PFAS in drinking water and fish - risk management

One glass of water


The Swedish Food Agency (SFA) has recommendations on risk-management measures for drinking water contaminated with poly- and perfluorinated alkyl substances (PFAS).

These recommendations are directed at drinking water producers, local authorities and consumers who have private wells or are consumers of locally caught fish.

The aim of these measures is to reduce the exposure of consumers to PFAS from contaminated drinking water and fish and minimize the long-term intake of PFAS.

In some cases, contamination following fire-fighting training using highly fluorinated firefighting foams has led to high concentrations of many different PFAS in ground water and private wells. The SFA’s recommendations on risk management measures are based on what was known about the presence of these substances in drinking water up until 2016.

New information has been published about the occurrence and toxicity of different PFAS in aquatic environments, in both Sweden and abroad. Also, new risk assessments of PFOS, PFOA, PFNA and PFHxS from the EFSA were released at the beginning of 2020. The recommendations on measures for PFAS substances in drinking water will be revised after the EFSA opinion 2020 is established and decisions have been made on maximum limits for PFAS in the EU drinking water directive.

In summary, current recommendations include monitoring 11 different PFAS in drinking water (PFAS11). Case-by-case risk management discussions with the SFA might be necessary when high concentrations of PFAS are observed. In terms of the consumption of fish, recommendations are limited to perfluorooctanesulfonate (PFOS).

The following applies to drinking water:

  • PFAS should not be present in drinking water.
  • The long-term consumption of drinking water with high concentrations of PFAS might reduce safety margins to levels that are suspected of causing health risks.
  • Exposure to PFAS also comes from sources other than drinking water, such as fish, and the substances accumulate in the body. Thus, the sum of PFAS11 in the drinking water should be as far below 90 nanograms/liter as possible.

Monitoring of drinking water

If a drinking water supply is, or is suspected of being, contaminated by PFAS, the concentrations in the drinking water should be monitored.

Analyse drinking water for the PFAS listed in the table below. Monitor the drinking water regularly over time and under different conditions in order to identify potential contaminant sources, PFAS composition, seasonal variations and possible trends.

The PFAS pattern in drinking water might provide information about the source of the contamination. Even areas not initially suspected of being affected might at a later stage need to be monitored due to the properties and mobility of the substances in the soil.

A risk assessment of the observed PFAS concentrations in drinking water should be conducted by comparing the concentrations with the action levels specified below.

Suitable PFAS to analyse in drinking water

1 Perfluorobutanesulfonate (PFBS)
2 Perfluorohexanesulfonate (PFHxS)
3 Perfluorooctanesulfonate (PFOS)
4  6:2 Fluorotelomer sulfonate (6:2 FTS)
5  Perfluorobutanoate (PFBA)
 6  Perfluoropentanoate (PFPeA)
 7  Perfluorohexanoate (PFHxA)
 8  Perfluoroheptanoate (PFHpA)
 9  Perfluorooctanoate (PFOA)
 10  Perfluorononanoate (PFNA)
 11  Perfluorodecanoate (PFDA)

 

Action levels

According to Section 7 of the Drinking Water Ordinance (Livsmedelsverkets föreskrifter (2001:30) om dricksvatten), drinking water shall not contain substances in such concentrations that they might pose a risk to human health. The SFA has therefore established an action level for PFAS.

The action level is intended for drinking water producers, health authorities and owners of private wells as a guide when determining whether PFAS concentrations in drinking water are so high that they might pose a health risk and therefore should be reduced or that consumers must be advised not to consume the water until such concentrations are reduced.

Within the EU, work is currently ongoing to establish legally binding maximum limits for PFAS in drinking water. Once these limits have been established, they will be legally binding for all EU Member States.

Read more about this under the heading “Upcoming drinking water directives from the EU regarding PFAS”. The SFA action level will be revised when the EU has decided on the new drinking water directive.

Risk assessment of PFAS in drinking water

Calculate the total concentration of PFAS in the drinking water in each sample as the sum of all PFAS in the table above. Results that are reported as “less than” (<) should not be included in the summation. If PFAS other than those listed in the table above significantly affect the total concentration, the SFA should be contacted for recommendations on risk management measures.

The limit of quantitation (LOQ) for individual PFAS should be in the range of 1–10 nanograms/litre.

Compare the total PFAS concentration with the action level of 90 nanograms/litre. Also, compare the total PFAS concentration with the health-based guideline value (based on the previous TDI (Tolerable Daily Intake) for PFOS), which is 900 nanograms/litre.

Recommendations on risk management for drinking water

- covered by the Drinking Water Ordinance (Livsmedelsverkets föreskrifter (2001:30) om dricksvatten)

If PFAS are detected in drinking water at concentrations below the action level, i.e. PFAS11 is below 90 nanograms/liter

The long-term goal should be to minimize PFAS exposure to drinking water. This is justified by there being other sources of PFAS exposure than drinking water, for example, freshwater fish. Moreover, some PFAS accumulate in the body during long-term exposure.

If the action level is exceeded in drinking water, i.e. PFAS11 is above 90 nanograms/liter

  • Act as soon as possible so that PFAS in drinking water are reduced to concentrations as low as possible below the action level.
  • Monitor PFAS in the raw water if the drinking water is from surface water. Inform the local health authority if the PFAS concentration in the raw water exceeds the action level for drinking water. This is justified because it might require additional risk management for the consumption of fish (see below).
  • Contact the Swedish Water and Wastewater Association for further information on measures to reduce the concentration of PFAS in the waterworks.

If PFAS11 is above 900 nanograms/liter

  • Avoid drinking the water or preparing food with the water until the concentration is reduced as low as possible below the action level.
  • Contact the Swedish Food Agency for further recommendations on risk management.

Recommendations for the local health authority when risk managing PFAS-contaminated fish

  • Monitor the concentration of PFOS in the fish species and sizes being consumed if PFAS contamination is suspected in watercourses used for recreational or commercial fishing.

Recommendations if you have a private well

If your water supply is from your own private well or private waterworks, you are responsible for the quality of the drinking water and for keeping the well in good condition. This means, for example, that you are responsible for monitoring the drinking water quality.

Long-term consumption of drinking water with high concentrations of PFAS reduces the safety margins to levels that are suspected of causing health risks. It is therefore important to check that the drinking water from your well does not have high concentrations of these substances. Contact your local health authority or municipality to find out whether you live in an area that might be contaminated with PFAS.

The municipality can also help with information on how to analyse the content of PFAS in your drinking water.

Actions at different concentrations of PFAS

The SFA recommends the following actions depending on the concentration of PFAS in your drinking water:

  • If the drinking water contains 0–90 nanograms PFAS/liter:
    No specific action is needed. You can continue to drink the water.
  •  If the drinking water contains more than 90-900 nanograms PFAS/liter: 
    You can continue to drink the water, but you should ensure that the concentration is lowered as much as possible as soon as possible.
  • If the drinking water contains more than 900 nanograms PFAS/liter:
    Avoid drinking the water or preparing food with the water until the concentration has been lowered as low as possible below the action level.

If the drinking water in your well contains more than 90 nanograms PFAS/liter, seek advice at your local health authority and consult companies that provide technological solutions for treating the water.

Upcoming EU drinking water directives

Within the EU, work is currently ongoing to establish maximum limits ​​for PFAS in the drinking water directive. Once these limit values ​​have been determined, they will be legally binding for all EU Member States. Following the final decision, Member States will have two years to implement the national drinking water directive in their national legislation.

The EU drinking water directive is a so-called minimum directive, which means that Member States can choose to introduce stricter legislation in their regulations if there are grounds to do so. Sweden has had action limits for PFAS in drinking water since 2014. Some of the PFAS covered by PFAS11 are not included in the EU Commission’s proposal for maximum limits. These are PFAS substances that have been found in drinking water in Sweden and there may be grounds for adding these substances to the Swedish regulations. The PFAS not included in the EU Commission proposal are PFPeA, PFHpA and 6: 2 FTS.

 

The EU Commission’s proposal on maximum limits:

PFAS 20: 100 ng/L

PFAS total: 500 ng/L

 

PFAS 20:

- Perfluorobutanoic acid (PFBA)

- Perfluoropentanoic acid (PFPA)

- Perfluorohexanoic acid (PFHxA)

- Perfluoroheptanoic acid (PFHpA)

- Perfluorooctanoic acid (PFOA)

- Perfluorononanoic acid (PFNA)

- Perfluorodecanoic acid (PFDA)

- Perfluoroundecanoic acid (PFUnDA)

- Perfluorododecanoic acid (PFDoDA)

- Perfluorotridecanoic acid (PFTrDA)

- Perfluorobutanesulfonic acid (PFBS)

- Perfluoropentanesulfonic acid (PFPS)

- Perfluorohexanesulfonic acid (PFHxS)

- Perfluoroheptanesulfonic acid (PFHpS)

- Perfluorooctanesulfonic acid (PFOS)

- Perfluorononanesulfonic acid (PFNS)

- Perfluorodecanesulfonic acid (PFDS)

- Perfluoroundecanesulfonic acid (PFUnDS)

- Perfluorododecanesulfonic acid (PFDoDS)

- Perfluorotridecanesulfonic acid (PFTrDS)

Reviewed 2020-06-15