Diseo provides soil advice at the intersection of land and water

Dike reinforcement takes place at the interface between land and water. For construction consortium Mekante Diek it is important to have the contamination situation and the quality of the soil on the dike reinforcement between Tiel and Waardenburg mapped out, preferably well before work starts. Leave that to soil consulting firm Diseo with a lot of experience at the intersection of land and water. 

On the route between Tiel and Waardenburg, the necessary (water) soil, foundation and asphalt investigations were carried out in the past on behalf of the Rivierenland Water Board. "It was up to us in the first instance to assess those surveys for topicality and accuracy," says Martijn Veenhuis, owner of Diseo. "This showed that quite a bit of additional research had to be done. On the one hand because contaminants had been identified in those surveys that needed further mapping, and on the other hand because not every section where digging is going to take place has been surveyed. So work to be done."

Lots of experience

Based on the inventory, Diseo started drawing up plans for the additional research a year and a half ago. "We've been through many dike reinforcements by now and are still in the thick of it," says Martijn. "So we know from experience that a contractor likes to have a picture of all the risks of any soil contamination prior to implementation, and even better, that we go so far as to have the contamination removed before work begins. So that environmental problems in the soil, asphalt or foundation do not lead to delays in execution. We are in the middle of that process now. We are in the process of carrying out the investigations we discovered during the inventory. These too sometimes reveal contaminants that we need to investigate further to the level that we can remediate them with a BUS notification (Decree on Uniform Remediation) or plan of action, so that Mekante Diek is no longer bothered by them during execution."

Laws and regulations

The scope for Diseo is very broad here on the project. "We have to deal with water and land soils and therefore the Water Act and the Soil Protection Act. Two different laws with all kinds of legal aspects that frequently overlap in this project," Martijn knows. His colleague Bram van Tent adds: "So that means a lot of consultation with all stakeholders and in particular the environmental service and the Department of Waterways and Public Works to align the research method and the way of handling. We also take care of the Soil Quality Decree for the supply and removal of raw materials, so that the combination can use materials they have left over elsewhere without any problems. Another thing that makes it complex is that during execution there are sometimes minor design changes or chance discoveries, such as construction and demolition debris in ditch embankments. A matter of moving quickly, assessing the situation and making a plan of action for its removal together with the combination, so that the planned work can go ahead quickly." 

The latter is only possible through intensive involvement and mutual trust, Martijn believes. "We have carried out the necessary projects with this combination in the past, understand each other's business and are perfectly attuned to each other. That means we can switch quickly and easily, even in unexpected situations. In turn, Mekante Diek is assured of a robust solution in compliance with all laws and regulations."