1. Pesticide Handling Areas, Biobeds and Biofilters
V 1.5, 01/2015
Pesticide Handling Areas, Biobeds and Biofilters
A presentation for farmers, operators and advisers
CAUTION
Seek Advice
Before Building a Biobed
Contact local Catchment Sensitive Farming Officer or the Environment Agency
Developed for the Crop Protection Association and Agricultural Industries Confederation. The assistance of the ADAS, Environment Agency, SEPA, the Farming Unions and Bill Basford is also acknowledged. This is part of the voluntary initiative to minimise the environmental impact of pesticides

2. Contents Main issues Options for Pesticide Handling Areas Sizing
Management and operation
Likely costs
Final 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.

4. Sources of pesticides in the environment
Deposition
Atmospheric output,
volatilisation
Consented
discharges
Residues in soil, water, crop, food, livestock,wildlife
Crop protection
products
Drainage/
runoff to surface
waters
Biocides
Veterinary
medicines
Leaching
to groundwater
Borehole
Garden & amenity pesticides
Residues in water sediments/biota
Biocides

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
Funded by Bayer CropScience (UK) Ltd
40% of catchment pesticide load originated from concrete handling/washdown area

6. 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/base
faulty equipment
other hard
surfaces
seepage
leaching
spillages
amenity areas

7. Sources of Farmyard Pesticide Pollution
Bayer CropScience Cherwell Study

8. Concrete Filling Areas
Typical concrete filling areas showing contamination and run off

9. Always comply with advice
Best Practice - Aims
Minimise 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 from
handling 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 / grass
Field margin – not bunded
Drive over system
drained to treatment - biobed or chemical

11. to collection quantities
Concrete
Portable bund
localises any spills
collect and transfer back to sprayer tank.
Permanent bund
ensure area does not receive other drainage water
construct a 100mm high lip/bund around filling area
Direct drainage off concrete away from normal drains to...
Containment
Minimise rainfall
Match tank size
to collection quantities
Disposal
through a licensed
disposal contractor..
Treatment
Consider a Biobed

12. Portable Bund

13. Homemade Splash Catcher

14. Soil / Grass
Where 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 and non domestic boreholes, >250m from domestic 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 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 handling
area with disposal to land elsewhere, unless a lined
biobed is being used, a Permitted Area
(previously called a Groundwater Authorisation) must be
authorised 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) now referred to as Permitted Area 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 under Waste regulation Exemption T32. This is free and can be done on line
Scotland check with SEPA
Northern Ireland check with EHS

18. Design, Construction, Use and Maintenance
Biobeds
Design, Construction, Use and Maintenance

19. Biobed System Components
An area (bunded) where the sprayer stands
Drainage from that area to a biobed
The biobed
Drainage from the biobed
either direct to a vegetative area
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

21. Pesticide Handling Areas linked to Biobeds
What 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 deliver to a lined biobed under the T32 Environment Agency Exemption

22. Suitable for wash down under T32 Exemption
OFFSET LINED with disposal area
Suitable for wash down under T32 Exemption
Where bunded area is roofed then a biofilter or evaporation system may be appropriate, see separate ppt
Bunded concrete area
Irrigation by drip or sprinkler
Turf over
Animation to show how and offset lined system functions.
Biobed may not neccesarily be underground but would increase pumping demand.
LINER
Pump within biobed 22

23. Direct Lined Biobed with drive over
DRIVE OVER LINED
-with disposal area
Suitable for wash down under T32 Exemption
Direct Lined Biobed with drive over
Disposal by drip or sprinkler
Steel Grid
Turf over
BIOBED
Liner
Pump

24. Fill area, Biobed, Biofilter, 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 /boreholes(>10m;>50m non domestic borehole;>250m from domestic borehole)
Groundwater Risks?

25. Pesticide Handling Area DimensionsW
Concrete pad L
300 mm
Bund
W = Sprayer transport width + 2 m
L = Sprayer length m
100 mm
Drain via silt trap to pump chamber

26. Sprayer loading area - Direct
Size - as for offset
Grid - to support total full sprayer weight not compressing liner
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:
a composted mix 50% by volume straw,
25 % soil, 25% peat-free compost (biomix)
with turf on top
In principle the biobed may be within an impervious container above ground
The hole is lined with an impermeable liner

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 Good turf growth
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 pipe
Good turf growth

30. Sizing Summary
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. Maximum size needed 1:1 biobed surface area : fill area

31. Offset - System Plumbing
From offset loading area, install silt trap approx 300 l capacity supplying pump in small chamber, e.g x 0.75 x 1m deep.
Pump, with integral float switch - approx. 40 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 or central porous tube containing pump. Liner normally to be 1.5mm synthetic membrane thick with no unsealed seams laid on top of a geotextile
membrane (190g/m2) and 25 mm of sand blinding.

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 as with Indirect system. See further biobed installation notes in design manual

33. Biobed - Installation 1
Biobed can either be a biomix - straw, soil and peat-free compost, or loamy soil, note that ratios are given as % by volume
Lining must be sealed to outlet drain effectively with coarse filter over drain inlet, e.g. 6 mm mesh
Where pump is installed within porous tube sufficient clearance must be allowed for float switch activation.
Lining should overlap top of side batter by approx. 300 mm thereby preventing unnecessary rainfall reaching biobed

34. Biobed Installation - 2
Direct 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. Drip irrigation better than spray as spray will cause turf kill.
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.
Check irrigation function

37. Biobed management - long term 2
Biomix material in the hole is required to be exchanged after 5 years use.
Removal of biomix should be done carefully (with appropriate operator protection) to a covered non porous 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.
The spent biomix material may then be spread to land must be in accordance with U10 exemption from Environment Agency.

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 - Offset
Sprayer loading area - depends on whether adequate concrete present with bund added or new material - range £ £3000
Each chamber £200, pump £
Biobed, excavation and materials £1000
Liner, with drain £
Drip irrigation to biobed and final disposal, depends on areas £100- £400

40. Typical Costs - Direct Sprayer vehicle grid - range £2000 - £5000
Biobed, excavation and materials / foundations £1000
Liner, with drain £
Each chamber £200, pump £
Drip irrigation to final disposal, depends on area £

41. More Information
- Detailed information on designs and principles
then Water leading to
My area WIYBY
H2OK? Campaign
Biobeds
Catchment Work
Environment Agency
search biobeds
Scottish Environment Protection Agency
/biobeds

42. Practical Simple Solutions Protecting the Environment
CPD
BASIS CPD Points AP/032/034/d = 1AP
NRoSO CPD Points N c = 1AP
Practical Simple Solutions
Protecting the Environment