Two Maui community groups are suing Maui County’s Department of Water Supply to block construction of an Alexander & Baldwin plant that would treat water from four central Maui streams.

Hui no Na Wai Eha and Maui Tomorrow are being represented by Earthjustice in the lawsuit filed Monday in state court on Maui.

The proposed Waiale Water Treatment Facility would process 9 million gallons of water per day that A&B subsidiary Hawaiian Commercial & Sugar diverts from four Na Wai Eha streams.

Earthjustice says the water would be used for A&B’s development projects and for sale to Maui County. The water wouldn’t be used to grow sugar at the HC&S plantation.

Earthjustice wants the court to invalidate the environmental impact statement for the plant.