Elected officials and community leaders gathered at City Hall Friday to demand an investigation into what they call a scandal surrounding the construction of the Croton water filtration plant.

The rising cost of the construction project is at issue. Community leaders and officials complain that the estimated cost of the construction of the Van Cortlandt Park plant has risen from $1.3 billion to nearly $3 billion.

They go further to say that the city claims the reason the filtration plant was approved for the Bronx location was because it was less expensive than the Westchester site proposed.

Officials say the increased cost of the project is resulting in significant hikes in the city?s water rates.

Those in opposition to the rising costs also take issue with the actions of the former Department of Environmental Protection commissioner Chris Ward. They say Ward left his job after the plant was approved. One year later, he became the head of an association that championed building the plant in the Bronx location.

Elected officials say Bronx and city taxpayers deserve a thorough investigation into the matter. They fear the cost could become even greater without intervention.

DEP Commissioner Emily Lloyd said in a statement that the higher costs are a result of inflation and cost increases in the construction industry. She said the DEP put an integrity monitor on the construction plan with the full authority to investigate if necessary.