GODDARD, Kan. (AP) — A new federal study said dozens of people got sick after visiting a splash park near Wichita, Kansas, last summer.

The study by the federal Centers for Disease Control and Prevention said that 21 people contracted Shigella bacteria and six others became sick with the norovirus after visiting the splash park at Tanganyika Wildlife Park in Goddard. Another 36 people reported gastrointestinal illnesses after visiting the splash park but didn’t have lab tests confirming what caused their illnesses, according to The Wichita Eagle. At least four people were hospitalized afterward.

Previously, state and local health officials had said that eight people who visited the park contracted Shigella and other people tested positive for the norovirus, sapovirus and a type of E. coli called enteropathogenic E. coli.

The CDC report is based on a survey of 404 people who visited the splash park last year between May 28 and June 19.

The splash park located about 14 miles (22.53 kilometers) west of Wichita was allowed to reopen last July after upgrading its pump and filtration system and passing a health inspection.

The report confirmed the illnesses weren’t linked to any of the animals at the interactive zoo.

At least three lawsuits have been filed against the splash pad. One of those was settled, but two others remain pending.

The director of the wildlife park Matt Fouts told the newspaper he didn’t find the study useful although he’s “all for analyzing data to learn from the past.”

“It offered little advice for other splash parks besides ensuring you have signage that states ‘don’t swallow the water’ and offered no additional insight into the investigation,” Fouts said. “Regardless, it did affirm that there have been no additional incidents because we took the situation seriously and found ways to enhance our system and processes so that the Splash Park is safer than ever.”

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