The state Department of Environmental Conservation says the Town of Islip has made significant progress in cleaning up the toxic waste dumped in Roberto Clemente Park.

The park has been fenced off for more than two years after the discovery of tons of illegally dumped materials, including asbestos, metals and pesticides. Last summer, the town hired a contractor to remove nearly 39,000 tons of contaminated materials from the soccer field and recharge basin.

Greg Pepe, of Central Islip, says 50,000 tons of debris was initially dumped, and the town only removed 39,000 tons. Pepe and other residents say the DEC's tests were only conducted on the surface of the excavated material.

The DEC says tests show that all the contaminated material is gone.

"The tests were done for the contamination that was removed and all the samples came out clean, so we know they removed all the debris that had been disposed of in 2014," says Ajay Shah, of the DEC.

Shah says more work needs to be done before the park can open. He says additional monitoring is needed due to the discovery of old waste materials last year that existed in the 1950s and 1960s.

The DEC says the town's next step is to restore the soil in the soccer field, where most of the toxic debris was removed. State officials also say the town must monitor the groundwater and gas in the park.

Islip Town Supervisor Angie Carpenter says she hopes the park will be reopened by next summer.