This advanced microscope had a great effect upon the study of water purity and water filtration.

Testing for radon, termites, and water purity should be handled by specialists.

Measures of water purity often rely on measuring turbidity, not aromaticity.

The aqueduct was known for its water purity and its cold temperature.

But much of the land it buys becomes, in the name of water purity, off limits for many uses, including hiking and camping.

Each holding system controls the water purity and pH and has a capacity of 10,350 adult fish.

The lack of public disclosure about water purity at some beaches may make it hard for people to protect themselves.

There are worse threats to water purity than plastics.

The second issue is linked to resolving the geo-ecological problems along the Danube and about water purity.

Many enviros think the need for improved water purity can be dealt with in small ways.