BRUNSWICK, Maine (AP) — Maine environmentalists have criticized Bowdoin College’s planned solar panel expansion at Brunswick Landing that could harm a coastal grassland.

The expansion will add an 18,000-panel solar array across 20 acres to the 2,150-panel array built in 2014 and be built on the Little Bluestem-Blueberry Sandplain Grassland, Bangor Daily News reported.

The site is one of four that were identified by the Maine Natural Areas Program to be “critically imperiled” due to its rarity.

According to the Maine Department of Inland Fisheries and Wildlife, the low-lying grassy habitat is home to two species of “special concern,” the prairie warbler and eastern towhee. A third species of “special concern,” the black and white warbler, have been documented using the forest edges of the college’s 115-acre parcel at Brunswick Landing.

In addition to concerns surrounding native wildlife, Kristen Puryear, an ecologist with the Maine Natural Areas Program, said in a letter to Brunswick town officials that the grassland must be maintained with prescribed burns.

Bowdoin and its project partner, Sol Systems, said that a controlled burn will clear the site and the panels would be installed to avoid the grasses.