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Toxic Algae Threatens Summer Swims in Pierce County Lakes
2 Aug
Summary
- Toxic algae advisories issued for Palmer Lake and Lake Lawrence.
- Blooms appear as green scum, can cause illness in humans and pets.
- Climate change and nutrient pollution worsen toxic algal growth.
Local lakes in Pierce County are currently under health advisories due to toxic algae blooms. The Tacoma-Pierce County Health Department (TPCHD) has issued a caution for Palmer Lake, with visible cyanobacteria noted during recent inspections. Similarly, Thurston County Public Health and Social Services issued an advisory for Lake Lawrence following reports of high microcystin toxin levels.
These harmful algal blooms can manifest as green scum or clumps on the water and come in various colors. The CDC advises avoiding discolored water or areas with dead fish. Ingestion of water containing toxic algae can lead to severe health issues in humans and pets, including muscle weakness, vomiting, and diarrhea. Pets are particularly vulnerable due to their size and tendency to drink from or groom algae-contaminated fur.
Algal blooms are natural but become toxic under specific conditions: warm, slow-moving water rich in nutrients like nitrogen and phosphorus, often exacerbated by fertilizer runoff and sewage. Climate change is also contributing to more frequent and intense blooms. TPCHD monitors 12 lakes historically prone to such issues and popular with recreational users. While advisories were issued for three lakes in 2025, only Palmer Lake has an active advisory this year as of August 2, 2026.
