At the request of a problem owner and Flemish engineering firm, Verhoeve investigated the possibility of buying off a 'coupling file' in Haaght. By making risks negotiable and involving OVAM with co-financing, an integral whole emerged on which a contract could be based. The site was heavily contaminated by former business activities with volatile chlorinated solvents and floating layers of mineral oil. After years of insistence by OVAM and complex utilization situations, a regular contract for construction proved impossible. In agreement with the owner, a special form of contract was agreed upon, in which remediation including study services was carried out on a lump sum basis after an initial remediation-oriented survey. Negotiations lasted about 6 months, during which the contracting amount was "estimated" based on available budget possibilities and co-financing.
A crucial phase was the GO/NO GO acceptance study, which considered the extent of the VOCL contaminants, the permeability of the soil (injectability), and the final cost. The remediation was to be conducted biologically, and a commitment agreement was signed with OVAM to provide additional assurance that the remediation would be carried out. With good cooperation between the owner, OVAM and the contractor, the site could be tackled energetically after years of discussions, and the coupling issue was resolved.
Identification of contaminants, pay attention to risks
Many files are examined according to standards and legislation, but this still does not provide a guarantee. In addition to environmental contaminants, factors such as high concentrations, biodegradability, soil permeability, and makro parameters are of great importance. Source zones and historical data are relevant and should be carefully investigated. Management measures should be installed if remediation is delayed but spreading is a risk.
Remediation options and methods
In remediation, it is important to find an innovative and collaborative contractor. Various methods are possible, such as biodegradation, chemical or thermal techniques, or combinations thereof. Decisions must be made based on boundary conditions such as time, cost, risk, accessibility and operations. Innovative remediation techniques are available, but testing and pilots are necessary to reduce risks and avoid stagnation.
Verhoeve, with more than 35 years of experience, provides customized soil and water remediation services. The company specializes in innovative methods and offers various options, from traditional excavation to biological or chemical techniques. Contract forms are adapted to the client's requirements, where trust between client and contractor is crucial.
'Lessons learned': Trust, transparency, and balanced contracts are essential. Verhoeve advises clients and contractors to discuss risks, schedule, and preconditions without stipulating penalties and unattractive payment arrangements in advance. A balanced contract ensures successful execution of projects.
