessment Floor wall connection coated with CIM noted.

Interior Tank Walls

Assessment Cracks and hollows noted throughout interior tank wall. CROM performed a destructive investigation of the interior wall while onsite of five coupons where cracks and hollows were noted. The destructive investigation was performed to determine the integrity of the diaphragm. The destructive investigation of the interior corewall showed minimal cover (¼” to ½”) over the steel shell diaphragm and the cracks went through the inside core wall and corroded steel shell diaphragm into the outside core wall. Remaining shotcrete appeared to be deteriorated and flaking off the corroded steel shell diaphragm under the failed coating system. Coating system appeared to be installed over exposed aggregate on the surface of the inside corewall, suggesting that the paste and section loss occurred prior to the surface preparation and coating installation. Areas were cleaned, prepared, and patched back according to

Level 2 Inspection Report 12 manufacturer’s recommendation. The destructive investigation was performed in accordance with standards specified in AWWA D110-13, Section 6.4.7.

Recommendation Remove failed interior coating system. Reinspect walls and floor/wall joint. Repair cracks. Prepare surface and install an appropriate interior coating system.

Level 2 Inspection Report 13

Interior Piping

Assessment Pipe coated by others with CIM coating system. Corrosion was noted coming from inside interior piping and three missing bolts were noted on pipe flange.

Recommendation • Prepare the surface of the interior pipes and apply an appropriate coating system.

• Replace missing hardware with 316 stainless steel hardware.

Level 2 Inspection Report 14

Interior Tank Dome

Assessment Noted loss of concrete, spalls, and corrosion with exposed reinforcement and bolster feet noted on interior tank dome.

Recommendation • Prepare the surface of interior dome removing coating system and cleaning any corroded exposed reinforcement.

• Repair interior tank dome by squaring off and chipping back the concrete to provide a minimum depth of ¼”.

• Apply a rust-inhibiting coating system to structural steel according to the manufacturer’s recommendation.

• Patch back with an appropriate cementitious surface repair system according to the manufacturer’s recommendation.

• Apply an appropriate coating system according to the manufacturer’s recommendation.

Level 2 Inspection Report 15

Next Inspection: CROM recommends a Level 2 Inspection by June 28, 2029, in accordance with AWWA and ACI 350.

The inspection performed by CROM was a visual survey of the structure interior and exterior with minor selective destructive tests. Therefore, CROM cannot offer an opinion on the condition or performance of the covered or hidden elements of the structure not visible from the surface.

The preceding report is submitted for your review and discussion. We would be pleased to discuss the results with you. If you have any questions or concerns, please do not hesitate to contact us.

Chris Barton

Project Manager