Final Conference June 24 - 25 Maastricht, The Netherlands

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Case Study : River Vantaa

Matti Verta,Tuomas Mattila, Jukka Mehtonen, Kimmo Silvo, Jaakko Mannio, Susan

Londesborough, Sari Väisänen, Kirsti Lahti

Final Conference June 24 - 25 Maastricht, The Netherlands

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Introduction case study: River Vantaa

• Catchment area 1 686 km2• Population of 1 milj. inhabitants• Agriculture (24 % cultivated)• Industry (dairy, food, metal, paint, detergent, plastics)• Drinking water source (secondary) to Helsinki

Metropolitan area • Irrigation source• Recreation object• Cultural scenery and objects

Final Conference June 24 - 25 Maastricht, The Netherlands

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Introduction case study: River Vantaa

• Substances

– PAH, PBDE, Nonylphenol, DEHP, TBT (TPhT)

• Sources– 250 potential plants/sources

• Connected to MWT plants

– Atmospheric sources (PAH)– Harbor activity, source of TBT in the estuary– Diffuse sources (DEHP, PAH, PBDE)/urban run off

• Occasional exceedances of EQS – PAH, DEHP, TBT

• TBT concentrations high in sediments

Final Conference June 24 - 25 Maastricht, The Netherlands

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Final Conference June 24 - 25 Maastricht, The Netherlands

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Specific challenges• Most measurements from river mouth

– Compliance upstream?– Use of models

• Source/sector specific emission factors not applicable, – Need for STP data, extrapolation– Use of sewage sludge data

• Overflows and operational problems in pumping stations

Final Conference June 24 - 25 Maastricht, The Netherlands

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Specific challenges

• Urban run off water – Probably an important source for PAH and

DEHP (PBDE, NP)• No measurements available• Modeling may be used for PAHs (emission estimates

available)

• Sludge use for landscaping, gardens, public parks

• Leakage of PSs?

Final Conference June 24 - 25 Maastricht, The Netherlands

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Lessons learned from case study

• SOCOPSE tools applicable – DSS, Substance reports

• Stakeholder involvement essential– Local knowledge– Acceptability of measures (inc. costs/benefits)

• Defining complience sometimes difficult– Low EQS compared with analytical uncertainty– Lack of data

– Modeling

Final Conference June 24 - 25 Maastricht, The Netherlands

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Lessons learned from case study

• Costs of complience hard to estimate for PS– Proposed mangement options serve many

objectives• Improved management of urban run off• Better sewage treatment plant operation• Renovation of sewer systems

• Management (dredging) of TBT-contaminated sediments expensive compared with (uncertain) benefits

• Adaptive monitoring when combined with modeling proved to be cost efficient