Pesticide Handling Areas and Biobeds

A presentation for farmers, operators and

advisers

Ver1.4

Developed for the Crop Protection Association and Agricultural Industries Confederation by ADAS. The assistance of the Environment Agency, SEPA & the Farming Unions is also acknowledged. This is part of the voluntary initiative to minimise the environmental impact of pesticides

CAUTION

Seek Regulatory Advice Before Building a Biobed

Contact the Environment Agency's Agricultural Waste Line for advice

0845 6033113

2

Contents

Main issues Options for Pesticide Handling AreasSizingManagement and operationLikely costsFinal water disposal

3

Background

High levels of some pesticides have been found in surface water

In UK water companies now need to mix or treat water to comply with the EC Drinking Water Directive

Sprayer use, and in particular pesticide handling areas, can be a significant source of water contamination.

The Water Framework Directive identifies priority substances and the need to meet good ecological status thus indicating a further need for compliance.

Sources of pesticides in the environment

Biocides

Atmospheric output,volatilisation

Deposition

Garden & amenity pesticides

Borehole

Residues in water sediments/biota

Residues in soil, water, crop, food, livestock,wildlife

Veterinarymedicines

Sources of pesticides in the environment

Drainage/runoff to surfacewaters

Biocides

Leachingto groundwater

Crop protectionproducts

Consenteddischarges

5

Catchment Studies

In UK, Germany and Sweden– 20-70% pesticide load in surface water

catchment is derived from point sources

UK - River Cherwell study 1998-2000– Funded by Bayer CropScience (UK) Ltd– 40% of catchment pesticide load originated

from concrete handling/washdown area

6

Pesticides in water

Pesticides in water: sources of contamination

Diffuse Point Source Non-crop use

drift tank filling roads

drainflow waste disposal pavements

surface flow washings railways

interflow/baseseepage

faulty equipmentother hardsurfaces

leaching spillages amenity areas

7 Sources of FarmyardPesticide Pollution

17 %

8 %

28 %

12 %

10 %25 %

Mud from tractorwheels

Tractor exteriorwashings

Spillage of containerwashings

Spillage whilemixing

Tank RinseWater

Foil Seals

Results from Year 1 Aventis Cherwell StudyBayer CropScience Cherwell Study

8

Concrete Filling Areas

Typical concrete filling areas showing contamination

and run off

9

Best Practice - AimsMinimise contamination incidents through

good operational routine– Limit contamination spread from inadvertent

actions– Minimise water volumes (rain and washings) on

handling area– Store empty containers safely and upright after

use– Dispose of containers frequently and safely as

permitted.Through best practice

pesticide contamination of water fromhandling areas can be reduced

by as much as 99%

Always comply with advice

in Codes of Practice

10

Sprayer loading area - Options

Concrete – with / without portable bund– with permanent bund

» drained to sump» drained to treatment -biobed or chemical

Soil / grassDrive over system

» drained to sump» drained to treatment - biobed or chemical

11

ConcretePortable bund

– localises any spills– collect and transfer back to sprayer tank.

Permanent bund – ensure area does not receive other drainage water– construct a 100mm lip/bund around filling area– Direct drainage off concrete away from normal drains to...

ContainmentMinimise rainfallMatch tank size

to collection quantities

Disposalthrough a licensed

disposal contractor..

TreatmentConsider a Biobed

12

Portable Bund

Available from www.spillsave.co.uk

13

Homemade Splash Catcher

14

Soil / GrassWhere site allows, filling the sprayer over a

permeable surface can be useful. Natural breakdown of the pesticides is achieved by microbial action in the soil

BUT– Site >10m away from field drains and

watercourses;>50m from springs, wells and boreholes– Prevent soil compaction by use of drive over grid or

hardcore– May need to move site around periodically if compaction

occurs– Avoid use on heavy clay

15

Handling Area - with a biobed

A well planned, designed and operated area linked to a biobed will allow pesticides to be retained and degraded by a considerable amount (10,000 -100,000 fold reduction)

A pesticide handling area (mixing and sprayer loading only) may be linked to a biobed without the need for a Groundwater Authorisation from the local environment agency.(See sprayer washing note on next slide)

16

Sprayer Washdown - Special note

Best Practice for tank washings and sprayer exterior surfaces is to carry this out in the field– Any washings should be discharged onto the

previously sprayed cropped area– Observing maximum dose for that area– Follow Statutory (Green) Code advice

If sprayer washdown is intended at the pesticide handlingarea with disposal to land elsewhere, unless a lined

biobed is being used, a Groundwater Authorisation must be obtained from the your local environment agency

17

Biobeds and The Law EA and SEPA support Lined Biobeds as

significant improvement over current practice

NEW Regulatory advice for England and Wales from EA – Groundwater Authorisation (GWA) not required for

lined Biobed– Water from lined Biobed can be “irrigated” or re-

used without GWA – Site will have to be registered with EA in the future

but is expected that registration will be free and can be done on line

– Scotland check with SEPA– Northern Ireland check with EHS

Biobeds

Design, Construction, Use and Maintenance

19

Biobed System Components

1 An area (bunded) where the sprayer stands

2 Drainage from that area to a biobed

3 The biobed

4 Drainage from the biobed•either direct to the soil•or to a designated disposal area

20

Biobed Design Types

Offset - the sprayer mixing and loading area is separate from the biobed area

– Features:

• Bunded concrete,

• Slope of 1:100 to silt trap

• Drain - to supply biobed

Direct - the sprayer mixing and loading area is directly over the biobed area

– Features• Direct - bunded

• Steel drive over grid or wheel tracks

21Pesticide Handling Areas

linked to BiobedsWhat do the designs look

like?

– Offset - A separate area, bunded concrete, where the sprayer stands and any liquids drain to a biobed

– Direct - A drive over grid all liquids drain directly to the biobed below the grid.

Both designs may use lined or unlined biobeds; but only lined biobeds are suitable for washdown

22

Offset Biobed with Disposal Area

BIOBED

LINER

Bunded area

OFFSET LINEDwith disposal area

Turf over

Disposal by drip or

sprinkler

Pump

Suitable for wash down if Registered

23

Direct Lined Biobed with drive over

BIOBED

DRIVE OVER LINED-with disposal area

Turf over

Steel Grid

Pump

Disposal by drip or

sprinkler

Liner

Suitable for wash down if Registered

24

Location.. Location.. Location..

Close to sprayer water filling point, chemical store and electricity supply

Away from other traffic / access routes, footpaths etc.

Avoiding collecting extra rainfall - check yard contours, other drain routes and overflow issues

Separate from other drains / watercourses (>10m;>50m)

Groundwater Risks?

25

Pesticide Handling Area Dimensions

300 mm

100 mm Drain via silt trap to pump

chamber

W

L

W = Sprayer transport width + 2 m

L = Sprayer length + 1.5 m

Concrete pad

Bund

26

Sprayer loading area - Direct

Size - as for offset

Grid - to support total full sprayer weight

Mesh must be removable for biomix annual top-up

Grid size 100 x 40 mm to suit foot safety and soil/mud flow through

27

The Biobed -What is it?

Normally a hole in the ground filled with:– Either a composted mix 50% by volume straw,25 % soil, 25% peat-free compost (biomix)with turf on top– Or a friable loamy soil with turf on top

The hole may be lined with an impermeable liner - or not, dependant on system function, soil type, local drains, local environment agency advice etc.

28

Biobeds - Function, location and size

How do they work?– By locking up the pesticides and then providing

conditions for enhanced microbial degradation of the active ingredients over time

Location– A biobed can be sited independently from the loading

area, taking account of local drainage, access, groundwater risks, contours etc.

Size– Where a 24 m, 3000 l sprayer has been used then 5 x 4 x 1 m deep bed has been satisfactory, though

local rainfall and frequency of use will influence final size.

Biobeds should always be at least 1m deep

29

Biobeds - Components The biomix materials could be varied from the mix

suggested. Guidance must be sought to ensure required properties exist.

Turf cover over the biomix is vital to encourage the biological activity of the mix and assist in the management of the moisture status of the biomix.

Efficient distribution of the water over the biobed surface is considered critical, drip irrigation is suggested at 400 mm spacing

Drip header

pipeGood turf growth

30

Sizing Summary

Sprayer type Overalllength (m)

Overallwidth (m)

Self propelled 7 5Trailer 7 5Mounted 4 5

Loading area with working allowances, guidance only, best to measure unit on site.

Biobed - excavated in soil, 1 m deep, 300 batter on sides, 5 x 4 m area suggested as suiting most situations.Rule of thumb: Biobed area should be at least two/thirds of the area from which it is receiving liquids

31

Offset - System PlumbingFrom offset loading area, install pump in small

chamber, e.g. 0.75 x 0.75 x 1m deep.

Pump, with integral float switch - approx. 40 l/min@6m head, installed to appropriate regulations.

Site all pipe runs for adequate frost protection.Pipe to optional holding tank or direct to drip over biobed.

Excavate biobed and liner with sealed drain as appropriate. Liner to be 1.5mm geotextile membrane on specified inner liner and/or sand as detailed.

32

Direct System Design

Design and construct grid to adequately support spray vehicle and ensure safe operator use.– Operator should be kept off biobed surface for

functional and safety reasons. – Allow for grid to be removed in sections for annual

biomix top-up.Construct foundations, as appropriate,

avoiding support on biobed liner if used.Excavate biobed and liner with sealed

drain as appropriate.Liner to be 1.5 mm geotextile membrane

on specified inner liner and/or sand as detailed.See further biobed installation notes

33

Biobed - Installation 1Biobed can either be a biomix - straw, soil and

peat-free compost, or loamy soilBiobed will need lining where washdown is to be

practised (with Groundwater Authorisation)Lining must be sealed to outlet drain effectively

with coarse filter over drain inlet, e.g. 6 mm mesh

Where unlined, ensure that subsoil is uncompacted

Lining should overlap top of side batter by approx. 300 mm thereby preventing unnecessary rainfall reaching biobed

34

Biobed Installation - 2Direct drain to optional tank or small pump

chamber as before, or to pump to final disposal area

Biomix must be composted for 4-6 weeks before use and evenly loaded into hole. Overfill hole to allow for early sinkage

Turf should be laid at time of filling to encourage growth. Turf does not need to be high quality and is laid over the surface of the biomix, watering early to encourage growth

Install drip irrigation, hard hose type best, laid onto the biobed turf surface as well as the final disposal area, lightly anchor drip lines

Test pump system before use

35

Biobed Management - short term

Biobed irrigation will maintain regular watering of turf and thus control biomix moisture condition

Grass growth will encourage moisture use and thus evapo-transpiration from biobed

Check weekly for condition and function. Investigate any tendency for waterlogging.

Any foliage cut from biobed turf cover to be mulched over biobed area

36

Biobed management - long term 1

Where biomix is used, material will degrade and level sinks by approx. 300 mm per year

Biomix top-up annually necessary. Dependent on turf growth, turf may be peeled back (with adequate operator protection) and new mix added to restore level, replace turf.

Soil based systems probably will not ‘shrink’ as fast.

Check irrigation function

37

Biomix material in the hole will probably have a life of 6 -8 years before replacement or recycling

Removal of biomix should be done carefully (with appropriate operator protection) to a concrete area for further composting for one year. Research suggests any pesticides remaining are fully degraded in that period.

Drainage from this area should be preferentially routed to the replenished biobed.

Final disposal of the spent biomix material must be in accordance with advice from local environment agency.

Biobed management - long term 2

38

Water distribution - disposal area

Where drip irrigation used, lay hard hose pipes at 400 mm spacing with drippers at around 1.5 l/h flow rate.– 1-1.5 running hours per day applies 2-4 mm

of water, dependant on equipment used.

Set controls, e.g. level switch and any timers, to achieve this, allowing for override in intense rainfall – buffer available from optional tank if installed

39

Typical Costs - OffsetSprayer loading area - depends on

whether adequate concrete present with bund added or new material - range £300 - £850

Each chamber £140, pump £60Biobed, excavation and materials £500Liner, if needed with drain £1000Drip irrigation to biobed and final

disposal, depends on areas £200- £400

40

Typical Costs - Direct

Sprayer vehicle grid - range £2000 - £5000

Biobed, excavation and materials / foundations £800

Liner, if needed, with drain £1000Each chamber £140, pump £60Drip irrigation to final disposal,

depends on area £300

41

More Information www.biobeds.info www.voluntaryinitiative.org.uk

– choose Library, then publications then Best Practice Guides,

• Pesticide handling areas • Biobeds• Biobed Manual

ADAS Gleadthorpe Cranfield University Environment Agency

– www.environment-agency.gov.uk/farming

Scottish Environment Protection Agency– PEPFAA Do’s and Don’t’s Guide

42

CPD

BASIS CPD Points AP/032/034/d = 1APNRoSO CPD Points N0340530c = 1AP

Practical Simple Solutions

Protecting the Environment