Identify deficiencies that may impact IEQ and/or sources of odor concerns. Typically includes the following depending on the nature of concern, but not limited to:
- interview/questionnaire of concern individual(s)
- inspection above drop ceiling (condition of roof deck, pipe insulation, return air plenum)
- inspection of ventilation system (operation of variable air volume box and outdoor air dampers, check controls, measurements of carbon dioxide, temperature and relative humidity, sources near outdoor air intake, measure return and supply air volume, cleanliness of coils, liner and condensate pan)
- inspection of exterior
- inspection below drop ceiling (housekeeping, sink and floor drain traps, signs of past and present moisture concern via visual and/or moisture meter, mold growth, ensure connection of current and capping of abandoned sanitary vents, odorizers, excessive plants and fabric items, identify potential pathways, and measure volatile organic compounds, carbon monoxide, and lighting)
Dates of Assessment: December 27, 28, 29, 30, 2022 and January 1, 3, 4, 5, 6, and 9, 2023
On December 26, Building Maintenance responded to a water leak incident involving roof top ventilation unit OAHU 2, which impacted the hallway intersection outside rooms 210, 211, and 214, pipe insulation (coming down from OAHU2) above the drop ceiling, ceiling tiles, the bulkhead (two isolated areas about 1 square foot each) surrounding the border of the commons area, and the carpeting of the commons area. Building Maintenance notified the Office of Environment.
On December 27, the Office of Environment arrived to assess the incident using visual cues and moisture meters. Upon arriving, another water leak took place that morning involving the unit ventilator in room 112 which impacted rooms 108,109, 112, 113, 115, 116, 119, and the open commons area outside these rooms. Building materials impacted: common's carpeting; portions of carpeting in rooms having carpet near classroom doorway; large area rug in room 108; and base of the wood cubby locker areas in the classrooms.
Upon leaving, roof top ventilation unit OAHU 3 started to leak impacting room 226 and the hallway outside room 226 (from student restrooms to the plumbed casework at the commons area). Assessment indicated the following were impacted: wood base of plumbed casework and small section of carpet in commons area; walk off mat outside the hallway restrooms; and in room 226, materials (cushions, books, papers, etc.) directly below leak and base of wood cubby lockers.
During the assessments an odor associated with the bio-degradation of trace amounts of propylene glycol (anti-freeze) within the mechanical system (served the failed fan coil unit) was detected in each of the three impact zones. Propylene glycol is generally recognized as safe by the Food and Drug Administration and it is often found in cosmetics, food, and pharmaceuticals. It is also used to make smoke/fog in fire-fighting training and theatrical productions. The odor was only noted in the hallways and within section(s) of OAHU 2 and 3 and not within the classrooms, except 226.
A Board approved restoration contractor was utilized to dry wetted building materials and clean carpeting (twice). Impacted wood casework was dried by removing vinyl cove base, drilling holes, and placing air blowers to direct air at the base and into the holes.
The Office of Environment recommended to Building Maintenance to assess and remove impacted ventilation equipment's pipe, exterior duct, and internal sound liner insulation to address the propylene glycol odor knowing they had first hand knowledge of what took place and was impacted. Also to remove trash cans used to capture the water in order to properly assess the odor and other possible materials containing the odor.
December 28, the Office of Environment met with the restoration company to go over the scope of work. The Office of Environment requested Facility personnel to remove trash cans and cleaning equipment to extract the water from the hallways so the odor can be properly assessed.
On December 30, the restoration contractor executed the scope of work which only included to dry bulkhead and the base of wood casework, cleaned gym mats from room 112, and clean and dry carpeting.
On January 1, the Office of Environment determined all wetted materials were dry with exception to the base of the wood casework in room 115. The odor was present in the hallways of all three areas.
The odor was present in the hallway intersection outside rooms 108 and 115 and noted within sections of the carpet in the commons area.
The area outside room 226 - the odor was coming from trash receptacles that once contained some water (recommended to be discarded or thoroughly cleaned), walk off mat outside student restrooms (recommended to be replaced), and materials (boxes, books, etc.) within room 226 (recommended school and/or custodial staff to review and remove from the room).
The hallway intersection outside rooms 210 and 214 - the odor was noted within sections of the common's area carpet. A light lens appeared to have a water stain along with a remaining ceiling tile surrounding a sprinkler head (recommended to be cleaned and/or replaced). The Office of Environment reminded Building Maintenance to review ventilation equipment since they were familiar with the what components and sections leaked.
The Office of Environment requested Building Maintenance inspect the floor receptacle boxes for any liquid residue.
The Office of Environment believed the impacted OAHUs were off due to various reasons and informed Building Maintenance to clean impacted surfaces that could not be removed and remove any impacted insulation before turning units back on and potentially dispersing the odor in the areas/rooms they served.
On January 2, the restoration contractor recleaned and dried the carpeting in the three commons area and dried the base of wood casework in room 115.
On January 3, the Office of Environment performed an early morning assessment before staff arrived. All carpet and the base of wood casework in room 115 were dry. The classroom doors were closed. With the exception of room 226, the "propylene glycol odor" was not present within the impacted rooms. The odor was still noticeable in the impacted hallways. The carpeting in the common areas was still holding the odor. It was believed the odor was enhanced due to the carpet blowers moving air across the carpet. The Office of Environment notified Building Maintenance recommending these carpeted areas be removed, especially if school reports an odor.
In room 226, the odor was detected. Custodian indicated the items requested to be removed remained so teacher can go through and determine what can be discarded. The Office of Environment removed the trash cans, books, cushions, papers, and baggies with content (baggies had water in them containing the smell) and placed in the boiler room so the odor in the classroom could dissipate before occupancy.
On January 4, the school reported an odor which was the propylene glycol associated smell. The Office of Environment responded with the assistance of two HVAC technicians who initially responded to the leaks. The odor was sensed when approaching the impacted areas. Sections of the common area carpeting still contained the odor. Wet pipe insulation above the drop ceiling in the hallway outside room 214 was identified. The stained ceiling tile around the sprinkler still existed and trapped some of the odor. The same as for two additional water stained ceiling tiles in room 214.
Upon inspecting OAHU 2, it was off and an odor was noted within a couple of sections containing the piping and/or coils that leaked. The odor was noted on pipe insulation, coils, and in condensate drains. The findings were the same with OAHU 3, except the unit was operating upon the inspection.
On January 5, the wet fiberglass pipe insulation above the drop ceiling in the hallway outside of room 214 was removed in the morning. A contractor was utilized to address the OAHUs by cleaning coils, flushing the condensate drains, and removing pipe insulation. The carpeting in three common areas was removed.
On January 6, the Office of Environment reviewed the work and noted some pipe insulation remained in OAHU 3 which was then removed by Building Maintenance. The odor was still present on the bare pipes in both units. As a result, the units were operated over the weekend during non-occupied hours to air out the interior of the units to dilute any potential odors.
On January 9, the Office of Environment visited the school to assess any residual odor. No odors were present.
On January 12, the Office of Environment received and responded to the school's inquiry to inspect items within room 112. The teacher pointed out items of concern and their original position in the classroom prior to the leak. Using a moisture meters, it was determined all items were dry with exception to a wood toy piece of furniture. It was determined this wood will not dry in a timely fashion due to the construction, thus warp and possibly grow mold. In addition, the base broke during moving due to the particle board being saturated. The toy item was to be discarded.
New carpeting (in the areas where carpeting was removed) was installed January 19, 2023.
The above actions to were meant to eliminate the odor and prevent the potential for microbial growth.