Cleaning up mold at Tokay High requires 8-step process

Ever since experts diagnosed Tokay High School with a severe mold problem last week, Lodi Unified School District officials have been throwing around phrases like "mold remediation" and "containment." Those terms may not mean much to the average Joe who's never had to fight off a mold contamination.

"It's a fair bit of work," said James Mallory, operations manager at Environix, a mold evaluation and remediation company based in Washington with offices in Modesto.

According to Mallory there are eight steps to mold remediation:

Evaluation

During the evaluation phase workers pin down where in the building the mold is and how far it has spread. Those lucky enough to have the mold contained to a corner or a specific part of the wall will only have to section off that part of the room.

Buildings that have mold growing throughout the entire room or structure, like some of the classrooms at Tokay High, though, will have to use more drastic containment procedures.

Containment

In order to prevent the mold from spreading to clean parts of the building, workers put up thin plastic sheets around the affected areas.

To prevent mold spores from coming out of the building, workers also set up a staging area, where they can change out of their protective clothing without causing further contamination.

If moldy materials, such as carpet or Sheetrock, need to be taken out of the building, a tunnel will be erected out of the same thin plastic material that's used for the work area leading to the nearest exit.

"Even the most perfect containment job is going to have some leaks," Mallory said.

That's where the fans come in.

Negative air pressure

Using large fans, workers create a negative air pressure inside the room they're working on. Mallory said that the pressure created by the fans is so strong that the walls should billow slightly inward.

Since the pressure inside the room is lower than pressure outside, mold spores are pushed back into the building through the small holes in the containment area. This ensures that no spores will escape to infect other nearby rooms or buildings.

A strong HEPA filter is attached to the fans to clean the air that is circulated out of the building.

Removal

After workers ensure that no mold will escape the contained area, they get to work on removing the infected materials. Moldy carpets and Sheetrock are double-bagged and brought out of the contaminated area via the plastic tunnel.

According to Mallory, since mold occurs naturally in the atmosphere, disposal of moldy materials isn't usually regulated and it can just be dropped off at the dump.

Vacuuming

Mold removal, like any sort of construction, creates a lot of dust. What's unique to mold removal, though, is that the dust, or spores, can plant itself back into the affected area and create a whole new problem.

To make sure that doesn't happen, workers use a special type of vacuum, originally designed to remove asbestos, to suck up most of the remaining spores.

The HEPA filter attached to the vacuum prevents those spores from being blown back into the room's atmosphere.

Anti-microbial solution

To eradicate any remaining spores, workers wipe down everything in the room with an anti-microbial solution.

Ideally, Mallory said, the solution should kill off the spores that are left in the room, but it doesn't always turn out that way.

"If you miss one or two, it's not a big deal," Mallory said.

Because mold is naturally in the air, it will find its way back into the building as soon as its regular inhabitants return. The trick is to get as many as you possibly can.

Clearance testing

Workers then conduct an air quality test to determine the amount of mold in the room.

"In a school, a zero level of mold spores is nearly impossible," Mallory said. What workers want to do is compare the amount of mold outside to the amount of mold inside and make sure they're the same.

According to Mallory, only in very specialized rooms, like those in the transplant wing of a hospital, will a mold remediation company try to remove all traces of mold.

Rebuild

Construction workers usually keep up the containment barriers when putting up replacement dry wall or Sheetrock.

Mallory said that a crew of three to four men can remove all the mold from one average-sized classroom in a couple of days.

Tokay High's mold problem could potentially affect 60 classrooms.