Contra Costa County Health officials are warning people against coming in contact with the water inside New York Point near Pittsburg’s Yacht Club after blue-green algae there tested 175 times over the safe limit.
A resident observed globs of algal blooms in the water in late July, prompting Contra Costa Environmental Health officials to test the water. Lab results confirmed the levels of potentially harmful cyanotoxins were at 3,500 micrograms per liter in the northeast corner of the yacht harbor, compared with a “danger” level at 20 micrograms per liter, according to Kristian Lucas, supervising environmental health specialist.
“It’s very high — the highest readings we have ever received,” Lucas said. “There was a perfect storm of warmer waters, a lot of sun, water stagnation and a nutrient source.”
Health officials are recommending that the city, which owns the property there, do additional testing to determine the extent of the toxins.
“With that high of a reading, it would behoove people in the city of Pittsburg to find out how extensive it is throughout the marina — wherever they have boats inside the breakwaters,” supervising environmental health specialist Joe Doser said, noting the county has offered to do more testing.
Laura Wright, Pittsburg’s environmental affairs manager, said she was surprised to see the blue-green algae near the yacht club.
“It’s the first time that I’m aware of,” she said. “I am surprised in all the years I have only seen a little bit of algae growth — all marinas get a little bit — but this is the first time I have seen it in that volume of material.”
Wright noted that Pittsburg experienced an extended period of hot weather ranging from the upper 90s to 100s a few weeks ago, which could have contributed to the problem.
“Sometimes in the hot weather and when the water is not circulating too well, that’s when the blue-green algae grows,” she said. “Temperature can really drive it. It’s cooler now, so it has (mostly) dissipated.”
Health officials caution, however, that even if one doesn’t see the floating bright blue-green algae or telltale scum, that doesn’t mean the waters are safe.
“Without testing, no assumptions can be made,” Doser said. “We would not consider it safe without testing.”
People should avoid coming into contact with water anywhere near the blue-green algae until further notice, Lucas said. Livestock and pets should also be kept away from any water that tests positive for toxic cyanotoxins, which can sicken or even kill them, he said.
“Pets are more susceptible because they weigh less,” he said, noting they tend to lick their wet fur too. “It changes a little bit with humans — they can ingest it a little more readily. With swimming, it’s more incidental ingestions.”
Marilyn Underwood, Contra Costa’s health director, said some blue-green algae produces a cyanotoxin called microcystin, a liver toxin. That poison can cause an array of ailments, including rashes, eye irritation, diarrhea, stomach cramps, vomiting, fever and a sore throat, according to the California Department of Health. Exposure to high levels can lead to serious illnesses and even death, public health officials say, although there are no reports so far of illness in East Contra Costa County due to exposure this year.
County health officials say they received the Pittsburg blue-green algae tip on the same day they were analyzing a complaint in Discovery Bay’s Willow Lake, which revealed a 4.0 microgram-per-liter result, triggering a “caution” level in the lake community. Earlier in July, the town’s yacht club posted a “danger” sign when the algae tested at 50 micrograms per liter, while several other locations produced results in the “caution” level.
East Bay Regional Park District officials recently also found toxic blue-green algae at levels greater than 10 micrograms per liter in two tests a month apart, the last on Aug. 8, at Oakley’s Big Break Regional Shoreline’s kayak launch and around the fishing dock where “danger” warning signs have been posted since mid-July.
Whether the signs say “caution,” “warning,” or “danger,” health officials say the message is the same: Stay away from the toxic algae (or completely out of the water if it’s in a “danger” zone), don’t eat shellfish or fish caught there, keep pets out of the water and don’t drink it or cook with it.
“Based on where we are testing, just because we are seeing it in one location, doesn’t mean it couldn’t be in other locations in the future,” Lucas said. “If you see it in the water, assume it is toxic. When it (blue-green algae) does reduce, sometimes the toxins can linger.”
Wright said the city of Pittsburg is investigating the blue-green algae issue and looking at ways to prevent it in the future.
“This is the first time we ever had this situation,” she said. “‘We’re still investigating, trying to figure out how it got to that point. I can’t recall the last time I’ve seen it look blue-green like that.”
The city will work with the county environmental services, possibly re-sampling the waters later, Wright said.
Although no one knows why the toxic blue-green algae levels are so high at New York Point, health officials speculate that available nutrients likely play a big role.
“Nutrients are probably the biggest factor,” Doser said. “Maybe there’s storm water runoff — hopefully people are not dumping in the area. They (city officials) need to look upstream to see what might be occurring in the area.”
Doser added that fertilizers — phosphorus and nitrogen — are key for the growth of blue-green algae.
“We encourage people not to overfertilize and not let fertilizers get into our waterways,” he said.
Doser noted engineering methods such as aerators can help get the water circulating, but they are expensive and might not be doable because of state Fish and Game regulations.
Chemical treatments are available, but are not recommended because they could harm the fish and cause more problems, he said.
Routine testing is not being done this year, Lucas said, noting the county instead has responded to individual complaints. At this point, county health officials say they will re-test in November when the algae has mostly dissipated.
“It’s too labor-intensive and cost-prohibitive,” he said of the routine sampling done in past years.
Concerns about blue-green algae first surfaced in East County in 2015 in Discovery Bay when Contra Costa environmental health officials, responding to complaints, tested the waters and found some harmful blooms. In 2016, the county began routine sampling of various parts of Discovery Bay where one child, unaware of the dangers, became sick after swimming in water near some blue-green algae.
For updates and more information on diagnosing blue-green algae, go to https://cchealth.org/eh/hab or call the CEHD at 925-692-2500.
For information on harmful algae bloom incidents, visit https://mywaterquality.ca.gov/habs/where/freshwater_events.htm
