illegal interconnection of drinking water and irrigation water system (case study) workshop on water...
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Illegal interconnection of drinking
water and irrigation water system (Case study)
Workshop on Water and Climate Adaptation Workshop on Water and Climate Adaptation (Amsterdam, 1–2 July 2008)(Amsterdam, 1–2 July 2008)
Martina BehanováPublic Health Authority of Slovak Republic
Dep.of environmental health
Involved stakeholders
• Regional authority of public health in Trnava
• Water company „TAVOS“
• Municipality of Jaslovské Bohunice
Step by step
• 16.7.2007 phone call to the PHA from citizens from Jaslovske Bohunice about suspicion on drinking water quality causing gastric problems
• 16.7.2007 PHA analysed 2 samples of drinking water from the blocks of flats where affected citizens lived
EARLY DETECTION: • 17.,18.7. laboratory confirmation of microbiological,
biological, chemical contamination start of epidemiological investigation
Step by step
QUICK RESPONSE
• 19.7 a ban of drinking water usage from public water supply
• Active investigation for cases in Jaslovske Bohunice in close cooperation with local GPs and municipality
• The contamination of drinking water was confirmed also by laboratory analysis provided by TAVOS
• Water company made checks along the whole distribution system in Jaslovske Bohunice and ensured emergency tanks of water for affected households
Step by step
Samples were taken from 4 places in Jaslovske Bohunice:
● block of flats
● municipality office
● amphitheatre
● fastfood kiosk
Parameter JB Municipality
JB Blocks of flats,No.420,4th
floor
JB Amphitheater,No
.420 JB,fastfood
E.coli 0 150 150 32
Coliform bacteria 0 1800 2000 65
Enterococci 0 120 130 30
Colony count 37ºC 5 146 134 50
Abioseston 5 40 40 3
Flagellates colourless 0 80 20 0
Dead organism 0 120 280 0
Living organism 0 680 1120 0
Fe and Mn bacteriae 0 5 5 0
Filamentous bacteriae 0 0 0 0
Microscopic micromycetes 0 20 0 0
Ammonium LOD 0,66 0,51 LOD
Chemical oxygene demand 0,74 1,94 1,98 0,54
Nitrites LOQ 0,166 0,157 LOD
Nitrates 9,76 6,21 6,4 10,02
Colour 0 30 20 0
Conductivity 69,83 70,84 70,84 68,83
pH 7,76 8,08 8,14 8
Turbidity 2,43 7,65 8,59 1,85
Odour without odour 2 2,5 without odour
Iron LOQ 0,23 0,282 LOQ
Manganese 0,016 0,04 0,038 0,008
Measures taken by water company
• Laboratory analysis from 17.7., 18.7. showed biological contamination and zero level of chlorine in samples taken near the block of flats
• Flush of the whole distribution system + chlorination was done
• Samples taken on 19.7 and 23.7 were NEGATIVE
Results of epidemiology investigation
Outbreak in J.Bohunice, 2007
4
15 13
26
2017
14
410
1 105
1015202530
12.7
.200
7
13.7
.200
7
14.7
.200
7
15.7
.200
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16.7
.200
7
17.7
.200
7
18.7
.200
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19.7
.200
7
20.7
.200
7
21.7
.200
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22.7
.200
7
date of first symptoms
nu
mb
er
of
ca
se
s
Number of cases
Outbreak summary
• Duration 12.7. – 22.7.2007
• Number of cases: 125 (1500 exposed people, attack rate 8,3%)
• Place: Jaslovske Bohunice
• Vector of disease: Drinking water from public water supply
• Etiology: not confirmed (according to microbiological cultivation of contaminated water, it is supposed to be infectious of E.coli (EPEC) or other coliforms or Entamoeba coli)
Interesting findings
• Comprehensive investigation taken by TAVOS and municipality testified, that the epidemic outbreak occurred due to illegal interconnection of irregation water with drinking water from public supply
• It is suspected that interconnection of systems was made in a garden area near the block of flats
• PHA in cooperation with a water company informed the police and pressed charges against anonymous for the public danger