Updated May 16, 2018 12:50pm EDT More than a decade after its construction, a new plant at Sewage, South Carolina, is generating an estimated $1.2 billion in revenue annually for the state’s Department of Health.

In 2015, the state and federal governments pledged to provide up to $10 million in annual support to build and operate the facility, which is operated by an affiliate of the American Water Works, Inc. The facility was approved for federal and state contracts worth $1 billion, and has been in operation since 2009.

But as of this year, the plant’s revenue is expected to be more than $1 million per day, a rate that is expected keep growing as it provides water treatment services to hundreds of thousands of South Carolinians every day.

The plant has faced criticism from some residents and some business owners, who say it is being too costly and is being used for wasteful purposes.

A recent Associated Press analysis found that a third of the South Carolina Water Supply Authority’s annual budget went toward paying for water treatment equipment.

“It’s going to be very expensive to build this thing, and it’s going be very, very expensive not to build it,” said David McQuillan, who owns a barbershop near the plant.

This is a $3 billion dollar project that is being funded by a federal program that’s been there for a long time.

And this is going to cost us $1,200 per acre for our grass, which we can’t afford.

So, it’s not worth it.

As a result of the AP’s analysis, a coalition of business and government leaders including the Business Roundtable, the South Carolinian Chamber of Commerce, the Southern Association of Broadcasters and the Southern Coalition for Health and Environment filed a lawsuit in federal court on Tuesday challenging the plant as being overspending.

The lawsuit contends the South Charleston Water Supply Board has violated state law by overspend, misusing federal money, and failing to provide adequate water treatment facilities to residents of South Carolina.

Water and wastewater treatment costs are growing at the plant and the agency, which has a contract with the South American Association of Stream & Pipeline Companies, is not meeting its obligations, according to the complaint.

South Charleston Water and Sewer Board Director James Sargent told the Associated Press that he was unaware of the lawsuit and declined to comment further.

During the first year of operation, the company had to spend $3.7 million to upgrade the wastewater treatment facility, the complaint said.

The plant is scheduled to finish the project by 2021, but it may take longer than that, according the AP.

While the cost of the project has increased in recent years, it has not been entirely offset by an increase in the amount of water and wastewater the plant pumps into the state, according a March 2017 report by the Associated Council on Science.

Some residents of the community of St. James have been pushing for the water treatment facility to be upgraded since the beginning.

In May 2017, residents of St James gathered in front of the plant to demand improvements, and a video of the protest was posted on social media, according.

Residents also have questioned whether the state was properly reimbursing the company for its construction.

The water treatment plant in South Carolina is the only water treatment site in the United States to be funded by the federal Clean Water Act.

The bill passed by Congress last year allows states to use federal funds for projects that are funded through federal tax incentives, according at the U.S. Department of Justice.

After receiving federal funds, South Carolinas Water and Wastewater Authority must meet standards for water quality and ensure the treatment plant is not contaminating other water sources, according South Carolina Department of Environmental Quality.

Since the project started in 2010, South Charleston has experienced significant flooding, according CBS affiliate WTVD.

When the plant first opened in 2013, officials were concerned that the water would overflow and spill into the nearby Charleston River, which runs through the community.