SwimZone

Pond · Somerset County · ME

Is Elm Pond safe to swim?

Advisory

Blue-green algae is above the safe-contact threshold.

Updated July 22, 2026 · EPA CyAN satellite

Recent rain
0.2 in
Water type
Pond
Last updated
Jul 22
Bacteria
E. coli, fecal
Not monitored
Tested
Not monitored

No bacteria advisory or sampling for this water.

Blue-green algae
cyanobacteria
Advisory
Tested
1,013,778
cells/mL
Advisory over
100,000
cells/mL

Cyanobacteria 1,013,778 cells/mL (satellite, 7-day max), imaged 2026-07-21.

Sampled Jul 21 · EPA CyAN satellite

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There's an advisory on Elm Pond right now.

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What's in the water at Elm Pond right now

As of July 22, 2026, Elm Pond in Somerset County, Maine is not recommended for swimming. Satellite imagery measured 1,013,778 cells/mL of blue-green algae on July 21, 2026, above the 100,000 cells/mL advisory threshold. Rainfall over the past week totaled 0.2 in, which can wash bacteria and nutrients into the water.

How this read is built

Blue-green algae at Elm Pond

Elm Pond is a pond in Somerset County, Maine covering about 0.4 sq mi, the 317th-largest of the 319 lakes SwimZone monitors in Maine. Satellite imagery measured 1,013,778 cells/mL of blue-green algae on July 21, 2026, above the 100,000 cells/mL advisory threshold.

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 Elm Pond

From EPA CyAN's satellite archive

2020: peak 985,424 cells/mL — above the 100,000 advisory level202021: peak 1,013,778 cells/mL — above the 100,000 advisory level212022: peak 1,042,949 cells/mL — above the 100,000 advisory level222023: peak 785,350 cells/mL — above the 100,000 advisory level232024: peak 1,308,648 cells/mL — above the 100,000 advisory level242025: peak 1,236,468 cells/mL — above the 100,000 advisory level252026: peak 1,308,648 cells/mL — above the 100,000 advisory level26Advisory100k cells/mL

Each bar is that summer's peak satellite reading (log scale). The red cap is the part above the advisory level.

Over 7 summers of satellite monitoring since 2020, Elm Pond has reached blue-green algae advisory levels in 7 of them, most recently in June 2026. This is a lake that blooms most summers. Its highest recorded reading was 1,308,648 cells/mL in September 2024.

When to swim at Elm Pond

It is currently peak season for blue-green algae, when warm, calm water lets blooms form fastest. This lake has bloomed in most monitored summers (7 of 7), historically peaking around September. Early summer, before the water fully warms, has generally been the safer window here; check the current read before you go either way.

Frequently asked: swimming in Elm Pond

Is it safe to swim in Elm Pond right now?
Elm Pond is not recommended for swimming today. Satellite imagery measured 1,013,778 cells/mL of blue-green algae on July 21, 2026, above the 100,000 cells/mL advisory threshold. Conditions can change quickly with wind, heat, and rain, so check the posted signs and look at the water before you get in.
Does Elm Pond have blue-green algae (cyanobacteria)?
Yes. Satellite monitoring measured 1,013,778 cells/mL of blue-green algae (cyanobacteria) at Elm Pond on July 21, 2026, above the 100,000 cells/mL advisory level. Avoid swimming and keep children and pets out of the water.
Can dogs swim in Elm Pond?
No. Blue-green algae at Elm Pond is above the safe-contact threshold (1,013,778 cells/mL on July 21, 2026). Cyanobacteria toxins can be rapidly fatal to dogs, which swallow it while swimming and lick it from their fur. Keep dogs out of the water and away from any scum along the shore.
How often does Elm Pond have blue-green algae blooms?
Over 7 summers of satellite monitoring since 2020, Elm Pond has reached blue-green algae advisory levels in 7 of them, most recently in June 2026. This is a lake that blooms most summers. Its highest recorded reading was 1,308,648 cells/mL in September 2024.
How many Maine lakes and beaches are unsafe for swimming today?
Today, 15 Maine waters are above a safe-contact threshold and 33 more warrant caution, out of 457 monitored waters SwimZone tracks in the state.
How is Elm Pond'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 Elm Pond, and a recent-rainfall overlay, all refreshed daily. It was last updated July 22, 2026.

Before you swim: the basics

Swim spots near Elm Pond

All Maine →

Of the 6 monitored waters nearest Elm Pond, 1 is flagged today.

WaterDistanceTodayAlgae readSampled
Fifth Saint John PondPond · Somerset County8.7 miClear to swimNone detectedJul 21
Loon LakeLake · Piscataquis County12 miClear to swimNone detectedJul 21
Big Hurd PondPond · Piscataquis County12 miAdvisory527,938 cells/mLJul 21
Rowe PondPond · Piscataquis County16 miClear to swimNone detectedJul 21
Canada Falls LakeLake · Somerset County17 miClear to swimNone detectedJul 21
Brandy PondPond · Piscataquis County17 miClear to swimNone detectedJul 21