Haulbowline Remediation Project

Haulbowline Remediation Project

Bespoke Waste Recovery Process for Haulbowline Island East Tip Remediation Project

Enva delivered specialist slag and metal recovery processes for the Haulbowline Island East Tip Remediation Project and the environmental monitoring of these activities.

The works were carried out for P.J Hegarty and Sons who were awarded the Remediation Project. The site will ultimately be developed into a public recreational area for local communities and will include playing pitches, walking/jogging circuit, picnic areas, viewing points and a car park.

Client Issue

Slag and Metal Recovery Process Required for Remediation Works

Haulbowline Island is situated in Co. Cork, Ireland. The headquarters of the Irish Naval Service is located on the western portion of the island with the Naval Dockyard to the east.  Separating these is the “East Tip”, an area of land (approx. 9 hectares) reclaimed from the sea by infilling with processing waste from a former steelworks site.

The waste is made up of slag (64%), refractories (15%), millscale (13%) and scrap metal (7%). In specifying a waste recovery process to meet the requirements of the project, a combination of factors unique to the Haulbowline site were taken into account including:

  • Site history and past operations on the Haulbowline site;
  • The nature of the slag material present on the site and its characteristics,
  • The mixture and variety of waste streams across the site (Inert, Non-Haz and Haz), in particular how these waste streams interact during processing and/or blending;
  • Site location (Site access, tidal zones and local weather patterns);
  • Location to sensitive receptors (National Navy Base, Cobh, Spike Island Etc);
  • Planning and EPA Hazardous Waste Licence and Conditions set out therein;
  • Engineering requirements for materials to form part of the remediation works;
  • Market requirements for materials to be removed offsite – either for disposal or recovery;
  • Site end use.

Due to the range of factors outlined above, Enva along with our project partners developed a bespoke waste recovery process for the Haulbowline Island East Tip Remediation project.

Enva Approach

Maximise Recovery and Value for the Client

Our experienced and capable project team developed a tailored waste recovery process to:

  • Maximise recovery of waste materials for utilisation onsite in the East Tip remediation works;
  • Minimise offsite disposal costs of waste streams where recovery options on the site are unavailable;
  • Limit and negate environmental nuisance during all waste processing works;
  • Value for the client – offer a solution that offers best value for money for the client.

There were several key activities carried out by the Enva team and our sub-contractors in carrying out a successful remediation project.

i) Processing of material and the stockpiling of Engineering Grade Materials Material Processing was undertaken using a specially designed and manufactured crushing & screening processing line.

The slag recovery process was largely undertaken via the following sequence:

  • Material was excavated from the slag stockpiles using a tracked excavator;
  • Oversize metal (i.e. >1mtr) was extracted during excavation and segregated at a central location onsite for further specialist cleaning and recovery;
  • Undersize material was loaded into the processing line for treatment and grading;
  • Clean undersize metal was produced as a bye-product from the process line
  • Engineering grade material was produced at the front end of the process and stockpiled and tested prior to utilisation/recovery onsite.

The operation consisted of one processing line on the site which was mobile and had the ability to move around the site to the various stockpiles in order to reduce traffic across the site.

ii) Metal recovery – Process for metal recovery and storage on site Metal was gathered during the slag processing stages using a tracked excavator and a magnet attachment. The metal was stockpiled on site and inspected for potential recovery.

iii) Health, Safety and Environmental Monitoring: Throughout the project monitoring was carried out on dust, noise and vibration.

Asbestos:

An asbestos management plan was put in place and the occupational health and safety was monitored throughout. This was done by placing monitors on all personnel on site to get a reflection on the exposure to contaminants. Monitoring apparatus was also strategically positioned around the island and the samples sent for analysis. A decontamination unit was set up onsite to prevent contaminants from being brought off site. Full PPE was worn by every person entering the east tip including boots, a tyvec suit, gloves glasses and a dust mask if operating inside 5 meters of the slag processing line.  Asbestos and heavy metals were of particular concern onsite and regular training and toolbox talks were carried out.

Enva were responsible for daily dust checks. This involved walking the site and noting any fugitive dust emissions arising and making recommendations on how these could be controlled in liaison with our partners.

Noise and Vibration:

Monitors were set up around the site for the  primary sources of noise. These included:-

  • Site machinery, e.g., the crusher, screener, piling rig, excavators, etc.; and
  • Site traffic i.e. material haulage
Results

50,000 m3 of Slag Material Processed

The processing of stockpiles was completed in 4 months. The client was extremely happy with the work carried out by Enva throughout the project and a total of 50,000m3 of slag material was processed during the remediation project.

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