Full excavation and off‑site removal of approximately 30m³ of Knotweed‑affected soils, enabling safe development after contamination was identified both on the site and extending onto neighbouring land.
Full Excavation & Off‑Site Removal for a Residential Development Site
A residential development site in Beckenham, Kent was found to contain a significant Japanese Knotweed infestation, with rhizomes extending approximately 2 metres onto neighbouring land. The contamination posed a direct risk to the planned construction works and required a controlled, compliant excavation to prevent further spread and ensure the development could progress safely.
During initial investigations, buried bags of contaminated soil were discovered on the adjacent flats site, likely the original source of the infestation. IVM was instructed to undertake a full excavation and off‑site disposal of all affected soils, ensuring the site met development, warranty and environmental requirements.
Project Overview
Location: Beckenham, Kent
Site Type: Residential development site
Contamination: Japanese Knotweed extending onto neighbouring land
Requirement: Full excavation & safe off‑site disposal
The Challenge
The Knotweed had spread beyond the development boundary, affecting neighbouring properties and complicating access. The discovery of buried contaminated soils indicated historic improper disposal, increasing the risk of deeper rhizome presence. The works required precise excavation, strict movement controls and careful coordination to avoid spreading viable material around the site or onto adjacent land.
Additional challenges included restricted access, boundary fencing that needed temporary removal, and the need to maintain safe working conditions while ensuring full compliance with warranty providers and environmental legislation.
Our Solution
IVM carried out a full excavation of all Knotweed‑affected soils, removing approximately 30 cubic metres of contaminated material from site. Prior to excavation, the area was CAT scanned to identify buried services, and both Heras and wooden boundary fencing were temporarily removed to allow safe access to all affected ground.
All operations were undertaken under strict movement controls to ensure no Knotweed material was transferred around the site. Once excavation was complete, the area was made safe by banking the edges with clean soils already present on site, leaving the plot ready for development to continue.
Outcome
• Approximately 30m³ of contaminated soils removed
• Full excavation completed under IVM supervision
• Knotweed removed from both the site and affected neighbouring land
• Excavation made safe and ready for development
• Monitoring scheduled as part of warranty conditions
Project Photos
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