ST. PAUL, Minn. (AP) _ The Minnesota Pollution Control Agency has spent years documenting and monitoring all 80 of Minnesota's major watersheds in order to gain data about the health of the state's rivers, lakes and streams.

Reports say that pollution control agency staff members are now revisiting places that were first tested a decade ago.

Water is sampled from every watershed yearly to check for clarity and pollutants, and intensive monitoring is done on a rotating basis about every eight to 10 years. The sampling includes studying fish found in the watersheds.

Steve Woods is the executive director of the water conservation nonprofit Freshwater Society. He says water in the northern part of the state is good, but that many bodies of water in the southern part have pollution.