Silt management on Scottish construction site

Construction, Infrastructure & Development

Case Study

Silt management on Scottish construction site

Construction, Infrastructure & Development

Client

Balfour Beatty Power Transmission and Distribution

Location

Scotland

Objective

Building new overhead transmission line running across the west coast

Challenge

Pollution prevention for challenging linear site topography and during unprecedented weather

The challenge

Working on behalf of Scottish and Southern Electricity Networks, Balfour Beatty Power Transmission and Distribution’s near completed newbuild overhead transmission line running across the west coast of Scotland encountered very challenging ground conditions at a number of protected locations.

The project’s scale and location were challenging factors. Aside from the topography and unprecedented weather, the works also had to account for Special Sites of Scientific Interest (SSSI), Special Areas of Conservation (SAC), sensitive habitats (including peat bog, moorland, farmland and watercourses, private water supplies) and a number of protected species including golden eagle, hen harrier, and red-throated diver.

As the area spanned a section of one of the wettest areas of Scotland, during a period of intensive rainfall, the Scottish regulator (SEPA) was approached to permit the use of flocculant on the site to help treat silty water. Balfour Beatty sought a variation to their construction site license to protect the local water environment, including the specification of our products.

The solution

Effective products which prevent pollution and handle challenging ground and sensitive environments

Our technical team supplied treated coir mats (Floc Mats®) to support Balfour Beatty’s water treatment and silt pollution preventative aims.

Trapping up to 50kg of silt per mat, our unique and environmentally-friendly Floc Mats® provide a safe, cheap, and easy solution to support the removal of pollutants from the water. They come in untreated or treated forms, with treated versions having a highly effective, non-toxic gel flocculant impregnated into the natural fibres to aid their silt binding performance.

The 2x1x0.1m Floc Mats were deployed in areas that were difficult to reach with their existing, traditional water treatment plant.

Long-term silt capture

Floc Mats were used within our Silt Capture Channels to maximise water treatment on site

No accessibility issues

Floc Mats were also used in roadside ditches along access tracks where other equipment couldn’t reach

View the products

Silt polishing channels developed for the site's individual needs

Frog Environmental and Balfour Beatty Green Apple Environment Awards (Floc Mats) (Large)

The results

Perfect products for linear sites with difficult topography

Our products are designed with ease of install and use in mind. This site had very challenging topography and kilometres of thin footprints to work within.

Environment protected

Protections put into place that kept wildlife safe from silt pollution.

Cost-effective solutions

Early intervention and planning ahead saved money.

Low carbon design

Low carbon solutions which deliver immediate, effective and beneficial results.

The products

Floc Mat®

Low cost, low carbon way to treat clay-impacted water run-off
Can be used on land and in ditches
100% biodegradable for easy disposal or seed onsite
Simple to deploy and highly effective at controlling fine particle silt pollution

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Silt Capture Channel

Captures silt and flocculated fine silt particles
Unique design utilising Frog Environmental products
Standard design polishes up to 900 litres per minute
Supplied with site review service to ensure correct placement on site

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“The key takeaway from this project is that it is possible to manage silt pollution to a very high standard with minimal incidents, even across huge scales, varying ground conditions and extreme weather.

“The Floc Mats proved to be a game changer providing innovative silt management. We are now using them on another overhead line project and look forward to the opportunity to work with Frog Environmental again in the future.”