A "fixed plant" means that the facility has been designed to operate in one location for some reasonably extended period of time. The plant is therefore not designed to be easily relocated. Feed materials - soils and/or sediments - are immediately accessible at the plant location or are transported to the plant from some regionally reasonable location.

In Europe, we refer to our plants of this type as "Soil Treatment Centers". The plants have been design and operate recognizing that a wide range of materials to be treated will be brought to the facility. As such, the flexibility of the plant - that is, the ability to handle a broad range of physical and chemical soil characteristics - is essential. The soil treatment centers offer high quality treatment at lower unit prices since the capital cost of the facility can be amortized over a very large volume of incoming soils and sediments. Boskalis Dolman operates six Soil Treatment Centers in Europe.

In the US, the soil treatment center has not yet been used to regional advantage. This approach has been complicated due to local siting constraints, permitting difficulties, and the continuing availability of relatively cheap landfilling.

On the Fox River Project, Stuyvesant utilizes a Boskalis Dolman engineered and built fixed plant with a very high throughput capacity of more than 250 cy/hr. This fixed plant is made possible - and cost effective - because it is dedicated to one customer and one large remedial volume of sediments.

Fixed plants make sense both technically, economically, and socially, and we expect that the era of soil treatment centers will develop in the US.