Site remediation will focus on breaking what are termed “Source-Pathway-Receptor” pollutant linkages.
Breaking the pollutant linkages successfully through remediation allows any outstanding planning conditions to be discharged, allowing development to proceed.
There are many ways in which a site can be remediated, depending on the size of the site and the nature of the contaminants in the ground.
Remediation can be something as simple as fitting a gas proof membrane in new property foundations to mitigate risks of gas ingress into buildings (by inserting a membrane you remove the “pathway” thereby breaking the pollutant linkage), removing selected areas of Made Ground to remove localised areas of contaminant impacted ground, through to large scale bioremediation and other in situ treatment projects to treat organic contamination on site in soils and/or groundwater.
Often, and again this depends on the size of the site and its history, a combination of remedial solutions will be implemented on any one site to achieve sustainability credentials, to minimise remediation costs and to allow a site to be redeveloped safely.
The key to successful cost effective remediation is to ensure that the site characterisation work undertaken at Phase 1 and Phase 2 stage is undertaken accurately, as the initial work to characterise a site ultimately provides the information needed for a successful remediation scheme to be designed and executed. DBS can design remedial works that take into account sustainability, making them viable under the National Planning Policy Framework (NPPF). We consider sustainability at all stages of site assessment, we focus on the way that actual site chemistry data is managed at the Phase 2 stage in order to minimise costs during remediation. It is essential to fully understand the spatial distribution of contaminants on the site, and their relationship with the environment and future receptors once a site is redeveloped (for example future human health risks), and that the data is managed accordingly and the risk assessment refined to reflect this. Good risk assessment is key to delivering sites successfully and to minimise project costs.
As part of our remediation design, we undertake an Options Appraisal in accordance with CLR11 Model Procedures for the Management of Land Contamination guidance. An options appraisal evaluates the potential remedial solutions available to break pollutant linkages successfully, and it also evaluates sustainability against cost for each technique to formulate the correct scheme for any one project.
DBS will appoint an earthworks contractor or specialist remediation contractor to undertake the physical remediation works on site, and we monitor and validate the work on site to ensure it is undertaken to the requirements of the remediation plan.
We have excellent links with local and national contractors that have proven capability for undertaking remedial works successfully on site.
Following the successful remediation of the site, we will prepare a detailed factual Verification Report for submission to the regulator’s to enable final planning condition discharge to take place.
Throughout the remediation process we maintain dialogue with key stakeholders in the scheme, such as the LPA, local residents and the client. This ensures that remediation can take place transparently, and there are no surprises at the end of the project.
The Verification report confirms that the requirements of the Remedial Strategy have been met, it documents any work undertaken to deal with any unexpected contamination during the course of the works (for example dealing with previously unidentified underground tanks), and provides the results of chemical validation testing to confirm that risk from contaminants have been successfully mitigated.
For medium to large sized sites/projects, we can take your site forward cost effectively and quickly by preparing a Remediation Action Plan (RAP). This is a concise report that contains all of the various stages and results of site assessment in one volume.
DBS can also assist with the preparation of a Materials Management Plan (MMP), and/or sign off by a Qualified Person under the CL:AIRE Code of Practice scheme. A MMP can alleviate some of the onerous regulatory hurdles previously faced during site remediation where an environmental permit may have been required from the Environment Agency for the handling and management of wastes. Under a European Court ruling referred to as Van Der Waals, any soils dug up on a contaminated site, or clean soils imported to site from a donor site for re-use to obtain an earthworks balance, were classified as wastes and were regulated under wastes management legislation. This has had a negative effect on realising the UKs strategy of re-using brownfield land. The CL:AIRE approach was a joint initiative between key industry figures and the regulators to come up with an approach to ease the regulatory burden during site redevelopment.
If you would like to read more about a MMP, then please follow the link to CL:AIRES website http://www.claire.co.uk . You can also read about the framework for assessing contaminated land and CLR11 Model Procedures guidance on the Environment Agency’s website here