For every project, the Stuyvesant Environmental Contracting team analyzes the project specific conditions to most effectively configure and operate the deployed treatment facilities. This is also part of the integrated approach. Treatability studies are normally performed in the Boskalis Dolman laboratory in Papendrecht, The Netherlands or on site.

All projects start with a treatability study. "Representative" samples from the project area are collected by the Stuyvesant Environmental Contracting team or by others. Accurately characterizing any large site is a complicated, and necessarily an artful, undertaking. The number of samples collected is carefully discussed and selected. Part of the pre investigation is an historical investigation to determine the past use of the dredge area. Unexpected debris like ammunition can harm the progress dramatically!

To determine the best available project approach for excavation, treatment, beneficial use and disposal, several key laboratory tests are standard.

The key tests will include:

• Soil sieving to construct the particle size distribution curve. This information will provide the analytical predictive information of the mass of material to be found in the oversize, the sand, and the fines fraction. This information will drive the construction of the process flow sheet and will be a direct input into the sizing of the process equipment. In projects involving contamination, each sieved fraction will be analyzed for the contaminants of concern to quantify the fractions of concern.
• Jar tests using a range of theoretically applicable coagulants and flocculants to determine the optimum polymer and dosage to promote rapid and well-consolidated settlement of the fines in the clarifiers/prethickeners.
• Mechanical pressure filtration tests on the thickened fines to determine the most cost effective dewatering method and to make reasonable estimates regarding the dry solids concentration of the produced filter cake.

Other tests will be performed for specific issues presented by the soils, the contaminants, and site requirements.

The findings of the treatability study are used directly in the design of the processing facility to be used for the project and for one of the regulatory deliverables to be used in the final disposition of the site.