The Minnesota Pollution Control Agency has added 511 streams, lakes and other bodies to its updated impaired waters list. The state agency now lists a total of 3,643 waters as impaired, which means they fail to meet standards for activities such as swimming, boating and fishing. Waters added to the list undergo further study to determine how they can be restored to health. The list is updated every two years as the MPCA studies additional bodies of water. There are a total of 91 new entries this year in the Minnesota River Basin. The agency is also recommending that 13 formerly-impaired waters be taken off the list because they now meet water quality standards. The success stories include Jewitts Creek in Meeker County and Credit River in Scott County, which have undergone cleanup projects. Much of the Minnesota River was delisted as well after being on the impaired waters list since 1994.