United States Office of Water EPA816-F-01-031
Environmental Protection (4606) July 2001
Agency
oEPA Source Water Protection
Practices Bulletin
Managing Small-Scale
Application of Pesticides to
Prevent Contamination of
Drinking Water
Pesticides (including insecticides, herbicides, and fungicides) contain a variety of chemicals used
to control pests, insects, and weeds. They are used in many applications to reduce the damage
to plants by insects and other pests, and to control overgrowth of undesirable plant species. This
fact sheet describes measures to prevent contamination of drinking water sources from small-
scale pesticide application (i.e., on lawns, golf courses, cemeteries, parks, and roadways); see
also the fact sheet on prevention measures for large-scale pesticide application for agricultural
or farm conditions.
SOURCES OF PESTICIDES
Pesticides are used in a variety of applications in areas with
green spaces. They are used by homeowners, in commercial
establishments such as golf courses and cemeteries, and along
roadways. Homeowners use pesticides in lawn care and
gardening activities. Many homeowners plant non-native plant
species, which require pesticides, fertilizers, and watering to
keep them healthy.
Golf courses and recreational areas such as parks and other open spaces use pesticides for
similar purposes. Shorter grasses typical of golf courses are less resistant to insects and require
application of pesticides to keep them healthy. Pesticides are also used to maintain lawns in
cemeteries and commercial areas. Herbicides are used along roadways and transportation and
utility corridors to limit vegetation growth and increase visibility for drivers or access to power
lines.
Excess rain can wash pesticides from plants and soil. This can, in turn, run off into streams.
Pesticides can leach into the soil if plants are watered or rainfall occurs soon after application.
Some pesticides resist degradation by microbes in the soil and will eventually leach into the
ground water. Pesticides can reach ground water through drains, sink holes, and other conduits
as well.
WHY IS IT IMPORTANT TO MANAGE SMALL SCALE APPLICATION OF
PESTICIDES NEAR THE SOURCES OF YOUR DRINKING WATER?
Pesticides contain a variety of organic and inorganic compounds. By nature, they are poisonous,
and while they can be safely used if manufacturers' usage directions are followed, they can, if
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mismanaged, seep into surface water and ground water supplies. They can be difficult and
expensive to remove, and, if inhaled or consumed, be hazardous to human health. The synthetic
organic chemicals in pesticides have been linked to serious health problems, including cancer,
liver and kidney damage, reproductive difficulties, and nervous system effects.
Once a water supply becomes contaminated with a pesticide, it can be very difficult and costly
to treat. Treating the water supply is a lengthy process and is not always successful. Using an
alternative water source may also be costly and impractical. For example, it would be very
expensive to connect to another public water system, and drilling new wells does not necessarily
guarantee that the new ground water source will not be contaminated.
AVAILABLE PREVENTION MEASURES TO ADDRESS SMALL-SCALE
PESTICIDE APPLICATION
Prevention measures are available to protect source water from pesticide contamination. They
range from simple, common-sense activities (e.g., reading the label) to more complex activities
such as properly storing and disposing pesticides. Most prevention measures for small-scale
application of pesticides tend to be easy, low cost activities. The most effective pesticide
contamination prevention measures encompass both simple and complex practices to reduce the
potential for pesticides to move into source water. Prevention measures can be divided into
those that protect surface water from pesticide runoff and those that protect ground water from
leaching or percolation.
Please keep in mind that individual prevention measures may or may not be adequate to prevent
contamination of source waters. Most likely, individual measures should be combined in an
overall prevention approach that considers the nature of the potential source of contamination,
the purpose, cost, operational, and maintenance requirements of the measures, the vulnerability
of the source waters, the public's acceptance of the measures, and the community's desired
degree of risk reduction. The following are the more conventional prevention measures used to
avoid contamination from small-scale application.
There are many options available to minimize the need for pesticides. Integrated Pest
Management (IPM) is the use of all means of pest control (chemical and non-chemical) in a
compatible fashion to reduce pesticide use. Pesticides are the last line of defense and are used
only when pest levels are causing sufficient damage to offset the expense of the application.
IPM includes regular monitoring to check levels of pest populations and their damage to
determine management needs, be it pesticide application or
other management actions. Monitoring can be accomplished
by a trained employee such as a facility manager. IPM also
includes non-chemical control measures such as
mechanical, cultural and biological controls, sanitation, and
pesticide-resistant plants are highly recommended. Where
possible alternate plants, select pest-resistant plant
varieties, and mulch the gardens or flower beds to reduce
weeds. Maximize the benefits of naturally occurring
biological controls by using pesticides only when necessary.
Many insecticides are broad spectrum materials and affect
beneficial insects and other arthropods as well as pests. If
pesticides must be used, select those that are designed
specifically for the pests you wish to control, and are low-
persistent in the environment. Ladybugs are a natural control for
aphids
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Proper Pesticide Application
Reading the label on the pesticide container is one of the simplest and
most important prevention measures. The label indicates the proper use,
rate of application, whether the pesticide is broad spectrum or selective
(i.e., kills everything or only a certain type of insect), and proper handling
of the pesticide. The label also provides information on proper storage and
disposal, and emergency contact numbers, if accidentally ingested. In
cases where the pesticide is highly toxic, the label will contain special
warnings and use restrictions, such as setbacks for mixing and application
away from wells or drinking water sources. Reading the label and following the directions will
ensure that pesticides are not over-used and are used in a way that is consistent with the pest
problem.
EAD
Proper application of pesticides reduces the amount of chemicals applied to the ground and
saves landowners money by reducing the amount of pesticides purchased. Calibrate application
equipment to allow correct application, follow pesticide manufacturers' directions, and select
leaching-resistant or "slow release" pesticides. Apply in large droplets to resist carrying away
by the wind. Mix and load pesticides only over impervious surfaces, such as cement, that do not
contain floor drains or storm water drain inlets; these drains may convey spills to ground water
sources. Check the pesticide label for pesticide application procedures; do not over-apply the
pesticide.
Pesticides should not be applied immediately before or after rainfall, as this may cause soil
runoff at the application site and the need to reapply the pesticide. The soil in the runoff can
carry the pesticide to the local storm water drain, and contaminate local source waters.
Ways to Reduce Pesticide Use
Select healthy seeds and seedlings that are known to resist diseases and are suited to the
climate. Strong seeds are likely to produce mature plants with little need for pesticides.
Planting pest-resistant plant varieties and local plant species will also reduce pesticide needs.
Alternate your plants each year; plants will not be vulnerable to the pests that survive the
winter. Insects will move to another location where they can find nutrients, and weeds will
remain dormant until their nutrient
source is replenished.
Manual activities such as spading,
hoeing, hand-picking weeds and
pests, setting traps, and mulching
are all good ways to get rid of pests
without using pesticides.
Homeowners have a tendency to
over-use pesticides, and should take
care to use only what they need.
Proper plant management can
improve plant health, reduce the
need for pesticides, and reduce
runoff and infiltration. Use mowing and watering techniques that maintain a healthy lawn and
minimize the need for chemical treatment. Maintain proper drainage and aeration to encourage
the growth of microbes that can degrade pesticides. Reduce watering to control seepage of
pesticides to the ground water; this conserves water and reduces runoff.
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Use of biological controls reduces the need for chemical pesticides. Plants that attract
predatory species, such as birds and bats, can enhance landscaping and naturally reduce pests.
Proper Pesticide Storage and Handling
Proper storage is important in preventing both surface water and ground water contamination.
Store pesticides in intact containers in a shed or covered structure on an impermeable surface
such as concrete. You must follow directions for storage on pesticide labels, although the
directions are usually general, such as "Do not contaminate water, food, or feed by storage or
disposal." Do not store pesticides in areas prone to flooding. Keep pesticides in their original
containers; if the label is unreadable, properly dispose of the product.
Spill clean up is another important prevention measure. Promptly
sweep up dry spills and reuse the pesticides as intended; dry spills are
usually easier to clean. For liquid spills, recover as much of the spill
as possible and reuse it as intended. It may be necessary to remove
some contaminated soil. Have cat litter or other absorptive materials
available to absorb unrecovered liquid from the floor. Be sure to
have an emergency contact number to call for help, if necessary. Be
sure to check the label for proper handling of the chemicals.
Disposal of pesticide containers can lead to ground water contamination if the containers are
not stored or cleaned properly. Chemical residues from these containers can leak onto the
ground. Homeowners and other users may have smaller quantities of pesticides and empty
containers and different disposal options than farmers.
Homeowners usually use nonreturnable containers, and have the option of participating in their
local community household hazardous waste collection events. Partially-full and empty
containers may be given to household hazardous waste collection. Homeowners should only
triple rinse pesticide containers if they are able to use the rinse water immediately, e.g., on
plants that require pesticides. Rinse water should never be disposed down a drain or into a
sewer system. Recycle plastic and metal containers whenever possible, keeping in mind that
non-hazardous container recycling programs may refuse to take pesticide containers. Empty
containers may be disposed in regular trash. Shake out bags, bind or wrap them to minimize
dust, and put them in regular trash. Do not bury or burn pesticide containers or bags on private
property. Homeowners may give unused pesticides to a neighbor rather than throw them away.
Farmers and users of larger quantities of pesticides (e.g., golf course managers) may have
larger quantities of pesticides to store and dispose, and are often prohibited from participating in
community household hazardous waste collection events. To prevent ground water
contamination, use returnable containers as often as possible and take them back to the dealer.
For non-returnable containers, pressure-rinse or triple-rinse containers immediately after they
are empty, since residue can be difficult to remove after it dries, and apply the rinse water
appropriately (i.e., on plants that require pesticides). Most States have collection programs for
farmers and other pesticide users with unwanted pesticides, often referred to as Clean Sweep
programs. Many States also have pesticide container and recycling programs. Puncture
nonreturnable containers and store them in a covered area until they can be disposed according
to your State's guidelines. Shake out bags, bind or wrap them to minimize dust, and take them to
a permitted landfill. Do not bury or burn pesticide containers or bags on private property.
Contact your State Department of Agriculture or Department of Environmental Quality for
information. If containers are full or partially full and the pesticide is in good condition, it may be
given to another pesticide user. However, if the pesticide is labeled a restricted use pesticide, it
can only be distributed and used by certified applicators.
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FOR ADDITIONAL INFORMATION
These sources contain information on pesticide management measures. All of the documents
listed are available for free on the Internet. Contact local government authorities in your area to
see if there are ordinances in place to manage pesticides.
AgSafe Coalition. Safely Handling Pesticides. Retrieved February 15, 2001, from the World
Wide Web: http://www.agsafe.org/series_l/pesticide.html.
California Environmental Protection Agency, Department of Pesticide Regulation. Tips for
Handling Pesticides Safely. Retrieved March 12, 2001, from the World Wide Web:
http://www.cdpr.ca.gov/docs/factshts/safeuse.htm.
EXTOXNET FAQs. Pesticides: How They Affect You and The Environment. Retrieved
March 8, 2001, from the World Wide Web: http://ace.orst.edu/info/extoxnet/faqs/.
Florida Department of Agriculture and Consumer Services and Florida Department of
Environmental Protection. Best Management Practices for Agrichemical Handling and Farm
Equipment Maintenance. (1998, May) Retrieved May 30, 2001, from the World Wide Web:
http://www.dep.state.fl.us/water/slerp/nonpoint_stormwater/documents/pubinfo.htm#Best
Management Practices
Home*A*Syst. NationalHome*A*SystProgram. Retrieved May 22, 2001, from the World
Wide Web: http://www.uwex.edu/homeasyst/index.html.
Massachusetts Department of Food and Agriculture, Pesticide Bureau. A Homeowner's Guide
to Environmentally Sound Lawncare. Retrieved June 4, 2001, from the World Wide Web:
http://www.massdfa.org/pesticides/publications/homeowner.htm
Massachusetts Department of Food and Agriculture, Pesticide Bureau. Pesticide Storage and
Handling Practices in the home. Retrieved June 15, 2001, from the World Wide Web:
http://www.massdfa.org/pesticides/publications/publications_storage_home.htm
Massachusetts Department of Food and Agriculture, Pesticide Bureau. Storage, Mixing and
Loading of Pesticides: Guidelines. Retrieved May 30, 2001, from the World Wide Web:
http://www.massdfa.org/pesticides/waste/index.htm
National Pesticides Telecommunications Network. Pesticide Fact Sheets. Retrieved June 4,
2001, from the World Wide Web: http://nptn.orst.edu/nptnfact.htm
Natural Resources Defense Council. Pesticide Exposure and Toxicity to Infants and
Children. March 1998. http://www.nrdc.org/health/kids/cdw0398.asp.
New England Interstate Water Pollution Control Commission. Source Protection: A Guidance
Manual for Small Surface Water Supplies in New England. March 1996.
Pesticide Watch. Pesticides and Human Health. Retrieved March 12, 2001, from the World
Wide Web: http://www.pesticidewatch.org/Html/PestProblem/HumanHealth.htm.
Schueler, Thomas R. and Heather K. Holland. "Toward a Low-Input Lawn." The Practice of
Watershed Protection: Techniques for protecting our nation's streams, lakes, rivers and
estuaries 2(1): 254-264.
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The Northwest Coalition for Alternatives to Pesticides. Alternatives Fact Sheets. Retrieved
January 24, 2001, from the World Wide Web:
http://www.pesticide.org/factsheets.htmltfalternatives.
Toxic Alert. Poison In The Grass: The Hazards And Consequences Of Lawn Pesticides.
Retrieved March 12, 2001, from the World Wide Web: http://www.cqs.com/elawn.htm.
United States Environmental Protection Agency, Office of Environmental Health Hazard
Assessment. Pesticide Programs. Retrieved January 23, 2001, from the World Wide Web:
http://www.oehha.ca.gov/pesticides/programs/index.html.
U.S. EPA, Office of Prevention, Pesticides, and Toxic Substances. Healthy Lawn, Healthy
Environment - Caring for Your Lawn in an Environmentally Friendly Way. 700-K-92-005.
June 1992. Retrieved January 24, 2001, from the World Wide Web:
http://www.epa.gov/oppfeadl/Publications/lawncare.pdf.
U.S. EPA, Office of Prevention, Pesticides, and Toxic Substances. Citizen's Guide to Pest
Control and Pesticide Safety. Retrieved January 24, 2001, from the World Wide Web:
http://www.epa.gov/OPPTpubs/Cit_Guide/citguide.pdf.
United States Geological Survey, National Water Quality Assessment Pesticide National
Synthesis Project. Pesticides in Ground Water. Retrieved January 23,2001, from the World
Wide Web: http://water.wr.usgs.gov/pnsp/gw/index.html.
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