SEPA
United States
Environmental Protection
Agency
Office of Water (WH 550)
EPA 570/9-91-UIC4
July 1991
Restricting Service Station
Wastes In Shallow Injection
Wells
EPA has sampled wastewater at motor vehicle service stations that use shallow injection
wells and found that more than half these samples far exceed the Maximum Contaminant
Levels (MCLs) established under the Safe Drinking Water Act. In addition, samples did not
pass new limits established under the Resource Conservation and Recovery Act (RCRA)
and would be considered hazardous waste.
EPA and State authorities urge service stations that use discharge pits, dry wells, cess-
pools, septic system drain fields, or other shallow injection wells to close them and
dispose of their waste by other means.
BACKGROUND
Ground water provides approximately 50 percent of the
nation's drinking water. Seventy-five (75) percent of our cities
derive all or part of their drinking water from underground
sources, and rural America is 95 percent dependent upon ground
water. It follows that underground sources of drinking water
must be kept free of contamination. The U.S. Environmental
Protection Agency (EPA) is required by the Safe Drinking Water
Act to protect the quality of these drinking water sources.
To fulfill this responsibility, EPA is empowered to regulate the
disposal (injection) of fluids by wells of all kinds. Under EPA's
Underground Injection Control (UIC) regulations, an injection
well can be thousands of feet deep or it can be as shallow as a dis-
charge pit, dry well, cesspool, or septic system drain field.
EPA's UIC programs have been in operation since 1983. Only
since 1988, however, has EPA been able to turn its attention to
the ground-water threat from shallow injection wells. EPA has
banned the injection of hazardous wastes into these wells.
DO AUTOMOTIVE SERVICE STATION
WASTES THREATEN GROUND WATER?
Tests conducted by EPA on fluid samples from service station
bay drains indicate that improper disposal of waste generated
during vehicle servicing poses the threat of ground-water con-
tamination. Waste oil, antifreeze, and solvents are washed into
floor drains that often are connected to septic systems with
shallow injection wells. Many of the ingredients of these fluids
are water soluble and are not separated from the wastewater by
conventional oil-water separators. Shallow injection wells are
designed to allow drainage of fluids into the subsurface. As a
result, contaminated fluids migrate through the soil to our
underground sources of drinking water.
HAVE AUTOMOTIVE SERVICE STATION
WASTES BEEN LINKED TO GROUND-WATER
CONTAMINATION?
While specific causes of drinking water contamination are
difficult to document conclusively, EPA has identified more than
100 cases where shallow injection wells appear to be an important
source of contamination. For 35 of these cases EPA estimates
that a total of more than 1.5 million people could have been
affected. Eight of these cases resulted from shallow injection of
automotive wastes, potentially affecting at least 122,000 people.
These figures underestimate the population potentially exposed,
since data frequently are unavailable on the-number of people
who use a contaminated drinking water source.
DO SERVICE STATION WASTES EXCEED EPA
STANDARDS?
Waste oil may contain several hundred milligrams per liter of
benzene and other volatile organic compounds. Waste solvents
contain a high percentage of chlorinated hydrocarbons. Some of
these chemicals are known or suspected carcinogens. For all of
these chemicals, there are EPA standards, Maximum Contami-
nant Levels (MCLs) established under the authority of the Safe
Drinking Water Act (SDWA). Typical fluid samples contain
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Service Station Wells
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chemicals in concentrations that greatly exceed EPA drinking
water standards.
EPA tested wastewater samples from 17 vehicle repair and
maintenance shops in a program to determine the environ-
mental impact of motor vehicle waste disposal wells. EPA
found that all the samples exceeded the MCLs for lead and
cadmium. In nine of the samples, EPA determined the con-
centrations for benzene and trichloroethylene. All nine
samples exceeded the benzene MCL, and eight of nine
exceeded the trichloroethylene MCL.. EPA has found similar
results in other tests nationwide.
In most cases, typical fluid samples exceed EPA's recently
revised criteria for identifying properties or characteristics that
define a waste as hazardous under the Resource Conservation
and Recovery Act (RCRA). Benzene and a number of
chlorinated solvents are among the 25 chemicals that have
been added to EPA's Toxicity Characteristics list under
RCRA. EPA has found that samples of used crankcase oil
from automobiles measure ten to twenty times the permissible
benzene limits.
In addition, any facility that generates more than 275
gallons of wastewater per month containing any of the newly
listed chemicals in amounts exceeding EPA's regulatory levels
needs either to recycle the material or to dispose of it as
hazardous waste. Effective March 28,1991, facilities that
generate more than 27 gallons of wastewater per month were
included in this requirement. A typical garden hose delivers
27 gallons of water in less than three minutes. (Facilities that
generate less than 27 gallons of wastewater per month are con-
ditionally exempt).
WHAT ALTERNATIVES DO OWNERS OF
SHALLOW INJECTION WELLS HAVE?
EPA believes that owners and operators of automotive
service stations or similar operations should immediately stop
using shallow injection wells to dispose of such wastes as
battery acid, used oil, antifreeze, and degreasers and other
solvents. The Agency has enlisted the commitment of trade
associations nationwide to spread this message, contained in
the brochure. Does Your Facility Generate Automotive Service
Waste?. To obtain a copy of the brochure, contact the Under-
ground Injection Practices Council at:
UIPC
525 Central Park Drive - Suite 304
Oklahoma City, OK 73105
(405) 525-6146
(800) 762-0190
EPA originally required service station owners and opera-
tors to inventory injection wells and to provide this informa-
tion to their State UIC Program within one year of the estab-
lishment of the State UIC Program.
An owner or operator may wish to apply for a Class V UIC
well permit from the State UIC Program and demonstrate that
the well or wells do not threaten underground drinking water
sources. Each State UIC Program has its own permit proce-
dures and requirements. Some States ban all shallow injection
wells, not just those receiving hazardous wastes.
The American Petroleum Institute (API) and a number of
trade associations are developing a recommended practice for
handling water discharges from automotive service facilities
located at petroleum marketing operations. API has identified
several disposal alternatives to shallow injection. To receive a
copy of the recommended practice (to be completed during the
summer of .1991), ask API for RP 1633, Technical Guidance
for Handling Water Discharges From Automotive Service
Facilities. API can be reached at:
American Petroleum Institute
1220 L Street, NW
Washington DC 20005
(202) 682-8000
OTHER CONTACTS
Many trade associations, such as API, the National Automo-
bile Dealers Association (NADA), the National Independent
Autodealers Association (NIADA), and the Society of Inde-
pendent Gasoline Marketers of America (SIGMA) will provide
assistance to owners and operators of automotive service
station wells. Owners and operators may need to contact the
agency responsible for their State's UIC program or the EPA
Regional office covering their State.
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