A mysterious sewage leak on White Rock's West Beach Sunday (July 24) caused the city to post warning notices and close the beach for swimming indefinitely.
And while the source of the problem was cleared within hours, reopening of the beach and Semiahmoo Bay to swimmers will most likely wait until Wednesday.
City engineering and operations director Rob Thompson said Fraser Health would be testing for coliform counts at medium tide in the bay Monday afternoon, with follow-up tests the same time Tuesday.
"We've asked for those reports to be made available as soon as possible so we can make the decision whether it's safe," Thompson said.
Meanwhile people who were in the water Sunday were being asked by Fraser Health to monitor themselves for any sign of gastro-intestinal problems, Thompson said, and to consult a physician if they experienced symptoms.
"There is a slight possibility that people were exposed to something," he said.
Notices to stay out of the water were posted throughout the waterfront after the sewage spill was reported Sunday morning on West Beach, near Vidal Street and Marine Drive. The beach remained open for non-swimming activities.
Thompson said operations staff were first notified on the emergency line around 11:30 a.m.
"I heard there were some reports of toilet paper being observed on the beach and in the water," he added.
He said the cause of the problem appears to have been a "build-up and blockage" of the sanitary sewage main under Marine Drive.
The main overflowed into a storm water diversionary system and sewage was dumped on the beach, according to a city press release.
The blockage, which was fully cleared by a flushing crew by 5 p.m. Sunday may have been caused by "grease, animal and vegetable material," Thompson said.
"The people who cleared the blockage said there was a lot of grease there," he told Peace Arch News, adding that city staff are "somewhat perplexed" by the incident, as preventative maintenance – including flushing the mains in the area – is done on a regular basis.
"It must have been the result of something in the last few weeks," he said.
However, he said he was not pointing a finger at waterfront restaurants or other businesses, as the source of the blockage could quite as easily have come from a residential garburetor.
Thompson said such an incident is a rarity, noting the last significant sewage spill on the beach occurred in the late 1980s, as a result of heavy rainfall.
"Considering the preventative measures we take, we're surprised it occurred at all," he said of the latest incident. He added that staff believe it is most likely a "one-off event".
"We're doing the best we can with preventative maintenance, but occasionally something will happen."