Fuel Solvents and Pesticides
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Hazardous Materials (HM) are substances that cause adverse health effects via inhalation,
physical contact, ingestion, or combustion. These substances can also threaten water
quality through accidental spills at fixed sites as well as during transportation.
Fixed sites include both businesses (industrial and commercial operations that use
HM) and homes (from residential heating oil tanks and various hazardous household
products).
Transportation-related risks come from cars, trucks, aircraft or rail cars that
traverse the watersheds. The potential severity of a water quality impact by a release
of hazardous materials
depends on its proximity to the reservoir or its tributaries,
the type of material discharged, and the amount of material released.
Solvents include a range of organic liquids that are used in a variety of household
products such as paint, cleaners, degreasers, and other applications. The most dangerous
solvents often contain a chlorine atom and are usually referred to as chlorinated
hydrocarbons. This class of solvents includes compounds such as carbon tetrachloride
and methylene chloride. Some pesticides are also chlorinated hydrocarbons. They
include:
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DDT |
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Aldrin |
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Dieldrin |
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Chlordane |
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Heptachlor |
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Lindane |
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Endrin |
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Toxaphene |
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Chlorinated hydrocarbons have low solubility in water and a strong tendency to attach
to soil particles, thus rarely contaminating groundwater. Originally they were thought
to be safe for the environment; later they were discovered to accumulate and build
up to toxic concentrations in the food chain. The use of many of these pesticides
has been restricted, suspended, or cancelled.
Modern pesticides include a diverse number of compounds, grouped according to the
pest they control (such as their names imply): insecticides, miticides, nematicides,
herbicides, plant growth regulators, fungicides, bactericides, etc. The first pesticides
contained toxic metals such as arsenic, mercury, copper, and lead, but these were
seldom used after World War II and rarely appear in groundwater today.
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