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Monitoring biocides in the rivers Rhine and Meuse

important sources for drinking waterproduction

André Bannink, RIWA

7 May 2014

environmental risk assessment of biocides

3rd International Fresenius Conference, Mainz (D)

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Outline

• RIWA: who are we?– Why do we monitor water quality?

• Which biocides concern(ed) us? Three examples1. 3-(3,4-dichlorophenyl)-1,1-dimethylurea

2. N,N-diethyl-m-toluamide

3. Tetrakis(hydroxymethyl)phosphonium sulfate • Conclusions

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RIWA: who are we?

• Association: water companies that use river water as source for the production of drinking water

• Sources: rivers Rhine, Meuse and Scheldt• Members: supply drinking water to

several millions of consumers• 530 Mm3/a in NL and 275 Mm3/a in B

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Our mission statement• The water quality in the rivers Rhine and

Meuse should be such that it can be purified to drinking water using natural treatment

Not the same as but in line with

Article 7 Water Framework Directive• Avoid deterioration of water quality in order

to reduce the level of purification treatment required in the production of drinking water

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Location of Meuse and Rhine river

basins

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Our monitoring programme• Purpose is twofold:

1. To know the status of the river water quality

2. To detect trends in the river water quality• RIWA Members monitor their source at

the intake– To meet regulatory obligations,– To control the production process, and– To fulfil RIWA monitoring programme

• RIWA coordinates and reports annually

RIWA Members monitor their source at intake

Two examples of monitoring pointscontinuous automatic sampling grab sampling

Keizersveer (Meuse) Nieuwegein (Lek Canal, Rhine Basin)

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Our monitoring programme• We focus on drinking water relevant

substances– Substances that fail to meet Regulatory Water

Quality Standards– Substances that breech Target Values from

the European River Memorandum• We sometimes detect substances that

(could) have been used as a biocide

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Our monitoring programme• Three major concerns

1. Plant Protection Products, Biocides and their metabolites

• Glyphosate / AMPA major water quality problem• Glyphosate is considered a PPP, but emissions

originate mostly from use outside agriculture• AMPA is a metabolite of PPP’s as well as of

coolant additives (phosphonates)

2. New Emerging Substances / Substances of Emerging Concern

3. Impact of Climate Change

European River

Memorandum

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Biocides in our monitoring programme• Who determines that a substance we have

detected was used as a biocide?– We do not have this specific expertise

• NL: Board for the permission of plant protection products and biocides (Ctgb) sends a list of PPPs and Biocides which are authorised annually– In return we send Ctgb our monitoring results

over the past 5 years

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Biocides in the Netherlands

• Water Quality Standard in NL for PPPs and Biocides in Surface Water used for drinking water production is 0.1 µg/L– WQS exceedances at intake points play a role

in the authorisation process– Hence our co-operation with Ctgb

• Sometimes multiple uses of substances– We are unable to distinguish the use as PPP

from the use as a biocide

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Biocides detected in rivers

Going back in time to learn for the future

Diuron (3-(3,4-dichlorophenyl)-1,1-dimethylurea)

• Major problem due to use as weed killer on paved areas– Technicality: this use does not protect any crop but

still it is seen as a PPP

• Caused the longest intake stop ever recorded back in 1993

1993• Intake of water from the River Meuse

was stopped for 7 weeks– Diuron levels exceeded intake criterion (= 10

times the Water Quality Standard)– Maximum bridging capacity of reservoirs is

approximately 90 days

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Biocides detected in rivers

Diuron• The use of the active substance in PPPs was

banned in NL in 1999 / in B in 2002• Temporary ban in EU in 2007, re-admission in

October 2008• December 2008: placement on the list

of Priority Substances under WFD

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Diuron in Dutch surface water: average concentrations

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Diuron levels in Rhine and Meuse

01

/Jan

/91

14

/Ju

l/92

25

/Jan

/94

08

/Au

g/9

5

18

/Feb

/97

01

/Se

p/9

8

14

/Ma

r/00

25

/Se

p/0

1

08

/Ap

r/03

19

/Oc

t/04

02

/Ma

y/0

6

13

/No

v/0

7

26

/Ma

y/0

9

07

/De

c/10

19

/Ju

n/1

2

31

/De

c/13

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

Keizersveer (Meuse) Nieuwegein (Rhine Delta)WQS

This peak originates from an incident in B

Co

nce

ntr

atio

n i

n µ

g/L

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Biocides detected in rivers

Diuron• Since 1999 no PPP-authorisation in NL• Currently two Biocides based on Diuron

are authorised in NL1. ACTICIDE MKX (for use in paint and plaster)

2. MIRECIDE-TF/480.F (for use in paint)

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Biocides detected in rivers

DEET (N,N-diethyl-m-toluamide)

• Use as active substance authorised in 35 biocides in NL / 17 in B– Various anti-mosquito sticks, rollers,

gels and sprays

• There have always been detections– Until recently under WQS– Now we also see breeches of

WQS

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DEET in Dutch surface water average concentrations

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DEET levels in the River Meuse

2004 2005 2006 2007 2008 2009 2010 2011 2012 20130

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

0.2

Luik (M600) Heel (M690)Keizersveer (M865) WQS

23 October

Co

nce

ntr

atio

n i

n µ

g/L

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Biocides detected in the RhineTHPS (Tetrakis(hydroxymethyl)phosphonium sulfate)

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Biocides detected in the RhineTHPS (Tetrakis(hydroxymethyl)phosphonium sulfate)

What had happened?• Treatment of the coolant of the Leibstadt (CH)

Nuclear Power Plant– 28 June 2011: 15 tonnes of 13% Sodium hypochlorite

• Sodium thiosulfate was used to neutralise unused chlorine before emitting the coolant in the Rhine

– 30 June 2011: 2.1 tonnes of THPS was added to the coolant system• Hydrogen peroxide was added, transforming THPS into

THPO (Tris-hydroxymethylphosphine oxide) before emitting the coolant in the Rhine

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Biocides detected inthe RhineTHPS (Tetrakis(hydroxymethyl)phosphonium sulfate)

Drinking water companies in CH, DE and NL were agitated because• No information was shared beforehand even though the

company involved did inform the authorities• There were no analytical methods available to measure

THPS and THPO at the time• Intakes for drinking water production in CH and DE were

stopped out of precaution

Modelling was performed to estimate concentrations at intake points, samples were take for future analysis

THPO in the RhineModel results vs measurements

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Biocides detected inthe RhineTHPS and THPO Measured concentrations were significantly lower than the predictions from the model• But still well over the 0.1 µg/L

Drinking water companies demanded steps to be taken to prevent future incidents• Better information sharing and stricter permits• International Commission for the Protection of the Rhine

makes inventory of all coolant emissions

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Biocides of concern for drinking water productionRIVM Study 601712007/2010

KWR Study BTO 2013.205(s): LC/MS and GC/MS methods adapted, only irgarol was found (< WQS)

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Conclusions

• Biocides are currently not a continuous concern to the production of drinking water from Rhine and Meuse– caution is necessary since incidents have occurred

• Concerns about the future, because– Not all individual substances can be analysed yet– New techniques are developed and implemented

(2014: method for quaternary ammonium compounds operational)

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Recommendations

• Emissions of coolant into the rivers is an issue to follow up on– Besides biocides also other compounds are emitted

eg. anti-foaming agents, anti-corrosion agents

• Emissions have a larger impact under low flow conditions (especially for the Meuse)– This should be considered in the permit– This becomes more important under changing climate

Thank you for your attention!

www.riwa.org

André Bannink

Are there any questions?

@BanninkAndre

My publicationscan be found on 30