Transcript No Slide Title

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
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Contents
Main issues
Options for Pesticide Handling Areas
Sizing
Management and operation
Likely costs
Final water disposal
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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
Sources of pesticides in the environment
Deposition
Atmospheric
output,
volatilisation
Residues in soil,
water, crop, food,
livestock,wildlife
Crop protection
products
Leaching
to groundwater
Veterinary
medicines
Drainage/
runoff to
surface
waters
Biocides
Borehole
Residues in water
sediments/biota
Biocides
Consented
discharges
Garden &
amenity
pesticides
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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
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Pesticides in water:
sources of contamination
Pesticides in water
Diffuse
Point Source
Non-crop use
drift
tank filling
roads
drainflow
waste disposal
pavements
surface flow
washings
railways
interflow/base
seepage
leaching
faulty equipment
other hard
surfaces
spillages
amenity areas
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Sources of Farmyard
Pesticide Pollution
Spillage while
mixing
28 %
8%
12 %
Tank Rinse
Water
Foil Seals
Mud from tractor
wheels
17 %
25 %
10 %
Tractor exterior
washings
Spillage of container
washings
Results from Year 1 Aventis Cherwell Study
Bayer CropScience Cherwell Study
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Concrete Filling Areas
Typical concrete
filling areas
showing
contamination and
run off
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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
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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 sump
» drained to treatment - biobed or chemical
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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
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Portable Bund
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Homemade Splash Catcher
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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
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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)
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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
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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 reused 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
Biobeds
Design, Construction, Use and
Maintenance
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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 a vegetative area
• or to a designated disposal area
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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
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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
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OFFSET
LINED with
disposal area
Bunded
concrete 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
Irrigation by drip or
sprinkler
Turf over
LINER
Pump within
biobed
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DRIVE OVER LINED
-with disposal area
Direct Lined Biobed with drive over
Suitable for
wash down
under T32
Exemption
Disposal by drip
or sprinkler
Turf over
Steel
Grid
BIOBED
Liner
Pump
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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?
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Pesticide Handling Area Dimensions
Concrete
pad
W
L
300 mm
Bund
100 mm
Drain via
silt trap to
pump
chamber
W = Sprayer
transport
width + 2 m
L = Sprayer
length + 1.5
m
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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
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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
The hole is lined with an impermeable liner
 In principle the biobed may be within an
impervious container above ground
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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
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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
pipe
Good turf
growth
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Sizing Summary
Loading area with working allowances, guidance
only, best to measure unit on site.
Sprayer type
Self propelled
Trailer
Mounted
Overall
length (m)
7
7
4
Overall
width (m)
5
5
5
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
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Offset - System Plumbing
 From offset loading area, install silt trap approx 300 l
capacity supplying 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 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.
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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
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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
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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
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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
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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
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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.
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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
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Typical Costs - Offset
 Sprayer loading area - depends on whether
adequate concrete present with bund
added or new material - range £2000 £3000
 Each chamber £200, pump £90 - 200
 Biobed, excavation and materials £1000
 Liner, with drain £1000 - 2000
 Drip irrigation to biobed and final disposal,
depends on areas £100- £400
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Typical Costs - Direct
 Sprayer vehicle grid - range £2000 - £5000
 Biobed, excavation and materials /
foundations £1000
 Liner, with drain £1000 - 2000
 Each chamber £200, pump £90 - 200
 Drip irrigation to final disposal, depends on
area £100- 400
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More Information
 www.biobeds.info - Detailed information on designs and principles
 www.voluntaryinitiative.org.uk then Water leading to
•
•
•
•
My area WIYBY
H2OK? Campaign
Biobeds
Catchment Work
Environment Agency
– www.environment-agency.gov.uk/ search biobeds
 Scottish Environment Protection Agency
– www.sepa.org.uk /biobeds
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CPD
BASIS CPD Points AP/032/034/d =
1AP
NRoSO CPD Points N0340530c = 1AP
Practical Simple
Solutions
Protecting the
Environment