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Farmstead BMP Recommendations for Groundwater Protection from Pesticides
AE-1112, July 1996
Bruce Seelig, Water Quality Specialist
John Nowatzki, Water Quality Associate
According to the North Dakota State Department of Health, pesticide detections in North
Dakota groundwater are sporadic and do not present a general public health hazard. When
detected, pesticides in North Dakota groundwater have not exceeded health standards
established by EPA. Information from most studies in North Dakota indicate that pesticide
detections in groundwater are generally related to the condition of the well and
activities around the well.
Pesticide management on the farmstead plays a key role in groundwater contamination.
Appropriate pesticide handling practices that help protect the well should always be used
whether pesticide contamination is documented or not. Detailed discussion of farmstead
best management practice (BMP) implementation is found in the references listed at the end
of the fact-sheet. Each reference title includes the source of information and the related
BMP numbers.
BMPs
1. Prevent spillage and back-siphoning from spray equipment into the well by
preventing overflow and maintaining an air gap between the filling hose and the water
level in the tank.
Use anti-backflow devices on filler hoses.
2. Maintain as much distance as possible from the well and the pesticide mixing and
loading site.
Distance recommendations range from 25 to 150 feet.
3. Mix, load, and rinse pesticides over an impermeable surface that is designed to
drain to a sealed catchment, whenever possible.
4. Rinse chemical containers thoroughly using the triple rinse method or a pressure
rinser.
Rinsate can be used as part of the make-up water in the sprayer tank.
5. Recycle pesticide containers and avoid the need to locate an acceptable landfill
site.
Use of dissolvable packaging, reusable containers, or returnable containers also avoids
the problems associated with finding a suitable disposal site for empty containers. If
these options are not practical, dispose of pesticide containers in an acceptable manner.
Stockpiles of empty containers should be avoided through timely disposal.
6. Dispose of unused pesticides that have been banned or are no longer wanted to
reduce the overall contamination potential from the farmstead.
These chemicals are a particular problem because of possible leakage from containers that
have lost their integrity through time. Often the labels are gone, so if there is leakage,
the proper method of clean-up is a guess. Until recently, disposal of these types of old
chemicals has been a problem due to questions of legal responsibility. New programs have
been developed to assist producers with disposal. These chemicals should be stored in a
secure location where clean-up of spills or leakage can be accomplished with a minimum of
difficulty.
7. Store pesticides in a secure, properly ventilated location where product
usefulness can be maintained with minimal risk to people, animals, and the environment.
Moisture and temperature need to be controlled to maintain the life of the product and
integrity of its container. This location should have an impermeable surface where spills
can be easily contained and cleaned up. All drains must be self-contained or plugged, so
that spilled pesticides have no direct connection with surface water or groundwater. The
building should be located down-slope and as far away from the well as possible. It should
not be located in areas that flood or that have standing water for any length of time.
Each pesticide container should have its label plainly visible with the date of storage
clearly marked.
Containers should be inspected regularly for leakage, and the proper equipment and
materials to rapidly respond to a spill should be easily accessible in the storage area.
8. Attend to all pesticide spills immediately.
After human medical attention has been secured, the proper response includes containment
of the spill, if possible, and then contacting the appropriate authorities, if necessary.
After the spill has been contained, the area of spillage should be covered with an
absorbent and/or neutralizer recommended by the manufacturer of the chemical. Do not hose
down the spill; this merely spreads the problem. Shovel or sweep the clean-up material and
affected soil into a leak-proof drum and dispose of it according to local regulations for
contaminated materials.
9. Attend to all back-siphoning incidents immediately.
If pesticides are back-siphoned into a well or hydrant, report the incident to the North
Dakota State Department of Health (NDSDH). Pumping the well as soon as possible after the
incident will help to minimize pesticide movement into the aquifer. Recommendations from
the NDSDH should be followed regarding the proper disposal of pumped water. Contaminated
soil around the hydrant may have to be removed for effective remediation. Follow NDSDH
recommendations regarding the extent of excavation and proper disposal of contaminated
soil.
10. Clean the pesticide sprayer properly. In the farmyard, clean over an impermeable
surface.
Rinse water can be recovered from a sealed catchment and used as part of the makeup-water
the next time that chemical is applied. Sometimes, haul-back tank mixes are unavoidable.
When this occurs, the haul-back should not be dumped but should be stored and used in a
similar fashion as rinse water. In the field: To avoid the need for a rinsing pad
and storage of rinse water, clean water can be taken to the field in a separate tank. The
system can be cleaned by applying the rinse water to an acceptable field.
11. Use closed-handling systems for mixing pesticides where practical.
Closed-handling systems consist of a pump and series of pressure-hoses that allow the user
to siphon concentrated pesticide and mix with water without direct contact with the
chemical. These systems reduce the safety risk of handling pesticides and also the
environmental risk of spills.
12. Locate and construct new wells according to codes that are intended to avoid
contamination.
The well contractor cannot avoid sites such as old dumping pits and pesticide mixing areas
unless advised about them. Prior to well construction, consider a plan for farmstead
expansion, so that future pesticide handling and storage on the farmstead do not
jeopardize the integrity of the water source.
13. Decommission or plug old wells, if not intended for future use.
Many farmsteads have several abandoned wells. Abandoned wells should never be used to
dispose of any form of garbage or hazardous material, because they are a direct conduit to
the groundwater. In many cases abandoned wells are located in the same aquifer as active
farmstead wells. All abandoned wells should be plugged with materials and methods that
will not allow settling in the future.
Further Information
This circular is one of seven GROUNDWATER/PESTICIDE FACT SHEETS. Please refer to
the following fact sheets for additional information.
References
Protect Your Water Supply From Agricultural Chemical Backflow Michigan State
University Extension Bulletin E-2349 BMP1
SAFE Storage, Handling and Disposal of Pesticides and Containers NDSU Extension
Bulletin AE-977 BMP3
Designing Facilities for Pesticide and Fertilizer Containment Midwest Plan Service
Bulletin MWPS-37 BMP3 BMP7 BMP10 BMP11
Pesticide Container Rinsing and Water Quality NDSU Extension Bulletin AE-1052 BMP4
SAFE Storage, Handling, and Disposal of Pesticides and Containers NDSU Extension
Bulletin AE-977 BMP5 BMP7 BMP10
Pesticide Act Chapter 4-35 NDCC ND Department of Agriculture BMP5
Chemical Container Disposal Sites in North Dakota ND Department of Agriculture BMP5
Assessing Your Hazardous Waste
Management Practices NDSU Extension Bulletin AE-1076 BMP6
PROJECT SAFE SEND ND Department of Agriculture. BMP6
Applying Pesticides Correctly -- A Guide for Private and Commercial Applicators USDA/EPA
BMP8 BMP3 BMP6
Hazardous Substances Used in North Dakota Agriculture NDSU Extension Circular No.
947 BMP8
Sprayer Field Wash System NDSU Extension Circular AE-1041 BMP10
Closed Systems for Handling Liquid Pesticides Cornell University Extension Bulletin BMP11
Water Well Construction and Water Well Pump Installation Article 33-18 NDAC ND
State Department of Health BMP12
Assessing the Condition of Your Well and
Its Location NDSU Extension Bulletin AE-1074 BMP12
A Guide to Plugging Abandoned Wells NDSU
Extension Bulletin AE-996 BMP13
AE-1112, July 1996
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