Most ground water used for drinking occurs near the
earth's surface and is easily contaminated. Of major
concern is the potential contamination of underground
sources of drinking water by any of the hundreds of
thousands of subsurface wastewater disposal injection
wells nationwide. Waste disposal wells dispose of
approximately 11 percent of the nation's fluid
waste. Injection wells can be either beneficial or a
major problem. These wells are used in a broad variety
of ways from beneficial uses such as aquifer recharge
and the production of oil, gas and minerals, to the
improper use for disposal of toxic and hazardous wastes.
The Safe Drinking Water Act of 1974 established the
basic framework for protecting the drinking water of
the United States. Congress recognized the potential
threat of injection wells to ground
water quality when they passed this Act instructing
the U. S. Environmental Protection Agency (EPA) to establish
a national program to prevent underground injection
activities that endanger drinking water sources. The
EPA is required to regulate underground injection of
fluids and fluid wastes through wells that discharge
or that may discharge into or above an underground
source of drinking water. EPA has promulgated a
series of Underground Injection Control (UIC) regulations
to protect underground sources of drinking water. States
may choose to have primary responsibility for carrying
out these regulations. In New England, all six states
are authorized to administer State Underground Injection
Control Programs. The EPA New England Region works with
state, tribal and local governments to support their
management of injection wells in order to prevent contamination
of drinking water resources by these wells. EPA provides
states with technical support and program guidance.
EPA defines five
classes of injection wells according to the type of waste they inject and where
the waste is injected. New England State Underground
Injection Control Programs focus primarily on regulation
of shallow Class
IV and Class V wells. There are no known Class I, II or III injection
wells in New England. Non-hazardous fluids and wastewater
are commonly discharged below ground through several
Class V well types. There are many different types of
Class V wells; however, they are all similar in their
basic function--to dispose of waste fluids underground.
EPA recently adopted a new
rule for Class V wells which sets new requirements for large-capacity cesspools
and motor vehicle waste disposal wells.
Class V subsurface wastewater disposal wells are common
in New England. Often they are located in rural and/or
unsewered areas where people depend on ground water
for their drinking water. Some Class V wells are technologically
advanced wastewater disposal systems used by industry;
however, many injection wells are "low tech"
man-made or improved "holes" in the ground
that are deeper than their widest surface dimension.
Generally, they are shallow and depend upon gravity
to drain or "inject" fluid waste underground.
New England Class V well injection systems commonly
use septic system leach fields, leaching pits and trenches,
dry wells, cesspools and wells to dispose of their wastes.
When properly sited, constructed, and operated, these
systems can be an effective and environmentally safe
means of waste disposal. A Class V well's potential
to endanger a nearby underground drinking water supply
source depends largely on the type and/or quantity of
fluid it injects. Their simple construction provides
little or no protection against possible ground water
contamination; so, it is important to control what goes
into wastes discharged. See EPA's 1999 Class V Underground
Injection Control Study for further information about the types of wells found
nation-wide.
EPA requires all well owners and operators to submit
inventory information about their wells; and, EPA and
state regulations prohibit well operators from endangering
underground drinking water sources. Owners of injection
wells are not allowed to discharge fluids or waste fluids
containing any contaminant that may cause a violation
of any National
Primary Drinking Water Quality Standard or that may otherwise adversely affect human health.
Class V wells that inject Resource
Conservation Recovery Act (RCRA) listed hazardous waste are Class IV wells and Class
IV wells are prohibited by federal and state law.
If a facility generates waste fluids and is not connected
to a municipal sewer, it is important to find out where
sewage and non-sewage fluid wastes are discharged. If
these wastes are discharged into a septic system, dry
well, leach field, leaching pits and trenches, cesspool
or well, the facility may have a Class V subsurface
wastewater disposal well which may endanger a drinking
water supply. If the facility has an injection well,
the owner or operator should call their State
Underground Injection Control Program for information
concerning the best ways to manage their wastewater
disposal.
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