Attachment J-1A - Gandalf ATCT Junction Lvl - Above Comprehensive Mold Report 1-13-20.pdf

APPENDIX C

Comprehensive Mold Assessment DIA ATCT (upper levels)

January 13, 2020

GANDALF ASSOCIATES, INC.

Introduction

Gandalf Associates Inc. (GA) conducted a comprehensive mold and moisture damage assessment of the upper levels of the Denver International Airport – Air Traffic Control Tower (ATCT). The purpose of the assessment was to evaluate the current conditions of the built environment and to identify, describe and specifically locate any mold-contaminated and/or moisture damaged building materials. This assessment of the ATCT was limited to inspections of the Junction level and above, which included the Penthouse level, Cab level, Cable Access level, and Junction level of the tower but not inclusive of the elevator shaft. Evaluation of the Sub-junction level, tower shaft, and base building was not part of the scope for this evaluation.

The methods used for this assessment consisted of:

Review of building plans and available historical water intrusion information;

Informal discussions with facility and engineering personnel, safety and health personnel, and a representative of the NATCA union; to determine the known history of water damage, information concerning suspected water damage that they had observed, and any concerns possibly related to water damage and mold;

A visual evaluation that consisted of an inspection of all accessible interior and exterior surfaces to collect information about water damage and mold in an effort to determine the extent of the water/mold related problems;

Coordination and consultation with Building Science Corporation, the engineering firm evaluating water intrusion, leakage, and condensation issues within the tower;

The use of a moisture meter and intrusive evaluation techniques to assist in the determination of the extent of water damage and mold contamination;

The collection of samples of fungal growth to determine the types of fungi present within the building envelope, to assist with the development of remediation recommendations, and to document existing conditions.

This mold and moisture damage assessment was completed by Timothy Herrin, CIH, the Director of Technical Services for Gandalf Associates, Inc. Initial discussions and observations of the area were completed on December 20, 2019. Follow-up intrusive evaluation and sampling were completed on January 6, 2020.

Engineering concerns for this project, including pathways of water intrusion, leakage and condensation issues that have combined to create the water/moisture intrusion concerns identified are being addressed by Building Science Corporation (BSC).

OBSERVATIONS & FINDINGS

Water damage was either reported or observed associated with eight locations during this assessment. Some amount of fungal growth (mold) contamination was determined to exist associated with building materials (wall board) at three (3) of those eight (8) water damage locations.

1. Penthouse Level – Sagging paint on interior drywall below the louvers for the HVAC ductwork on the east wall and near the ceiling on the southwest wall in the PH-2 area indicates that water intrusion/condensation has occurred sometime in the past. Moisture measurements were unremarkable. Drywall was removed from the inside of the Penthouse exterior wall, at the location near the HVAC wall penetrations, where water damaged paint had been observed. A minimal amount of mold (< 1 ft. 2) was discovered in the wall cavity on the backside of the interior drywall. The fungal growth associated with the water damage at this location was sampled and determined to be Alternaria species.

Remediation and replacement of the visibly water-damaged drywall in PH-2 is recommended to ensure that all mold contamination is identified and removed from this area. The fungal growth observed at this location is not currently active and is considered historic in nature, likely associated with water leaks from the exterior or condensation that occurred sometime in the past. Additional moisture issues associated with the Penthouse walls could re-activate the existing mold growth. Refer to Photographs 1-5 for additional information; Appendix A for remediation recommendations; and Appendix D for specific location information.

2. Cable Access Level – The drywall wall that separates the interior area from the outer ring was evaluated. Although the wall is a location where moisture damage concerns, as a result of condensation seem likely, findings associated with the wall in general were unremarkable and there was no mold identified except for a small amount associated with an historic steam leak that occurred in about the 2004 timeframe. Mold was remediated from this steam leak area near the east access doorway in 2007, and the completed remediation appears to have been successful as there is no additional mold evident on the remediated surfaces.

The fungal growth that continues to be present is not currently active and is considered historic in nature. The mold that exists is in the outer ring area and is located on the exterior of the drywall wall and only on the drywall surface that directly abuts the wall base-plate (1 inch by ~15 feet), a location that cannot be accessed without the wall’s removal. The fungal growth that exists is a minimal amount that is encased/sealed in the exterior side of the wall. Remediation of this material would only be recommended if the drywall outer ring wall needed to be removed for other reasons. Refer to Photographs 6-7 for additional information; Appendix B for remediation recommendations; and Appendix D for specific location information.

3. Junction Level – Water damage and the associated existence of mold was determined to exist on the exterior wall board soffits above the walkways between the microwave balconies on the north, south, and east sides of the tower. The exterior of these surfaces appear to have been exposed to the elements allowing the water stains, water damage and mold to develop. It is recommended that the wall board soffits be removed and replaced with glass fiber faced exterior Gypsum Wall Board (GWB), or equivalent, if this material does not interfere with the towers operation. Refer to Photographs 8-11 for additional information; Appendix C for remediation recommendations; and Appendix D for specific location information.

The remaining five (5) of the eight (8) potential water-damage locations were found to be free of any mold contamination concerns.

4. Cab Level – Recently installed unfinished drywall that exhibited evidence of water staining in the Cab stairwell below the Cab sink was removed to allow observations of the back of the drywall and adjacent material. This is a location that had been remediated in July 2019 because of historic water leaks below the sink not being addressed in a timely manner. Although the unfinished drywall exhibited evidence of water staining, there was no mold identified at this location.

5. Junction Level – The interior of the HVAC units (AHU-13 & AHU-14) that service the Cab and Junction levels of the tower were visually inspected. Findings were unremarkable and there was no evidence of standing water, bio-growth, or potential indoor air quality concerns identified.

6. Junction Level – The ceiling plenum above J-8 was evaluated as a result of water reportedly leaking from the ceiling/light fixtures at this location. It is believed that blowing snow/rainwater entered the air exhaust louver at the cab walkway; water then migrated down inside of the non-lined ductwork, leaked from inside of the ductwork at a corner seam, and day lighted in the J-8 ceiling plenum. A water-damaged ceiling tile had reportedly been replaced since the water intrusion had occurred. Findings of our evaluation were unremarkable, water streaks on the ductwork were visible but there were no signs of water damage or mold identified.

7. Junction Level – The ceiling plenum above J-12 was evaluated due to the observed existence of water stained ceiling tile in the area. Findings of our evaluation were unremarkable; there were no signs of mold identified. Water stained ceiling tile were observed to be associated with HVAC plumbing valves in the ceiling plenum. Ceiling tile in this room were old and unlike J-8 have not yet been replaced as part of the modernization project.

8. Junction Level – Drywall was removed from the south wall of the J-12 mechanical room as this was an historic water leak location that was remediated in 2007. There was no water damage or mold identified at this location.

CONCLUSIONS & DISCUSSION

The evaluation identified three (3) locations where some amount of fungal growth/mold was determined to exist.

The mold associated with the Penthouse (PH-2) walls is in the wall cavity of the exterior wall and should be remediated in conjunction with or after the potential leak locations in that area are addressed. Although it is believed likely that only minimal mold exists within the wall cavity, approximately 25 square feet of drywall will need to be removed to ensure that all water damage/mold is identified and removed.

Mold at the base of the Cable Access/Outer Ring separation wall is currently encased/sealed on the exterior side of wall. It is believed likely that less than 2 square feet of mold on drywall exist at this location. Removal of this material is currently not recommended.

The microwave balcony exterior wall board soffits have been exposed to the elements as a result of paint maintenance issues that have allowed water stains and mold to develop. There is approximately 400 square feet of GWB soffits that need to be removed and replaced to address the mold concerns in this area. As the air intakes for AHU-13 and AHU-14 are located below this soffit material on the north elevation, appropriate precautions will need to be utilized during any work in this area to ensure that contaminates are not entrained into these units when the work is completed.

Based upon the visual observations, evaluation results, and review of all available data, GA recommends that the following remediation steps be conducted. The goal of remediation is to clean or remove the materials affected by fungal growth in a way that prevents the emission of fungi and dust contaminated with fungi from leaving the work area and entering other areas of the residence and building.

As with any water damage/fungal growth event, the source of the moisture needs to be identified and corrected prior to or in conjunction with any remediation in order to minimize the possibility of the fungal growth problem reoccurring.

Necessary water damage and mold remediation activities based upon findings to date:

• The exterior remediation procedures shall be utilized for exterior GWB soffit removal on the microwave balconies. These procedures shall be utilized during the removal of any visible water damaged exterior wall board and associated insulation, if any exists.

• The interior remediation procedures shall be utilized for the removal of all interior wall board that is water damaged and any associated insulation in the PH-2 area.

Mold has been identified associated with the visible water damage indicating the existence of possible wall cavity contamination. At wall locations where water damage has been observed, mold is likely to exist inside of the wall cavities, and interior remediation procedures will be necessary.

This comprehensive mold assessment identified only a minimal amount of fungal growth/mold on interior building materials. The mold in the Penthouse is associated with water intrusion from the exterior. The mold on the exterior microwave soffits is on unprotected materials on the exterior of the tower as a result of being exposed to the elements. The mold in the Outer Ring area is a result of a piping leak that occurred in approximately 2004 and was remediated leaving the currently existing mold sealed in place.

Minor amounts of mold on water damaged building materials are a common condition and can be expected whenever wallboard is exposed to water and not properly dried.

Major mold concerns were not identified by this evaluation.

The water damage/mold growth locations identified do not present any potential health or indoor air quality concerns for the tower occupants. The water damage/mold identified is also not a concern with regard to the structure or the towers operation.

Exposure to airborne mold, based upon what has been identified by this assessment is not an issue; however, if tower occupants are concerned as the tower modernization project moves forward, the FAA might consider the use of periodic air monitoring to help ensure and document the tower occupant’s exposure potential with regard to airborne spores.

Photograph 1 – Penthouse (PH-2) water damage and location where intrusive testing was performed. Arrow denotes location (inside of wall cavity) where mold growth was discovered. Location will require wall board removal (20 ft2) to remediate inside of the wall cavity

Photograph 2 – Penthouse (PH-2) location showing water damage (sagging paint) evident on interior wall board. Current moisture content was not elevated.

Photograph 3 – Penthouse (PH-2) water damage below penetrating ductwork with HVAC grill removed. Intrusive sampling was completed at lower right corner of ductwork opening at location of sagging paint.

Photograph 4 – Penthouse (PH-2) intrusive opening in drywall. Arrow denotes location of the minimal amount of mold (Alternaria species) that was found to exist inside of the wall cavity.

Photograph 5 – Penthouse (PH-2) water damage location at ceiling level. The second location in PH-2 that will require wall board removal (5 ft2) to remediate inside of the wall cavity.

Photograph 6 – Cable Access Level showing the interior side of the east Outer Ring separation wall, access door on the right. Foil backed insulation is being pulled back from the wall board wall that is coated with anti-microbial paint.

Photograph 7 – Cable Access Level showing the exterior side of the east Outer Ring separation wall, access door is on the right. Section of wall board wall is coated with anti-microbial paint and base of wall is sealed. Mold exists along base of wall board.

Photograph 8 – Junction Level exterior balcony soffit with water damage and mold.

Removal and replacement of soffit is recommended. Estimate approximately 133 ft2 of soffit GWB per balcony.

Photograph 9 – Junction Level exterior balcony soffit with water damage and mold.

Removal and replacement of soffit is recommended. Total GWB removal and replacement, approximately 400 ft2.

Photograph 10 – Junction Level south elevation exterior balcony soffit with evident mold on the GWB. Removal and replacement of soffit is recommended.

Photograph 11 – Junction Level north elevation exterior balcony soffit. Removal and replacement of soffit is recommended. Note: HVAC intake louvers at left of photograph below soffit, proper precautions will need to be exercised to ensure contaminates are not entrained into HVAC system.

These services were performed in a manner consistent with the level of care and skill ordinarily exercised by members of the environmental health profession currently practicing under similar conditions. Gandalf Associates, Inc., its employees and officers do not accept any responsibility for undiscovered or unknowable conditions at the site or within the building structure. The findings, conclusions, and recommendations presented here are based on information available at the time this site was evaluated.

This report is a summary of the work that GA has completed for this project. Supporting documentation for this report is contained in our project files and may include photographs, writings, complete laboratory reports and other documents.

If you have any questions or concerns regarding this matter, please contact us at any time at 303.499-2749.

Respectfully Submitted, Timothy Herrin, CIH Director of Technical Services

19447-DIA ATCT Mold Assessment-01132020

Attachments: Appendix A – Remediation Recommendations Penthouse (PH-2) Appendix B – Remediation Recommendations Cable Access Appendix C – Remediation Recommendations Exterior Balcony Soffits Appendix D – Identified Mold Locations Bulk Sample Laboratory Data

REMEDIATION RECOMMENDATIONS

Appendix A – Penthouse (PH-2)

Interior Remediation Procedures

These recommendations are designed to assist in the interior evaluation, removal and cleanup of materials contaminated or likely contaminated with visible fungal growth and surfaces contaminated with fungal contaminated dust. These remediation procedures should be completed in the order provided and documentation that each step was properly completed should be maintained.

1. Identify and correct all potential sources of moisture intrusion.

2. Remediation workers shall be trained in the handling of hazardous waste materials and the health effects of fungal growth.

3. Proper protection for remediation workers should at least consist of, disposable protective coveralls, eye protection, gloves, and a properly fitted N-95 NIOSH-approved respirator.

4. All contents within the designated work area (PH-2 exterior wall) shall be inspected, cleaned with a high efficiency particulate air (HEPA) vacuum and/or by wet wiping if necessary, and properly stored.

5. Isolate the work area from other areas and equipment in PH-2. Ensure that any gaps between the work area and the other areas of the building have been sealed.

Ensure that the doors to PH-2 remain closed during the actual wall board removal and clean up activity. This is to ensure that fungal spores and dust from the construction does not migrate to other areas of the tower during the cleanup activity.

Any non-contaminated difficult to clean equipment that are to remain within the work area shall be sealed from the area by the use of critical barriers after being HEPA vacuumed.

6. Ensure that any supply and return air grills located in the work area are isolated from the work area.

7. Remove the materials that are contaminated or likely contaminated with fungal growth at each location where water damage is determined to exist.

7.1. Remove the interior drywall walls in PH-2 that show signs of water damage.

This will include drywall and any existing wall insulation.

7.2. In all circumstances, removal of drywall and insulation shall be at least 2 feet beyond where visible fungal growth is observed.

7.3. Dust suppression methods, such as misting (not soaking) surfaces prior to remediation, are recommended.

8. Thoroughly clean all surfaces that remain within the enclosed area. Following the removal of all visible fungal growth, with a HEPA vacuum, all surfaces should be cleaned with a damp cloth, hard brush and a detergent solution.

9. Materials to be removed should be taken from the work area sealed in a minimum of 6-mil plastic.

10. Upon completion, all areas within the work area should be dry and visibly free of fungal contamination, dust, and debris.

11. A visual inspection of the work area coupled with air sampling will be used to determine if the fungal growth remediation has been successful prior to the start of re-construction activities. Gandalf Associates, Inc. can conduct this interim inspection once all of the required remediation work has been completed, and the contained area has not been disturbed for at least 24 hours.

12. Following any remediation activity, visual inspections should be conducted at appropriate intervals to ensure that completed corrective actions have eliminated the cause of the fungal growth.

In addition to the above procedures, documentation (i.e. checklists) should be maintained on a daily basis for the following:

Engineering controls such as critical barriers and containment, are being properly maintained;

Safety and security of the site and site conditions are verified;

Any potential fire and/or health hazards are properly managed;

Proper fungal growth remediation procedures are being followed to ensure that materials are being removed in a way that prevents the emission of fungi and dust contaminated with fungi from leaving the work area, and that workers performing the remediation activities use appropriate personal protective equipment.

Appendix B – Cable Access Outer Ring Separation Wall

These recommendations are designed to assist in the interior evaluation, removal and cleanup of materials contaminated or likely contaminated with visible fungal growth and surfaces contaminated with fungal contaminated dust. These remediation procedures should be completed in the order provided and documentation that each step was properly completed should be maintained.

1. Remediation workers shall be trained in the handling of hazardous waste materials and the health effects of fungal growth.

2. Proper protection for remediation workers should at least consist of, disposable protective coveralls, eye protection, gloves, and a properly fitted N-95 NIOSH-approved respirator.

3. All contents within the designated work area (60 ft2 section of separation wall near east access door) shall be inspected and removed.

4. Isolate the work area and create a directional airflow from other areas of the Cable Access area into the work area. Turn the work area into a negative pressure enclosure by constructing isolation barriers and exhausting air from the work area to the outside through negative air machines equipped with HEPA filtration. Ensure that any gaps between the work area and the other areas of the tower have been sealed. This is to ensure that fungal spores and dust from the construction does not migrate to other areas of the building during the cleanup activity.

5. Ensure that any supply and return air grills located in the work area are isolated from the work area.

6. Remove the materials that are contaminated or likely contaminated with fungal

a. Remove the wall board wall that is coated with anti-microbial paint. This will include drywall (all layers) and insulation.

b. In all circumstances, removal of drywall and insulation shall be at least 2 feet beyond where visible fungal growth is observed.

c. Dust suppression methods, such as misting (not soaking) surfaces prior to remediation, are recommended.

7. Thoroughly clean all surfaces that remain within the enclosed area. Following the removal of all visible fungal growth, with a HEPA vacuum, all surfaces should be cleaned with a damp cloth, hard brush and a detergent solution.

8. Materials to be removed should be taken from the work area sealed in a minimum of 6-mil plastic.

9. As the removal of fungal growth from semi-porous surfaces is a difficult task, coat any semi-porous surfaces that remain within the work area with a fungal protective coating.

10. Upon completion, all areas within the work area should be dry and visibly free of

11. A visual inspection of the work area coupled with air sampling will be used to determine if the fungal growth remediation has been successful prior to the start of re-construction activities. Gandalf Associates, Inc. can conduct this interim inspection once all of the required remediation work has been completed, the negative air is temporarily disabled, and the contained area has not been disturbed for at least 24 hours.

12. Following any remediation activity, visual inspections should be conducted at appropriate intervals to ensure that completed corrective actions have eliminated the cause of the fungal growth.

Engineering controls such as critical barriers, containment, and negative pressure are being properly maintained;

Safety and security of the site and site conditions are verified;

Any potential fire and/or health hazards are properly managed;

Proper fungal growth remediation procedures are being followed to ensure that materials are being removed in a way that prevents the emission of fungi and dust

Appendix C – Junction Level Exterior Soffit

Exterior Remediation Procedures -

These recommendations are designed to assist in the exterior removal and cleanup of materials contaminated with visible fungal growth. These remediation procedures should be completed in the order provided and documentation that each step was properly completed should be maintained.

1. Identify and correct all potential sources of water intrusion.

2. Remediation workers shall be trained in the handling of hazardous waste materials and the health effects of fungal growth.

3. Proper protection for remediation workers should at least consist of disposable protective coveralls, eye protection, gloves, a properly fitted N-95 NIOSH-approved respirator and fall protection.

4. Restrict access to the work area and keep out unauthorized personnel. This is to help ensure that fungal spores and dust from the construction does not contaminate other areas and to minimize exposure concerns during the cleanup activity.

5. Remove the exterior GWB soffit materials from above the Junction Level walkways.

Dust suppression methods, such as misting (not soaking) surfaces prior to

6. Thoroughly clean all adjacent areas. Following the removal of all visible fungal growth, all surfaces (soffit cavities) should be cleaned with HEPA vacuum.

7. Contaminated materials should be taken from the work area sealed in a minimum of

6-mil plastic.

8. Upon completion, all areas within the work area should be dry and visibly free of fungal contamination, dust, and debris.

9. A visual inspection of the work area should be used to determine if the fungal growth remediation has been successful.

Appendix D – Identified Mold Locations

APPENDIX D

DIA ATCT Base Building – Boiler Room

February 28, 2020

INTRODUCTION

Gandalf Associates Inc. (GA) conducted a comprehensive mold and moisture damage assessment of the Denver International Airport – ATCT Base Building Boiler Room. The purpose of the assessment was to evaluate the current conditions of the built environment with regard to fungal growth concerns and determine how the identified conditions would impact the current boiler replacement project. This assessment was limited to inspections of the Boiler Room and adjacent locations.

The methods used for this assessment consisted of:

Review of building plans and available historical water intrusion information;

Informal discussions with facility and engineering personnel, and safety and health personnel; to determine the known history of water damage, information concerning suspected water damage that they had observed, and any concerns possibly related to water damage, mold, and the scheduled boiler replacement project;

A visual evaluation that consisted of an inspection of all accessible interior locations to collect information about water damage and mold in an effort to determine the extent of the water/mold related problems;

The use of a moisture meter and intrusive evaluation techniques to assist in the determination of the extent of water damage and mold contamination;

The collection of samples of fungal growth to determine the types of fungi present within the building envelope, to assist with the development of remediation recommendations, and to document existing conditions.

This mold and moisture damage assessment was completed by Timothy Herrin, CIH, the Director of Technical Services for Gandalf Associates, Inc. Initial discussions and observations of the area were completed on February 12, 2020.

Engineering concerns for this project, including pathways of water intrusion, leakage and condensation issues that have combined to create the water/moisture intrusion concerns identified are being addressed by Building Science Corporation (BSC).

OBSERVATIONS & FINDINGS

There is a heat exchanger located in the southwest corner of the boiler room that is leaking and is the source of moisture that has allowed mold to develop in this part of the boiler room and the adjacent locations. The leak from this heat exchanger cannot be fixed without shutting down the heating/cooling system for the building. This is being addressed as part of the boiler replacement project, which will include the installation of temporary boilers to allow the building to remain occupied while the project is completed.

Water damage was evaluated in the boiler room, and any adjacent locations possibly affected by the water leak from the heat exchanger. Some amount of fungal growth (mold) contamination was determined to exist associated with building materials (wallboard) at four (4) of the five (5) suspect locations.

1. Boiler Room (119) - Wallboard in contact with water from the heat exchanger has allowed mold to develop at the base of the walls in the southwest corner. Mold exists (mainly behind vinyl base) at the base of the south and west walls in the boiler room as a result of the heat exchanger leak. Unrelated to the heat exchanger leak, a small amount of historic water damage/mold was determined to exist at the base of the wall in the northeast corner of the boiler room in the vicinity of the hot water heater. Currently, there was no moisture identified at this location and the minimal damage that exists is believed to be historic in nature.

Mold was sampled at the base of the west wall in the boiler room and determined to be Penicillium/Aspergillus, and Ulocladium species. There is approximately 15 square feet of mold behind the vinyl base at this location with an unknown amount inside of the wall cavity. On the east wall, behind the water heater there is <1 square foot of mold also at the base of the wall behind the vinyl base.

Remediation will require the removal of wallboard to a height of 4 feet from the entire south and west walls, and approximately 10 linear feet from the northeast corner. Approximately 200 square feet of wallboard will need to be removed in the boiler room to address the current mold concerns. It is recommended that, as part of the project, the bottom 4 feet of wallboard be removed from all of the boiler room walls and replaced with materials more resistant to water damage and mold such as glass fiber faced Gypsum Wall Board, or equivalent. Consult with Building Science Corporation (BSC) with regard to wallboard replacement material for the boiler room.

2. Mechanical (118) – Water damaged wallboard and small amounts of mold were determined to exist at the base of the north wall that is shared with the boiler room. Again, the mold identified was only at the base of the wall and behind the vinyl base, and is the result of the heat exchanger leak.

There is approximately 5 square feet of mold behind the baseboard at this location with an unknown amount inside of the wall cavity. Remediation will require the removal of wallboard to a height of 4 feet from the north mechanical room wall, adjacent to the boiler room, from the doorway to the northwest corner and a small section of the west wall. Approximately 80 square feet of wallboard will need to be removed from this location to address the current mold concerns.

3. CCMS (112) – Mold was found to exist in the northeast corner of the CCMS room and at this location the mold was visible to a height of about 2 feet up the wall behind a storage cabinet. Unlike in the boiler and mechanical rooms, where it appears that residual heat in the area has likely dried moisture from the wallboard minimizing mold growth on the exposed wall surface, conditions in the CCMS have allowed mold to develop on the exposed surface and not just behind the vinyl base. There is over 10 square feet of mold contamination on finished surfaces at this location.

Mold was sampled on the east wall in the CCMS room and determined to be Stachybotrys species. Remediation will require the removal of wallboard to a height of 4 feet from the east, north and a small section of the west walls.

Approximately 80 square feet of wallboard will need to be removed from the CCMS room. Sealing the return air vent and minimizing access into the CCMS room is recommended to help minimize any potential for exposure should the exposed mold be inadvertently disturbed prior to its removal.

4. Fiber Optics Electronics (111) – The northeast corner of Room 111, that is adjacent to the areas of concern, was evaluated by removing the vinyl base, testing for moisture, and visually inspecting for signs of water damage and mold.

Findings in this area were unremarkable as signs of water damage/mold in this area were not identified. Remediation at this location is not necessary.

5. Stair No. 1 (102) – Moisture was determined to exist in the south wall of the stairwell to a height of about 2 feet above the bottom level of the stairs. Mold was observed behind the vinyl base at this same location, which is adjacent to both the boiler room and the CCMS water damaged locations. Mold was not observed on the finished walls above the vinyl base.

Mold was sampled from behind the base on the south wall of Stair No. 1 and determined to be Penecillium/Aspergillus and Stachybotrys species.

Remediation will be required to remove the wallboard to a height of 4 feet from the south and east walls at this location. Approximately 56 square feet of wallboard will need to be removed from this location. The thickness and number of layers of wallboard that will need to be removed will need to be field verified.

CONCLUSIONS & DISCUSSION

Mold remediation will need to occur in the identified locations and should occur in conjunction with the current boiler replacement project. Based upon the visual observations, evaluation, and review of all available data, GA recommends that the following remediation steps be conducted. The goal of remediation is to clean or remove the materials affected by fungal growth in a way that prevents the emission of fungi and dust contaminated with fungi from leaving the work area and entering other areas of the building.

Project Sequence -

As with any water damage/fungal growth event, the source of the moisture needs to be identified and corrected prior to or in conjunction with any remediation, in order to minimize the possibility of the fungal growth problem reoccurring. As work in the boiler room will be necessary in order to address the source of the water that has caused the noted damage, sequencing the remediation with the construction work will be necessary.

It is recommended that the following actions be completed in the boiler room in order to help ensure a successful project.

1. Walls inside of the boiler room that are contaminated with mold should be protected to ensure that the mold is not disturbed by work/demolition activities inside of the boiler room. This can be accomplished by installing plywood along the bottom of the west and south walls of the boiler room at any location that could possibly be damaged. The plywood should be held up off the floor so that it does not wick moisture.

2. Complete the cutover and install for the temporary boilers. Ensure that work activities, including temporary plumbing and electrical work, do not disturb any of the identified mold contaminated wall locations.

3. Complete demolition work of equipment from inside of the boiler room. Again, ensure that work activities do not disturb identified mold contaminated locations.

4. Remediate the mold/water-damaged materials from the boiler room and adjacent locations. Complete necessary inspections, testing, and rebuild. It is estimated that this work activity will require approximately 2 weeks to complete.

5. Continue with boiler replacement project work.

Necessary water damage and mold remediation activities based upon findings to date:

• The attached interior remediation procedures shall be utilized for the removal of all interior wallboard that is water damaged and any associated insulation in the Boiler Room and adjacent locations.

The potential health hazard for building occupants and maintenance personnel to the fungal growth material that has been identified is currently minimal. Addressing the materials identified as recommended will help ensure that the risk to personnel and the facility are appropriately managed.

REMEDIATION COST ESTIMATE

Estimated costs for this remediation work to be conducted at this location:

$ 11,250.

Estimated costs for remediation oversight and project clearance:

$ 7,400.

Photograph 1 – Boiler Room southwest corner with leaking heat exchanger on the left and water still puddled. Note damage to vinyl base and base of wallboard wall. Mold exists behind base. Location will require wallboard removal (200 ft2) to remediate inside of the wall cavity.

Photograph 2 – Southwest corner of Boiler Room floor. Note water tracking around column and under wallboard wall.

Photograph 3 – Boiler Room (119) west wall sample location. Note mold on wallboard paper stuck to vinyl base. Mold identified as Penicillium/Aspergillus and Ulocladium species.

Photograph 4 – Mechanical Room (118) north wall adjacent to Boiler Room. Mold growth visible behind vinyl base, amount of mold inside of wall cavity is unknown.

Location will require 80 ft2 of wallboard removal to remediate observed mold and wall cavity.

Photograph 5 – CCMS Room (112) northeast corner adjacent to Stair No. 1 and Mechanical Room. Mold growth on visible finished wall above vinyl base was determined to be Stachybotrys species. Location will require 80 ft2 of wallboard removal to remediate observed mold growth and wall cavities.

Photograph 6 – Stair No. 1 (102) south wall adjacent to CCMS. Mold growth behind vinyl base was determined to be Penicillium/Aspergillus and Stachybotrys species.

Approximately 56 ft2 of wallboard will need to be removed from this location.

These services were performed in a manner consistent with the level of care and skill ordinarily exercised by members of the environmental health profession currently practicing under similar conditions. Gandalf Associates, Inc., its employees and officers do not accept any responsibility for undiscovered or unknowable conditions at the site or within the building structure. The findings, conclusions, and recommendations presented here are based on information available at the time this site was evaluated.

This report is a summary of the work that GA has completed for this project to date.

Supporting documentation for this report is contained in our project files and may include photographs, writings, complete laboratory reports and other documents.

If you have any questions or concerns regarding this matter, please contact us at any time at 303.499-2749.

Respectfully Submitted, Timothy Herrin, CIH Director of Technical Services

202013-DIA Base Building Boiler Room Mold Assessment-02282020

Attachments:

Appendix A – Remediation Recommendations Boiler Room & Adjacent Locations Location Sketch - Depicting Damage & Sample Locations Bulk Sample Laboratory Data with CoC

REMEDIATION RECOMMENDATIONS

Appendix A – Boiler Room and Adjacent Locations

These recommendations are designed to assist in the interior evaluation, removal and cleanup of materials contaminated or likely contaminated with visible fungal growth and surfaces contaminated with fungal contaminated dust. These remediation procedures should be completed in the order provided and documentation that each step was properly completed should be maintained. All remediation and clearance work activities shall be completed in accordance with the FAA’s ATO IAQ Program Implementation Requirements – Chapter 5.

1. Identify and correct all potential sources of moisture intrusion – remove leaking heat exchanger.

2. Remediation workers shall be trained in the handling of hazardous waste materials and the health effects of fungal growth.

3. Proper protection for remediation workers should at least consist of, disposable protective coveralls, eye protection, gloves, and a properly fitted NIOSH-approved respirator with P-100 HEPA filters.

4. All contents within the designated work areas (Boiler Room and adjacent contained locations) shall be inspected, cleaned with a high efficiency particulate air (HEPA) vacuum and/or by wet wiping if necessary, and properly stored.

5. Isolate the work areas and create a directional airflow from other areas of the building into the work area. Turn the work area into a negative pressure enclosure by constructing isolation barriers and exhausting air from the work area to the outside through negative air machines equipped with HEPA filtration. Ensure that any gaps between the work area and the other areas of the base building have been sealed. This is to ensure that fungal spores and dust from the construction does not migrate to other areas of the building during the cleanup activity.

6. Ensure that any supply and return air grills located in the work area are isolated from the work area.

7. Remove the materials that are contaminated or likely contaminated with fungal

7.1. Remove the interior wallboard walls to a height of 4 feet at locations as depicted in the attached location sketch. This will include drywall and any existing wall insulation.

7.2. In all circumstances, removal of drywall and insulation shall be at least 2 feet beyond where visible fungal growth is observed.

7.3. Dust suppression methods, such as misting (not soaking) surfaces prior to

8. Thoroughly clean all surfaces that remain within the enclosed area. Following the removal of all visible fungal growth with a HEPA vacuum, all surfaces shall be cleaned with a damp cloth, hard brush and a detergent solution.

9. Materials to be removed shall be taken from the work area sealed in a minimum of 6-mil plastic.

10. As the removal of fungal growth from semi-porous surfaces is a difficult task, coat any semi-porous surfaces (unfinished drywall in wall cavities) that remain within the work area with a fungal protective coating.

11. Upon completion, all areas within the work area should be dry and visibly free of

12. A visual inspection of the work area coupled with air sampling will be used to determine if the fungal growth remediation has been successful prior to the start of re-construction activities. Gandalf Associates, Inc. can conduct this interim inspection once all of the required remediation work has been completed, and the contained area has not been disturbed for at least 24 hours.

13. Following any remediation activity, visual inspections should be conducted at appropriate intervals to ensure that completed corrective actions have eliminated the cause of the fungal growth.

Engineering controls such as critical barriers and containment, are being properly maintained;

Safety and security of the site and site conditions are verified;

Any potential fire and/or health hazards are properly managed;

Proper fungal growth remediation procedures are being followed to ensure that materials are being removed in a way that prevents the emission of fungi and dust

LOCATION SKETCH

APPENDIX E