(AP) – Lawrence-area companies want to take an additional 1 million tons of sand and gravel for the Kansas River each year, but environmentalists are objecting.

Currently, five companies are authorized to dredge 2.2 million tons annually from 10 locations on the river. They are seeking to increase that amount to 3.2 million tons from 13 sites.

Environmental advocates, including Friends of the Kaw, say dredging hurts the water supply and natural habitats along the river.

The Lawrence Journal-World reports that the U.S. Army Corps of Engineers is taking public comment on the proposal until Dec. 9.