The nonprofit environmental law firm Earthjustice filed a lawsuit Monday against Hawaii’s Agribusiness Development Corporation alleging it allows pesticides and chemicals to flow unchecked through Kauai’s Mana Plain and into waterways.

The ADC is an attached agency of the Department of Agriculture. Earthjustice threatened to sue in May, on behalf groups including the Surfrider Foundation and Pesticide Action Network, according to a press release.

The ADC leases thousands of acres of land in the area to seed companies.

The lawsuit claims that a 40-mile-long drainage ditch on Kauai’s west side is in violation of the Clean Water Act, which requires a permit before discharging hazardous chemicals into state waters or wetlands.

The ADC decided not to renew its permit in May and instead pursue an exemption to create a plan to care for the soil and water in the Mana Plain.

A $100,000 government study in response to concerns about pesticide use concern showed four pesticides were found in the area, but the amount was low enough that they wouldn’t have “significant negative” impacts on the environment.

The Department of Agriculture declined to comment, citing the pending lawsuit.