ROCHESTER, N.Y., Sept. 8 (UPI) -- New York says a "sprayground" water feature in a state park was not at fault when 4,000 people were allegedly sickened by a parasite in the recycled water.

A class-action suit seeking unspecified damages was filed against Seneca Lake State Park alleging negligence in designing, building and operating the filtration system for the 100-plus jets that spray water, the (Rochester) Democrat and Chronicle reported Wednesday.

The incident was one of the largest outbreaks of waterborne illness nationwide in at least 10 years, the newspaper said.

The state attorney general's office, representing the state Department of Parks, Recreation and Historic Preservation, said in court filings the sprayground was consistent with industry standards and used the same chlorine filtration system as all other spraygrounds in the state in August 2005.

After people became ill, state health officials found cryptosporidium in the spray park's water tanks and closed the park in mid-August 2005.

The state Department of Health concluded one or more visitors with gastrointestinal illnesses passed the microscopic crypto parasite into the sprayground's recycling water system through a diarrhea bowel movement. The parasite, which is resistant to chlorine-based disinfectants, likely infected other visitors, the state said.

Crypto contamination "can and has occurred in recreational water facilities that are state of the art, that are well run and even in those that have installed an ultraviolet light disinfectant treatment system," court papers filed by the state said.