Meridian One was a heavily contaminated and contained former gas works site lying vacant for over 40 years. Once acquired by Enfield Council in 2015, plans to transform the area into a vast residential area were formed. However, due to its historical use as a gasworks site the soil was largely unusable. Partial remediation of the site had been conducted in 1998 and again from 2001 to 2006. While these efforts were effective in terms of mass removal, there still remained significant levels of residual NAPL beneath the site. As time went on, contamination of underlying aquifers made bioremediation of the area paramount to any future plans.
Due to these concerns, remediation was likely to exceed both original time and cost proposals. A preliminary Conceptual Site Model (CSM) that was developed for the site was soon realized to be oversimplified. From there, a strategy was formed that emphasized the reuse of extracted materials from the site. The US invented NET System was chosen as the preferred technique for the clean up. This system used a hydrophilic, or absorbent, material to continuously extract contaminants. Exceptional MGP contaminated soil on site wastreated with SkyHawk Global’s “HydroEater” advanced micro bacteria product and nutrient package. This novel bioremediation advanced micro bacterial application solution was able to treat the tough naphthalene impacted soil effectively enough for the area to not only be useable, but safe.
Naphthalene content was the main risk driver for the project. By using the HydroEater product, bioremediation efforts were completed 4-8 weeks into the project schedule. Naphthalene levels were reduced by 99% from an initial average of 1,108mg/kg to 9mg/kg as well as recording significant contamination level reduction across all of the hydrocarbon chain groups to a magnitude far lower than the EA remedial criteria required. These innovative methods helped achieve a goal of zero off-site disposal of hazardous materials to landfill.
In addition, the use of the “HydroEater” product solution concept provided Meridian Water and their team to be recognised in these achievements in winning the Brownfield Briefing Award for Project of the Year in 2019. The site area now includes a new highway junction and TfL rail station with plans for the addition of a medium pressure gas main to be ran through the district . The use of Skyhawk Global’s “HydroEater” Bioremediator product solution can be directly linked to the successful bioremediation of the Meridian One gas site, and the subsequent use of the land for residential works.