The House passed a bill Thursday clarifying a 2015 law that requires buffer strips around state waterways to protect them from pollution. It passed by a vote of 105-24 after winning unanimous Senate approval last week.

DFL Gov. Mark Dayton is expected to sign the bill into law, which, he said in a statement last week, “provides greater certainty for landowners and gives local officials better tools for proper enforcement.”

The 2015 bill was the subject of months of negotiation between Dayton and House Republicans. It was aimed at protecting water from farm pollution, which state scientists say has left large swaths of southern Minnesota in particular with lakes, rivers and streams that are unsafe for swimming or fishing.

Dayton has also proposed a $220 million package to upgrade the state’s aging water infrastructure, including money for outstate water treatment plants that need upgrades to clean farm pollution from drinking water supplies.

The buffer requirement around waterways has long been in state law but was left unenforced by many local governments. The new law makes it easier to administer the regulations, provides incentives for local government to step up enforcement and gives significant oversight to the Board of Water and Soil Resources.

Rep. Rick Hansen, DFL-St. Paul, who voted against the bill Thursday, said he was dissatisfied with enforcement mechanisms, which he said would be unfair to farmers who are complying while others manage to avoid it.

For Dayton, the passage of the bill caps off a week of lobbying that he hopes will galvanize Minnesotans on clean water, which has become one of his signature issues.

“More and more citizens and communities throughout Minnesota are being threatened by water that is unsafe for their drinking, washing and recreation,” he said in his statement last week. “These water quality problems must be addressed by all of us recognizing our shared need for safe and clean water, and our by shared willingness to protect this priceless resource.”