skip to content, health centers and clinics, search, accessibility statement
CCHS

Press Release

Contra Costa Health Services Releases Findings on the Antioch Water Park Incident


Note to Editors: Environmental Health Director Marilyn Underwood
will be available for media interviews today at the EH Offices:
3:30 p.m. to 5 p.m. Wednesday, July 8
2120 Diamond Boulevard Suite 200, Concord 94520


Wednesday, July 8, 2015



Archived. This is an older press release from 2015 and may not contain the latest information. Please view our current press releases for 2017 items.


Contra Costa Health Services (CCHS) released its findings today on the cause of the June 18 incident at the Antioch Water Park that sickened 34 children and caused the park's closure.

CCHS' Hazardous Materials and Environmental Health divisions both investigated the incident, and their reports found that a concentrated amount of pool chemicals was inadvertently pumped into one of the park's five pools while swimmers were present. Whether a system malfunction or human error was the cause remains under investigation, said Environmental Health Division Director Marilyn Underwood.

"It is unclear whether the incident was caused by a system malfunction or human error or a combination of both, and we are working with the pool operators to address all potential issues. We have provided them with the requirements that must be met to ensure the safety of swimmers before the Sports Pool can be reopened," Underwood said.

The reports include details of the incident, factors that may have led to the incident and the corrective actions that the City of Antioch, which operates the park, must take before the Sports Pool can be reopened. The park's four other pools reopened to the public on June 20 after being inspected by Environmental Health, which regulates public pools.

On June 18, 34 children swimming in the Sports Pool at the Antioch Water Park reported having symptoms that included trouble breathing, burning skin, and eye and throat irritation. Seventeen of the children were treated at the pool and 17 were transported to local hospitals and released. Contra Costa Environmental Health and Hazardous Materials staff responded to the incident.

"Our investigation shows that the night before the incident, the pool water pump stopped running for unknown reasons, but the chemicals continued to flow into the pipes. The water pump restarted for unknown reasons about 2:20 p.m. on June 18, flushing the concentrated chemicals into the pool. Minutes later, the children started reporting symptoms," said Matt Kaufmann, Hazardous Materials Assistant Director.

The chemicals, sodium hypochlorite and muriatic acid, are safe when used properly in a fully functioning recirculation system and are needed to keep pools clean. Because the recirculation system was not operating, the two chemicals may have reacted and possibly created chlorine gas, which is toxic. No gas was detected at the scene when Hazmat arrived but the children's symptoms are consistent with chlorine exposure.

The reports outline the steps that the pool operators must take to reopen the pool, including participation in a plan review process and implementing policies, procedures and training focused on monitoring the recirculation system. The city has already replaced the controller mechanism that dispenses the chemicals into the Sports Pool. The deadline for the city to submit the plans for meeting all the requirements to Contra Costa Environmental Health is July 15.

Both reports are available online at cchealth.org.


# # #