The Big River, Co Louth, Ireland: a case study in recovery

Results of analysis of the chemical and biological effects of organic wastes, from the Cooley Alcohol Factory, on the water quality of the Big River, Co. Louth, during the March/April period - from 1983 to 1986 - showed the river to be grossly polluted downstream of the factory outfall - being devoid of living organisms, with the exception of sewage fungus. When the factory ceased production in June 1986, water quality showed an immediate improvement and within eight months significant signs of recolonisation, by macroinvertebrates, were evident. Water quality continued to improve until the end of the survey in March 1988, when the river returned to near pristine conditions.