On Friday, September 1, 2006, a toxic spill took place in Caldas de Reis, Pontevedra. Awide variety of chemical compounds were spilled as a result of a fire in the Brenntagfactory located there. The spill, which consisted mainly of volatile organic compounds,ferric chloride, alumina sulfate, and a colorant, probably malachite green, contaminatedabout 4 kilometers of the Umia River until the Regional Executive of Galicia decided toraise a series of docks to temporarily dam the river.This caused various problems. First, as the spill took place on a Friday, it was hard tofind a laboratory that could rapidly analyze the spill composition and conduct monitoring.Second, a decision had to be made quickly about how to contain the river and keep thespill from entering the water supply of the Arousa region where about 200,000 people live.Third, the spill had to be kept from reaching the shellfish beds of the Ria of Arousa.This paper examines all the decisions that were made in the first daysafter the spill, which were influenced by the need to ensure water supplies to thepopulation affected. A water treatment system was improvised in the river using treatmentponds to eliminate the contaminants. Stopping the flow of the river had the followingconsequences: algal blooms; microcystins in drinking water; construction of a by-passpipeline from a point upstream to the spill to a point below the last dock (15 km in 7 days);an effort that coincided with the grape harvest in a major winemaking area; difficulties insupplying water to different population centers; and others. Includes table, figures.
