PFASs in groundwater – a risk for Swedish drinking water?

Stefan Banzhaf 1, Jeffrey Lewis 2, Charlotte Sparrenbom 3, Roland Barthel 1

1 Department of Earth Sciences, University of Gothenburg, Göteborg, stefan.banzhaf@gu.se2 Tyréns AB, Umeå3 Department of Geology, Lund University, Lund

Grundvattendagarna 13-14 oktober 2015, Göteborg– Session Föroreningar –

Gone viral…?

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What are PFASs?

PFASs = perfluoroalkyl and polyfluoroalkyl substances

- Multiple industrial uses, e.g. as water repellent surfaces on clothing, leather, paper and as firefighting foam

- Produced since the 1950s

- Very diverse group with different properties, mainly depending on their chain length

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Transport behavior in (ground-)water

- PFASs are insoluble in the form used for industrial applications and in end consumer products

- They form ions in the aquatic environment, which are then highly water soluble

- Chain length influences mobility: short-chained PFASs are more mobile in groundwater than long-chained ones

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“Prominent” PFASs compounds

PFOS C8HF17O3S

- Major applications: firefighting foams, fabric protector- Banned in the EU 2006- PFOS-containing firefighting foam banned from sale 2008,

usage no longer allowed since 2011- Listed in the Stockholm Convention (Annex B, restriction) since

2009: “Restriction of production and use, in accordance with the provisions of that annex.”

- Listed in EU Water Directive as priority substance since 2013

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“Prominent” PFASs compounds

PFOA C8HF15O2

- Major applications: carpets, firefighting foam, production of PTFE (“Teflon”) and water repellant clothing (e.g. “Gore-Tex”)

- EU will submit proposal to add PFOA to the Stockholm Convention (Annex A, elimination): “Elimination of production and use of all intentionally produced persistent organic pollutants.”

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A problem for the aquatic environment…

- Highly mobile in the aquatic environment, persistent and bioaccumulative

- Found worldwide in the aquatic environment and wildlife

- Toxicity is known for some PFASs, e.g. PFOS

- More PFASs are suspected to be toxic to mammals, not thoroughly studied yet

= Anthropogenic environmental pollutants!

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How do PFASs enter groundwater?

Point sources- Firefighting training areas- Wastewater treatment plants- Landfills

Diffuse sources- Application of biosolids from wastewater treatment plants to

agricultural fields- Bank filtration - Managed aquifer recharge

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www.defense.gov/home/images/photos/2006-02/index/Hi-Res/060210-F-7564C-021.jpg

PFASs in drinking waterHow do they get there?- Via contaminated surface water, e.g. at bank filtration sites

- Via contaminated groundwater

- Low elimination during drinking water treatment

Why problematic:- PFASs-contaminated food and drinking water are assumed to

contribute significantly to PFASs uptake of humans

- Both public water works and private wells are affected

- Especially in private wells there is no regular control of drinking water quality

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PFASs in Swedish groundwater – why bother?

- PFASs are detected in Swedish groundwater

- 50 % of Sweden’s drinking water comes from groundwater

- Exposure via contaminated drinking water is linked to increasing PFASs concentrations in blood serum, e.g. in Uppsala

- Once contaminated, an aquifer will form a long lasting problem due to the persistence of PFASs

- Adverse health effects for humans as a consequence of long time exposure not finally clarified but highly suspected!

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The current situation in Sweden- First environmental screenings already 10 years ago – did not receive

much public attention

- Detections of PFASs countrywide, both at public water works and in private wells

- Concentration on firefighting training areas as sources for PFASs

- According to Livsmedelsverket 3.4 million people in Sweden are exposed to PFASs contaminated drinking water

- Some groundwater based waterworks already had to cease operation, e.g. Kallinge, Botkyrka

- No threshold value for PFASs in groundwater or surface water

- No guidelines on sampling frequency for PFASs at water works11

The current situation in Sweden- First environmental screenings already 10 years ago – did not receive

much public attention

- Detections of PFASs countrywide, both at public water works and in private wells

- Concentration on firefighting training areas as sources for PFASs

- According to Livsmedelsverket 3.4 million people in Sweden are exposed to PFASs contaminated drinking water

- Some groundwater based waterworks already had to cease operation, e.g. Kallinge, Botkyrka

- No threshold value for PFASs in groundwater or surface water

- No guidelines on sampling frequency for PFASs at water works12

Until then: PFASs7 according to Livsmedelsverket

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Name, Livsmedelsverket Abbreviation Name, English

Perfluorbutansulfonat PFBS Perfluorobutanesulfonic acid

Perfluorhexansulfonat PFHxS Perfluorohexanesulfonic acid

Perfluoroktansulfonat PFOS Perfluorooctanesulfonic acid

Perfluorpentanoat PFPeA Perfluoropentanoic acid

Perfluorhexanoat PFHxA Perfluorohexanoic acid

Perfluorheptanoat PFHpA Perfluoroheptanoic acid

Perfluoroktanoat PFOA Perfluorooctanoic acid

What if PFASs7 are detected in drinking water?PFASs7 present but <90 ng/l “found”- Try to minimize PFASs exposition via drinking water

PFASs7 >90 ng/l “limit of action”- Take action asap to reduce PFASs below limit of action - Analyze PFASs in raw water if drinking water comes from surface water,

if also above limit of action inform the local control authority

PFASs7 >900 ng/l “health based guideline”- Women trying to become pregnant, are pregnant or breastfeed should

avoid drinking the water - Livsmedelsverket has to be contacted for individual risk assessment

Summarized from Livsmedelsverkets recommendation “Riskhantering - PFAA i dricksvatten”14

PFASs7 in Swedish water bodies

Type Number of water bodies Detection frequency [%]*Surface water 27 37Artificial recharge 12 50Groundwater 193 19

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*Detection limit for individual species: 1 or 2.5 ng/l

Holmström, K., Wetterstrand, S., Hedenberg, G., 2014. Nationell screening av perfluorerade föroreningar (PFAA) i dricksvatten. Svenskt Vatten Utveckling. Rapport Nr 2014–20.

- Svenskt Vatten survey 2014, raw and drinking water- Dataset represents water production for 4.3 million end consumers

in 112 communities- In total 22 % of all samples (52 out of 236) contained PFASs in

detectable amounts- PFOS and PFOA were the species most frequently detected

What is awaiting us in the future?

Ongoing new contamination with PFASs as also banned PFASs compounds (e.g. PFOS) are simply replaced by other PFASs that might be as toxic as the ones replaced

Remaining contamination due to the persistence of PFASs in the aquatic environment

Contamination due to derivatives of PFASs compounds and even new formation of banned compounds like PFOS that form without further release into the environment

PFASs are a long term problem for drinking water supply! It will maybe get even worse in the future!

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PFASs in groundwater – a risk for Swedish drinking water?

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Unfortunately a clear ”Yes” is the answer!

PFASs in groundwater have to be considered as ”trouble contaminants of the future”

Tack! Frågor?

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