Why the water in California’s capital stinks right now
The water district of Sacramento, California, has always fielded calls from concerned residents reporting a weird taste and odor in the water coming out of their taps. A naturally occurring compound called geosmin can give the water an earthy taste when water levels are low and temperatures are high.
The water isn’t dangerous, but it is stinky. Typically the complaint calls don’t start until autumn or late summer. But this year is different, thanks to a worsening drought that has hit the region hard.
Mark Severeid, the city water quality superintendent, says temperatures have been higher and water levels lower than most people can remember. “That’s why we are experiencing the earlier onset of this problem, a problem the city has been telling folks about for years,” he says.
The situation prompted the city to issue a statement that the water was safe to drink, and recommending that residents chill the water or add a little lemon to mask the muskiness. The suggestion raised some eyebrows, but officials are hoping to assuage people’s fears and say the situation is a reminder of the daily challenges of dealing with extreme drought.
Related: ‘Potentially the worst drought in 1,200 years’: scientists on the scorching US heatwave
The changes in water quality aren’t limited to Sacramento. Other districts across California have reported concerns about water taste and smell, especially during dry periods, and the issue is one of several symptoms of the drought disaster. In other areas, wells are expected to go dry and already more than a million Californians lack access to safe drinking water. A report issued by the state water resources control board this year found that roughly 620 public water systems and 80,000 domestic wells were at risk of failure.
Geosmin is a chemical compound created by organisms and the levels in the water aren’t dangerous, but they aren’t filtered out during purification.
“This water meets or surpasses all federal water quality guidelines. It is safe and healthy to drink,” Severeid says. “We are dealing with very low concentrations. We are talking about concentrations of geosmin in the parts per billion range – tiny, tiny amounts,” he adds. “But people are extremely sensitive to changes in tastes, odor and temperature of their water.”
Geosmin is produced by blue-green algae that thrive when water levels are low and temperatures are high. Filtration takes care of the algae but doesn’t catch the weird-tasting compound. The drought has produced record-low flows from source waters along with record-high temperatures, which has complicated the issue and produced its early arrival. The problem is likely to continue through the year.
Carlos Eliason, the spokesperson for the Sacramento department of utilities, says that, as a resident of the city, he has experienced the issue himself. “It almost smells like petrichor,” he says, describing the same smell one can often detect after the first rain following dry weather.
While adding lemon can help for now, plans are in place for a more robust response. Severeid says the district is at the start of a planning process to reimagine water treatment over the next 50 years and filtration that removes the taste- and odor-causing compounds is one of their highest priorities.
Eliason says the plan centers on improving water treatment in the face of more adverse weather, and ensuring more resiliency during threats from droughts and wildfire, which are expected to get worse due to climate change.
“Obviously we are experiencing it in real time,” Severeid says. “Less flow, higher temperatures – more complaints. After a couple hundred years of talking to people about this, we are just getting tired of it.”
