Remediation

Conception and Implementation

Our highly specialised customer support teams find practical, integrated solutions - even for difficult problems:

The remediation of contaminated sites.

Former industrial and military sites in particular are frequently contaminated with hazardous substances and require thorough remediation.

HIM offers integrated concepts from a single source including exploration, conception and planning, all excavation measures, soil and groundwater cleanup as well as effective, disciplined project management.

Building Renovations

For the renovation of commercial buildings, HIM mainly offers dismantling and gutting along with the removal of hazardous substances from the structure. Buildings can also be demolished and removed, including the remediation of the underlying property.

As a general contractor, HIM assumes responsibility for all of the applicable measures.

Remediation of a Chemical Plant

Project:Demolition and Removal of Buildings at a Chemical Plant
Time periodMarch 1998 to August 2000
TaskA total of 12 buildings with floor space of approximately 170,000 m2 needed to be demolished at a chemical plant in the Rhine-Main region which had produced pigments and other chemicals for several decades. The buildings in question were former production facilities along with decommissioned laboratories, warehouses and office buildings. Disrupting ongoing plant operations had to be avoided.
SolutionIn preparation for demolition, the individual buildings were analysed for possible contamination in order to obtain an inventory of the expected waste types. A demolition and removal concept, including recommendations for suitable disposal options, was developed on this basis. In order to detect possible contamination from the previous use of the buildings, investigations of the soil beneath the buildings and of the groundwater were also conducted at the same time. The investigation results and recommendations for each building were summarised in an expert opinion that formed the basis for the demolition permit application. After the demolition and removal measures were complete, the excavation pits left by the buildings - some of which had basements - were backfilled and the site was restored for subsequent use.
Disposal volumeOver 500 tonnes

„Cargo-City South“ Airport Remediation

Project:„Cargo-City South“ Airport Remediation, Frankfurt / Main
Time period1996
TaskStandard preliminary investigations of the subsoil were conducted by the explosive ordnance disposal service within the scope of construction on today?s „Cargo-City South“ freight centre on the premises of Frankfurt Airport. Remnants of approximately 11,000 kg of „Clark“ ordnance were found. This contamination was the result of the improper and unsystematic disposal of explosive and ordnance by simple detonation after World War I. The detonations scattered munitions residue across the area, leading to the contamination of soil and groundwater directly and through displacement. Initial exploration in a grid pattern revealed a contaminated area of approximately 40,000 m2 in need of remediation. Contamination of up to 2,650 mg/kg of arsenic in the surface soil and up to 900 mg/l of nitroaromatics in the groundwater was found. This high level of groundwater contamination caused the Darmstadt Regional Commission to declare the area a contaminated site.
SolutionBecause of the risk that hazardous substances might spread, a groundwater extraction well was immediately established downstream from the contaminated site. Based on the hazardous substances that had to be removed and the low target values required, a reverse osmosis system with a capacity of 25 m2/h was constructed and operated to clean the extracted groundwater. The treated groundwater was discharged and the concentrate disposed of in a CP facility operated by HIM.

In the first project phase, the remediation concept including the detailed occupational safety and quality assurance plan were developed and submitted for approval. In view of the specific range of toxic hazardous substances in question, occupational safety and recovery the excavated material were key focal points with a significant impact on approval, the financial framework and the duration of the project.

An analysis of the options conducted during the offer phase, which examined the „on-site“ treatment of excavated material on the one hand and external thermal or chemical-physical treatment on the other hand, revealed that these solutions did not offer the required level of security from a technical, economical and scheduling perspective in regards to the established deadlines and also the target values specified for the eluate. This meant recovery options had to be found that permitted the substances to be recoverd without preliminary treatment subject to the acceptance limits of the respective treatment plant. Subsequently and after establishing these recovery options, the excavation concept had to include the separation of the excavated material into suitable material classes along with the corresponding logistics for sample collection, analysis and storage. Compliance with deadlines and the required traceability had to be assured during implementation.

HIM completed the remediation project directly after approval was obtained. Excavation work commenced in January 1996, the cleanup of the entire site was approved by the monitoring authorities in September 1996 and the construction site was cleared in December 1996. More than 237,000 tonnes of excavated material, mostly contaminated with soluble arsenic and nitroaromatic compounds along with mercury in some cases, was recoverd in various approved ways over the course of the remediation project. A complex disposal and recoery concept had to be developed and implemented because of the unusual composition of the contaminants and the large quantities of material.

Up to 5,000 tonnes of excavated material had to be analysed, moved and recoverd each day.

The construction works were completed subject to follow-up investigations under the technical supervision of HIMTECH as an independent consultant and in the course of remediation, i.e. the implementation of occupational safety requirements, volume declaration and control, compliance with the remediation specifications and documentation.

Disposal volume240,000 tonnes