Getting into the bay at Aquatic Park (with no wetsuit!) on a cold, foggy morning in San Francisco — the water quality was not my top concern.
I was afraid of the cold — and sharks.
I was here, facing my fears, because I’d asked Nancy Iverson, long time open water swimmer and former pediatrician, if I could talk to her about water quality. She happily agreed, but insisted I come swimming with her as well.
Iverson is a member of the South End Rowing Club, one of the famous swimming and boating communities out at the end of Fisherman’s Wharf. Iverson loves introducing people to swimming in the Bay. She even started her own organization that trains people to swim to Alcatraz.
Iverson says most new swimmers ask about water quality before diving in. It was certainly on her mind when a friend took her swimming for the first time at Aquatic Park, 24 years ago. She was still working as a pediatrician at the time. “I went back to my office and sort of stood and looked at the antibiotic shelf and thought: ‘I want to take everything in here,’” she told me. “Then I just started thinking, ‘That's really stupid.’”
Bay Area beaches have some of the cleanest water in California. Where Iverson swims at Aquatic Park, near the mouth of bay, the water is constantly circulating due to tides. The biggest dangers when swimming at a place like this are large boats and strong currents. But in the winter, water quality can be an issue, too. “Especially this winter, with all the flooding,” Iverson says, “Certainly there was the possibility for overflow of sewage systems [and] runoff of bacteria.
The San Francisco Public Utilities Commission monitors the water quality of the bay and ocean weekly. It posts the data on its website and sends email alerts. That’s helpful to swimmers like Iverson, and surfers like John Brandon, of Pacifica. I met Brandon at a popular San Francisco surf spot, where Sloat Boulevard dead ends at the Pacific Ocean.
Brandon created a Twitter account that automatically tweets out the city’s water quality data. “It was kind of an outlet for my childish humor,” Brandon said. He named the account “Beach Poo” and used the cartoon smiling poop emoji for the account profile picture.
Subscribers can follow “Beach Poo” on Twitter and get updates on E. coli levels and sewer overflows. “It's just an automated way to do what you can already do through your web browser, but it adds a little bit of convenience to it.”
Brandon pulls up the Twitter account on his phone and scrolls through the most recent Tweets.
“The latest sample that was posted on the web was five days ago,” he said. “That was the one at Lincoln.” Ocean Beach, near Lincoln Way. It’s one of the fifteen places where the city’s public utility commission tests the water quality.
“Beach Poo” also tweets out when the public utility commission reports a sewer overflow. This is a problem somewhat unique to San Francisco. The city treats both the sewage from houses and the water from storm drains before releasing it. When it rains a lot, the treatment facilities can’t keep up. They have to discharge some of the sewage before it’s fully treated.
Brandon showed me a tweet from the “Beach Poo” account on April 7th, reporting one such sewer overflow on Ocean Beach at Sloat, right where we were standing. The tweet had red exclamation marks and skull emoji, just to emphasize the point. It’s been re-tweeted four times.
“People care about the sewer overflows,” Brandon said, “And for good reason too. That's one of the things that I really care about and one of the things that I personally am looking for, especially during the winter.”
Right down the beach from where we're standing is a squat concrete structure that seems to appear out of nowhere. There are multiple structures like it along Ocean Beach. They get covered in graffiti, the sand piles up around them and they somehow manage to blend into the environment without anyone questioning what they are. These are the overflow sites. In a big winter storm, sewage is sometimes discharged right there. That could certainly have an impact on a surfer like Brandon. If he got a tweet from the Beach Poo account alerting him of a sewer overflow there, he’d told me, “I would look for somewhere else to surf.”
Now if you want to go for a dip over in the East Bay, you’ll probably end up at one of the East Bay Regional Park District’s lakes, like Lake Temescal. It’s a small reservoir in the Oakland hills and a popular swim spot for families and kids’ camps in the summertime.
Hal Maclean is the Water Management Supervisor for the District. He and his team are responsible for monitoring the water quality of seven different swim areas in the parks.
Maclean scooped up a water sample in the shallow waters in front of the lifeguard chair at Lake Temescal. He labeled the vial and placed in a cooler, with other samples. Later he’ll take these to a lab to be tested for E. Coli and other pathogens.
Each week, East Bay Parks grades swim areas on a traffic light system: green means the beach is open. Red means the beach is closed. Yellow means the beach had a high bacteria count in the last 30 days.
The bacteria in a lake is caused, in part, by human swimmers. “We all have bacteria on us and when we go swimming we transfer that bacteria to the water,” Maclean said. But other animals introduce bacteria into the lake, too - like fish, birds, even the occasional otter.
Maclean’s protocol is to test in the shallow waters where young kids are most likely to be — not because they are the ones most likely to add bacteria into the water — but because they’re the ones most vulnerable to getting sick. If you swim further out in the lake, there’s likely to be less bacteria.
“In the deeper water you get a lot more mixing. ‘Dilution is the solution to pollution,’” Maclean said. It’s a common saying among those that think about water quality.
There’s one other thing Maclean is on the hunt for, and that’s cyanobacteria or blue-green algae. It’s naturally occurring, but has been increasing in East Bay lakes and across the country. It can contain toxins that are harmful if ingested. No one in the U.S. has died it from it. But some dogs have, because dogs are more likely to drink water from the lakes.
“If you're not swallowing the water, then you're going to be all right,” Maclean says.
Still the Park District errs on the side of caution and closes Lake Temescal during big algal blooms...like they did this week.
The lakes can also have swimmer’s itch, a parasite from duck feces. It won’t hurt you but it can cause your skin to crawl. All you need to do to avoid it is shower and towel off - but it’s not the most pleasant thing to think about.
Despite some of these unpleasantries, Maclean says he still swims in the East Bay Lakes. He admits that a couple of his colleagues at the district don’t. He didn’t want to go into the details but explained that it didn’t have to do with the water quality; it was about observing some beach-goers’ activities at the lakes.
I can take a guess as to what these might be. It’s not uncommon to see a dirty diaper at the beach, for example. That could make you think twice before going in. It brings up a good point — if we want clean water where we swim, it’s largely up to us as people who recreate there.
The fact that Maclean tests these waters and still goes swimming there is certainly a comfort to me. Maclean says: to have your fun in the sun, just check the water quality before you go and don’t swim in closed beaches. It’s true — dilution really is the solution to pollution.