Illegal interconnection of drinking water and irrigation water system (Case study) Workshop on Water and Climate Adaptation (Amsterdam, 1–2 July 2008) Martina Behanová Public 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 phone call to the PHA from citizens from Jaslovske Bohunice about suspicion on drinking water quality causing gastric problems 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

ParameterJB Municipality JB Blocks of flats,No.420,4th floor JB Amphitheater,No.420JB,fastfood E.coli Coliform bacteria Enterococci Colony count 37ºC Abioseston540 3 Flagellates colourless Dead organism Living organism Fe and Mn bacteriae0550 Filamentous bacteriae0000 Microscopic micromycetes02000 AmmoniumLOD0,660,51LOD Chemical oxygene demand0,741,941,980,54 NitritesLOQ0,1660,157LOD Nitrates9,766,216,410,02 Colour Conductivity69,8370,84 68,83 pH7,768,088,148 Turbidity2,437,658,591,85 Odourwithout odour22,5without odour IronLOQ0,230,282LOQ Manganese0,0160,040,0380,008

Measures taken by water company Laboratory analysis from 17.7., 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 summary Duration – 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

Lessons learned Importance of public awareness and early detection system Importance of well managed surveillance system of water-borne diseases Close cooperation of water company and local authorities (public health, municipality)