Leachate Treatment System Works, South East Scotland

Lothian & Borders, South East Scotland

The Story

We successfully assessed and delivered improved leachate system works at a landfill site in the South East of Scotland. In addition, our delivery enabled the client remote control of its newly installed MEICA system.

Strategy

This project was defined by a two-pronged approach. This involved the implementation of improved leachate works to bolster the efficiency and performance of existing systems. The team also had to plan and execute key Mechanical, Electrical, Instrumentation, Control and Automation (MEICA) works.

Phase one included the removal of the existing temporary leachate extraction system pipework and air pumps, alongside the stockpiling of redundant and unusable pipework. During this phase, we endeavoured to maintain, reuse and recycle as much of the existing pipework as possible, without limiting the performance of the new system.

Once completed, phase two saw the installation of a new buried leachate extraction system in service trenches. These came in a series of guises, including 800m of 90mm leachate main, 3000m of 63mm leachate collector lines, 6000m of ducting, draw pits, rodding points, and flow meter boxes.

A network of electrical pumps was installed to pump and remove leachate from 17 wells across the site. The construction of three road crossings, meanwhile, helps to improve the logistics of site operations.

The project’s final stage was marked by the supply, design, and installation of a leachate lagoon access platform. This was connected to the site’s existing steps to maximise the circularity of materials used throughout. The design and installation of a new remotely controlled MEICA system now enables the client to monitor and control the leachate field from afar.

Key Highlights

Reuse and recycling of extracted pipework
Reuse of the site’s existing steps for new lagoon access points
Works sensitive to environmental concerns.

Solutions

Monitoring, investigating, and rectifying the existing leachate systems on the closed landfill site represented a key challenge. Works of this nature involve the installation of pipework, down-well airlines, down-well leachate lines, exhaust lines and pumps. The team had to be meticulous with the planning, development, and installation of the works to meet the client’s needs.

It was also vital to deliver the safe, retrospective installation of a leachate management system to return the site to permit compliance. This required the installation of numerous extraction points.
These necessary works were delivered in conjunction with the development of site-specific health and safety plans and procedures. The job-specific plans were drawn up to carefully consider the waste materials, liquids and gases that may be encountered. As ever, safety remains a priority.

Re-configuration works of tank pipework, leachate lines and leachate manifolds, as well as the installation of Eboxx controllers and level sensors, help to further improve the control and monitoring of the tank. Upon completion, we were then able to disconnect the existing leachate tank, leaving only the new, optimised tank in operation.

Having drafted tailored plans for the client and its site, we were able to adapt the drilling and pin well installation methodology. This allows us to minimise the potential for uncontrolled release of gas or liquid into the environment and ensures our works remain sensitive to environmental concerns.

The design and testing of a well-jetting system helps to negate the release of fibrous material into the atmosphere, maintaining our sustainable approach to projects. We were also able to develop new installation techniques and methods for decontaminating equipment after use, in line with environmental principles. This coincided with the development and trialling of safe systems of work for use at other similar locations, empowering future projects across the UK. Importantly, the installation was safely completed without the release of dangerous materials into the atmosphere.

Results

We were successful in improving the performance, efficiency and sustainability of its leachate system, whilst giving the client remote control capabilities for the maintenance and execution of its MEICA system.