Page 648 - Materials Chemistry, Second Edition

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Construction and Demolition Debris 619
Presidio Army Compound was turned over to the National Park Service following clean-up
(Regula-Thompson, 1997).
Several buildings at a former naval supply center in the port of Oakland are being decon-
structed. The warehouse being deconstructing has over 400,000 board feet of lumber including old-
growth Douglas fir and redwood. An open house was held at the port and invitations were sent to
local architects and contractors advertising the materials available (Regula-Thompson, 1997).
Deconstruction is labor-intensive and often relies on the use of hand tools and manpower to take
apart buildings and structures. When deconstructing buildings, workers should take precautions to pro-
tect themselves from exposure to substances such as lead-based paint and asbestos (U.S. EPA, 2002).

Benefits of deconstruction include (CEC, 1997):
● Lower building removal costs. Deconstruction can cost less than demolition because
costs are offset by reselling materials salvaged during the process.
● Avoidance of disposal costs. The majority of materials from deconstructed structures can
be salvaged, thereby decreasing debris going to landfills and avoiding shipping costs and
tipping fees.
● Increased employment opportunities. Deconstruction is an opportunity to create interim
jobs. Deconstruction projects have been linked to job training programs, where less
skilled workers can gain experience in carpentry, construction, and materials recovery.
● Regulatory compliance. Many states now require a substantial reduction in the amount
of solid wastes disposed in landfills by a specified date.
● Local business development. Salvage industries have strong growth potential.
● Cheaper and better quality building materials. Reused materials are less expensive and
sometimes of higher quality than new materials. For instance, some wood structures on
military bases contain old growth wood, which is excellent quality and rare lumber.
● Reduced environmental impacts. Deconstruction has fewer environmental impacts on
adjacent property because it creates less dust and noise than demolition.
● Diverts valuable materials from landfills and provides consumers and builders with an
alternative to buying building products made from virgin resources.

20.7 HAZARDOUS MATERIALS
A number of hazardous materials may be removed from structures during demolition and may include
floor lamps, mercury thermostats, and PCB-containing lighting ballasts (Table 21.4). Mercury found

TABLE 21.4
Common Building Components Containing Hazardous Materials
Component Hazardous Material
Flourescent light bulbs Mercury
High-intensity discharge (HID) lamps Mercury
Thermostats Mercury
Lighting ballasts for fluorescent light bulbs PCBs, bis(2-ethylhexyl) ester
and HID lamps di(2-ethylhexyl) phthalate
Silent wall switches Mercury
Batteries Lead, cadmium
Roof vent flashings Lead
Lead pipes and lead painted surfaces Lead
Discarded paint, oil, pesticides, cleaning agents Assorted
CCA-treated wood Chromium, arsenic