Monitoring of bathing water quality

Introduction

Environmental Health Services is responsible for monitoring the quality of bathing water at public beaches by taking regular samples during the bathing season. The organoleptic quality and presence of blue-green algae are monitored with inspections and sampling.

The inspections focus on the condition of the facilities, the cleanliness of the beaches, waste management and the information provided on notice boards.

The control of public beaches is based on the Health Protection Act. The decrees…of the Ministry of Social Affairs and Health apply to the control of bathing water quality.

The Finnish Safety and Chemicals Agency (Tukes) is responsible for monitoring consumer safety.

Sampling results

The latest sampling results are also available on the beaches’ notice boards.

The bathing waters of large beaches are classified based on the Escherichia coli and intestinal enterococci levels in the samples taken during the last four bathing seasons. Bathing waters are classified into four quality categories: excellent, good, sufficient and poor. The quality rating is updated annually.

In 2024, the bathing water at the beaches of Kuusijärvi and Vetokannas was classified as excellent.

A bathing water profile has been developed for the beaches of Kuusijärvi and Vetokannas in accordance with the legislation concerning bathing waters. Among other things, bathing water profiles present the issues which could jeopardize the quality of bathing water and thus affect the health of bathers. The notices board at the beaches have a summary of the bathing water profiles.

Water quality is good when E. coli is less than 1000 mpn/100 ml and enterococci less than 400 cfu/100 ml.

Leppäkorpi
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
12/8	20.6	16	12	no	good
29/7	25	3	19	no	good
15/7	24	25	10	no	good
1/7	18.3	2	6	no	good
17/6	19.6	47	29	no	good
3/6	16.1	<1	3	no	good

Kuusijärvi
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
12/8	21	170	33	little	good
29/7	25,2	30	18	little	good
15/7	23.5	130	32	no	good
1/7	18.6	29	8	no	good
17/6	19.2	20	17	no	good
3/6	16.6	13	<1	no	good

Vetokannas
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
14/8	20.9	49	13	no	good
12/8	21.7	2400	150	no	poor
29/7	25.1	110	35	no	good
15/7	23	59	47	no	good
1/7	19.1	37	23	no	good
17/6	19	35	16	no	good
3/6	16.1	6	2	no	good

Bathing sites along the Keravanjoki river

Havukoski
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
12/8	17,6	88	80	no	good
29/7	21,5	200	320	no	good
23/7	20.6	440	440	no	poor
15/7	19.6	390	400	no	poor
3/7	17.2	130	260	no	good
1/7	14.5	1200	> 800	no	poor
17/6	17.2	44	41	no	good
3/6	14.4	50	44	no	good

Matari
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
12/8	17.8	48	77	no	good
29/7	21.8	410	290	no	good
23/7	21	580	530	no	poor
15/7	19.3	730	750	no	poor
3/7	17.2	140	290	no	good
1/7	14.6	1600	> 800	no	poor
17/6	17	100	70	no	good
3/6	14.2	56	68	no	good

Nikinmäki
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
12/8	17,3	64	100	no	good
29/7	21,4	32	180	no	good
23/7	20.2	690	610	no	poor
15/7	19.5	190	460	no	poor
3/7	16.7	120	310	no	good
1/7	14.5	1300	> 800	no	poor
17/6	16.9	12	45	no	good
3/6	14.5	15	28	no	good

Water quality is good when E. coli is less than 1000 mpn/100 ml and enterococci less than 400 cfu/100 ml.

Kuusijärvi
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
15/4	6,3	1	3	no	good
12/12	0,7	1	5	no	good
16/12	1,5	8	2	no	good
14/10	8.8	16	31	no	good

Vetokannas
Date	^OC	E. coli	Enterococci	Blue-green algae	Quality
15/4	6,8	<1	<1	no	good
12/12	1,3	2	<1	no	good
16/12	2,2	2	0	no	good
23/10	8.8	3	1	no	good

Water quality

The assessment of bathing water quality is based on the monitoring the levels of intestinal enterococci and Escherichia coli in the water. Bathing water contaminated with faecal bacteria and blue-green algae can harm the health of bathers, causing nausea as well as stomach and skin symptoms.

Water quality is considered good when the sampled water meets the following requirements:

Escherichia coli: less than 1000 cfu/100 ml
Intestinal enterococci: less than 400 cfu/100 ml

If the sample exceeds the critical limit, an additional sample is taken, and the cause and potential health hazard is assessed. If necessary, the health protection authority may instruct the beach operator to take corrective action and prohibit bathing at the beach. If blue-green algae are found at the beach, a notice must be displayed at the beach to inform beachgoers about the health hazard and to provide instructions.

The frequency of water sampling

Water samples are collected from the beaches of Vantaa every two weeks between June and August. The first samples are taken two weeks before the start of the bathing season. The bathing season runs from mid-June to the end of August. From winter swimming places, water samples are taken twice in the autumn and spring.

In Vantaa, water quality at bathing sites is usually good. However, heavy rain and the presence of wildlife, among other things, may reduce the water quality. The water samples only indicate the current situation, and especially river water quality may vary due to streams and heavy rainfall. Rainwater can significantly affect water quality if the surface runoff carries a high pollutant load to the bathing waters.

Bathing water quality at the bathing sites along Keravanjoki river is occasionally poor

In previous years, elevated intestinal bacteria levels have been found in the bathing water samples collected in connection with heavy rainfall from the bathing sites along the Keravanjoki river. Therefore, the Environment Centre recommends avoiding swimming after heavy rains at the beaches of Havukoski, Matari and Nikinmäki.

Blue-green algae and swimmer’s itch

The presence of cyanobacteria, or blue-green algae, is monitored with organoleptic checks. Blue-green algae can be observed from spring to late autumn, but the most blue-green algae occur in the middle and end of summer. Their occurrence is affected by, among other things, the level of nutrients in the water and water temperature.

Blue-green algae can be seen in the water as small sticks and pieces, a greenish colour in the water, green stripes on the shore, or it can even resemble thick paint or pea soup. The amount and appearance of blue-green algae may change quickly, even during the same day, depending on the wind and temperature.

Some blue-green algae are toxic. Blue-green algae should always be treated with the presumption that they may be harmful to health. Toxic blue-green algae can produce nerve and liver toxins. Sensitivity to symptoms caused by blue-green algae varies greatly. Blue-green algae can cause irritation of the skin, eyes and respiratory tract as well as fever and stomach symptoms.

You should not enter or swim in waters that have large amounts of blue-green algae. Even if there aren’t many algae blooms in the water, you should be cautious and take a shower after swimming. Don’t allow small children to enter the water to prevent them from swallowing water containing algae.

Learn more about blue-green algae

Website of the Finnish institute for health and welfare.

Swimmer's itch appears after swimming as itchy skin and raised papules. The strong itching disappears in a few hours, but the papules can last up to a week. Swimmer's itch is caused by the larvae of trematode worms. It is a harmless but uncomfortable condition. The larvae die within a few hours as they cannot stay alive in humans.

Careful showering immediately after swimming and drying the skin with a coarse cloth will help remove any larvae that may cause a swimmer’s itch.

Based on the information provided by local residents, the City of Vantaa will place a warning regarding swimmer’s itch at the beach. No separate water sampling is carried out to detect swimmer’s itch.

More information on swimmer’s itch

Duodecim Terveyskirjasto (in Finnish)

Suggestions and comments on the beach list

The public has the opportunity to make proposals and comments on the beach list. Proposals related to the public beaches of Vantaa should be submitted in writing to the Vantaa Environment Centre.

The circles in different colours indicate whether swimming is allowed (blue), not recommended (orange) or prohibited (red).

Bathing sites on the Vantaa Map Service

More information

Beach water quality control

Sari Rajajärvi

Health Inspector

+358 40 563 4521 sari.rajajarvi@vantaa.fi

Supervision and maintenance of swimming beaches

You can find beach-specific contact information for swimming supervision and maintenance on the beaches' own websites in the Contact section.

Bathing waters Beach

Units

Service has 9 units in total

The Environment Centre of Vantaa promotes the sustaining of healthy and safe environment and advances the residents' health and wellbeing.

More information about The Environment Centre of Vantaa

Address

Lauri Korpisen katu 9 C
01370 Vantaa
Finland

+358 50 318 1648 (local network charge/mobile call charge)