For information contact:
    Region 1
    Ground Water Management Section
    John F. Kennedy Federal Building
    One Congress Street
    Boston, MA 02203  (617)565-3615
    Region 2
    Underground Injection Control Section
    26 Federal Plaza, Room 853
    New York, NY 10278   (212)264-1547
    Region 3
    Underground Injection Control Section
    841 Chestnut Building (3WM43)
    Philadelphia, PA 1910   (215) 597-9928
    Region 4
    Underground Injection Control Section
    345 Courtland Street N.E.
    Atlanta, GA 30365  (404) 347-3379
    Region 5
    Underground Injection Control Section
    77 W. Jackson Street
    Chicago, IL 60604  (312)886-1492
    Region 6
    Underground Injection Control Program
    1445 Ross Avenue
    Dallas, IX 75202-2733   (214) 655-7160 or
    Region 7
    Underground Injection Control Section
    726 Minnesota Avenue
    Kansas City, KS 66101  (913) 551-7369
    Region 8
    UIC Program/Enforcement Section
    999 18th Street - Suite 500
    Denver, CO 80202-2466  (303)293-1413
    Region 9
    Source Water Protection Section (W-6-2)
    75 Hawthorne Street
    San Francisco, CA 94105  (415)744-1838
    Region 10
    Ground Water Section (WD-133)
    1200 Sixth Avenue
    Seattle, WA 98101  (206) 553-1369
             United States         EPA 813-F-94-003
             Environmental Protection      July 1994

             Office of Water (4602)
,n,FPA  Class  II  Injection
^^** **  ...   ..        j Vr
             Wells  and Your
             Drinking Water

      :ore than 89 percent of U.S. public
      water supply systems draw some
      or all of their drinking water from
sources found underground in rock,
sand, and gravel. Ground water also
feeds rivers, lakes, and streams used for
drinking water.  Ground water has no
respect for state boundaries. It contin-
ually moves, sometimes recharging
surface waters hundreds of miles away
from where it started.

 Most ground water used for drinking
is located near the earth's surface and
is easily contaminated. Of major con-
cern is the potential contamination of
underground sources of drinking water
(USDWs) by any of the hundreds of
thousands of injection wells nationwide.
Injection wells dispose of approximately
11 percent of the nation's fluid waste.

 The U.S. Environmental Protection
Agency (EPA) is working in partnership
with state and local governments to
prevent injection wells from contamin-
ating your drinking water resources.
You can help by learning about EPA's
Underground Injection Control (UIC)
program so that you can identify injec-
tion wells in your community that may
contaminate your drinking water.
 Basically, injection wells are man-made
or improved "holes" in the ground,
which are deeper than their widest
surface dimension and are used to
discharge or dispose of fluids under-
ground. When properly sited, construc-
ted, and operated, injection wells can be
an effective and environmentally safe
means of fluid waste disposal. There
are many different types of injection
wells, but they are all similar in their
basic function.

What is a Class II Well?
 Class II wells inject fluids associated
with oil and natural gas production.
Most of the injected fluid is brine that is
produced when oil and gas are extrac-
ted from the earth (about 10 barrels of
brine for every barrel of oil). The brine
is reinjected to increase production, or
for disposal. Some Class II wells are
used to store hydrocarbon products.
Class II wells inject 300 billion gallons
of fluid each year.

  Under the  UIC Program, EPA and
   the states regulate more than
  400,000 injection wells. Class II
  wells comprise 41 percent of the
     injection wells in the U.S.

 Texas has more Class II wells than any
other State. However, California, Kan-
sas, Ohio, and Oklahoma each have a
large number of operating Class II

How Does EPA Protect
Your Drinking  Water
from Class II Wells?
 Although Class II injection wells pene-
trate underground sources of drinking
water, they do not significantly threaten
them, provided that the wells are sited
properly, used correctly, and tested
regularly. The brine they inject is often
saltier than sea water and can contain
toxic metals and radioactive substances.
Therefore, if brine were to leak from the
well or to move from the injection zone,
it could contaminate underground
drinking water sources.

 Ninety percent of Class II wells are
located in rural areas, where most
people get their drinking water from
underground sources.  The failure of
even one Class II well could threaten
the health of thousands of people.  For
this reason, and to ensure the purity of
all underground sources of drinking
water, EPA closely oversees Class II
injection practices.
 Federal regulations set minimum
national standards for siting, construct-
ing, operating, and testing these wells.
States with EPA approved underground
injection control programs can adopt
more stringent regulations, as neces-
sary. At a minimum, Class II operators
must test the casing of the well for leaks
at least once every five years. In addi-
tion, EPA or the state authority period-
ically inspects Class II wells to confirm
that operators are adhering to Class II

 To continue preventing Class II wastes
from contaminating underground drink-
ing water sources, EPA is developing
more stringent construction and testing
standards for Class II wells.

                                                    How Can You Help?
                                                     Federal and state UIC programs help
                                                    protect drinking water resources, but
                                                    must have local support. Local govern-
                                                    ments and citizens themselves often are
                                                    in the best position (and have the
                                                    great-est incentive) to ensure that
                                                    injection wells do not endanger under-
                                                    ground drinking water sources, public
                                                    health, and the environment. To find
                                                    out more about the UIC program and
                                                    what you can do to protect your
                                                    drinking water, contact your EPA
                                                    Regional Office.
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