Beachgoers are being urged not to swim near stormwater drains, even if it’s a beautiful day, after three western suburbs beaches recorded faecal pollution.
Werribee South, Altona and Williamstown beaches were deemed unsafe for swimming for days following a one-in-100 year storm on December 29.
Werribee South recorded the worst water quality of the three beaches this summer, and was deemed too risky for swimming 10 out of 31 days in December.
Altona and Williamstown were rated as risky for six of these days.
The EPA’s Dr Anthony Boxshall said the health risks were predominantly gastro attacks and infections from open cuts or other wounds.
“Werribee South has probably been the lower performer of those three, and that’s because Werribee gets impacted by stormwater run-off more so than the other two, just because it’s a bigger waterway,” he said.
“When we had that massive storm, it just kind of picked up everything and washed everything off the streets and into the water, so pretty much all of the bay beaches at some point, we are pretty convinced, had poor water quality right at the height of that storm.”
Dr Boxshall said the biggest risk was 28-48 hours after rainfall.
“We’ve been doing this for 25 years and we know that for 24-48 hours after rain, our beaches are impacted and water quality is lower,” he said.
“By about 48 hours, more than 95 per cent of the pathogen that we’re detecting has died off.
“A bit over 80 per cent dies off in that first 24 hours,” he said.
“We’ll be giving forecasts twice a day, and we’re out there sampling it once a week, or more if we see incidents, and we’ll keep reporting that information so people can make their own choices.
“Even if it’s a nice day, we know it’s a good idea to avoid swimming at the end of a stormwater drain. More broadly, we can be really aware of what’s happening on our streets – so pick up after your dogs. If you see a leaky portaloo, report it.”
