Long-term changes in the environmental quality of water in Latvia (chemical composition of inland waters, waste-water treatment, and drinking-water treatment practices and quality) as a response to socioeconomic changes have been studied. Water composition, the major factors influencing water chemistry, and human impacts (waste-water loading) were studied to determine changes that occurred after recent reductions in pollution emissions, particularly nutrient loading, to surface waters. After 1991, (Latvia regained independence in 1991) inland water quality has begun to improve mainly as a result of decreases in nutrient loads from point and nonpoint sources and substantial efforts in the area of environmental protection. The situation differs, however, for drinking-water treatment, where practices have also changed during the whole period from 1980 till 2000. More stringent drinking-water-quality standards and novel insights regarding changes in water quality in the distribution network, necessitate further improvements in public water supply, and place this particular water issue among Latvia's main priorities.