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Advice on Jelsumer and Lytse Feart

Wetterskip Fryslân has measured too high a concentration of PFOS in the water of the Jelsumer Feart between the Leeuwarden air base and the Dokkumer Ee. They discovered this when planning dredging work. They always measure the quality of the waterbed in advance. Follow-up studies have revealed that there is also too much PFOS in the water of the Lytse Feart.

GGD Fryslân has therefore advised against using the water from the Jelsumer Feart and the Lytse Feart for the time being as a precaution:

  • Do not drink the water from the Jelsumer and Lytse Feart.
  • Do not use water from the Jelsumer and Lytse Feart for watering vegetable gardens.
  • Do not swim in the Jelsumer and Lytse Feart.
  • Do not eat fish from the Jelsumer and Lytse Feart.

This advice applies to people and (domestic) animals. For these recommendations, the GGD looks at long-term use of the water. For example, have you swum in the water once? Then the additional health risk due to PFAS from the Jelsumer Feart is very small.

It is not yet sufficiently clear what exactly the health risks are. Whether there really are health risks depends on many things. According to the GGD, further research is also needed into the spread.

Advice on chicken eggs

It has been found that (privately owned) chickens that previously drank water from the Jelsumer Feart and/or Lytse Feart have laid eggs with high concentrations of PFOS (PFAS). Advice from the GGD is therefore: do not let your (domestic) animals drink water from both canals and do not eat eggs from (hobby) chickens around the Jelsumer Feart or Lytse Feart. The local authority is having eggs from the area examined in collaboration with the GGD. This investigation is ongoing.

The local authority has conducted exploratory research into soil and groundwater

The local authority has had soil and groundwater tested at a few locations around the Jelsumer and Lytse Feart as a precautionary measure to establish whether PFOS is also in the soil. This way we can better inform and advise residents and users together. This takes place on the plots shown on the Soil Survey Locations map.

These are locations that we investigate on the advice of the GGD and locations that have been suggested by residents. The surveys were in March and April and the results were analysed afterwards.

Owners and users of the surveyed sites have been informed of the results of the study. Almost all the sites surveyed are suitable for their current use. The soil and groundwater of all the vegetable garden and allotment sites surveyed are suitable for use.

Summer maintenance Jelsumer Feart and surroundings

Maintenance of the main waterways is needed in the area where the Jelsumer Feart and the Lytse Feart are located. That is how we ensure the proper supply and drainage of water. Maintenance is also needed to keep part of the Jelsumer Feart and Lytse Feart accessible for small boats. During maintenance, we remove excess aquatic plants from canals and ditches. Wetterskip Fryslân and the City of Leeuwarden do the summer maintenance together.
We are doing the maintenance extra carefully and differently than usual, because the surface water and water bottom is contaminated with PFAS. For that reason, we will only using a plant collection boat. This method ensures we stir up the contaminated water bottom much less than with dredging. The clippings (the cut aquatic plants) will not be left on the waterfront. We dispose of this directly by water to an approved site where it can be processed.

In the autumn, maintenance is also needed in other waters in the area. We are working on a tailor-made solution for this, just as we did for summer maintenance.

Would you like to receive questions and news about the Jelsumer and Lytse Feart?

  • All information and the latest news is available on the Wetterskip Fryslân website. Here you can also sign up for digital news updates. Here you will also find a list of questions and answers. Is your question not listed there? Please contact Wetterskip Fryslân. Or call us on 058 292 22 22. You can also send an email to info@wetterskipfryslan.nl.
  • Do you have questions about health with PFAS? Please feel free to contact the GGD Fryslân via telephone number 088 229 92 22 (available on working days between 8:30 am and 4:30 pm). You can also send an email to Milieuengezondheid@ggdfryslan.nl.

Frequently asked questions surveys on Jelsumer and Lytse Feart

What did the local authority investigate in the area around the Jelsumer and Lytse Feart?

The local authority wants to find out whether surface water pollution from the Jelsumer Feart and Lytse Feart is affecting the adjacent land (soil and groundwater). In March and April 2024, engineering firms took samples of soil and groundwater at several locations in the vicinity of the Jelsumer Feart and Lytse Feart. To study and explain this, the local authority takes advice from various experts (e.g. engineering firms, GGD Fryslân and other authorities).

Which locations has the local authority investigated?

Soil and groundwater testing was carried out at the most sensitive locations on the advice of GGD Fryslân. By this we mean, for example, land used for growing food, such as allotments in the area and locations where there is a lot of recreational activity. Pieces of land on Tsjessingawei directly adjacent to the Jelsumer Feart were also studied.

Sites suggested during the residents’ evening were also examined. This concerns some private pieces of land and a former dredging depot. Finally, locations along the Lytse Feart where piling sludge had been lying on the shore for a short time were investigated.

All investigated sites can be found on the map Study sites for the soil survey.

What are the results of the soil and groundwater investigation?

For the calculations, the total amount of PFAS that a person is allowed to ingest per day was taken as the starting point, which we call the Tolerable Daily Intake (TDI). It is common for a health risk assessment to take into account the exposure you already have in everyday life. The Dutch are already known to ingest PFAS through food and drinking water. By testing at 50 per cent of the TDI, we stay on the safe side and ensure that residents do not ingest too much of these substances.

The City of Leeuwarden and GGD Fryslân took advice from the central government (Ministry of Infrastructure and Water Management), the National Institute for Public Health and the Environment (RIVM), the Municipality of Dordrecht, the Province of Zuid-Holland, Environmental Department Zuid-Holland Zuid and other GGD regions.

Various options

Several options were used in the testing, which depends on how people use the soil (site use function). If a vegetable garden that people use for all the vegetables they eat annually is assessed, the test will be much more stringent than if a home’s garden is assessed. Because of this, people get much less PFAS from the soil.

Results in 3 categories

  1. Soil provides a user intake of PFAS of less than 50 per cent of the TDI. This is safe and therefore given the colour green.
  2. Soil provides a user intake of PFAS of between 50 and 100 per cent of the TDI. From soil alone, the user does not get too much PFAS, but due to background exposure, people do absorb too much PFAS. This is given the colour orange.
  3. Soil provides a user intake of PFAS of more than 100 per cent of the TDI. People get too much PFAS from the soil. So the soil is not suitable for the way it is currently used. This is given the colour red.
GREEN: almost all sites surveyed are suitable for current use. The soil and groundwater of all the vegetable garden and allotment sites surveyed are suitable for use.

This is the outcome of surveys commissioned by the local authority in March and April 2024. The use of the sites and the risks of any substances found in the soil and groundwater were considered. This means, for example, that residential plots can be lived in without a health risk and crops on allotment and kitchen garden plots can be eaten without health risks.

The study further revealed that groundwater from the allotment and kitchen garden complexes can be used by gardeners for crop irrigation.

Important advice

Do not drink the water from the Jelsumer Feart  and Lytse Feart.

ORANGE: sometimes user advisories or restrictions apply when excavating soil.

For some parts of (residential) plots suitable for their current function, a vegetable garden is possible, but with user advisories. This is the case for 3 of the total 36 sites surveyed by the local authority. Examples include advice to garden in containers, grow other crops that absorb less PFAS or to alternate eating vegetables from the garden with vegetables from the supermarket or the greengrocer.

Surveys along Lytse Feart

The surveys of the dredging slurry locations along the Lytse Feart have now been completed and these results are currently being explained. All the sites studied can be used as residents and users currently do, without health risks. If soil is excavated in the future (e.g. when digging a pond), there may be restrictions on reusing that soil elsewhere. If that happens, please contact the local authority for more information. The local authority can then give you specific advice on what steps to take.

User recommendations may therefore vary from one location to another. This was explained by the local authority and GGD in the talks with owners, users and residents of the surveyed sites.

RED: none of the sites surveyed by the local authority are red.

Will the local authority conduct further soil and groundwater surveys?

At present, there is no reason for the local authority to conduct more soil and groundwater investigations. The investigation into eggs from (hobby) chickens is ongoing.

Can the soil and groundwater on my land near the Jelsumer and Lytse Feart also be studied?

Soil and groundwater have been investigated at various locations in the vicinity of the Jelsumer Feart and Lytse Feart. See also the explanation of the sites surveyed. The soil of most plots can be used as usual, sometimes with user advice. There is no reason for the local authority to investigate more plots. As a landowner, you can of course hire a survey agency yourself.

Are crops from allotments being studied?

The soil from the sites investigated by the local authority can be used without risk in most cases. Food can be grown on the kitchen gardens surveyed. Therefore, there is no need to have crops examined.

What measures are in place to prevent the spread of pollution during summer maintenance?

  • Maintenance is carried out using a plant collection boat. This cuts vegetation out of the water. This method ensures we stir up the contaminated water bottom much less than with dredging.
  • The clippings/plant material released will be taken to an approved processor. Prior studies are being conducted to determine the environmental quality of this material.
  • The released plant material is not being placed on the water side as usual, but taken directly from the water.

Why is summer maintenance necessary?

  • The main waterways in the area need preventive maintenance due to currents. No maintenance can lead to flooding of water to adjacent (agricultural) plots in extreme situations.
  • Jelsumer Feart and Lytse Feart are main basin watercourses. These are wide enough, which is why Wetterskip Fryslân does not usually need to remove vegetation here from a water management point of view. (Two years ago, this was done to free the supply to the inlets, but since the inlets now remain closed due to contamination, this is not an option until remediation is done).
  • The municipality of Leeuwarderadeel built mooring facilities at Dekemastate for tourism purposes a few years ago. The City of Leeuwarden has taken over the contract to keep Dekemastate accessible for sloops. That means the Jelsumer Feart and the Lytse Feart are additionally cleared of vegetation each year by the local authority.

Can’t summer maintenance be skipped for a year?

  • Summer maintenance, is always based on necessity. This always depends on situation and potential risks.
  • Currently, for some of the main watercourses, there is still a risk of potentially explosive plant growth that will prevent proper flow. In extreme rainfall situations, this poses a risk of contaminated water spreading onto adjacent plots.
  • Boating is possible in the Jelsumer Feart and Lytse Feart. This creates a risk of jammed screws/vessels running aground if there is plant growth. This in turn poses risks of contact with contaminated water/or uncontrolled disturbance of the water bottom.

Frequently asked questions PFAS in local authorities

What is PFAS?

PFAS stands for Per- and polyfluoroalkyl substances. PFAS is a group of chemicals that have unique water and dirt-repellent properties. PFAS are widely produced and found in many common products because of these beneficial properties. Consider, for example, non-stick coatings, water-repellent textile treatments and fire-resistant foams.

These chemicals have been made and used for decades in various industries and consumer products. A few common examples of PFAS are PFOS (Perfluorooctane Sulfonate), PFOA (Perfluorooctanoic Acid), PFBS (Perfluorobutane Sulfonate), and PFHxS (Perfluorohexane Sulfonate).

PFAS are also known as “forever chemicals” because they hardly break down and can therefore accumulate in the environment (plants, animals and people). They occur everywhere in the environment. Due to their potentially harmful effects on human health and the environment, PFAS have received a lot of attention. A lot of research is still being done into the properties of PFAS and how these substances behave in the environment (including by RIVM).

What are the potential health risks of PFAS?

The consequences of exposure to PFAS depend on the duration and level of exposure. Long-term exposure to elevated levels of PFAS can have health consequences. It probably has an effect on the immune system. In addition, it can have an effect on the functioning of the liver, the hormonal system and forms of cancer. More information can be found on the GGD Living Environment page.

What is the role of the municipality?

Since 2003, the municipality of Leeuwarden has been legally entitled and responsible for making decisions about the soil. Think of:

  • Granting permits for soil activities.
  • Establishing soil quality standards.
  • Monitoring compliance with regulations regarding soil management and protection.

For example, the municipality is now working to clarify the PFAS levels for its entire territory. This will be included in a PFAS soil quality map. This also happened with the presence of other substances. You can find information about this on the Zicht op Grond website.

The City of Leeuwarden considers a healthy living environment to be very important and that is why PFAS is included in soil surveys commissioned by the municipality (for example in new developments and maintenance work).

Where in Leeuwarden has PFAS been found?

Elevated levels of PFAS have recently been found in the soil and water of the Jelsumer and Lytse Feart. For more information, see the heading ‘Current: Jelsumer and Lytse Feart’ on this page.

What is the municipality doing to map PFAS?

The municipality creates a soil quality map within the City of Leeuwarden. PFAS levels are also listed here. See also the answer to the question ‘What is the role of the municipality?’. Other organizations, such as Wetterskip Fryslân, also investigate the waterbed before starting dredging work, for example.

What is the municipality doing to clean up PFAS contamination?

So far, no major contamination with PFAS has been found, except for the Jelsumer and Lytse Feart, see the heading ‘Current: Jelsumer and Lytse Feart’. The contaminated waterbed there must be remediated (cleaned) by Wetterskip Fryslân.

What is the municipality doing to prevent contamination with PFAS?

The municipality includes PFAS in the soil investigations carried out on its behalf. Furthermore, the municipality uses and monitors the national laws and regulations regarding PFAS. The municipality also collaborates with other authorities, such as the province, the water board and the GGD. Together we take measures to prevent PFAS contamination and to protect the environment and human health.

How are PFAS spread in the environment?

PFAS can enter the environment through various routes. For example, wastewater discharges, the use of products containing PFAS and through the air.

Can the soil on my land be tested for PFAS?

There is currently no reason to test soil on private lands for PFAS. As the owner, you can hire an agency for this yourself.

More information

More information about PFAS can be found at: