Dozens of local leaders and environmentalists attended a hearing Tuesday that targeted reducing the nitrogen in Long Island's water.

The public meeting was held at the Suffolk County Water Authority in Hauppauge.

Experts say residents have already seen the consequences of contamination, including red and brown tides spurring algae growth and record fish kills at Flanders Bay in Riverhead.

"We need to start upgrading these antiquated sewage treatment plants with more modernized technology and also upgrade our septics and cesspools that are failing," says Adrienne Esposito, of the Citizens Campaign for the Environment.

The current plan hones in on nitrogen, but Esposito warns that other contaminating culprits such as volatile organic chemicals, pesticides and pharmaceutical drugs are also entering the water.

State officials will continue the discussion Wednesday in Nassau. County residents can offer their suggestions to improve water quality at the public hearing.