Monitoring of ecological risks with active soil management for filled ditches in the Krimpenerwaard. Final report T1-monitoring Ecology.
Ditches in this area in the province of Zuid-Holland, Netherlands, are often causing soil pollution due to the use of contaminated materials (including refuse) to fill the ditch. A programme to cover ditches with clean local soil was implemented and this report describes its efficiency 2-4 years after covering. The measure improved numbers of earthworms and decreased levels of heavy metals in earthworms. PCB levels in moles varied much but showed higher PCB levels if caught in filled ditches.