The Flix water reservoir, in Tarragona, has been receiving the impacts of the toxic chemical industry for more than a century. More than 700,000 cubic meters of toxic waste containing substances such as mercury, cadmium and other toxic organochlorine components (such as hexachlorobenzene, PCBs or DDT) have been dumped by the Ecros company to the Ebro river from Flix.

Ercros S.A, established in 1897, is considered to be the most polluting chemical industry in the Ebro river basin. The company has been struggling for years to avoid paying to clean up the river. It is the only Spanish company producing PCBs.

In the beginning of the 1980s, due to an increase in the awareness of the dangers of mercury, some environmental groups (Greenpeace), started pointing out the polluting activities of Ercros company.

In 1993, a long Court case began against Ercros for the pollution caused since 1988. That year, the Environmental Department of the Catalan Regional Government decided to evaluate the pollution in the Ebro river and the area next to the Flix water reservoir. Three reports were published in which it was pointed out that it was possible to identify the place where the toxic pollutants had been dumped as well as the type of pollutants. Many dangerous chemicals were found including heavy metals such as mercury, cadmium, zinc and other persistent organochlorines. Mercury concentrations were up to 500 times higher than other areas which were not polluted and the total concentration of PCBs were almost 80 times higher than other areas.

In 2003, the company was declared guilty by the Court of Justice for continuously polluting the environment. The Public Prosecutor asked for 6 months of jail-time and disqualification for any other job for those responsible at the company (althought up to date, no one has paid the fine nor stepped into a prison due to legal delays). Unfortunately, no decision was taken on the restoration of the water reservoir nor the river, despite the threat that it represents for relevant Natural Parks nearby and the 65 surrounding towns. This court decision did not hold the company completely responsible for these damages, and today most of the cleaning costs (200 million euros) has still to be paid by public funds.

The local population has never formed a specific platform against the company, perhaps due to or influenced by job blackmailing. Despite that, several national environmental groups (Greenpeace, Ecologistas en Acción) and academics have been denouncing the Flix case over many years.

The Ercros company has in 2017 closed down the factory in Flix (because the use of mercury was forbidden by European regulations). There has been a programme for cleaning up the waste dumped in the river (funded by European money), plagued by corruption. Contamination in the soils belonging to the factory has not been remedied. Research has been done (Pujadas, 2016) estimating the environmental liability of ERCROS at about 400 or 500 million euros. Local resistance is feeble.  A documentary film by Arturo Hortas was launched in 2018. 

In 1949, after the construction of the Flix hydroelectrical power station, a chlorine/soda electrolysis plant with a mercury cell also began operation.

In 2004, the manufactured commodities were: chlorine (150,000 Tonnes/year), soda, chlorine derivatives and dicalcium phosphate (740,000 Tonnes/year).

In the past, the company also produced DDT pesticide as well as PCBs and chlorine solvents.

See Marta Pujadas doctoral thesis at ICTA UAB Barcelona for further information. https://ddd.uab.cat/pub/tesis/2015/hdl_10803_300739/mpg1de2.pdf