Reduce risks and enjoy benefits through effective erosion control
Sediment is the biggest pollutant generated on construction sites so measures to effectively manage it are essential.
Silt control and erosion control will prevent sediment – soil, silt, sand, mud or clay disturbed by construction works or weather – getting into nearby waterways and impacting the environment. It is the responsibility of anyone operating a construction site to ensure effective control measures are in place to reduce environmental impact.
This is more than just a moral duty though – the consequences of not fulfilling silt control compliance can be serious financially. The Environment Agency (EA) and Scottish Environment Protection Agency (SEPA), responsible for ensuring compliance and investigating breaches, have powers to impose heavy fines for non-conformance.
In recent times a highways contractor incurred a £280,000 fine for polluting 17 watercourses, including two of Scotland’s most important salmon rivers, with silt from work on a bypass in Aberdeen. A housebuilder was recently fined £120,000 after ineffectual silt control techniques at a site in Huddersfield caused pollution in watercourses up to 3km away from the site. Be aware the EA/SEPA do have teeth and will enforce!
Reducing Risk & Delivering Benefits.
Erosion control will not only reduce the risk of environmental, financial and reputational damage but also deliver immediate project benefits.
Implementing a surface water management plan during construction will ensure good ground conditions and reduce the risk of delays and associated downtime costs. It will also make best use of space, such that reliance on settlement ponds is reduced and land required is lessened. Additionally, returning the site back to an attractive landscaped environment in less time and with less expense will then bring reputational and financial benefits. Building trust with neighbours and demonstrating competence to the main client will reduce risk of complaints or even potential compensation claims and improve reputation within the industry.
But most importantly, a plan supports compliance with the relevant regulation. Preventing pollution and reducing degradation, at a construction site, will ensure no environmental risks for aquatic life in nearby rivers, streams or lakes as well as for neighbours, including residents, dog walkers or livestock.
Developing a Plan
Erosion control must be both an initial and ongoing consideration on a construction site. Ensuring only land necessary for construction is disturbed and phasing works so ground is not broken until necessary will reduce the volume of sediment to be managed. Controlling the runoff water which causes erosion, using traps or ditches, will then reduce what, how and when sediment needs to be managed.
The areas where silt is being formed must be identified. This can include access routes, excavations and dewatering areas as well as wheel washing facilities and storage areas. Checks on these areas must be carried out regularly, particularly after adverse weather.
There are a number of tools available to deploy for surface water management, including:
- Silt Fence – trenched into the ground to divert or filter surface water runoff
- Silt Curtain – placed in water to control, block or absorb sediment which reaches waterways
- Sediment Mat – placed in traps or ditches to catch sediment as it drops out of suspension in water
Figure 1 – Silt build up on a construction site
These tend to be the most commonly used products but there are also specialist technical solutions available. Which of these is the right solution for a development, whether standalone or a combination, will depend on a number of factors, including the volume of sediment, geography of the land and proximity to watercourses. Without expert guidance on which of the tools to use and how to effectively install them the optimum solution is unlikely to be found.
A trusted partner, with a sound understanding of silt control, will help to design an optimal solution that covers products and their applications and installations, over simply supplying geotextile products.
The conclusion? Make sure your site is de-risked and you have a plan and remember that it is all our responsibility to make ground good and for those that don’t want too ….the EA/SEPA do have teeth!
