SAHUARITA, Ariz. (KGUN) — Visitors to Sahuarita Lake have recently been met with an unusual sight: a layer of brownish sludge coating parts of the water’s surface. The unusual appearance sparked concerns among residents, some of whom speculated it might be oil or pollutants.
However, officials from the Town of Sahuarita have confirmed that the substance is a harmless algae bloom caused by seasonal temperature changes.
Parks and Facilities Manager Dylan Pruitt explained that the odd color is the result of an algae bloom. The phenomenon, known as lake “turnover,” occurs every year in the spring and fall.
“When the temperature equalizes, nutrients at the bottom of the lake are kicked up to the surface,” Pruitt said. “This creates ideal conditions for an algal bloom once the algae has enough nutrients.”
Although the sight of the algae has disappointed some residents, the Parks and Recreation Department has assured the community that the lake remains safe for both people and pets. Pruitt confirmed that the bloom is not made up of toxic algae and poses no health risks.
The town began treating the lake on November 20, providing regular updates to the community throughout the month.
“Everything we’re using is safe for humans and dogs,” Pruitt added, referencing the algaecide treatments currently being applied to address the issue.
The Town of Sahuarita website states that: “All algaecides applied to Sahuarita Lake are approved by the EPA as safe for fish, fishing, swimming, and irrigation.”
Each morning, crews scatter granular algaecide onto the lake’s surface. The treatments help break up the algae clumps, allowing them to settle back down.
The town’s website also states that, “Treatments are done in compliance with all applicable regulations, requiring a 7-14 day waiting period between treatments, depending on the algaecide used.”
This process is expected to take about six to eight weeks to fully clear the lake.
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Jose Sotelo, a frequent visitor to Sahuarita Lake, first noticed the algae bloom during a walk with his wife.
“It’s such a beautiful place,” Sotelo said. “When we saw it, we were a little disappointed, but I know they work hard to keep it nice. I’m glad to hear it’s not harmful.”
Town officials have warned that similar algae blooms may appear again as temperatures change following the summer months, but additional treatments will be applied as needed to keep the lake clean and enjoyable for visitors.
