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Keeping Pesticides out of Water: Local Environment Risk Assessment for Pesticides (LERAP)

DescriptionAdvice leaflet for farmers and growers on preventing pesticides reaching ground or surface water.
ISBN0 7559 0659 4
Official Print Publication Date
Website Publication DateJanuary 06, 2003

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KEEPING PESTICIDES OUT OF WATER
LOCAL ENVIRONMENT RISK ASSESSMENT FOR PESTICIDES (LERAP)

This document is also available in pdf format (652k)

Introduction

Most pesticide users are aware of the need for care in selecting and applying suitable products to their crops. Such action helps to minimise the amount of pesticide reaching ground or surface water by seepage or run-off from sprayed crops. This contributes to our water quality, keeps water treatment costs down and makes further restrictions on pesticide use less likely.

Run-off from a crop is not, however, the only way that pesticide can enter our water. Spillage of concentrate or spray falling outside the crop area can also result in significant quantities reaching our water supplies.

This booklet gives advice on good practice for handling pesticides before, during and after spraying. It also illustrates the pollution potential for concentrates and thus the importance of operator awareness and care.

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The EC limit for an individual pesticide in drinking water is 0.1 micrograms per litre (g/1) - equivalent to one drop of concentrate in an Olympic-sized swimming pool.

Key points to remember
PREPARATION - MIXING CONCENTRATE

Take care to avoid spillage while mixing concentrate.

  • If possible, set aside a special area for mixing, where spills cannot enter watercourses or drains etc., because spills that are washed into yard drains can reach ground or surface water directly, e.g. a biobed.

  • Discharge to sewers must be licensed; sewage treatment may not remove the pesticide.

  • Spills that are left to dry on a concrete yard will be washed into the drains by the next rainfall.

  • Avoid back siphoning by ensuring there are no direct connections between a sprayer and the water supply.

If spillage occurs, take special care to contain it.

  • Soak up small spills with absorbent material, e.g. dry soil or sand. Disposal of such absorbents should be arranged through a reputable specialist disposal contractor.

  • For major spills, contain the liquid and contact the Scottish Environment Protection Agency on their emergency hotline: freephone 0800 807060.

  • Do NOT hose down.

FILLING SPRAYER
  • Take care to avoid overflow when filling the sprayer.

  • Fill the sprayer well away from ditches, watercourses and field drains.

  • Should an overflow occur on a hard surface, soak up with absorbent material and dispose of as described above.

Just one teaspoonful of spilled concentrate could be enough to reach the EC limit in 25,000 cubic metres of water - enough to supply 200,000 people for a day.

An overflow of half a litre of mixed concentrate could contaminate 60,000 cubic metres of water to the EC limit - equivalent to the contents of a reservoir for a large town.

SPRAYING NEAR WATER
  • Make sure that there will be a margin between where the spray falls and the bank of any watercourse. Turn off boom sections as appropriate.

  • Do not spray near water when windy.

  • Allow for the effect of drift by keeping further away from water when spraying up-wind.

In just one second two nozzles can deliver enough pesticide to contaminate the water in a 3 kilometre length of a good-sized brook.

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CLEARING UP

TANK WASHINGS

  • Minimise or eliminate tank washings by careful planning, use of rinsing equipment or direct-meter sprayers.

  • Keep any washings and all washing procedures, away from yard drains, ditches, field drains and surface water.

  • Dispose of washings by spraying on to suitable uncropped land where there is no possibility of run off or flooding, or on to crop, provided the terms of the product approval allow, i.e. be sure not to exceed the maximum dose.

EMPTY CONTAINERS

  • Rinse empty containers thoroughly.

  • Keep upright, under cover in a secure store, until disposal.

If the tank is filled twice with clean water, the second rinsing could still be 10,000 times more concentrated than the EC drinking water limit.

Conclusion

Food production and water abstraction are both dependent on agricultural land. From the time you first open a container of concentrate to when you finally dispose of the waste container, there is a great potential hazard to water quality. It is good practice to minimise the risk at every step. The advice in this booklet gives pointers to help you exercise the care that is needed and information to increase your awareness of the magnitude of the potential danger.

The key message is - prepare and spray with care
FURTHER INFORMATION

Code of Practice for the Safe Use of Pesticides on Farms and Holdings (PB 3528).
(ISBN 0-11-242892-4) DEFRA/HSE
Available free from DEFRA Publications, Admail 6000, London SW1A 2XX, tel 08459 556000.

Or alternatively write to: The Pesticides Safety Directorate, Mallard House, Kings Pool, 3 Peasholme Green, York YO1 7PX www.pesticides.gov.uk

Page updated: Wednesday, June 29, 2005