United States
Environmental Protection
Agency
Office of Water
Office of Pesticides and
Toxic Substances
Fall 1990
&ER& National Pesticide Survey
,2-Dibromo-3-Chloropropane
(DBCP)
H H H
I I I
H-C—C-C-H
I I I
Br Br a
1,2-Oibromo-3-Chloroprop«n«
(DBCP)
What Is
DBCP?
How Does
DBCP
Behave in
So// and
Ground
Water?
How Do**
DBCP Get
Into Ground
Water?
The U.S. Environmental Protection Agency (EPA) has completed its five-year
National Survey of Pesticides in Drinking Water Wells (NPS), a study of the presence
of 127 pesticides, pesticide degradates, and nitrate in community water system (CWS)
wells and rural domestic drinking water wells. l,2-dibromo-3-chloropropane (OBCP)
was detected in the Survey. This fact sheet provides a description of OBCP, its
potential health effects, and guidance on both treating and preventing well
contamination.
l,2-dibromo-3-chtoropropane is known by the common names dibromochloro-
propane and DBCP. DBCP was registered for use in the late 1940s. DBCP was used
as a soil fumigara for nematode control prior to its cancellation in the United States.
Commercial names for DBCP included Nemafume, Nemanax, Nemaset, Nematocide,
BBC 12, Fumazone, Nemagon, and Oxy DBCP.
The behavior of a pesticide after it is released to the environment is dependent
upon its movement in air, water, and soil as well as the rate at which it is transformed,
or broken down. Pesticides applied to crops or the soil surface may volatilize
(vaporize) to the atmosphere, be carried off by surface runoff, be carried to ground
water through leaching, or remain in the soil through adsorption (adherence) to soil
particles and undergo Uttle movement in air or water. Pesticides may be transformed
by reaction with water, microorganisms, and exposure to sunlight The likelihood that
DBCP wi migrate into ground water is influenced by its tendency to be transported
(move) from soil to air and water and to be transformed by these various processes.
as wet ee by the characteristics of the sfte, such as soil type, moisture, temperature.
and depth to ground water. DBCP has a high potential to be transported, and a low-
to-medium potential to be transformed.
DBCP migration into ground water could result from Its underground injection as
a soil fumigant for agricultural applications. DBCP could also reach ground water from
direct entry into a wen through accidental chemical spite or improper storage near a
well.
WPS f ,2-0ibromo-3-CMoropropcfw (DBCP)
-------
Findings of
the National
Pesticide
Survey
What Hea/t/t
Effects Might
be Caused by
DBCP in
Drinking
Water?
How is Water
Treated to
Remove
Contami-
nants?
How Can
Water
Contamina-
tion be
Prevented?
Based on the results of the NPS, EPA estimates that DBCP is present, at or
above the analytical detection level of 0.010 pg/L used in the Survey, in about 370
(0.4%) CWS wells and 38.400 (0.4%) rural domestic wells nationwide. Considering the
precision of the Survey, EPA estimates that the number of CWS wells with detectable
levels of DBCP could be as low as 33 or as high as 1,480, and the number of rural
domestic wells could be as low as 2,740 or as high as 164,000. DBCP is measured in
micrograms per liter (yg/L) which is equivalent to parts per billion (ppb). In rural
domestic wells DBCP was detected at concentrations above the proposed Maximum
Contaminant Level (MCL) of 0.2 mg/L EPA notified wells owners and operators within
24 hours when detections exceeded health-based guidelines or standards.
Non-Cancer Effects: A Lifetime Health Advisory Level for DBCP in drinking water has
not been established by EPA. Consuming DBCP, however, has been shown to result
in adverse health effects in animal studies, including decreased sperm production and
damage to the kidneys, liver, and testes. CWSs are required to notify customers if the
drinking water that they deliver contains contamination that exceed the MCL
Cancer R/*Jr: DBCP causes cancer in laboratory animals that are given high doses of
the pesticide over the course of their lifetimes. Therefore, EPA considers DBCP to be
a probable human carcinogen (cancer-causing agent). EPA estimates that if an
individual consumes water containing DBCP at 0.03 jjg/L over his or her entire lifetime,
that person would theoretically have no more than a one-in-a-miilion chance of
developing cancer as a direct result of drinking water containing this pesticide.
Standard: EPA sets enforceable standards for public water systems, called MCLs.
These, regulatory standards set achievable levels of drinking water quality to protect
human health. The proposed MCL for DBCP is 0.2 fjg/L (proposed as of May 22,
1989).
DBCP can be detected in drinking water by a laboratory using an EPA method
such as #504. If DBCP is detected in well water and confirmed by retesting to be
above 0.03 pg/L, State or County health officials should be consulted. They may
advise periodic retesting to get an accurate overall picture of the water quality
because changes in seasonal precipitation and changes in pesticide use can cause
variations in the amount of chemicals found in water wells. They also may advise
using an alternative drinking water supply (bottled water is an example of a temporary
alternative), treating the water, or drilling a new or deeper well. Public water suppliers
are required to notify customers if the drinking water that they deliver contains a
contaminant that exceeds its MCL
You may also be able to treat your well water to remove pesticides and other
contaminants. Treatment technologies that can remove DBCP from water include
aeration and carbon adsorption. However, these techniques are not necessarily
appropriate or avaflabte in every situation. Certain treatment methods are more
suitable for large community water systems than for individual domestic wells. State
or County heaftti officiate should be able to provide advice on the best approach to
foflow.
Several steps may be taken to prevent pesticides or nitrate from entering wells,
such as eliminating direct entry through the well wall, drilling a new wed, or modifying
or reducing pesticide and fertilizer use.
E//m/nate O/rect Entry Through tne Will Will
If pesticides or nitrate are present in well water, they may be entering the
ground water through the weir itself rather than through the soil. If the well is old or
Doorty constructed, or if there are visible cracks in the well casing, obtain expert
NPS
(DBCP)
-------
Why was the
National
Pesticide
Survey
Conducted?
Where to Go
for More
Information
advice on whether or not improvements can be made to the well. In addition,
investigate simple methods of capping the well or sealing it at the surface to prevent
entry. Do not conduct any mixing activities near the well if you use well water to mix
pesticides because a spill could lead to direct contamination of the well.
Drill a fVtw wall
If the soil surrounding the well is the source of contamination, drilling a new or
deeper well may make sense if water can be drawn from a deeper, uncontaminated
aquifer. Unfortunately, it often is difficult to know the quality of the ground water
without drilling or extensive testing. Seek expert advice before you drill.
Learn More about Patticida t/te
if you use pesticides, whether for agricultural or home lawn and garden
purposes, you should consider attending training courses given by your State or
County agriculture department on how to reduce activities that can contaminate
ground water. You may find that you can eliminate or lessen the frequency or quantity
of your pesticide usage by choosing alternative methods of pest control.
EPA conducted this Survey to determine the frequency and concentration of
pesticides, pesticide degradates, and nitrate in drinking water wells nationwide and to
examine the relationship between the presence of pesticides in drinking water wells
and patterns of pesticide use and ground-water vulnerability. The Survey sampled
566 community water system wells and 783 rural domestic wells for 127 pesticides,
pesticide degradates, and nitrate. The wells were selected as a representative
statistical sample to provide nationwide estimates of the presence of pesticides and
nitrate in drinking water wells, and are not meant to provide an assessment of
pesticide contamination at the local, County, or State level.
This fact sheet is part of a series of NPS outreach materials, fact sheets and
reports. The following additional fact sheets are available through EPA's Public
Information Center (401 M Street SW, Washington, DC 20460. (202) 382-2080):
Survey Datlgn
Survey Anatytat
Quality Assurance/
Quality Control
Analytical Method*
Summary Raaulta
Fact Sfteef tor each
detected anatyta
Pro/ect Summary
Glossary
How EPA Will Uaa
The NPS Raaulta
Additional information on the Survey and on pesticides in general can be
obtained from the following sources:
U.S. EPA Safe Drinking Water Hotline
1-80CM26-4791 On Washington, DC (202) 382-5533)
Monday-Friday, 8:30 am to 4:30 pm Eastern Time
National Pesticide Telecornmunications Network
1-800-858-7378
24 hours a day
U.S. EPA Office of Pesticide Programs (OPP) Docket
Public Information Branch (H7506C)
401 M Street, SW
Washington/ DC 20460
Telephone: (703) 557-2805
Information on regulation of
pesticides in drinking
water
Information on health
effects and safe
handling of pesticides
Background documents
for Survey (available
for review)
NPS f ,2-Dfbromo^CMoropropMW (DBCP)
-------
National Technical Information Service (NTIS) Copies of the
5285 Port RoyaJ Road NPS Phase I Report
Springfield, VA 22161 (available 1991)
(703) 487-4650 and
NPS Phase II Report
(when available)
If you are concerned about the presence of pesticides and nitrate in your
private water well, contact your local or State health department Other experts in
your State environmental agency or agriculture and health departments may also be
helpful to you. If you receive your drinking water from a community water system and
have questions about your water quality, contact your local community water system
owner/operator or the State water supply agency.
«
Bibliography Meister Publications. Farm Chemicals Handbook. Ohio: Meister Publications, 1990.
U.S. Environmental Protection Agency. Drinking Water Health Advisory: Pesticides.
Michigan: Lewis Publishers, 1989.
U.S. Environmental Protection Agency. Drinking Water Regulations and Health
Advisories. April, 1990.
U.S. Environmental Protection Agency. Health Advisory Summaries. January 1989.
U.S. Environmental Protection Agency. Pesticides in Drinking Water Wells. September
1989.
MPS t.2-Oftroflio-3-CWoreprep«n« (06CP)
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