Lake · Hancock County · ME

Is Duck Lake safe to swim?

Clear to swim

No advisory or algae bloom reported for this water today.

Updated July 20, 2026 · EPA CyAN satellite

Recent rain
2.4 in
Water type
Lake
Last updated
Jul 20
Bacteria
E. coli, fecal
Not monitored
Tested
Not monitored
Blue-green algae
cyanobacteria
Clear to swim
Tested
None detected
Advisory over
100,000
cells/mL
Sampled Jul 19 · EPA CyAN satellite

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Get an alert the day a bacteria or algae advisory goes up.

What's in the water at Duck Lake right now

As of July 20, 2026, Duck Lake in Hancock County, Maine is clear to swim. Satellite imagery detected no blue-green algae bloom as of July 19, 2026. Rainfall over the past week totaled 2.4 in, which can wash bacteria and nutrients into the water.

How this read is built

Blue-green algae at Duck Lake

Duck Lake is a lake in Hancock County, Maine covering about 1.8 sq mi, the 127th-largest of the 331 lakes SwimZone monitors in Maine. Satellite imagery detected no blue-green algae bloom as of July 19, 2026.

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.

Bloom history at Duck Lake

From EPA CyAN's satellite archive

Over 7 summers of satellite monitoring since 2020, Duck Lake has not reached a blue-green algae advisory level. Conditions can still change quickly, so check the current read before you swim.

Frequently asked: swimming in Duck Lake

Is it safe to swim in Duck Lake right now?
Duck Lake is clear to swim today. Satellite imagery detected no blue-green algae bloom as of July 19, 2026. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
Does Duck Lake have blue-green algae (cyanobacteria)?
No blue-green algae bloom is detectable at Duck Lake as of July 19, 2026 (below the satellite's roughly 10,000 cells/mL detection limit). Cyanobacteria can still appear within hours in warm, calm, nutrient-rich water, so look before you swim.
Can dogs swim in Duck Lake?
No bloom is detected at Duck Lake 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 often does Duck Lake have blue-green algae blooms?
Over 7 summers of satellite monitoring since 2020, Duck Lake has not reached a blue-green algae advisory level. Conditions can still change quickly, so check the current read before you swim.
How many Maine lakes and beaches are unsafe for swimming today?
Today, 21 Maine waters are above a safe-contact threshold and 27 more warrant caution, out of 469 monitored waters SwimZone tracks in the state.
How is Duck Lake'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 Duck Lake, and a recent-rainfall overlay, all refreshed daily. It was last updated July 20, 2026.

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