At Tuesday’s board of supervisors meeting, Public Works director, John Diodati said the contaminated water event was rare and unusual.
“For over the last 50 years, we've treated Lopez water for the five cities and this is the first boil notice," said Diodati. "We test the water at the treatment plant daily, weekly within our distribution system and have never exceeded the sample that has warranted a boil order.”
According to Diodati, over the next few weeks San Luis Obispo County’s public works department will work with the State Division of Drinking Water to find the source, and prevent future water contamination from happening again.
On April 30th, a boil water notice was issued because water samples from the Lopez Lake water distribution system showed a presence of E. coli. A second round of tests displayed higher levels of coliform bacteria, not E. coli.
The notice was lifted after the drinking water supply was tested and confirmed safe.
Testing to find the cause of the contaminated water is expected to take 30 days to complete.
Starting on May 7, the Five Cities water supply will be treated with free chlorine -- a stronger water disinfectant -- until May 28.
The change affects Arroyo Grande, Pismo Beach, Grover Beach, Oceano, Avila Beach and Port San Luis.
An advisory from San Luis Obispo County says the practice of treating water with free chlorine is effective at targeting bacterial contamination in water mains. The County last treated the water with free chlorine in November.
To reduce the odor or taste of free chlorine, you can boil the water, use a carbon filter, or let it sit uncovered overnight to allow the chlorine to dissipate.
