Black points : Detection, evaluation and control

“Black Points” are contaminated sites, which stem from former malpractices in waste management. Methodical campaigns have been launched to obtain an inventory of such sites. The strategies and techniques of prospection and investigation are reviewed and the parameters affecting risk evaluation are analysed.

Numerous factors have to be considered when preparing a remedial action. Depending on the forms of contamination more or less extensive safety precautions should be taken. Contaminated earth and buried wastes may have to be excavated and treated, prior to disposal. The most prominent methods, which recently were developed for the cleaning of earth are reviewed.

A major problem during the sanitation of most sites is the management of groundwater, leachate, and liquid wastes. In one strategy the contaminated site is completely isolated from the environment, in another it is hydraulically isolated by adjusting pumping rates from a series of wells and creating supplemental barriers. Also the problem of the treatment of leachates is briefly adressed.