by Paul C. Clark
July 30, 2009
Mold is back on the table as a possible culprit in the Oak Ridge Elementary School health mystery, as a federal team has found it in several places in the supposedly mold-free school.
Guilford County Schools announced on July 23 that Oak Ridge will not open on August 25, and that the school’s students will be sent to Oak Ridge Military Academy (grades two through five), Colfax Elementary School (kindergarten and first grade) and E.P. Pearce Elementary School (pre-kindergarten), at an estimated cost of $222,000. The school system hopes to remediate any problems found at Oak Ridge Elementary School by the end of October.
Much of the focus of the four-year Oak Ridge Elementary School saga has been on mold, which was found at the school as early as May 2005, three months before the official opening of the completely rebuilt school, and as late as May 2009. Students and teachers at the school have reported a slew of health symptoms, including headaches, fatigue, difficulty concentrating, respiratory problems and nosebleeds.
That focus shifted in recent months for two reasons: the Guilford County Department of Public Health on June 25 released the final results of its epidemiological study of the symptoms, discounting mold as a cause of any current symptoms, and recent air-quality tests at the school found no high mold levels.
That didn’t mean Oak Ridge Elementary School hasn’t had a mold problem – mold has been found at the school repeatedly, by Guilford County Schools employees and outside experts brought in to do tests. But health department and school officials alike thought the mold problem at the school had been fixed, and any remaining symptoms were probably caused by a badly calibrated heating, ventilation and air-conditioning (HVAC) system that wasn’t providing enough fresh air.
The arrival in Guilford County of a federal team from the National Institute for Occupational Safety and Health (NIOSH), part of the US Centers for Disease Control and Prevention, on July 14 was intended to bring a higher level of expertise to the Oak Ridge mystery, and also to provide a credible independent investigation of the symptoms for parents and teachers, some of whom felt that Guilford County Schools had stonewalled them, particularly in the early stages of the saga, before the symptoms were confirmed by the health department. The school system has been very open in its recent reporting on the problem.
The NIOSH team released its first report on the school’s environmental problem on Thursday, July 23, and that report is shot through with mold. The report also lends credence to reports by people in the Oak Ridge community that there were systemic construction problems when the school was rebuilt in 2005, and that those problems have made the school leak-prone, which has contributed to the mold.
The NIOSH team, which spent three days at the school, consists of at least four NIOSH officials – including Jean Cox-Ganser, an epidemiologist in NIOSH’s Division of Respiratory Disease Studies and an expert on building contamination; Rachel Bailey, a NIOSH medical officer; and industrial hygienist Ju-Hyeong Park. It also included Stephen Caulfield, a senior vice president of the Turner Group, a New England-based firm that tests and evaluates buildings with suspected environmental contamination; and Fred McKnight, a mechanical engineer and industrial hygienist for the same firm. The Turner Group was recommended to Guilford County Schools by NIOSH.
The team’s first report is very preliminary, and consists of an assessment by Cox-Ganser, Bailey and Park and a more detailed building analysis by the Turner Group. The team left monitoring equipment at Oak Ridge Elementary School, and may take up to two months to issue its final report.
The first thing you notice about the report is that, for a school that has been repeatedly cleaned of mold and has tested mold-free, Oak Ridge seems to have a lot of mold.
Cox-Ganser, Bailey and Park noted a “strong, musty, moldy odor” in the basement and crawl space under the school’s library, and lime on the floor of the crawl space, which is usually a sign of water intrusion. They also noted a musty smell in the corridor around the library, and in particular around the school museum.
Since the start of the Oak Ridge environmental problem, Guilford County Board of Education member Darlene Garrett has suggested that the air handlers in the HVAC system are contaminated with mold and may be contributing to the symptoms. The preliminary NIOSH report backs up Garrett’s contention.
“From our initial inspection, it is possible that some of the coils for the HVAC air handlers may have mold contamination,” the NIOSH team wrote. “As further discussed by the Turner Group, these issues will have to be addressed.”
The Turner Group’s report was more specific, saying that the dirt-floor crawl space under the old wing of the building is a likely source of mold. The company based that finding on an inspection of the crawl space and on reports from occupants of the school.
The Turner Group recommended that a flexible vapor barrier be constructed to seal off the crawl space, and that the crawl space itself be depressurized.
Another thread throughout the NIOSH and Turner Group reports is that Oak Ridge has pressure problems. Modern buildings are designed with the air pressure in specific rooms, hallways, attics and other spaces carefully calibrated to limit or control airflow. Air flows from areas with high air pressure, called positive pressure, to areas of low pressure, called negative pressure. That can be a problem with contaminated buildings, because contaminants in an area with positive pressure can travel to areas with negative pressure.
The NIOSH team found airflow issues between rooms and spaces. The NIOSH team said that classrooms should generally have positive pressure compared to hallways, and bathrooms should have negative pressure compared to outer rooms.
“This was not always the case,” the team reported. “During the day, the attic was under positive pressure in regard to the exterior of the building. However, at night, when the dehumidifier (which serves the classroom wings) was turned off, this resulted in the attic being under negative pressure in regard to the outside of the building. This allowed outside humid air to enter the attic.”
If there is a mold problem at Oak Ridge Elementary School, it’s also a water problem. Mold only grows in the presence of moisture. Another recurring theme at Oak Ridge is that the school has had persistent low-level leaks in its roof, walls and floors. The NIOSH report highlighted two possible causes of water getting into the school: moist air getting into the school because of HVAC problems and direct infiltration through the roof, walls and concrete foundation slab.
The NIOSH team reported that the foam roof on the old section of the school had multiple damaged areas, and there did not appear to be adequate flashing – metal sheets added to building components to prevent water intrusion – at the junction between Room 206 and the school’s gymnasium. The team also, using an infrared camera, found moisture in a recently repaired exterior wall next to the gym’s bleachers. The team said the roof and the flashing should be repaired.
The NIOSH team found that the inadequate flashing at the junction of the gym wall and Room 206 was the probable cause of mold found in the carpets in that room. The team reported that the flashing appears to be mounted on the surface of the wall, rather than continuing through the gym wall to prevent drainage. The team recommended that Guilford County Schools install through-wall flashing at the junction. The team also reported that flashing outside Room 400, which had already been repaired, had resulted in leakage and caused mold to grow in that wall.
Flashing mounted on the surface, rather than in the wall, may be a sign of flashing slapped on at the last minute, which fits with the records of the project team that monitored the reconstruction of the school in 2005.
Documents generated by the Oak Ridge Elementary School project team show that the mold and moisture problems predate the school’s opening – and that at least some flashing in the school had not been done by May 2005, when there were already students in the building and when heavy rains caused several leaks in the brand-new roof of the building, resulting in wet inside walls and puddles of water on hallway floors.
At that time, Chris Roth, the representative for HICAPS Construction Management Services, which was managing the construction project, reported that scuppers – drains to let water out of exposed parts of buildings – had not been flashed to prevent leaks. Roth said the contractor – Lyon Construction of Winston-Salem, or its subcontractor – was trying to identify and fix the leaks, and that the roof was covered by a warranty. Sources at the school say the contractor was called to the school to fix roof leaks under warranty several times after 2005. The roof is no longer under warranty.
The NIOSH team’s preliminary report also suggested that water could be leaking into the school’s concrete foundation slab, something that had been suggested by parents and teachers. The team found surface drainage issues around the school, particularly between two of the school’s wings, and that a storm drain outside the library was blocked and full of standing water.
“Such issues may lead to water infiltrating the concrete slab,” the team found.
The finding of new mold at Oak Ridge Elementary School doesn’t of necessity mean that the mold is causing the current health problems at the school, or that the health department’s fresh-air theory is wrong. But it disproves the theory that the mold and problems and water leaks at the school have all been solved.