Re: Addendum to Preliminary Water Damage Report, Mendocino Public Health Branch, 1120 South Dora Street, Ukiah, CA

Transcription

1 IAS 960 Ms. Kristin McMenomey Risk Manager County of Mendocino 841 Low Gap Road Ukiah, CA Re: Addendum to Preliminary Water Damage Report, Mendocino Public Health Branch, 1120 South Dora Street, Ukiah, CA Dear Ms McMenomey: Pursuant to your request, Indoor Air Sciences (IA Sciences) is providing industrial hygiene services related to the water damages that occurred within approximately 2/3 of the building at the Mendocino Public Health Branch building that occurred on January 21, Water Intrusion Damages As much of the water damage removal has been completed and walls have been opened, it has now been possible to evaluate all areas for other damages. In particular, water damage and areas of suspected microbial growth have been observed on exterior walls on the backside of the exterior sheetrock that is below the exterior finish panels. Water damage to these components is due to two sources, 1) leaking at the exterior wall panels and 2) leaking around windows. It is our recommendation that the Mendocino County perform water testing on the exterior of the building in order to identify and repair all areas of exterior water intrusion. As stated above, we have identified areas of water damage and suspected microbial growth on the inside, which is currently visible with the walls removed. We recommend that all windows be assessed and repaired as necessary.

2 Page 2 of 5 Tuberculosis Exam and Sharps Rooms Additionally, one exam room (room 293) has been identified as a location where TB patients are seen and the second, a janitors closet Room 295, is used to store spent needles from TB patients (Sharps room). During wall removal, it was observed that the backside of the drywall to Room 295 contained a significant amount of microbial growth. Work was halted at the time to re-assess the best manner to approach this area. Based upon the short lived properties of the tuberculosis bacteria and long term exposures necessary, no immediate threat is anticipated to workers cleaning these areas. However, IA Sciences does recommend that these areas be treated separately and that the respiratory protection requirements for these rooms be increased to include full face respirators. All other PPE including full Tyvek coverall suits and nitril gloves will still be required. CLEANING - The following cleaning procedures applies to rooms 247A, 247B, 249, 250, 251, 252, 275, 275A and Room 303. Conduct water testing in each room with an exterior wall and identify and repair all areas of water intrusion (room 293 is an exception to this step). Verify that all sources of water intrusion into the building have been repaired. Negative air pressure devices should be turned on and should remain operational until final cleaning is completed. All areas of damage should be thoroughly cleaned, HEPA vacuumed, and wiped down with a mild detergent solution to remove any remaining mold spores. Each area should then be cleaned with food grade hydrogen peroxide solution or alternative disinfectant solution (MSDS required prior to use). Once the cleaned areas again have been allowed to dry, each affected area should be sealed with a paint encapsulant such as Fosters or equivalent (MSDS required prior to use). (This step does not apply to rooms 293 and 295). Final cleaning should be augmented with air washing within each room. HEPA filtered air moving devices can be left in the operation mode up to and during final inspection. Verify that all wood framing materials are below a moisture content of 15% and all surfaces are dust free prior to calling for a final inspection.

3 Page 3 of 5 Once all areas are dry and water intrusion sources have been identified and repaired, the sheetrock walls and insulation can be replaced. Once the walls have been replaced final sampling will be performed. CLEANING - The following cleaning procedures apply only to rooms 293 and 295. Room TB Exam Room Due to asbestos content in the joint compound, workers in these rooms must be certified as asbestos abatement workers. Remove the drywall from each wall to a height of 4 feet. All removed drywall materials should be immediately placed in double bags. The materials do not need to be handled as bio-hazard materials. Disinfect all other surfaces within the room. Disposal for the removed drywall should be as non-hazardous waste (<1% chrysotile asbestos). Room Sharps Room Due to asbestos content in the joint compound, workers in these rooms must be certified as asbestos abatement workers. Remove the drywall from floor to ceiling on the west, south and east walls. Remove the drywall on the north wall (adjacent to the bathroom) to a height of 4 feet. All removed drywall materials should be immediately placed in double bags. The materials do not need to be handled as bio-hazard materials. Disinfect all other surfaces within the room. Disposal for the removed drywall should be as non-hazardous waste (<1% chrysotile asbestos). FINAL SAMPLING Air Sampling - Final air sampling should also be conducted inside of each containment after air washing, a final wipe down and HEPA vacuuming has taken place, (i.e., walls, floors, ceilings, etc.). Final air samples will be analyzed for nonviable microbial spores and should contain less than 80% of the total spore count of outdoor air samples and contain a similar fungal ecology (types of spores present).

4 Page 4 of 5 LIMITATIONS The conclusions and results contained herein are based solely on the information presented in this report. The sampling, testing, and observations described in the report represent conditions only at the specified times and locations. Additional information or contamination that was hidden, undiscovered, inaccessible, or are not a part of the finding presented herein, would result in the modification of the conclusions and recommendations made herein. The sampling methods, techniques, and scope of services were not comprehensive or to be considered all-inclusive. Any remediation guidelines are minimum general guidelines, based solely on the findings contained herein. The guidelines are presented as a courtesy and are not to be considered a complete or detailed set of remediation specifications. IA Sciences is not responsible for the accuracy of information provided by others, or for conditions or consequences arising from relevant facts that were withheld, concealed, undiscovered or not fully disclosed. IA Sciences is not a law firm; and therefore, makes no representations regarding any potential liability of any person or entity for site conditions. IA Sciences is not qualified to present medical advice. If any present or future health issues are in question, it is recommended that the findings in this report be presented to a qualified medical professional for evaluation. If you should have any questions or would like to discuss the contents of this report, please do not hesitate to contact me any time at (707) Respectfully submitted, Chip Prokop, PE, BCEE, CIEC, CAC, CLI Principal

5