According to a new poll, the majority of Americans worry about the purity of their drinking water.
The Gallup Poll said 53 percent of respondents were concerned "a great deal" about pollution of drinking water supplies.
The next highest concerns were over pollution of rivers, lakes and reservoirs, and contamination of soil and water by toxic waste, the poll said.
However, the survey indicated that, in general, the level of overall concern over environmental issues had dropped from highs reached several years ago.
Among issues presented to respondents, the environment ranked as the 10th highest concern. The top three issues cited as high concerns were the availability and affordability of healthcare, crime and violence, and drug use.
The survey's findings are based on telephone interviews with 1,005 U.S. adults, conducted March 8-11. The poll has a margin of error of plus or minus 3 percentage points.