Page 337 - Materials Chemistry, Second Edition

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308 Waste Management Practices: Municipal, Hazardous, and Industrial

FIGURE 10.10 Application of daily cover prevents pest infestations and controls odors.

10.4.14.3 Disease Vector Control

Vectors include rodents, flies, mosquitoes, or other organisms that transmit diseases to humans.
Putrescible waste attracts vectors, acting as a food source. Application of cover at the end of the
operating day is typically sufficient to control disease vectors; however, other practices may be nec-
essary (40 CFR Part 258.22). These include (U.S. EPA, 1993c):

● Reducing the area of the working face
● Increasing the thickness of the daily cover
● Changing cover type, for example, to a material less permeable to air and water
● Application of repellents, insecticides, and rodenticides
● Composting of organic wastes prior to disposal
● Use of predators for control of insect, bird, and animal populations

Standing water serves as a potential breeding ground for mosquitoes. Water collects in depres-
sions, open containers, leachate storage ponds, and siltation basins. To control mosquitoes, stand-
ing water should be removed and an insecticide possibly applied (U.S. EPA, 1993c). Table 10.8 lists
insecticides used at sanitary landfills. In order to control rodent populations, various birds of prey,
for example, hawks, falcons, and owls can be introduced.

10.4.14.4 Biological Control of Pests
Insecticides may serve as an effective means of combating insect pests at landfills; however,
genetic resistance to applied chemicals is always a consideration. Biological control methods may
be a viable alternative to chemical control at landfills. A number of workers have surveyed the par-
asitoids and predators active in municipal wastes and animal manures. Rueda et al. (1997)
recorded five species of wasp parasitoids in the pupae of house flies and two from blow flies.
Sulaiman et al. (1990) found nine species of pupal parasitoids of flies breeding in municipal
wastes and on poultry farms. Hoyer (1986) determined 22 species of fly parasitoids. In Washington
State, biological control was used in preference to chemical control of flies associated with manure
pits (Guhlke, 1985). Flies had developed resistance to insecticides. Parasitic chalcid wasps had the