The Sacramento, California Water District has always responded to calls from concerned residents reporting a strange taste and smell in the water coming out of their faucets. A natural compound called geosmin can make water taste earthy when water levels are low and temperatures are high.
The water is not dangerous, but it stinks. Typically, complaint calls do not begin until fall or late summer. But this year is different, thanks to a worsening drought that has hit the region hard.
Mark Severeid, the city’s water quality superintendent, says temperatures have been warmer and water levels lower than most people can remember. “This is why we are experiencing the earlier onset of this problem, an issue that the city has been telling people about for years,” he says.
The situation prompted the city to issue a statement that the water was safe to drink and to recommend that residents cool the water or add a little lemon to mask the musk. The suggestion raised a few eyebrows, but officials hope to allay people’s fears and say the situation is reminiscent of the daily challenges of dealing with an extreme drought.
The changes in water quality aren’t limited to Sacramento. Other districts in California have reported concerns about the taste and smell of water, especially during dry periods, and the problem is one of many symptoms of drought. In other areas, wells are set to dry up and more than a million Californians already have no access to safe drinking water. A report released by the state’s water resources control board this year found that around 620 public water systems and 80,000 domestic wells were at risk of failing.
Geosmin is a chemical compound created by organisms and the levels in the water are not dangerous, but they are not filtered during purification.
“This water meets or exceeds all federal water quality guidelines. It is safe and healthy to drink, ”says Severeid. “We are dealing with very low concentrations. We’re talking about parts per billion geosmin concentrations – very small amounts, ”he adds. “But people are extremely sensitive to changes in the taste, smell and temperature of their water.”
Geosmin is produced by blue-green algae that thrives when water levels are low and temperatures are high. The filtration takes care of the algae but does not catch the odd tasting compound. The drought produced record spring water flows as well as record temperatures, compounding the problem and causing it to arrive early. The problem is expected to persist throughout the year.
Carlos Eliason, spokesperson for the Sacramento Utilities Department, says that as a resident of the city he has experienced the problem himself. “It almost smells like petrichorium,” he said, describing the same scent you can often detect after the first rain following dry weather.
While adding lemon may help for now, there are plans in place for a more robust response. Severeid says the district is at the start of a planning process to reinvent water treatment over the next 50 years and that filtration that removes compounds responsible for taste and odor is one of their highest. priorities.
Eliason says the plan focuses on improving water treatment in the face of more adverse weather conditions and greater resilience to threats of drought and forest fires, which are expected to worsen due to the climate change.
“Obviously we’re experiencing it in real time,” Severeid says. “Less flow, higher temperatures – more complaints. After a few hundred years of telling people about it, we’re just sick of it. “