ANNAPOLIS, Md. (AP) — Maryland highway officials are planting thousands of trees statewide to help filter stormwater that runs off roads and pollutes waterways.

The State Highway Administration is planting nearly 120,000 trees on 480 acres along interchanges and grassy areas where they won’t hinder visibility. The trees are being planted in the counties of Anne Arundel, Baltimore, Carroll, Charles, Frederick, Harford, Howard, Montgomery and Prince George’s.

Reducing stormwater runoff is a key goal in Chesapeake Bay restoration efforts because rain carries pollutants that spawn oxygen-robbing algae blooms in waterways. Trees help slow and absorb the runoff, keeping it from reaching the bay. They also prevent erosion of soil and stream banks, which also clouds bay water. And trees absorb carbon dioxide, a greenhouse gas blamed for climate change.

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