Scottish Water Biodiversity Duty Case Study:

Drinking Water Protected Area: biofilter installation on Milbethill Farm

Scotland relies on a good quality environment to supply public drinking water. To protect rivers and reservoirs, we work with farmers and landowners to identify best practice, reduce diffuse pollution and prevent it entering the water courses. Where necessary we can finance sustainable measures on land within Drinking Water Protected Areas (DWPA) to reduce the level of treatment required at our Water Treatment Works. Reducing the resources needed to treat the water to the high standards set for drinking water.

Milbethill farm, run by Brian Greig and his parents Bill and Lydia, is a 360ha arable farm which grows oats, barley and wheat. The farm is set within a DWPA, approximately 11km from Turriff water treatment works and the fields contain numerous small watercourses which drain into the River Deveron.

1 - (L-R) Graham Skea, Catchment Liaison Officer, Scottish Water; Brian Greig, Farmer

Brian Greig made a successful application to Scottish Water’s Sustainable Land Management Incentive Scheme to install specialised machinery called a biofilter and to create an area on his farm where he could safely wash a large vehicle called a sprayer that he uses to apply pesticides on his farm. “I wanted to have a better way of washing down my sprayer and a safer way of disposing of the washings, what the Incentive Scheme was offering enabled me to do just that.”

A biofilter is used to treat washings from a pesticide sprayer loading area enabling the resulting polluted water, called washings, to be discharged for land irrigation or to be re-used for future spraying. The biofilter consists of Intermediate Bulk Containers

(IBCs) stacked on top of each other and linked by pipework. The IBCs are filled with a biomix which consists of straw, soil and compost.

2 -Top view of biofilter

As the pesticide sprayer is washed down after use the washings enter a silt trap, to remove any coarse sediment, before being pumped to the top IBC. As the washings move downwards through the IBCs, the pesticides bind to the organic matter and are slowly broken down by bacteria present in the biomix. Once the washings reach the bottom of the final IBC they are pumped to the final irrigation area where they can be disposed of, or alternatively re-used in the spraying process.

3 -Covered pesticide sprayer loading area with biofilter in background

As Brian uses his pesticide sprayer regularly throughout the year, the biofilter system is ideal as he can save water by reusing the sprayer washings. By reusing the washings he also ensures that water contaminated with pesticides does not reach the watercourse.

“Applying to the scheme was easy and they offered a good level of finance. It has allowed me to complete work to a high standard and I am proud to be part of the Incentive Scheme and help to protect drinking water sources for my area.”

Peter Brown, Head of Public Health and Water Regulation at Scottish Water added, “We are delighted that our incentive scheme has helped with the successful installation of this biofilter and sprayer loading area and with Mr Grieg’s support, we look forward to the benefits that this will provide to protecting drinking water sources in Aberdeenshire.”

4 -Pesticide sprayer above drain that leads to biofilter

Resources:

Scottish Water Sustainability Report 2014: http://www.scottishwater.co.uk/assets/about%20us/images/corporate%20responsibility/sustainabilityreport2014.pdf

Contact:

Doreen Bell

Environmental Science & Regulation Analyst

ScottishWater

Email: Doreen.Bell@scottishwater.co.uk