Soil remediation

Large-scale soil remediation involving explosive substances in Muiden

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Large-scale soil remediation involving explosive substances in Muiden

Since 2017, Verhoeve Environment & Water has been involved in the remediation of this beautiful site which is locally contaminated with gunpowder-related substances (non-normalized energetic contaminants such as TNT). The contaminants are present in the soil and groundwater. In addition, small spots of immobile contamination are present over a large part of the industrial site, which can be related to raising and/or paving the site. These contaminations consist mainly of heavy metals and, to a lesser extent, PAH, PCB and asbestos. Occasional mobile oil contamination is present.

The Warrior

Gunpowder factory "De Krijgsman" in Muiden closed its gates in 2004. The site has been used for the production of various types of gunpowder since 1702. The site of the former gunpowder factory has a total area of about 70 hectares and is being developed by the Royal Dutch Explosives Factory (KNSF). KNSF has set an ambitious goal by developing the site under its own management into a beautiful residential area with plenty of space for present rugged nature, industrial heritage and old waterways. The plan preserves the old structure of the factory site with various watercourses, tree-lined avenues and some beautiful historic buildings.

For the development, the soil was remediated in phases using function-oriented and cost-effective soil remediation as a starting point. Due to the complex contamination situation, the dozens of contamination sites to be remediated and the large quantities of contaminated soil to be released and processed, the development of the old industrial site is an achievement of stature.

Research and remediation

Verhoeve was engaged for the process and execution of the soil remediation up to and including the groundwater remediation and purification and coordination with foreign partners in order to conduct field research for explosives. Sister company Buro Antares took care of the supervision and control of the remediation and arranged for the processing of the removed soil. Furthermore, the necessary batch inspections were carried out in accordance with the Soil Quality Decree and Regulations.

Within a short period of time, a test chamber was further set up to conduct on-site analytical investigations to determine the presence and absence of explosives in soil samples. This allowed for efficient, effective, rapid and directional excavation.

For the site development, dozens of immobile spots were excavated during the period from May 2017 to the end of June 2018. Where possible, the cadastral annotation of the remediated plots was removed. The total approximately 5,000 m³ of released excavated soil was then rearranged on the southeastern part of the development area within the case. An additional 430 m³ of soil will be rearranged at a later stage in the process.

In addition to the excavation of the immobile contamination, just under 500 m3 of mobile contamination was also excavated and disposed of to an approved processor.

Furthermore, soil contaminated with energetic substances was excavated. A total of approximately 13,500 m³ of soil contaminated with explosives was removed to an approved processor. On site, groundwater will still be remediated over an area of 5,000 m².

Development

A spacious residential area with approximately 1,300 single-family homes and apartments is currently being built on the site of the former gunpowder factory. Thanks to the authentic location wedged between the Gooi, Amsterdam and the IJmeer and the special architecture, existing housing conventions are being broken down and a unique residential area is being realized. More information can be found via the following link: www.dekrijgsmanmuiden.nl