Rehabilitation of the DTD-Canal in Vrbas. Assessment of environmental status, pollution sources, and abatement measures

Abstract

During the years 2002-2006 there has been undertaken a Rehabilitation Plan Study of the Grand Canal on the problem stretch from Crvenka to the Triangle downstream Vrbas. The aim of the study has been to assess the environmental status, assess and rank the pollution inputs from the different sources, assess the amount of sediments as well as their content of pollution, and, based on these assessments propose the most relevant mitigation measures to rehabilitate the Grand Canal to an acceptable status to the best of the aquatic environment, the water use interests, and for the people living in the area. The environmental status of the canal is very bad downstream the entrance of the laterals just upstream Vrbas and for the stretch down to the Triangle where dilution water is coming in via the “by-pass” canal (Becej – Bogojevo Canal). Particularly the situation is bad through Vrbas town. Here the canal almost is completely filled in with industrial sludge, there is no oxygen in the water, and there is in fact a great surplus of oxygen demand in the water. The water smells badly of sulphides and there are extremely high concentrations of coliform bacteria (levels of raw sewage). The water causes a health threat for the people living there. The Farmakoop Pig Farm, the two sugar factories Crvenka Sugar and Backa Sugar, and the slaughter house and meat factory Carnex, are the four “hot-spots” which are mainly responsible for the poor environmental situation in the canal. The effluents from these have to be controlled. Otherwise other measures will be of little value. Thereafter, the sewage discharge from the population in the three towns ranks in importance. After the 5-6 main pollution sources are controlled the canal can be dredged for removal of accumulated sediments with long term effects.