Barge with divers who are working on cleaning the bottom of the Tagus River next to Vila Velha de R?d?o. These are sludges of organic matter deposited over several years in the river bed because of the reduced flow. These materials come from sewage effluents from several manufacturing companies, mainly from paper mills. As the flow of the Tagus river has been greatly reduced in Spain because of its transfer to the South these organic materials have accumulated over the years forming a thick layer of organic matter in the bed of the river that has killed the whole aquatic life. Organic pollution.These sludges are being conditioned in flexible containers at the bank and then moved to a place where they can be properly treated without environmental impact. Vila Velha de R?d?o, Portugal 2018