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

IMPACTS ASSOCIATED WITH OIL AND GAS
standards for oil and grease content, and pass a toxicity test prior to discharge. There are some
negative effects associated with this practice:
• Often, enormous quantities of CBM produced water are discharged all year long, which
alters the seasonal nature and timing of natural flows. If such practices are allowed to continue,
the water volume of some rivers may be doubled, and streamside trees and plants
that have adapted to the previous water conditions may not be able to survive. 309
• Dumping large volumes of produced water into streams can wash away stored nutrients,
and without these food sources, aquatic organisms may not be able to survive.
• In Wyoming and Montana, it is common practice to dump produced water from CBM operations
into streams. Often, however, discharges are permitted into streams and rivers without
proper testing. 310 This poses a danger to aquatic life and landowners living downstream
who use the water for irrigation, since the produced water may contain high concentrations
of salts and dissolved solids.
Surface Discharge: Discharges of produced water on land may flood the property of landowners,
which can lead to erosion and damage to soils and plants. 311 The effects of the surface disposal
of produced waters can also include swamping; siltation of streams, lakes, and reservoirs;
and contamination of soil, ground water and surface water by salts, hydrocarbons, metals,
and radioactive materials. 312
The discharge of produced water inappropriately onto soil can result in salinity levels too high
to sustain plant growth. In some areas, however, produced water may contain low enough levels
of salt that it may be used for beneficial use for irrigation or livestock watering.
Occasionally, produced water is spread on roads as a dust suppressant. Roadspreading is
declining as a disposal option, however, and in 1995 it accounted for less than 1 % of produced
water disposal. 313
NATURALLY OCCURRING RADIOACTIVE MATERIALS (NORM)
Naturally occurring radioactive materials may be present in oilfield solid or liquid wastes. As
well, radioactivity may be found on oil or gas industry equipment. 314
Depending on the geology, subsurface formations may contain radioactive materials such as uranium
and thorium and their daughter products, radium 226 and radium 228. Radionuclides are
leached into groundwater or surface water when the water comes in contact with uranium- and thorium-bearing
geologic layers. NORM can be brought to the surface in produced water from these formations.
In addition, radon gas, a radium daughter, may be found in produced natural gas. 315
The primary carrier of the NORM is the produced water from the reservoir. When the produced
water is brought to the surface, the changes in temperature, pressure and salinity cause a scale
to form. 318 For example, radium 226 and 228 found in produced waters may become concentrated
by attaching to barium sulfate scale in well tubulars and surface equipment. Elevated
concentrations of radium 226 and 228 may also occur in sludge that accumulates in oilfield
pits and tanks. 319 Often, high concentrations of oil-and-gas-related NORM are associated with
separator tanks, water storage tanks, and water lines where brine scale and tank sludge accumulate.
320 Consequently, workers employed in the area of cutting and reaming oilfield pipe,
removing solids from tanks and pits, and refurbishing gas processing equipment may be
exposed to radioactive materials that could pose health risks. 321 The main health risks for
humans are direct gamma radiation from NORM-bearing soils and equipment, breathing of
NORM-bearing dust, or breathing indoor radon in structures built on NORM-affected soils. 322
The U.S. EPA estimates
that 30 % of producing
oilfields in the United
States have enough
NORM to warrant health
and environmental concerns.
316 One industry
estimate suggests that if
strict regulatory requirements
for assessment
and cleanup of NORM
were put in place in the
United States, 20 % of oil
production and 8 % of
gas production would
become uneconomic. 317
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