Asbestos is a naturally occurring mineral that is also a known carcinogen. Unlike most minerals, which turn into dust particles when crushed, asbestos breaks up into fine fibers that are too small to be seen by the human eye. Asbestos was commonly used as an acoustic insulator, thermal insulation, and for fire proofing. Asbestos can be found in water pipes, sewer pipes, cement siding, tile, insulation, roofing felt, construction mastics, and cement wallboard among many other uses. Asbestos products can be found in most buildings built between 1950 and 1980. Asbestos is still in limited use. Often, individual fibers are mixed with a material that binds them together, producing asbestos-containing material (ACM). It is this ACM that our CABIs are looking for in a soil excavation site. ACM when encountered is identified by the CABI, laboratory samples collected and analyzed, and the material handled according to Section 5.0 of the Colorado Solid Waste Regulations.