New approach to domestic grey water footprinting: the country-scale accounting using statistical methods in Türkiye

Abstract

This study aimed to develop an approach for country-scale domestic grey water footprint (GWFdomestic) accounting and examine spatio-temporal differences using statistical methods. In this scope, the GWFdomestic was calculated as the amount of water required to reduce the total nitrogen concentrations of domestic wastewater released into receiving media from 81 cities in Türkiye. GWFdomestic values were estimated based on the data on wastewater amount and applied wastewater treatment process. GWF domestic was calculated by dividing the pollutant load of discharged water by the critical concentration in the surface water. The empirical results showed that (a) the produced wastewater amount increased up to 125 m3/year in some cities. (b) GWFdomestic values showed a difference between 330 and 1,900 depending on the level of treatment, and the average value was about 750 m3/ca.year. (c) A total of 81 cities were grouped under four categories, and applied water treatment technology was the main characteristic of this classification. (f) GWFdomestic has not statistically significantly changed over time in a large part of the country. It can be concluded that country-scale GWFdomestic accounting can assist water managers in developing prevention measures by analyzing spatio-temporal differences in the water footprint of domestic discharges.