Landfill - Engineering, Gas & Leachate Management

Landfill Design, Engineering & CQA

Based on numerous projects and many years of experience, SLR offers an extensive range of construction management services for the development, operation and aftercare of a modern integrated landfill facility. We are able to provide consultancy assistance for the delivery of the following aspects of landfill facility development and operation:

·         infrastructure design (roads, offices, wheel washes, environmental compounds, etc.);

·         lining system design;

·         leachate management systems and treatment plants (pre and post waste placement);

·         gas management and utilisation systems;

·         capping/closure systems; and

·         remediation schemes.

Our Engineers have a proven track record in utilising innovative engineering solutions to overcome specific environmental and construction problems on our clients’ sites, including: steep wall lining systems, band drains, surcharging, well points, dewatering, slurry cut-off walls, sheet piled walls, grouting of mine workings, dense asphaltic concrete, innovative geomembrane/geotextile composites and cut-off trenches.

To assist our clients, SLR is able to provide the following services: site identification, feasibility reporting, investigation, outline design, planning and permitting, materials balance and phasing analyses, detailed design (including specification and drawing preparation), tender preparation and management, contract preparation, site supervision, contract management and 3rd party validation such as Construction Quality Assurance (CQA). Throughout all these phases, we are able to provide detailed financial costings ranging from initial budget estimates through construction estimates to post closure and aftercare costs.

SLR employs a large team of in house Engineers whose expertise, skills and experience overseeing construction projects assists with the delivery of schemes on programme and to budget.

We are able to offer specific operational services for current and closed facilities, particularly in relation to optimising the management of leachate heads and landfill gas which are intrinsically linked.  SLR is also able to provide gas field balancing services. Finally SLR is able to investigate potential gas migration and provide advice as to the possible remediation options.

Landfill Gas Management

Landfill gas is an emotive subject that can give rise to particular public concerns relating to risks of explosion and asphyxiation from gas migration in the ground, and the health and environmental risks posed by emissions to air.  Landfill gas comprises primarily methane and carbon dioxide together with a large number of trace components. It is an asphyxiant and the many trace components can be odorous or harmful to health.  Methane is explosive and as a strong greenhouse gas is increasingly targeted for control and emission reduction due to its recognised adverse contribution to global climate change.

SLR has an experienced in-house team of landfill gas scientists and engineers and is well positioned to assist clients by providing specialist teams or individuals to carry out or offer guidance on:

·         Qualitative and quantitative landfill gas risk assessment;

·         Landfill gas utilisation and feasibility assessments;

·         Landfill Gas Clean Development Mechanism (CDM) project feasibility assessments and documentation, including Project Idea Notes (PIN) and Project Design Documents  (PDD);

·         Gas pumping trial design and management;

·         Landfill gas protection measures;

·         Gas extraction system design and performance review;

·         Gas utilisation specification and costing;

·         Gas system tendering and contract management;

·         Construction Quality Assurance (CQA) of landfill gas systems;

·         Assessment and remediation options for closed landfill sites;

·         Preparation of site landfill gas management plans;

·         Landfill gas site investigation and monitoring;

·         Data review and gas source determination; and

·         Landfill gas due diligence audits.

Landfill Leachate Management, Treatment and Disposal Services

The management of landfill leachate is an increasingly complex issue requiring significant resource input on both operational and closed landfill sites. This increasing complexity is likely to continue as the environmental regulations which govern the management of risks associated with landfill leachate and the quality of controlled waters develop.

Because disposal of landfill leachate is a costly activity and a typical landfill leachate will contain significant concentrations of Chemical Oxygen Demand, Ammonia, Methane and toxic Metals, specialist knowledge is required to ensure that;

·         The management system, installed to reduce leachate generation, collect and remove leachate from the landfill, is fit for purpose, and

·         Any pre disposal treatment system is safe, process efficient and cost effective.

The SLR team has that specialist knowledge, and has a history of providing clients with a wide range of innovative and effective solutions to landfill leachate issues. In employing that specialist knowledge SLR has undertaken the following tasks:

·         Development of Leachate Management Plans – ensuring that clients can meet their regulatory obligations effectively;

·         Feasibility Studies – assessments of the technical, commercial and legislative acceptability of leachate management strategies for groups of sites and for installing a treatment facility at a particular landfill site;

·         Design – Design and specification of the optimum treatment process for a particular application;

·         Planning and Permitting – this process often includes representing the client in coming to an agreement with local environmental regulators on the quality, quantity and disposal route of the treated leachate;

·         Tendering – development of tender and contract documents, tenderer selection, tender management and selection of successful contractor in conjunction with client;

·         Construction Supervision – on site supervision and continuous technical support on behalf of the client during construction;

·         Commissioning – development of commissioning schedules and overall commissioning and performance verification of the plant;

·         Operational Support and Process Optimisation – on leachate treatment plants which are found to be operating inefficiently; and

·         Technology Development – Monitoring technological developments and assisting clients with the integration of such developments to ensure best practice is employed in leachate management, treatment and disposal.