Water quality monitored at Helsinki public beaches throughout the summer

Helsinki Environmental Services recommends that people do not swim at the Iso Kallahti, Marjaniemi and Rastila beaches, because samples have found the water quality to be poor. Water samples taken at the beaches have occassionally contained elevated amounts of intestinal bacteria.
Beach in Helsinki.
Helsinki has 25 public beaches. Photo: Aleksi Poutanen

Helsinki is home to 25 beaches that are open to the public for swimming. Lifeguards are on duty at the beaches daily until 13 August 2023. The water quality at five of these beaches is currently under enhanced monitoring. The monitoring keeps track of water temperatures and blue-green algae concentrations. 

Water quality at Helsinki’s public beaches tends to vary throughout the summer. It is normal for bodies of natural water to contain small amounts of faecal-derived microbes originating from aquatic animals, birds and the soil. The water is never drinkable, but it is safe to swim in if the bacteria levels remain low. If the levels increase, however, swimmers have a higher risk of falling ill after swimming. 

Blue-green algae, or cyanobacteria, occurs in Helsinki's natural water from time to time. The bacteria can cause poisoning symptoms such as nausea, fever or skin irritations in humans and other animals. As the water warms, the concentration of blue-green algae increases and the quality of the water at swimming spots can deteriorate quickly. Most blue-green algae sightings fall later in the summer. 

You can find the most recent results of water sample testing posted on noticeboards at the beaches. 

Water quality of five beaches under enhanced monitoring

Helsinki Environmental Services recommends that people do not swim at the Iso Kallahti, Marjaniemi and Rastila beaches, because samples have found the water quality to be poor. Water samples taken at the beaches have occassionally contained elevated amounts of intestinal bacteria.  

The Marjaniemi beach has undergone extensive risk assessments and surveys in cooperation with environmental monitoring services. Based on the measurements, it was possible to determine that the concentration was caused by a wastewater leak. In addition, rain washes animal bacteria in the ground into streams and ditches. The water quality is being closely monitored at the Marjaniemi location. 

The source of the intestinal bacteria found in the water of the Iso Kallahti and Rastila beaches is still unclear, but extensive surveys are being carried out at the beaches to assess the water quality of the streams and stormwater flowing near the beaches. Management of city water is being enhanced in cooperation with the municipal water supply and waste management services HSY and various organisations of the city. 

Helsinki Environmental Services is performing enhanced water quality monitoring at the Iso Kallahti, Marjaniemi, Pikkukoski and Rastila beaches throughout the summer of 2023. In addition, enhanced water quality monitoring is being carried out at the Aurinkolahti beach, where the water quality has been classified as satisfactory. 

Water quality of beaches located along Vantaanjoki river may deteriorate during and after heavy rainfall

It is recommended that the public refrain from swimming at the Pikkukoski, Pakila and Tapaninvainio beaches during and after heavy rainfall in summer 2023. Results from samples taken in the previous summer show that the water quality at the beaches deteriorates during periods of heavy rainfall. Heavy rainfall means that rain amounting to at least 4.5 millimetres in a day. Rainfall upstream also affects the water quality of Helsinki beaches. When there is heavy rain, the noticeboards at the beaches inform visitors of the consequences and advise them appropriately. 

The beaches located along the Vantaanjoki river were also subject to swimming restrictions in the summers of 2021 and 2022. 

Lifeguards on duty at beaches until school begins

This year, Helsinki’s lifeguards will be on duty at each of the city’s public beaches until 13 August. During this time, the Aurinkolahti and Hietaranta beaches will be supervised by lifeguards daily from 10.00 to 20.00, while beaches in Munkkiniemi, Lauttasaari, Pikkukoski, Mustikkamaa, Tuorinniemi, Laajasalo, Marjaniemi, Rastila, Iso Kallahti and Kallahdenniemi will be supervised from 10.00 to 18.00 daily, including public holidays. At Plotti, the Pirkkola district’s outdoor swimming hole with a sandy bottom, lifeguards are on duty daily from 10.00 to 18.00. 

The Tobacco Act prohibits smoking at all of the above-mentioned beaches, and the City of Helsinki discourages smoking at all other beaches. The primary purpose of this is to protect small children from the harms of passive smoke exposure, but the ban also seeks to prevent littering and other environmental harms associated with the habit. The smoking ban is in force on public beaches throughout the summer season, from the beginning of May to the end of September. Designated smoking areas have been established adjacent to the larger beach areas and in partitions at the smaller beaches. 

This year, the number of personnel cleaning the beaches during the swimming season has been increased to maintain a higher level of cleanliness at the beaches. 

In addition, the use of life rafts instead of life buoys is being tested at the Aurinkolahti, Hietaranta and Pikkukoski beaches. The life rafts are intended for emergency use only. 

Specific light water-borne traffic routes have again been designated for all of the lifeguard-supervised beaches this summer. This means that these beaches can easily be reached by, for example, SUP board, rowboat or kayak. In most cases, the light traffic routes are located on the perimeter of the beach areas. 

Signage at Helsinki’s beaches is also being upgraded in 2023. The new signs will have information about beach services and rules, along with instructions for what to do in case of emergencies. All Helsinki beaches will receive new signs as part of the update. 

The article was published on 31 May and updated on 4 July.