Oil and Gas at Your Door? (2005 Edition) - Earthworks

IMPACTS ASSOCIATED WITH OIL AND GAS
benefits for the companies are that these systems greatly reduce or eliminate soil contamination,
thereby reducing remediation costs.
• Other measures to protect wildlife and livestock include systems to prevent oil from entering
waste pits; immediately cleaning up any oil spills into open pits; adequate fencing
around waste pits and tanks; and netting to keep birds from entering waste pits. If netting
is not installed properly or maintained well enough (e.g., if there are tears in the netting or
if it sags into the waste pit, which is common after it snows), the oil will be exposed. Nets
should be installed four or five feet above the pits to allow for sagging. 265
For example, a study conducted in 1994 documented the effects of a pipeline spill on livestock.
266 Cattle on two ranches were exposed to a mixture of gases including hydrocarbon
vapors, sour gas, and sulfur dioxide. The study concluded that:
• there was an increase in illness and death in both herds
• calves suffered a “failure-to-thrive syndrome” (i.e., calves failed to nurse, had slow weight
gain, and were prone to infection)
• open sores and other evidence of exposure to irritating substances were observed in the
upper respiratory tracts of calves
• changes in maternal behavior were observed in both herds
• some cattle had difficulty in placement of their limbs
Releases of Hydrocarbons—Land and Water
In addition to hydrocarbons being emitted into the air, releases of hydrocarbons can flow across
the land surface, seep into the soils and groundwater or flow into surface waters. Releases of
hydrocarbons may occur in a single event, e.g., a spill, or over longer periods of time, e.g., seepage
from pits, or slow leaks from pipes and storage tanks. Spills are the most common type of
release and are often small in quantity. 267 Spills and seepage may result from human error,
equipment failure, improperly designed containment facilities, past oilfield practices, vandalism,
or natural phenomena (e.g., lightning strikes, flood damage).
• Spills of hydrocarbons may come from several sources or operations at production and
drilling sites: leaking tanks, pipes, flowlines, valves, joints, or gauges; blowouts (see box on
next page); oil transfers; diesel from drilling operations; offloading of oily drilling muds and
production chemicals.
• High concentrations of hydrocarbons are found in the bottoms of oil storage tanks (i.e., tank
bottoms), which contain a mixture of crude oil, salt water, sand, and scale from the tank itself.
FIGURE I-32. SOUTHEAST NEW MEXICO: Left: produced water pit with layer of oil on top. Right: Leaking waste-oil
tank. No netting and inadequate fencing allows access to these toxic hydrocarbon wastes. Photo by C. Johnson.
I-55