Analysis of requirements for effluent quality and their impact on status of rivers

Abstract

The article analyses Lithuanian rivers, 32 of which have been selected as non-complying with the requirements of good condition. Furthermore, 15 discharge facilities that discharge wastewater to the aforementioned rivers from agglomerations with population equivalent (PE) greater than 2,000 have been selected. The assessment of the quality of treated wastewater according to the allowable impact on the reception facility has been carried out and has been compared with the currently regulated minimum allowable values of concentrations of pollutants. The analysis of the impact of quality of treated wastewater on the ecological status of rivers has been presented. It has been established that the pollution of rivers would be decreased by an average 8% (organic pollutants and total nitrogen) and by 22% (total phosphorus), if the allowable concentrations of pollutants according to the impact on the reception facility were ensured in the analysed treatment plants with PE greater than 10,000.