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Ver1.4. Pesticide Handling Areas and Biobeds. A presentation for farmers, operators and advisers. CAUTION Seek Regulatory Advice Before Building a Biobed Contact the Environment Agency's Agricultural Waste Line for advice 0845 6033113.
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Ver1.4 Pesticide Handling Areas and Biobeds A presentation for farmers, operators and advisers CAUTION Seek Regulatory Advice Before Building a Biobed Contact the Environment Agency's Agricultural Waste Line for advice 0845 6033113 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
Contents • Main issues • Options for Pesticide Handling Areas • Sizing • Management and operation • Likely costs • Final water disposal
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 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
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
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 faulty equipment other hard seepage surfaces leaching spillages amenity areas
Bayer CropScience Cherwell Study Sources of FarmyardPesticide Pollution
Concrete Filling Areas Typical concrete filling areas showing contamination and run off
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
Sprayer loading area - Options • Concrete • with / without portable bund • with permanent bund • drained to sump • drained to treatment -biobed or chemical • Soil / grass • Drive over system • drained to sump • drained to treatment - biobed or chemical
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 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
Portable Bund Available from www.spillsave.co.uk
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, 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
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)
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 Groundwater Authorisation must be obtained from the your local environment agency
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
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 the soil • or to a designated disposal area
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
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 may use lined or unlined biobeds; but only lined biobeds are suitable for washdown
Offset Biobed with Disposal Area Suitable for wash down if Registered Bunded area Turf over OFFSET LINED with disposal area Disposal by drip or sprinkler BIOBED LINER Pump
Direct Lined Biobed with drive over DRIVE OVER LINED -with disposal area Suitable for wash down if Registered Steel Grid Disposal by drip or sprinkler Turf over BIOBED Liner Pump
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?
Pesticide Handling AreaDimensions W Concrete pad L 300 mm Bund W = Sprayer transport width + 2 m L = Sprayer length + 1.5 m 100 mm Drain via silt trap to pump chamber
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
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.
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
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
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
Offset - System Plumbing • From 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.
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
Biobed - Installation 1 • Biobed can either be a biomix - straw, soil and peat-free compost, or loamy soil • Biobed 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
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 • Test pump system before use
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
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
Biobed management- long term 2 • 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.
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
Typical Costs -Offset • Sprayer loading area - depends on whether adequate concrete present with bund added or new material - range £300 - £850 • Each chamber £140, pump £60 • Biobed, excavation and materials £500 • Liner, if needed with drain £1000 • Drip irrigation to biobed and final disposal, depends on areas £200- £400
Typical Costs -Direct • Sprayer vehicle grid - range £2000 - £5000 • Biobed, excavation and materials / foundations £800 • Liner, if needed, with drain £1000 • Each chamber £140, pump £60 • Drip irrigation to final disposal, depends on area £300
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
CPD • BASIS CPD Points AP/032/034/d = 1AP • NRoSO CPD Points N0340530c = 1AP Practical Simple Solutions Protecting the Environment