CVG_OWS_Report_01212022.pdf

Kenton County Airport Board

Cincinnati/Northern Kentucky International Airport

Oil Water Separators Condition Assessment Report

December 2021

Table of Contents Executive Summary 1 Method of Inspections / Attributes Collected 2 OWS Sizing Review 3 Results 4 Cost Estimates for PArt Repairs 5 Conclusion Appendix A

OWS 1

OWS 2

OWS 4

OWS 5

OWS 6

OWS 7

OWS 8

OWS 9

OWS 10

OWS 11

OWS 12

OWS 14

OWS 15

OWS 17

OWS 26

OWS 27

OWS 29

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 1

List of Abbreviations Abbreviation: Term/Phrase/Name:

CVG Cincinnati/Northern Kentucky International Airport

DEM Digital Elevation Model

H2S Hydrogen Sulfide Gas

KCAB or Board Kenton County Airport Board

N/I Not Inspected

OWS(s) Oil Water Separator

TFR Treatment Flow Rate

Woolpert Woolpert, Inc.

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 2

EXECUTIVE SUMMARY

In August of 2021, the Kenton County Airport Board (KCAB or Board) contracted Woolpert, Inc.

(Woolpert) to perform Condition Assessment Services of the existing Oil Water Separators (OWS) in various locations on the airfield at Cincinnati/Northern Kentucky International Airport (CVG). The goal was to locate each OWS and assess its conditions via confined space entry or pole camera visuals. The intended results of the assessment would yield an overall condition rating for each OWS, identify any necessary improvements, and provide a repair or replacement strategy and rough order of magnitude cost estimate for the OWS and existing parts.

This assessment provided for a limited visual assessment of the general structural and maintenance condition of each OWS. The results are not intended to warrant or certify that leaks of fuel, oils, or other potential contaminates will not occur.

KCAB maintains approximately 20 OWSs. There are an additional 12 OWSs that are maintained by various tenants. The majority of the OWSs are installed in various locations on the airfield, mainly in the ramp areas. The separators vary in structure type, size, and age. Of the 32 OWSs, there is one above ground tank (OWS 28) that is in a fire training facility.

At the conclusion of this project, Woolpert was able to safely inspect 17 OWSs of the 20 KCAB maintained OWSs. Three (3) were not inspected due to lack of access. There are an additional twelve

(12) OWSs that were not inspected as they are maintained by a tenant.

The following elements are included in this report:

Section 1 – Method of inspection/Attributes Collected

Section 2 – Results

Section 3 – Cost Estimates for Repairs

Section 4 – Conclusion

Appendix A – OWS Condition Ratings and Photos

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 3

1 METHOD OF INSPECTIONS /

ATTRIBUTES COLLECTED

To complete the assessment of the OWSs, Woolpert used two (2) data collection methods:

confined space entry and pole camera inspections. Champion, the pumping and cleaning contractor, pumped out the water and sediment from the OWS and pressure washed the interior components and walls to allow for the visual inspections. Woolpert inspected the OWSs with man entry if conditions were allowable. If entry to the OWSs was unable to be made, Woolpert utilized a pole camera to inspect the tank. Whether confined space entry was made, or the pole camera was used, pictures were obtained, and attributes were collected to document the condition of the OWS. Photos and additional details of the inspection for each OWS can be found in Appendix A.

Figure 1: Locations of OWS

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 4

1.1 Attributes Collected

Before starting the field assessment, Woolpert worked with KCAB to understand which attributes of the OWSs were of importance to their operations and maintenance needs. The attributes collected included but were not limited to:

■ Weather conditions

■ Tank number

■ Manufacturer

■ Structure shape and size

■ Structure material

■ Location of structure

■ Year structure was installed

■ Date of inspection

■ Date structure was pumped clean

■ Permanent pool depth

■ Sediment depth in inches

■ Cracks and/or displacements

■ Joint failure

■ Loss of join material

■ Leaking

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 5

2 OWS SIZING REVIEW

Woolpert reviewed the capacity of each KCAB owned OWS with respect to the surrounding infrastructure and area to identify improperly sized OWS. This effort involved two components:

confirmation that incoming pipe sizes are appropriate for the size of each OWS and confirmation that the OWS is sized to treat its complete drainage area.

Pipe Sizing The first step was to confirm that the incoming pipe sizes were appropriate for the size of the OWS.

Using data obtained during the Woolpert-performed field inspection and from the Airport provided stormwater system inventory data, the inlet pipe of the tank was compared to the outlet pipe of the immediate upstream junction box or diversion box. This comparison provides an indicator of whether the inlet pipe to the OWS has sufficient capacity to handle stormwater flow being conveyed by the upstream pipe. The inlet and outlet pipe sizes for all tanks were verified that they were sized properly using the sizing chart provided in the Highland Tank Oil/Water Separator Sizing Guide document, and the results were recorded in Table 1 below. Of the 17 inspected OWSs, 4 were manufactured by Highland Tank & Manufacturing Company, Inc. Highland Tanks provides a pipe sizing chart for their tanks and this chart was used to verify all tanks as being Highland. The manufacturer of the additional 13 OWSs were not identified. In those cases, Woolpert utilized the Highland Tank data as an indicator that the inlet pipe may be of an appropriate size. Further investigation of the tank manufacturer is needed to verify proper sizing.

Two tanks demonstrated inconsistency with Highland Tank sizing. The incoming pipe size for Tank 26 is undersized. The tank can handle more flow than the incoming pipe will allow, but this does not impact the performance of the OWS. Tank 14 has two incoming pipes (one 12” pipe and one 30” pipe) and only one of them is sized appropriately to handle the OWS tank size. According to the Highland Tank sizing chart, the OWS should be designed for a 12” maximum inlet and outlet pipe diameter. The 30” inlet pipe is larger than this OWS can handle, which may indicate that it is receiving more flow than it can handle.

Therefore, Tank 14 may require further analysis.

Drainage Area

The second step of this analysis was the confirmation of each OWSs drainage area. The drainage area of each OWS should comply with its respective treatment flow rate (TFR) as according to the following formula provided by Highland Tank wherein A is drainage area of the tank and R is 10-year, 1-hour rainfall (1.99”):

𝐴𝐴 × 𝑅𝑅 × 1.0104 = 𝑇𝑇𝑇𝑇𝑇𝑇

Woolpert attempted to delineate the watershed draining into each individual OWS using a digital elevation model (DEM) from KyFromAbove and provided KCAB stormwater system inventory. However, nine (9) OWSs and their surrounding drainage systems were not shown in the stormwater system inventory requiring too many assumptions to accurately delineate watersheds for those OWSs as well as neighboring OWSs with intersecting drainage areas. Additionally, some OWSs were designed with

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 6

upstream flow diversion boxes. There was insufficient available design data for each of these diverter boxes to quantify the flow from each drainage area being directed to each OWS.

As noted, the stormwater system inventory provided by the Airport did not include the location of some of the OWSs that were identified during the inspection, pipe segments were found to be incorrectly labeled, and much of the data was not properly connected. The system inventory map was not clear on the flow diversion designs or the intended treatment areas for the OWSs. Due to this lack of information, many assumptions were made throughout the analysis. A thorough update to the Airport’s system inventory is crucial before being able to provide an accurate analysis of the OWSs on the facility.

To assist in any further investigation of the allowable treatment area, a back-calculation determined the maximum drainage area that can be treated by each OWS. Again, the Highland Tank sizing chart was used to determine the TFR and allowable drainage area for all OWSs (i.e., both Highland and unknown tanks) based on tank field measured sizes. These areas are tabulated in the table below.

Tank Number

Incoming Pipe Data

Outgoing Pipe Data

Flow Diversion

Box?

Is the Inlet Pipe Sized Properly?

Maximum Drainage Area

(ac) 1 48" RCP, 30" RCP 48" RCP No Yes 3.33

2 36" RCP, 15" RCP 36" RCP Unknown Yes 2.77

4-A 12" DIP 72" RCP Yes Yes 0.89

4-B 14" DIP 12" DIP Yes Yes 0.89

5 14" DIP 14" DIP Yes Yes 1.66

6 4" DIP 4" DIP Unknown Yes 0.11

7 4" PVC 4" DIP Unknown Yes 0.11

8 20" DIP 20" DIP Yes Yes 3.33

9 18" DIP 15" DIP Unknown Yes 3.33

10 20" DIP 24" DIP Yes Yes 4.44

11 18" DIP 20" DIP Yes Yes 3.33

12 18" DIP 18" DIP Unknown Yes 0.55

14 30" RCP, 12" RCP 30" RCP Yes (before 12" pipe only) No 1.33

15 4" PVC Unknown No Yes 0.33

17 15" DIP 15" DIP Unknown Yes 0.78

29 4" PVC 4" PVC Unknown Yes 0.03

26 10" PVC Unknown Unknown No 1.66

27 4" PVC 4" PVC Unknown Yes 0.11

Table 1: OWS Pipe Data

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 7

3 RESULTS

Below are details on what constitutes a good, fair, or poor rating:

The OWS has no visible structural damage or damage to the components. The device appears to operate and function as designed. There is a minimal amount of sediment and debris in the structure. Recommended to be inspected bi-annually.

The OWS has minor structural damage or minor damage to components. Filters or coalescing plates need to be cleaned but the device is currently functioning as designed.

There is a more moderate amount of sediment or debris in the structure. It is recommended to inspect the OWS annually and make repairs as appropriate.

The OWS has severe structural damage or severe damage to the components. Filters or coalescing plates need immediate attention due to being clogged with sludge and sediment. There is moderate to severe groundwater infiltration from the wall of the tank.

The device is not operating and functioning as designed. It is recommended to make the necessary repairs or replace immediately.

At the conclusion of this project, Woolpert was able to safely inspect 17 OWS. A synopsis of the overall ratings is shown below:

Overall Ratings Numbers of OWS

A high-level overview of the data captured during the assessment can be found in the below tables.

Table 3 shows a general information on each OWS, including the structure shape, dimensions, volume, structure material and year installed. Table 4 provides an overview of the rating for each tank and certain attributes collected during the assessment. Additional information on items collected during the assessment can be found in the excel spreadsheet which accompanied this report. It is also important to note that there is no guarantee that tanks are not leaking and causing groundwater contamination.

While reviewing the table below, it is important to note that the typical life span of an OWS is 15-20 years. Some may last longer with proper maintenance, but as they age, the risk of leaks and groundwater infiltration rises. Newer OWS’s are being designed with double-walled steel material with built-in leak prevention technology to help further preserve the life of the units.

Table 2: OWS Ratings

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 1

OWS

Manufacturer Structure Shape

Structure Length (feet)

Structure Width (feet)

Structure Height (feet)

Volume (gallons)

Structure Material

General Location Year Installed

1 Unknown Rectangular 24’8” 13” 14’4” Unknown Concrete Ramp 1 at Block 1E

2 Unknown Rectangular 24’ 13’ 11’2” Unknown Concrete Ramp 1 at A-12 1983

4 Unknown Rectangular 16’4” 7’ 10’4” Unknown Concrete Terminal Drive West of Radisson

Inn

5 Unknown Round 25’6” 10’ 10’ Unknown Steel Terminal Drive West of Radisson

Inn

6 Unknown Rectangular 4’ 3’6” 8’2” 1,000 Concrete Northeast Corner of Field

Maintenance

7 Unknown Rectangular 9’ 4’6” 4’6” 1,000 Concrete Southwest Corner of Field Maintenance

8 Highland Round Unknown 10’ 10’ 30,000 Steel Ramp 3 South of Gate B-13

9 Highland Round Unknown 10’ 10’ 30,000 Steel Ramp 3 South of Gate C-8/C-10

10 Highland Round Unknown Unknown Unknown 40,000 Steel Taxiway F, Northeast Block of 3F

11 Highland Round Unknown 10’ 10’ 30,000 Steel Taxiway G, Northwest of

Block 3G

12 Unknown Round 24’ 6’ 6’ 5,000 Steel Island between Taxiway J and K, KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 2

West of Taxiway F

14 Unknown Rectangular 20’ 8’ 11’1” Unknown Concrete Meyer Tool Ramp, West of

Ramp

15 Unknown Rectangular 9’ 4’6” 5’ 3,000 Concrete Ameriflight Hangar

17 Unknown Rectangular 16’ 8’ 8’1” Unknown Concrete Kenton Road (inside of AOA), East of Delta Hangar at Blast

Fence

Unknown

26 Unknown Round 24’1” 9’10” 9’10” 15,000 Steel Field Maintenance

Fuel Farm

27 Unknown Rectangular 7’6” 5’6” 5’ 1,000 Concrete Field Maintenance Cold Storage

29 Unknown Rectangular 7’10” 4’9” 5’ 500 Concrete Standard Parking 2007

Table 3: OWS General Information

KENTON COUNTY AIRPORT BOARD | CVG OWS CONDITION ASSESSMENT | DEC 2021 3

OWS # Overall Ratings

Evidence of H2S Deterioration of

Access Structure?

Top Slab Cracked or Spalling?

Sediment Present?

Sediment

Depth (inches)

Oil Present?

Oil Depth (inches)

Has Trash and Debris

Accumulated?

Cracks and/or Displacements?

Minor Spalling (1” or less)

Major Spalling

(exposed rebar)

1 Yes Yes Yes, 6” No, 0” No No Yes No

2 Yes Yes No, 0” No, 0” No No No No

4 No No No, 0” No, 0” No No No No

5 No No No, 0” No, 0” No No No No

6 No No No, 0” No, 0” No No No No

7 No No Yes, 3” No, 0” No No Yes Yes

8 Yes No No, 0” No, 0” No No No No

9 Yes Yes Yes, 10” No, 0” No No Yes No

10 Yes No N/I No, 0” No No No No

11 Yes No No, 0” No, 0” No No No No

12 Yes Yes No, 0” No, 0” No No No No

14 No Yes No, 0” No, 0” No No No No

15 No N/I Yes, 1” No, 0” No No No No

17 Yes No No, 0” No, 0” No No No No

26 No No No, 0” No, 0” No No No No

27 No N/I Yes, 3” No, 0” No No No No

29 No Yes Yes, 3” No, 0” No No No No

Table 4: OWS Assessment Data

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 1

4 COST ESTIMATES FOR PART REPAIRS

This section covers the cost estimates for repair parts of major items found during the OWS inspections. The following assumptions were used while determining the cost shown below:

■ Cost does not include labor for installation of materials; Woolpert would not perform labor associated with repairs

■ Replacement part pricing based on 30,000 gal OWS units

■ Quote received could increase due to inflation

■ Repairing leaking joints/cracked concrete would be handled by CVG maintenance staff and not priced in this section

To provide the best parts repair estimates as possible, Woolpert contacted Highland Tank Company to receive quotes for replacement of the Corella Corrugated Plates for their units. Each set costs $8,050 and includes 88 replacement plates. Our inspections suggested that 6 units receive these replacement plates, at a total estimated cost of $48,300 plus labor.

If the airport wanted to replace older OWS with newer units, each new unit will cost approximately $275,000 (depending the brand) for a steel tank. This estimate does not include escalation, contingency, demolition and removal of the existing tank and general contractor profit and overhead.

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 2

5 CONCLUSION

In conclusion, this project provided a good baseline assessment for KCAB’s OWSs. It is recommended that KCAB completes all suggested repairs and create a standard inspection schedule to stay ahead of deferred maintenance issues. It is also recommended that KCAB completes a full stormwater system inventory. The inventory will provide a detailed depiction of all assets within the stormwater collection system and how they work together. The inventory data could also be used to model storm events to ensure the system is properly sized and functioning as designed.

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 3

APPENDIX A

Inspection reports for each OWS inspected by Woolpert are on the following pages. The reports include a summary of findings, condition of components, and an overall condition rating of 1 Good, 2-Fair, or 3- Poor.

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 4

OWS 1

Condition Rating:

OWS 1 was cleaned and inspected on 11/5/2021.

CVG pumped out most of the water from the OWS leaving only about 8 inches of water allowing Woolpert to safely perform confined space entry into the structure. Following the inspection, Champion arrived on-site and cleaned the OWS. OWS 1 is located in the middle of a taxiway, which required CVG to have the area temporarily shut down to allow for inspection and cleaning. The tank is concrete, rectangular in shape, and has a length of 24’8”, a width of 13’, and a height of 14’4”. The permanent pool in the OWS is approximately 88”. During the inspection, it was determined there could be a presence of H2S gas due to the rust and corrosion present on the steps. There was also a significant amount of sediment and debris in Chamber A. The debris consisted of gravel, rocks, and concrete. The sediment and debris were likely removed when Champion performed the cleaning. Evidence of groundwater infiltrating the structure was observed about halfway down the manhole access to Chamber C or the outfall chamber. A portion of the wall was wet around the joints and the infiltration is minor. All pipes and the baffle wall were in good condition and there was no visual evidence of structural damage to the OWS interior. The top slab on the outside of the OWS had several cracks that had been sealed.

Recommended Action: Inspect overall tank condition annually and monitor leaks twice yearly and seal as appropriate.

OWS 1, Photo 1 CA S-48 Inch Coming into Pipe

OWS 1, Photo 2 CA-7-30 Inch Incoming Pipe and West Wall

OWS 1, Photo 3 CA-S-Chamber C manhole Access

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 5

OWS 2

OWS 2 was cleaned and inspected on 11/8/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. OWS 2 is located at Gate A12 under the jetway, which required the gate to be temporarily shut down to allow for the inspection and cleaning. The tank is concrete, rectangular in shape, and has a length of 24’, a width of 13’, and a height of 11’2”. The permanent pool in the OWS is approximately 89”. During the inspection, it was determined there could be a presence of H2S gas due to the rust and corrosion present on the steps. A minor amount of sediment remained in Chamber C or the outfall chamber after the OWS was cleaned. All pipes and the baffle wall were in good condition and there was no visual evidence of structural damage to the OWS interior. The top slab on the outside of the OWS has separation from the surrounding concrete and has been sealed in the past but may need to be resealed.

Recommended Action: Inspect overall tank condition annually and monitor top slab twice yearly and reseal as appropriate.

OWS 2, Photo 4 CA-E-36 Inch Incoming Pipe

OWS 2, Photo 5 CC-S-Rust and Corrosion on Steps

OWS 2, Photo 6 CA-SE-South and East Walls

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 6

OWS 4

OWS 4 was cleaned and inspected on 10/27/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. Water was refilling the tank at a significant rate during the inspection. There was about 14” of water at the start of the inspection and approximately 24” by the end of the inspection. The tank is concrete, rectangular in shape, and has a length of 16’4”, a width of 7’, and a height of 10’4”. The permanent pool in the OWS is approximately 77”. There are two 72” RCP pipes leaving the OWS that are on the north side of a wall in the structure that stands 5’7” off the bottom of the tank. Both pipes are filled with water suggesting there could be obstructions not allowing the pipes to drain properly. Whether or not there were obstructions could not be confirmed during the inspection. The OWS had no evidence of H2S gas and all components in the OWS had no visual evidence of structural damage.

Recommended Action: Inspect overall tank condition annually and perform CCTV inspection of pipes to investigate possible obstruction. Add elbow to incoming pipe to divert flow to bottom of unit.

OWS 4, Photo 7 CA-W-View from East to West

OWS 4, Photo 8 CA-E-Incoming Pipe

OWS 4, Photo 9 CA-Manhole on East Side of Tank

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 7

OWS 5

OWS 5 was cleaned and inspected on 10/26/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. Water from the adjacent stream was refilling the tank at a significant rate during the inspection. While performing the inspection there was approximately 18” of water in the tank. The tank is steel, cylindrical in shape, and has a length of 25’6”, a width of 10’, and a height of 10’. The permanent pool in the OWS is approximately 162”. The tank appears to stay full and fills into the manhole access area up to 3 feet above the actual tank. The OWS has coalescing plates that need maintenance.

There are several plates dislodged from their rack and most all the plates have a lot of remaining sludge after being cleaned. There is rust and corrosion present on some of the plates. Both the inlet and outlet pipes and the baffle are in good condition and there is no remaining sediment in the tank following the cleaning.

Recommended Action: Replace broken and rusted coalescing plates.

OWS 5, Photo 10 CA-E Dislodged Plates

OWS 5, Photo 11 CA-E-Coalescing Plates Rust and Corrosion

OWS 5, Photo 12 CA-W-Underside of Diffusion Baffle

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 8

OWS 6

OWS 6 was cleaned and inspected on 11/05/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to perform the inspection.

Confined space entry was not required to fully inspect the structure. Pictures of the interior of the OWS were taken with an iPad from the top. The tank is concrete, rectangular in shape, and has a length of 4’, a width of 3’6”, and a height of 8’2”. The permanent pool in the OWS is approximately 79”. Water is infiltrating the OWS from three different walls of the structure filling the structure at a significant rate. This could lead to more significant leaks and damage if not repaired. There is no elbow on the incoming pipe to direct the incoming flow towards the bottom of the tank. The incoming and outgoing pipes are in good condition and there is no evidence of H2S gas present.

Recommended Action: Seal leaking joints; add elbow to help divert incoming flow to bottom of tank.

OWS 6, Photo 13 Exterior

OWS 6, Photo 14 CA-S-Water Infiltrating Tank on South Wall

OWS 6, Photo 15 CA-N-Outgoing Pipe

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 9

OWS 7

OWS 7 was cleaned and inspected on 10/26/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to perform the inspection. Confined space entry could not be performed due to obstructions in both manhole access points. The inspection was performed and pictures of the interior of the OWS were obtained utilizing a pole camera. The tank is concrete, rectangular in shape, and has a length of 9’, a width of 4’6”, and a height of 4’6”. The permanent pool in the OWS is approximately 50”. During the inspection the water depth in the OWS was 1” and the sediment depth was 3”. Some sediment in the OWS could not be completely removed because it was very hard and stuck to the bottom of the tank. There is some minor spalling on the interior of the top slab along with a small area where rebar is exposed. This does not appear to be a major issue at present but should be monitored for future maintenance. The baffle on the west side of the tank is damaged and appears to be eroding due to forceful flow over time. Both the incoming and outgoing pipes are in good condition, but a cleanout directly beside the OWS in the parking lot for the incoming pipe has no cover. There is no evidence of H2S gas in the structure.

Recommended Action: Inspect overall tank condition annually and monitor spalling.

OWS 7, Photo 16 CA-W-Exposed Rebar and Deteriorating Top Slab

OWS 7, Photo 17 CA-W-Sediment

OWS 7, Photo 18 Incoming Pipe Cleanout with No Cover

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 10

OWS 8

OWS 8 was cleaned and inspected on 11/4/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to perform the inspection.

Confined space entry was performed in Chamber A only and could not be performed in Chambers B and C. Chamber B was obstructed by the filters and Chamber C was too small to access. Pictures of the interior of Chambers B and C were taken with a pole camera. The tank is steel, cylindrical in shape, and has a width of 10’, and a height of 10’. The overall length of the OWS could not be determined due to inaccessibility to Chambers B and C. Chamber A has a length of 21’6”. The permanent pool in the OWS is approximately 102”. After being cleaned there was about 2” of water in the OWS during the inspection. The coalescing plates and filter media are both filled with sludge and the filter media is dislodged in areas. Evidence of H2S gas is visible on the steps and within the access locations where rust and corrosion are present. The inlet and outlet pipes appear to be in good condition but the outlet pipe could not be fully inspected. The coalescing plates and filters need to be maintained to allow the structure to function as designed.

Recommended Action: Replace or repair coalescing plates and filters and monitor corrosion.

OWS 8, Photo 19 CC-N-Chamber C Manhole Access

OWS 8, Photo 20 CA-W-Sludge in Coalescing Plates

OWS 8, Photo 21 CA-Incoming Pipe

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 11

OWS 9

OWS 9 was inspected on 11/1/2021. CVG pumped the tank down to allow Woolpert to perform the inspection. Champion was unavailable at the time to clean OWS.

Confined space entry was performed in Chamber A only and could not be performed in Chambers B and C. Chamber B was obstructed by a baffle wall and Chamber C was too small to access. Pictures of the interior of Chambers B and C were taken with a pole camera, but with limited visibility. The tank is steel, cylindrical in shape, and has a width of 10’, and a height of 10’. The overall length of the OWS could not be determined due to inaccessibility to Chambers B and C. Chamber A has a length of 21’6”. The permanent pool in the OWS is approximately 102”. After CVG pumped the water down about 12” of water remained in the OWS during the inspection. The coalescing plates and filter media are covered with sludge and need to be cleaned. Evidence of H2S gas is visible on the steps and all the access points where there is rust and corrosion present. The top slab on the exterior of the OWS has some cracking that has been sealed.

Recommended Action: Replace or repair coalescing plates and filters. Seal cracking exterior slab and monitor corrosion.

OWS 9, Photo 22 CA-NW-Corrosion

OWS 9, Photo 23 CA-SW-Liner Peeling Off Tank Wall

OWS 9, Photo 24 CA-W-Sediment Visible

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 12

OWS 10

OWS 10 was inspected on 11/2/2021. There was an attempt to pump the tank clear of water, but there was significant inflow that was refilling the tank. Confined space entry could not be performed. Therefore, a pole camera was utilized to visually inspect the components of the OWS. It was difficult to fully inspect the OWS with the pole camera due to having to fit the camera into tight spaces with limited ability to adjust to different angles. During the inspection, it was determined that there were significant portions of the filter media completely missing. There was evidence of the presence of H2S gas in the access points and on the steps where rust and corrosion could be seen. Additional rusting could be seen in areas on the tank’s walls. The OWS is steel and cylindrical. The dimensions of the tank and the permanent pool depth could not be determined, and the incoming pipe in Chamber A was not visible due to being behind a baffle wall.

Recommended Action: Replace missing filter media and monitor corrosion.

OWS 10, Photo 25 CC-S-Rust and Corrosion

OWS 10, Photo 26 CB-W-Missing Filter Media

OWS 10, Photo 27 CB-E-Damaged Filter Media

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 13

OWS 11

OWS 11 was cleaned and inspected on 11/3/2021.

Champion pumped the water out and cleaned the structure allowing Woolpert to perform the inspection. Confined space entry was performed in Chamber A and B only and could not be performed in Chamber C. Chamber C was too small to access. Pictures of the interior of Chamber C were taken with a pole camera. The tank is steel, cylindrical in shape, and has a width of 10’, and a height of 10’. The overall length of the OWS could not be determined due to inaccessibility to Chamber C. Chambers A and B have a combined length of 47’7”. The permanent pool in the OWS is approximately 84”. After being cleaned there was about 4” of water in the OWS during the inspection. The coalescing plates and filter media are both filled with sludge and the filter media is dislodged in areas and completely missing in others. Evidence of H2S gas is visible on the steps and within the access locations where rust and corrosion are present. There is some deterioration and of the tank’s liner along with some rusting of the tank’s walls. The inlet and outlet pipes appear to be in good condition but could not fully inspect the outlet pipe in Chamber C. The coalescing plates and filters need to be maintained to allow the structure to function as designed.

Recommended Action: Replace or repair coalescing plates and filter media. Monitor for corrosion and deterioration.

OWS 11, Photo 28 CC-E-Chamber C Manhole Access

OWS 11, Photo 29 CB-N-Sludge in Coalescing Plates

OWS 11, Photo 30 CB-S-Missing Filter Media

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 14

OWS 12

OWS 12 was cleaned and inspected on 10/27/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. About 3” of water remained in the structure during the inspection. The tank is steel, cylindrical in shape, and has a length of 24’, a width of 10’, and a height of 10’. The entire interior of the OWS has rusting and corrosion. The coalescing plates are completely gone and the rack that holds them is severely deteriorating. All components are coated with sludge and are non-functional. The OWS is not functioning as designed and needs immediate attention.

Recommended Action: Replace OWS.

OWS 12, Photo 31 CA-East-Manhole Access

OWS 12, Photo 32 CA-W-Coalescing Plate Rack Corrosion

OWS 12, Photo 33 CA-Incoming Pipe Looking Up from Bottom

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 15

OWS 14

OWS 14 was cleaned and inspected on 11/09/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. Less than 1” of water remained in the structure during the inspection. The tank is concrete, rectangular in shape, and has a length of 20’, a width of 8’, and a height of 11’1”. The permanent pool in the OWS is approximately 86”. The interior of the OWS was in good condition besides a minor collection of debris in the outfall chamber. The debris consisted of pieces of 2X4 and other construction debris. The exterior of the top slab of both manhole access points has some cracking. The southernmost manholes slab had some spalling and deterioration present. The cracking could be due to having a heavy fueling truck parked over the OWS regularly. The CAD drawings as provided by CVG label OWS #14 as a fuel separator.

Recommended Action: Inspect overall tank condition annually and repair concrete slab.

OWS 14, Photo 34 CA-N-Debris

OWS 14, Photo 35 CA-S-Baffle Wall

OWS 14, Photo 36 CC-E-East Wall and Steps

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 16

OWS 15

OWS 15 was cleaned and inspected on 10/26/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to perform the inspection. Confined space entry could not be performed due to the small size of the manhole access point. Pictures of the interior of the OWS were taken with a pole camera. The tank is concrete, rectangular in shape, and has a length of 9’, a width of 4’6”, and a height of 5’.

The permanent pool depth in the OWS could not be determined. During the inspection the water depth in the OWS was 1” and the sediment depth was 1”. The outlet pipe could not be inspected due to being recessed and behind the baffle wall.

The overall condition of the OWS was good and appeared to have no significant issues. There was a minor amount of sludge and debris remaining in the tank after cleaning, which was likely due to it being difficult to access with the vacuum hose.

Recommended Action: Inspect overall tank condition bi-annually and repair components as-needed.

OWS 15, Photo 37 CA-Manhole Access

OWS 15, Photo 38 CA-W-Sediment

OWS 15, Photo 39 CA-W-Top of Outlet Baffle

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 17

OWS 17

OWS 17 was cleaned and inspected on 11/08/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. No water or sediment remained in the structure during the inspection. The tank is concrete, rectangular in shape, and has a length of 16’, a width of 8’, and a height of 8’1”.

Both the inlet and outlet pipes have no elbows and both pipes are rusted and deteriorating.

The overall condition of the OWS is fair and pipes should be monitored for future maintenance.

Recommended Action: Inspect overall tank condition annually and add elbow pipes to inlet and outlet structures to divert flow.

OWS 17, Photo 40 Exterior Manhole Access

OWS 17, Photo 41 CA-NW-Outgoing Pipe

OWS 17, Photo 42 CA-SE-Wall Below Pipe

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 18

OWS 26

OWS 26 was cleaned and inspected on 10/26/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to safely perform confined space entry into the structure. No water remained in the structure during the inspection. The tank is steel, cylindrical in shape, and has a length of 24’1”, a width of 9’10”, and a height of 9’10”. A minor amount of sludge remained in the tank next to the filters.

The filters obstruct the outlet pipe therefore the outlet pipe could not be visually inspected. OWS 26 is a non-typical separator with vertical walls and filters. Overall, the OWS appears to be in fair condition, but the filters likely need replacing and should be monitored for future maintenance.

Recommended Action: Inspect overall tank condition annually, replace filters and monitor filter media debris accumulation.

OWS 26, Photo 43 CA-Top View

OWS 26, Photo 44 CA-Clogged inspection ports

OWS 26, Photo 45 CA-Outlet Filter

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 19

OWS 27

OWS 27 was cleaned and inspected on 10/26/2021.

Champion pumped the water out and cleaned the structure allowing Wolpert to perform the inspection. Confined space entry could not be performed due to obstructions in both manhole access points. The inspection was performed and pictures of the interior of the OWS were obtained utilizing a pole camera. The tank is concrete, rectangular in shape, and has a length of 7’6”, a width of 5’6”, and a height of 5’. The permanent pool in the OWS is approximately 48”. During the inspection, the water depth in the OWS was 1” and the sediment depth was 3”. Both inlet pipes did not have elbows to direct inflow to the bottom of the tank and the outlet pipe had a T-fitting other than just a 90-degree elbow. Based on the CAD drawings provided by CVG, OWS 27 has the highest probability of going into the sanitary system. The drawings show the tank in yellow, being connected to the yellow sanitary system. The overall condition of the OWS was good.

Recommended Action: Inspect overall tank condition bi-annually and install elbow pipe on inlet pipe to divert flows to bottom of tank.

OWS 27, Photo 46 CA-SW-Sediment

OWS 27, Photo 47 CA-W-MH-Outlet Pipe and Additional Incoming

OWS 27, Photo 48 CA-SE-Sediment

KENTON COUNTY AIRPORT BOARD | CVG OWS CA | DEC 2021 20

OWS 29

OWS 29 was cleaned and inspected on 10/27/2021. Champion pumped the water out and cleaned the structure allowing Woolpert to perform the inspection. No water or sediment was present during the inspection. Confined space entry could not be performed due to obstructions or manhole access points being too small for entry. The inspection was performed and pictures of the interior of the OWS were obtained utilizing a pole camera. The tank is concrete, rectangular in shape, and has a length of 7’10”, a width of 4’9”, and a height of 5’. The permanent pool in the OWS was determined to be approximately 12” based on the outgoing pipe on the north wall of the tank. There are two 4” pipes on the north wall of the tank. It appears that the lower of the two, which is about 12” of the bottom of the tank is the active outlet pipe. The pipe closer to the top of the tank appears to be plugged or severely clogged. The outlet pipe appears to be clogged with sludge as well. Both the inlet and outlet pipes have no elbows. The overall condition of the interior of the OWS is good, but the outgoing pipe needs to be maintained and cleared of sludge. The exterior of the top slab is beginning to crack around the north manhole and should be monitored for future maintenance.

Recommended Action: Perform deep cleaning of all inlet and outlet pipes to remove debris. Repair exterior slab to prevent cracking.

OWS 29, Photo 49 CA-N-Opening that Appears Plugged

OWS 29, Photo 50 CA-Northside of Tank Cracking

OWS 29, Photo 51 CA-N-Clogged Outlet Pipe