Is MASAUSI safe to swim?

As of July 19, 2026, MASAUSI in Eastern District County, American Samoa is clear to swim. Blue-green algae are not currently monitored at this water. No fecal-bacteria advisory is posted (state beach program). Rainfall over the past week totaled 0.2 in, which can wash bacteria and nutrients into the water.

How this read is built

MASAUSI is a lake in Eastern District County, American Samoa. Blue-green algae are not currently monitored at this water.

Blue-green algae (cyanobacteria) blooms are most common from midsummer into early fall, when the water is warm, calm, and rich in nutrients from runoff. They can produce toxins that make people sick and can be rapidly fatal to dogs, so skip water that looks green, scummy, or like spilled paint, and keep children and pets out of it.

Is it safe to swim in MASAUSI right now?

MASAUSI is clear to swim today. Blue-green algae are not currently monitored at this water. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.

Does MASAUSI have blue-green algae (cyanobacteria)?

Blue-green algae are not currently monitored at MASAUSI. Watch for green, blue-green, or paint-like scum and avoid the water if you see it.

Can dogs swim in MASAUSI?

No bloom is detected at MASAUSI today, but dogs are much more vulnerable to blue-green algae than people, and blooms can form within hours. Always keep dogs away from water that looks green, scummy, or discolored, and rinse them off after swimming.

How many American Samoa lakes and beaches have swim advisories today?

Today, none of the 48 monitored American Samoa waters SwimZone tracks are under a swim advisory.

How is MASAUSI's water quality measured?

SwimZone builds this read from EPA CyAN satellite imagery for blue-green algae, official beach and fecal-bacteria advisories where a program monitors MASAUSI, and a recent-rainfall overlay, all refreshed daily. It was last updated July 19, 2026.