River Management Techniques. Upper Wharfedale Best Practice Project (Information Series No 6)

5.0. Improving sheep dipping practices

5.1. New dipper

5.1

LOCATION:
Hubberholme, SD 925784

DATE UNDERTAKEN:
Autumn 1999

COST: £20,000

BACKGROUND INFORMATION

Concerns about the effects of organophosphate dips on humans has led to the introduction of synthetic pyrethroid dips, which are less damaging to humans but are lethal to aquatic invertebrates at the base of the food chain. As a result, there are now major issues concerning not only the disposal of used sheep dip but also with regard to sheep dip chemicals entering watercourses during the sheep dipping process. Of particular concern in Upper Wharfedale is the number of sheep dips which have been historically located close to watercourses.

DESIGN

A full survey to locate all sheep dips in the project area was undertaken and an inventory of required improvements was produced. These ranged from relatively minor works, necessitating the waterproof rendering of dipper walls and sealing off redundant drainage systems, to the complete rebuilding/ re-locating of five sheep treatment facilities.

The requirements of individual farmers for a system that would cater for individual needs to manage their dipping programmes was used as a starting point in the design brief.

This was then developed through various design stages undertaken by a local Chartered Surveyor and Engineer, with input from the Health and Safety Executive and the Environment Agency. A state-of-the-art sheep dip was subsequently installed at Church Farm as a pilot scheme to demonstrate ‘best practice’ requirements for sheep dip design/construction.

SPECIFICATION

A prefabricated (fibre reinforced cement) circular dip tub with step out facility and capacity to take four sheep was used (shown opposite).

Other key features were included as follows:

  • A site was chosen well away from watercourses or field drain systems, having direct access to a pasture where sheep could be contained for a 24 hour period after dipping;
  • A polythene curtain was incorporated at the dip tub entry to minimise splash back and contamination of operators and surrounding areas when sheep entered the bath;
  • The floor was graded to facilitate the return of chemical from the draining pens and/or other areas back to the dip tub (on an unroofed dipper only that part of the forcing pen liable to contamination should drain back to minimise the amount of clean uncontaminated rain water entering the bath);
  • A filter catch pit with galvanised steel grate was provided at the dip tub exit to minimise contamination of dip tub contents from drying pen drainage;
  • A sectioned steel cover was provided to be used over the dip tub as a safety measure when not in use;
  • Arrangement of the dipper was to allow two draining pens (each with capacity to hold 45 sheep) to be constructed in parallel so that alternate use would permit a minimum of 10 minutes draining prior to moving the sheep forward into the secondary holding/drying pen;
  • All yard areas around the dip bath to be graded back to the bath;
  • Walls to be of solid construction and of a height to contain any splashing. They should also be made water-tight particularly at the base and rendered to aid cleaning down;
  • Kerbs of 2-4cm to be provided at doorways and gateways to prevent escape of chemical outside the dipper;
  • A lockable fireproof chemical store facility to be provided, together with clean water supply within the building;
  • A circular forcing pen and internal partitions of prefabricated galvanised steel to be provided;
  • A roof was specified as a preferred option to minimise the effects of rainwater on dip bath contents/chemicals. This incorporated venting in the ridge to aid ventilation of dip chemical.

SUBSEQUENT PERFORMANCE

The site was used for demonstration of ‘best practice’ principles shortly after construction and has since proved an effective design, providing substantial benefits of improved stock management for the farmer concerned.

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