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A Brief History of Waste Management 43
vectors, and less of an overall hazard to public health. This simple step was significant as it greatly
alleviated problems such as uncontrolled fires, windblown refuse, and rodent infestations.
Landfill practices gradually improved over time although proper planning, engineering, opera-
tions, and staff training were slow to evolve. By 1959, the sanitary landfill was the primary
method of solid waste disposal for U.S. communities (ASCE, 1959; McBean et al., 1995). The
American Society of Civil Engineers in 1959 published the first engineering guide to sanitary
landfilling which detailed the compaction of refuse and the placement of a daily cover to reduce
hazards of fire, odor, and rodents.
Although design and operation were a substantial improvement over earlier land disposal
efforts, the sanitary landfill still suffered from numerous deficiencies. It did not sufficiently
address groundwater contamination, surface runoff, odor and gas emissions, and related public
health concerns. At this time, there was only limited knowledge regarding the infiltration of sur-
face water through a covered landfill, and the consequent reactions of this water upon contact
with wastes. There also came the belated recognition of the potential impact of escaping con-
taminants (leachates) on groundwater quality. Eventually, it was decided that, to ensure minimal
protection of the local environment, the installation of an engineered cover system to reduce
long-term leachate generation and an impermeable or slowly permeable liner across the base of
a landfill to prevent the escape of any leachates to the environment, were essential (Tammemagi,
1999).
Many communities, however, continued open burning and open dumping into the 1960s.
According to the U.S. Federal Bureau of Solid Waste Management, 94% of all land disposal oper-
ations in the mid-1960s was inadequate in terms of air and water pollution, insect and rodent prob-
lems, and physical appearance (Tammemagi, 1999).
Public awareness of the potential hazards posed by MSW landfills increased. By the 1970s and
1980s, there was growing concern about the effects of landfills on contamination of groundwater.
Groundwater, stored in underground strata and tapped by wells, provides drinking water for approx-
imately 90% of the U.S. population (U.S. EPA, 2001b). Once groundwater becomes contaminated,
it is very difficult, slow, and expensive to remediate. The concentration and toxicity of some land-
fill leachates were considered capable of increasing the risk of cancer (Brown and Donnelly, 1988;
Tammemagi, 1999). A number of toxic materials from households (e.g., batteries, pesticide con-
tainers and paints ) were found in leachates along with a wide range of industrial wastes, previously
not restricted from municipal landfills.
As a result of the enactment of stringent federal regulations such as the Resource Conservation
and Recovery Act and its amendments (see Chapter 3), numerous modifications were made in san-
itary landfill design. Caps constructed of clay or impermeable synthetic materials, such as high-den-
sity polyethylene, were placed over landfills undergoing closure to decrease the infiltration of
precipitation, thus limiting the formation of leachate. Bottom liners, constructed of similar materi-
als, were introduced to capture any leachate that formed within the landfill. In addition, subsurface
and surface collection systems were installed to capture and remove leachate and landfill gas.
Monitoring of groundwater quality and gaseous emissions became a required component of proac-
tive landfill operation.
In spite of these technical advances, there was continuing concern about groundwater contam-
ination. Studies during the late 1970s indicated that leaking leachate was a problem facing all land-
fills. The U.S. EPA estimated that in 1990 more than 75% of U.S. landfills were polluting
groundwater with leachate (Lee and Jones, 1991). There was also concern that even state-of-the-art
municipal landfills with double liners and other modern leachate containment systems would even-
tually fail. In other words, the increased use and sophistication of engineering techniques could only
postpone the onset of groundwater contamination.
By the 1980s, the importance of selecting a site that minimized the environmental impact of a
landfill was recognized. New siting criteria emphasized the importance of sites that were well above
the groundwater table, that did not occur in groundwater recharge zones, that were not in natural