1. Methods of Mold Investigation and Remediation: A Case Study Dawn Bolstad-Johnson, MPH, CIH Christopher Hansen, CIH Michael Jimenez City of Phoenix

2. Background Info… Municipal Courts employees complained of non-specific health effects and requested an indoor air quality investigation. A walk-through of the building revealed additional information: There was a severe water leak about three weeks prior to the complaint

3. Background Info The water leak was a result of a pipe that had burst while being repaired. Several thousand gallons of water were released in a short time. The leak occurred in the basement area. Everyone was evacuated and a contractor was contacted to remove inches of standing water found throughout the basement.

4. Reported Health Effects The initial health effects reported included a municipal judge who reported that he had lost his voice while he was on the bench. Others reported non-specific symptoms and/or building conditions such as “feeling yucky”, “stuffy air”, not enough circulation, etc.

5. Indoor Air Quality Investigation A walk through of the building revealed no visual evidence of mold growth on any of the affected wall systems. Our hypothesis: If there was mold growth it may be contained within the wall cavities in the affected areas.

6. Sampling Plan Both non-viable and viable area samples were collected simultaneously within areas where the health complaints originated. Additionally, 6 wall cavity samples were collected. 14 non-viable samples were collected utilizing Zefon Air-O-Cells 8 viable samples were collected utilizing an Andersen single stage impactor equipped with a malt extract agar (MEA).

7. Sampling Methods Non-invasive wall cavity samples were collected by removing an electrical outlet plate and placing the Zefon cassette near the existing hole in the wall. The wall was tapped intermittently during the 3-4 minute sampling time.

8. Preliminary Sampling Results Sample IDViable (CFU/M3) Non-Viable (Spores/M3) Alcove to 16/1712 95 Courtroom 171224 Judge Taylor8,22128,976 Judge Taylor - wall cavity---60,038 Courtroom Pod-14/15530 1,895 Courtroom 14<1295 Judge Doug36475 Judge Doug- wall cavity---100,667 Outside1892,523

9. Schematic Drawing 11 10 12 13 15 14 16 17 STORAGE WM Water Leak Source

10. The Dilemma The sample results proved that we had mold growth in the wall cavities. We had employees experiencing health effects. This building is scheduled for demolition within the next 9–12 mos. A $12M new courts facility is under the final stages of construction.

11. The Dilemma We needed to remedy the problem: Using the least amount of $$$, and The least impact on the municipal courts system. (At least 4 courtrooms were shut down.)

12. Proposed Solution No. 1 Our insurance adjuster recommended a contractor to come in to: Clean/wet-wipe all walls Apply a biocide to all surfaces Followed by a chlorine dioxide bomb This solution appeared to be the best at the time as it would minimize down time and overall disruption of court activities.

13. Problems… Management witnessed the contractor training his staff on our job site. Apparently, he had gotten his crew from a labor pool. We gave the contractor an opportunity to supply us with minimal OSHA compliance training documentation. They could not.

14. Additional Sampling In the interim, additional sampling had been accomplished to determine the extent of the mold contamination. An additional eighty- one (81) samples were collected in the remaining occupied areas of the basement which had not been previously tested.

15. Sampling Methods Air Samples for viable and non-viable spores were collected simultaneously from the air delivery vent and the ambient room air. A tent was constructed around the air diffuser to accomplish this task.

16. Sampling Methods Additional non- invasive wall cavity samples were collected using a Zefon cassette and an existing hole in the wall as previously discussed.

17. Sampling Results Sample IDViable (CFU/M3) Ambient Non-Viable (Spores/M3) Wall Cavity Non-Viable (Spores/M3) Courtroom 1524 <25684 Courtroom 16<1250333 Courtroom 10<125002,073 Judge Garry’s Chambers1064,000583,519 Courtroom 121771,600171,074 Courtroom 12 Inside Tent<12300--- Women’s Restroom2467511,814 Outside49515,575---

18. Schematic Drawing 11 10 12 13 15 14 16 17 STORAGE WM Water Leak Source

19. Solution No. 2 Additional sampling allowed us to clearly define affected areas. In order to control the potential hazard, we elected to complete remediation in a limited number of areas. All other areas were to be thoroughly cleaned with a 10% bleach and water solution. Seal the walls above the ceiling with poly and expandable foam and all existing wall holes (e-outlets, phone jacks, etc.) with 6 mil poly.

20. Findings Visible mold was found on drywall within the office during cleaning. The wall cavity samples in these areas were also high. Strategy change: Remove sections of drywall with visible mold in office areas.

21. Solution No. 2 Addendum We hired a mold remediation firm to removed mold contaminated walls and do the plumbing repairs. Total Cost of Remediation: $57,165.00

22. Remediation Walls were cut about 4’ or at least 1’ above visible mold contamination. All work was accomplished under filtered negative air.

23. Remediation

24. Visible mold was found in the wall cavity.

25. Remediation Clearance sampling was accomplished after remediation and cleaning were completed with non- viable spore traps.

26. Sample Results Sample ID Wall Cavity Non-Viable (Spores/M3) Before Cleaning Non-Viable (Spores/M3) After Cleaning Non-Viable (Spores/M3) Courtroom 12171,0741,60025 Courtroom 1311,9277525 Courtroom 15684<25120 Courtroom 1633350 Eddie’s office68,2222,87524 Angie’s office2,4442,375120 Outside---15,5758,548

27. Conclusions All walls around courtrooms 12, 13, 14, 15, 16 and 17 were sealed using an expandable foam and plastic sheeting over holes. The wall between the men’s and women’s RR was removed as were areas within selected Judge’s chambers where visible mold growth was discovered.

28. Schematic Drawing 11 10 12 13 15 14 16 17 STORAGE WM Water Leak Source

29. Lessons Learned Building tents around air diffusers while taking simultaneous room samples will quickly show whether the HVAC system is contributing to the mold count in the room. There are non- invasive ways to check mold growth within wall cavity areas. While these samples cannot be compared to outside air, they will give you more info.