The school system undertook asbestos abatement programs in the 1980s and 90s, not asbestos eradication. That means that they removed the asbestos that was exposed and causing an immediate hazard, while leaving other asbestos that was in sealed spaces. Renovating would stir up some of the remaining asbestos-containing building materials in sealed-off spaces.

Not all asbestos in the schools is sealed off. Some rooms have floor tiles with asbestos in them.