Applying drinking water treatment residuals to land: opportunities and implications Tags CRW2019_01 Research Funding cycle: 2016-21 In 2018/19, Scottish Water’s treatment processes generated c.29,000 tDS2) of Water Treatment Residuals (WTR). WTR, also termed drinking water treatment sludges or bioresource, are produced due to the addition of chemical coagulants to water.