Environmental Engineering Reference
In-Depth Information
health problems associated with biological contaminants. Contaminant-spe-
cific source control methods are described in detail for these three contam-
ination and potential contamination problems in the following sections.
A. Asbestos
Source control is the only acceptable mitigation option for asbestos in build-
ings. This reflects its hazardous nature and the need to prevent asbestos fibers
from becoming airborne. A variety of source control methods are used to
minimize asbestos fiber exposures to service workers and building occupants.
These include O&M practices, repair, enclosure, encapsulation, and removal.
1.
Building operation and maintenance
Building O&M practices are considered to be an interim control approach
(during the period between when friable ACM is identified and assessed in
a building and long-term abatement efforts are implemented). In many cases,
O&M is used to minimize exposures to service workers and building occu-
pants until ACM must be removed as a result of USEPA regulatory require-
ments for removal during renovation or demolition.
Detailed guides that describe O&M practices for building ACM have
been developed for schools and for managers of other buildings, and a
guidance document for service and maintenance personnel has been devel-
oped and made available by USEPA.
Central to O&M programs is a requirement that service and maintenance
personnel know how to recognize ACM and know where it is located so it
is not inadvertently disturbed by their activities. Asbestos-disturbing activ-
ities to be avoided include: (1) improperly removing ACM during plumbing
repairs; (2) changing light fixtures in ceilings with asbestos-containing acous-
tical plaster; (3) causing physical abrasion by moving construction equip-
ment and furniture; (4) removing potentially contaminated ceiling tiles
below ACM; (5) disturbing ACM while installing or repairing HVAC system
ductwork, automatic fire sprinkler units, or electrical conduit or computer
system wiring; (6) drilling holes in ACM; (7) hanging or attaching materials
to ACM; and (8) resuspending asbestos fiber-contaminated dust under ACM
by dry sweeping and dusting.
Custodians in buildings with surfacing ACM are advised to conduct all
cleaning with damp cloths and mops to minimize resuspension of asbestos
fibers. Maintenance and custodial activities in which building employees con-
tact but do not disturb ACM are defined by the Occupational Safety and Health
Administration (OSHA) as Class IV asbestos work. In cleaning small quantities
of asbestos-containing dust from horizontal surfaces, custodial workers are
subject to OSHA work practice requirements. They must be trained in accor-
dance with OSHA's awareness training program, use wet methods and HEPA
vacuums, and promptly clean up and properly dispose of ACM debris.
When service workers conduct routine maintenance and service activi-
ties involving thermal system insulation (TSI) and surfacing materials (SM)
