BOISE - DNA test results show that fecal bacteria from dogs, geese and humans contributed to the recent E. coli contamination in several Boise ponds, city officials said on Sunday.

Ponds in Esther Simplot Park remain closed due to high E.coli levels, while Quinn's Pond reopened on Friday. The ponds were closed on June 21 after routine testing found levels above state water quality standards for recreation.

The Central District Health Department has received several reports of illness linked to swimming in the ponds, officials said.

DNA test results released Sunday point to three main causes of fecal bacteria in the ponds: dog feces, goose feces and human feces. The city said the human feces only showed up during a second round of testing.

Officials announced on Friday that dogs are no longer allowed at Quinn’s Pond or Esther Simplot Park, including the ponds and the previously designated dog off-leash area.

MORE: Quinn's Pond reopens, but no dogs allowed

Dog owners will still be allowed to use Greenbelt paths through Esther Simplot Park for connectivity, but dogs must be kept on-leash and out of closed areas.

“The health and safety of our citizens is paramount and the decision was made to keep dogs out of Quinn’s Pond and Esther Simplot Park to help manage bacteria levels and prevent sickness,” parks director Doug Holloway said in a statement.

The city is also ramping up efforts to scare the geese from the ponds, and is increasing frequency of goose feces removal at both parks. Officials also said they plan to continue to educate the public about the importance of using swim diaper for children recreating at the ponds.