Scope of Services
MWH provides practical and cost effective solutions for the identification and remediation of contaminated land liabilities comprising:
- Desk Studies
- Site Investigations
- Risk Assessments
- Feasibility Studies
- Remedial Option Studies
- Remedial Design and Construction Management
- Land Quality Statements
- Acquisition & Merger Audits
MWH can assist with the identification of contaminated land liabilities and management options through the production of Land Quality Assessments and Statements, Desk Studies, Site Investigations, Qualitative and Quantitative Risk Assessment and Investment Appraisal.
MWH’s approach to identifying contaminated land liabilities is in keeping with UK Government guidance and regulations which are best achieved in a phased approach. In general the more detailed and comprehensive the level of assessment the greater the confidence that can be achieved in proposing less conservative remediation standards and requirements, enabling financial savings to be made in place of more conservatively driven remedial action.
We have the in-house technical expertise to offer a full cradle-to-grave service in a cost effective manner. This Remedial Process Flow is consistent with UK Government guidance and is designed to meet clients’ business goal objectives.
Desk Studies
The aim of a Desk Study is to assess the site environmental sensitivity in terms of hydrogeological and geological setting, historical use of the site and current operations to determine the type and location of on-site pollutant sources and evaluate potential on-site and off-site receptors. This is completed by obtaining historical maps and site plans, public records information, site visit and discussion with key site personnel, where appropriate.
This information can be used to develop a conceptual site model in order to optimise the site investigation, or provide the client with an initial assessment of liability associated with the acquisition and/or development of the land.
Site Investigations
MWH use both non-invasive and invasive site investigation techniques to find answers to the assumptions made in the Desk Studies, such as direction of groundwater flow, depth to groundwater, presence of non-aqueous phase liquids and the extent and magnitude of contamination in the soils and groundwater underlying the site. MWH can tailor these works to suit the time and finance available, and prioritise the levels of information required. More information is provided in the Catalogue of Services for Surveying - Undertaking Contaminated Land Investigations.
Risk Assessment
Central to the Contaminated Land provisions within Section 57 of the Environmental Act 1995, is the use of Quantitative Risk Assessment (QRA) to determine the existence of contaminated land. MWH can undertake QRA to develop a set of site specific target levels for clean up, thereby reducing conservative assumptions which result in overly stringent guideline values and unnecessary remedial works.
MWH uses the Environment Agency’s (EA) CLEA Model and RISC 4 to derive site specific Soil Guidance Values (SGVs) to complete Human Health risk assessments. Groundwater risk assessments are completed using the EA’s P20 methodology and more sophisticated risk assessment involving groundwater flow and contaminant transport modelling such as MODFLOW and MT3D.
Remedial Optioneering
Reviews of remedial options are completed according to the following key criteria:
(1) That the technique is reasonable in terms of the cost involved and the seriousness of the harm to human health or pollution of waters to which it relates
(2) That it represents the best combination of practicability, effectiveness, durability and efficiency.
The benefits are maximised by working closely with clients and all parties to ensure that the zoning/end use of the site is adopted to accommodate any contamination at the site.
Full-Service Remediation
Having selected the most appropriate remedial option, MWH would undertake field testing to assess the technical effectiveness of the proposed approach.
During testing, MWH would approach the regulatory authorities with the proposals for remedial options and clean-up levels, to obtain approval prior to initialising the full scale system.
The MWH Approach and Team
Land Quality Assessments and Statements will be completed by an experienced team of consultants drawn from MWH’s offices in High Wycombe, Warrington and Newcastle upon Tyne. The team will be structured so that where site visits are required the staff from the nearest MWH office are used enabling cost savings to be made to the client in terms of mobilisation.
Michael Wright, our Knowledge Leader for Contaminated Land brings over 20 years of experience in contaminated land management and will ensure the projects incorporate innovative techniques, current guidance, regulations and best practice such as Model Procedures for the Management of Land Contamination CLR11 Report (EA 2004), Contaminated Land Risk Assessment - A Guide to Good Practice C552 (CIRIA 2001).
Further Information and related Services:
