Page 321 - Materials Chemistry, Second Edition

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292 Waste Management Practices: Municipal, Hazardous, and Industrial
● Rock falls set off by explosives
● Sudden liquefaction of soil after a long period of repeated wet–dry cycles
Unstable areas are susceptible to events or forces that may impair the integrity of landfill struc-
tural components (e.g., liners, leachate collection systems, final covers, and run-on and runoff
systems). Unstable areas include those susceptible to mass movements (landslides, avalanches,
debris slides, and rock fall) and karst topography. Karst topography has developed from the disso-
lution of limestone or other soluble rock. Common physiographic features present in karst terranes
include sinkholes, sinking streams, and caves. Such conditions may impair foundation conditions
and result in inadequate support for the components of a landfill unit.

10.4 REQUIREMENTS OF OPERATION

The operating requirements for MSWLFs, provided in RCRA Subpart C, came into effect in 1993.
These detailed requirements were formulated to ensure the safe daily operation and management at
MSWLF units and include:

● Detection and exclusion of hazardous waste from the facility
● Use of appropriate cover material for daily cells and the closed landfill
● Disease vector control
● Explosive gas control
● Air monitoring
● Facility access
● Run-on and runoff control systems
● Surface-water requirements
● Restrictions on liquids entering the cells
● Record-keeping requirements
The Subpart C requirements are by no means, however, the sole determinants of landfill oper-
ation. Operators must comply with a host of other federal laws. For example, discharges from a
MSWLF into surface waters must be in conformance with sections of the Clean Water Act. In addi-
tion, burning of MSW (on those infrequent occasions when it is permitted) is regulated under the
Clean Air Act.

10.4.1 RECEIPT OF HAZARDOUS WASTE
A key concern of regulators, site owners, and lenders is the possible transformation of a sanitary
landfill designed to accept only municipal and commercial wastes to a contaminated site.
Unfortunately, prior to the enactment of Subtitle D, several Superfund sites had their origins in this
manner. Long before the enactment of RCRA, some sanitary landfills accepted substantial volumes
of industrial wastes, some of which were hazardous and many were in liquid form. The hazardous
composition of the waste combined with their proximity to populations and other sensitive recep-
tors contributed to a high ranking on the National Priorities List. In order to prevent such situations
occurring in the future, operators of MSWLFs were required to implement a program for detecting
and preventing the disposal of hazardous wastes and polychlorinated biphenyl (PCB) wastes at their
facility (40 CFR Part 258.20). This program includes random inspections of incoming loads, train-
ing of facility personnel to recognize hazardous wastes and PCB wastes, and notification of regu-
latory authorities if a hazardous waste is discovered at the facility.
According to Subpart D of 40 CFR Part 261, a “solid waste” is deemed a “hazardous waste” if
it: (1) is listed; (2) exhibits a characteristic of a hazardous waste (ignitability, corrosivity, reactivity,
and toxicity) (see Chapter 11, Identification of Hazardous Waste); or (3) is a mixture of a listed