About the same time last year, two children playing in the baby pool were treated at Stanford Hospital after reacting to a "gaseous substance" released by a malfunctioning chlorination system. The city waited eight days before telling the public.
This time, it's been almost a month without notification.
A log of the Aug. 12 emergency call shows a request for medical aid and a possible hazardous materials investigation at 7:30 a.m.
Private contractor Menlo Swim and Sport, owned by Tim Sheeper, operates the city-owned Burgess and Belle Haven pool centers under an agreement that was just renewed in March.
"There is a continuing investigation of the incident by designers, builders, operators, and an oversight committee. Results are not yet available," Mr. Sheeper said when reached via email. "All pools are and have been operating within normal parameters using normal procedures."
The oversight committee consists of city staff from the public works and community services departments as well as Team Steeper staff, according to the city.
No evidence of problem
Three days after the Almanac repeatedly requested information about the incident from the city, Community Services Director Cherise Brandell responded, saying that a female swimmer requested medical aid and described a "gas bubble" rising from the pool. After staff determined that the pool was operating normally, Ms. Brandell said, they asked the plumbing contractor to examine the pool. The contractor arrived at the pool within hours, she said, and found no evidence of a leak or bubble or any other problem.
"It was determined at that time that there was no danger to other swimmers," Ms. Brandell's email said.
According to the city, engineers from the firm that designed the new plumbing also inspected the pool and "felt that it is virtually impossible for an event to have occurred in the way the victim described."
Asked why the city didn't notify the public, Ms. Brandell responded that with no evidence of a malfunction and no other swimmers in the immediate area who had smelled or seen a bubble, staff determined it wasn't newsworthy.
"City staff and the operator are confident that all the City's pools are, and have been, operating normally and safely," Ms. Brandell stated.
Still, the investigation continues. No update on the swimmer's health status was available.
Previous problem fixed
This was potentially the third exposure incident at Burgess pool since 2006. Five years ago, eight children using the children's pool experienced burning eyes and throats, shortness of breath, and violent coughing — all symptoms of low-level chlorine exposure, according to the American Association of Poison Control. Paramedics took one to the hospital.
The city then waited six days before informing the public.
That incident resulted from an accidental shutdown and restart of the pool's circulation pump, according to Mr. Sheeper. He told the Almanac that a contractor later added two mechanical safeguards to prevent a recurrence.
The American Association for Poison Control collected reports of 3,451 chlorine swimming pool exposures during the past eight years across the United States, nearly half for children under the age of 19 and requiring medical treatment.