While now, in late July, water temperatures allow for a pleasant swim, tests have revealed intestinal enterococci and other contamination indicators exceed the permitted limits, both at freshwater swimming spots and on Baltic Sea beaches.

According to the Health Board, there are several problematic sites, including the Kohtla-Järve city park pond, Külitse reservoir, Maidla lake, Narva-Jõesuu beach, Otiaru reservoir, Reola river, and the Sindi outdoor pool.

The Emajõgi city and open-air swimming areas in Tartu, Sillamäe beach, Türi reservoir and Türi lake are also areas of concern.

The last of these received heightened attention after several children required medical attention after swimming there over the weekend, when a family festival was held at the site.

Lauri Liepkalns, senior specialist at the Health Board's environmental health department, said the situation is somewhat more concerning compared with previous years.

Water quality usually deteriorates toward the end of July or the start of August, but this year the irregularities have been spread more evenly through the swimming season.

There are several reasons for this, Liepkalns said. "One reason may be that summer arrived later in Estonia, and water bodies warmed up at the same time, which in turn could have encouraged a rise in contamination indicators in many places at the same time," he told Vikerraadio's "Uudis+."

"The most likely scenario is that after heavy rain, contamination is carried from the ground into the water body," he said.

"In flowing waters, purification usually happens faster, but much depends on the weather and source of the contamination," he went on.

Blue-green algae (Cyanobacteria) is a frequent occurrence in more sheltered waters in summer; this year outbreaks at Harku järv near Tallinn have also been behind health issues affecting swimmers.

"Blue-green algae are always present in nature, but under suitable weather conditions they can rapidly multiply and move from one side of the lake to the other depending on wind direction," Liepkalns added.

Local government is responsible for providing information on official swim zones, but at unofficial spots, information may not reach the public, or may do so after a delay.

The Health Board's website contains a database listing all samples and contamination indicators, Liepkalns noted.

Liepkalns outlined how at official swimming areas at least, a minimum of three water tests must be conducted during the season, in addition to one before the season begins. At more popular locations, such as Pirita beach in Tallinn or Tartu's Anne canal, tests are conducted more frequently.

Enterococci get into water bodies mainly via precipitation and surface runoff: Rainwater washes pollution from the ground into the water, including bacteria and nutrients.

In flowing rivers like the Emajõgi, faster purification could be expected, according to Liepkalns, but even there, multiple cases where the permitted levels have been exceeded have been found.

Sources of contamination can be birds, animals, and also occasionally humans.
At official swimming beaches, red or purple flags clearly notify swimmers not to enter the water: A purple flag indicates algal contamination. In the meantime, swimmers should stay alert and check the water quality of their favorite spot before swimming.

If symptoms such as stomach ache, vomiting, rash, or itching appear after swimming, the cause may be contaminated water.

--

Follow ERR News on Facebook, Bluesky and X and never miss an update!