The process lines and chemical supply lines were checked and broken under controlled conditions as a preliminary step to the decontamination works. The aim was to remove the remaining traps of liquid in pipelines. A specialist decontamination team led by a decontamination technical specialist surveyed the pipelines on an area-by-area basis. They opened valves, unbolted flanges, cold cutting/drilling holes to low points, removing drain plugs under controlled conditions, in order to capture and recover the remaining liquid contents for disposal.
Spot-testing using pH test kits assisted in this process to identify the contents. Oil drains were utilised to recover bulk oils for disposal and duct works, and dust collector systems were inspected to enable assessment for decontamination.
At this stage, a red/blue colour coding system was introduced to highlight further cleaning requirements or suitability for passing into the scrap chain, an effective method that has been reliably used on previous decontamination projects.
Various protective methods were employed, including familiarisations, colour coded overalls, clean and dirty working zones with local changing stations, emergency drench showers and showering and changing before leaving the site.
A significant risk throughout this phase was the essential electrical systems that remained in operation throughout the decontamination works. We mitigated this risk by developing an accurate understanding of the locations of the live electrical assets, the development of detailed risk assessments and safe systems of work and carrying out the works with sensitivity and due diligence in collaboration with the client’s engineers.
The approach taken ensured that the number one priority was to protect life.
A high-level joined-up approach was instigated to understand the ATEX constraints starting with desktop studies, production of risk assessments and the individual evaluation of each ATEX area and system identifying any potential threat.
All findings were recorded in our explosion protection document and were used to determine the required safety measures whilst carrying out decontamination.
Staff working in high-risk areas were thoroughly trained regarding the hazards, best practices and methods, and how to take the necessary steps in the worst-case scenario with simulations carried out to provide psychological and technical preparation.
Additionally, all internal lighting was replaced with ATEX-rated temporary lighting, gas checks carried out on a prestart walk each day, use of gas monitors for each crew, alarms, ATEX rated PPE and cold cutting processes.
All site staff and operatives underwent a familiarisation and training regime to ensure they were aware of the hazards and measures being used to provide appropriate protection while working in the ATEX zones.
After reviewing the client’s Directive K24; Waste Management, we embedded their waste management principles into our approach to waste management on the project:
A full-time logistics and waste manager carried out the management of waste activities. They were responsible for the production and maintenance of the site waste management plan (SWMP) in compliance with Waste Management Acts 1996-2011, associate regulations and the waste electrical and electronic equipment (WEEE) waste with the WEEE Directive 2003, ensuring a “cradle to grave” process.
Checks and measures were put in place to ensure all waste was traceable throughout the project, i.e. GPS tracking. Equipment with IP (Intellectual Property Rights) was identified then physically destroyed, with the entire process clearly documented and evidenced.