Multi-barrier approach and Havelock North in August 2016

Transcription

1 Multi-barrier approach and Havelock North in August 2016 Brent Gilpin 1 June 2017 The Future of Our Water Peak Vision Church, Havelock North

2 Micro-organisms mm 1/1,000 mm TOPICS Pathogens Sources Drinking Water Outbreaks Groundwater mm 1/10,000 mm

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4 Pathogens Viruses Norovirus Enterovirus Rotovirus Bacteria Campylobacter Salmonella E. coli O157 Protozoa Giardia Cryptosporidium

5 Notified Diseases in New Zealand (Selected) Disease 2016 Cases Current Rate per NZ NZ Hawkes Bay Campylobacteriosis Cryptosporidiosis Giardiasis Legionellosis Leptospirosis Listeriosis Salmonellosis Shigellosis VTEC/STEC infection Yersiniosis Higher reported recreational water contact

6 Campylobacteriosis Campylobacter jejuni Illness onset 1 to 10 days following ingestion of the bacteria. Diarrhoea, severe abdominal pain, vomiting, fever, nausea Reactive arthritis, guillain barre syndrome

7 E. coli O157 (STEC/VTEC) Illness onset 3 to 9 days (mean 4 days) following ingestion of the bacteria. Bloody diarrhoea, severe abdominal pain, vomiting, no fever 10% of children infected develop Haemolytic Uraemic Syndrome (HUS) Renal failure leading to kidney dysfunction, seizures, coma, 1% of STEC cases result in death.

8 Cryptosporidum Incubation period 1 14 days, with an average of 7 days Copious watery non-bloody diarrhoea, vomiting, anorexia, fever, malaise, and abdominal cramping for up to 2 weeks Resistant to chlorine Survive for months Found 155 mammals

9 Sources of pathogenic micro-organisms Humans Viruses, Bacteria & Protozoa Animals Bacteria & Protozoa Excrete 10,000,000,000 cysts per day

10 Lamb faeces (105 samples) Campylobacter 81% samples positive 1 4,600,000 cfu/g Cryptosporidium spp. 37% samples positive 1 73,882 oocysts/g Giardia spp. 28% samples positive cysts/g STEC 3.8% positive Salmonella 1.9% positive EM Moriarty, N McEwan, M Mackenzie, N Karki, LW Sinton & DR Wood (2011) Incidence and prevalence of microbial indicators and pathogens in ovine faeces in New Zealand, New Zealand Journal of Agricultural Research, 54:2, 71-81, DOI: /

11 Multi-barrier Approach to Safe Drinking Water Protection of source of the water Water treatment Remove Particles Inactivate organisms Secure Distribution system Monitor water quality Response to adverse water test results

12 Year of Outbreak Outbreaks due to contamination surface water sources Location Pathogens Cases Confirmed 2001 North Battleford, SK, Canada 2010 Õstersund, Sweden 2001 Te Aute, College, Hawkes Bay, NZ 2012 Darfield NZ Cryptosporidium parvum type 1 (human) Cryptosporidium Campylobacter jejuni 375 >29 Total Cases Estimated 5,800 7, hospitalised 27, hospitalised Campylobacter jejuni Comments Sewage discharges upstream drinking water intake Cattle Sheep Rainfall Dr. Steve E. Hrudey, Converting Hindsight into Foresight Treatment Failures

13 Outbreaks due to contamination ground water sources Year Location Pathogens Cases Confirmed 2000 Walkerton, Escherichia coli 163 (E) ON, Canada O157:H7, Campylobacter 105 (C) Asikkala, Finland 2002 Transtrand, Sweden Campylobacter jejuni 12 both Total Cases Estimated 2, HUS 7 deaths Comments Cattle manure Rainfall Treatment failure Rainfall No treatment Norwalk-like virus 4 ~500 Leaking sewer pipe near bore No treatment Dr. Steve E. Hrudey, Converting Hindsight into Foresight

14 Outbreaks due to contamination in reticulation Year Location Pathogens 2007 Nokia, Finland 2008 Alamosa, CO, USA Campylobacter spp., Norovirus, Giardia, Salmonella spp. Clostridium difficile, Rotavirus Salmonella Cases Confirm ed 2 deaths death Cases Estimated 6, hospital 2008 Adliswil, Switzerland pathogens not identified Northampt on, England Dr. Steve E. Hrudey, Converting Hindsight into Foresight Cryptosporidium cuniculus Comments cross-connection at sewage treatment plant vermin contamination of water storage tank cross-connection at sewage treatment plant Rabbit in backwash tank

15 Ministry of Health Guidelines for Drinking-water Quality Management for New Zealand (2nd edn). Wellington: Ministry of Health. Documented waterborne outbreaks in New Zealand, Year Incident Causal agent Cases Confirmed 2005 Bridge Valley camp Campylobacter Hawke s Bay school camp Campylobacter Med student camp, Canterbury Campylobacter Otago bowling tournament Campylobacter Cardrona Skifield Norovirus School camp, Te Kuiti Campylobacter School camp, Wellington Gastro unknown cause Northland school Gastro viral unknown cause Springston Campylobacter South Canterbury youth camp Campylobacter Waiouru Commanders Course Campylobacter Runanga drinking-water supply Campylobacter 4 Probable 2012 Darfield drinking-water supply Campylobacter Hawke s Bay camping ground drinking-water Campylobacter Cardrona Hotel & water supplies Norovirus Nelson Lakes Scout camp Gastro unknown cause 13

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21 Mangateretere Stream Pond

22 BV3 BV2 BV

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24 Alluvial gravel aquifer Three main textures Sandy gravel Sand Open frameworks Murray Close & Lee Burbery

25 Stygofauna

26 Aquifer ecosystems Filter feeders Predators Scavengers Bacterial/ fungal biofilm Organic matter from surface Grazers/ detritivores Courtesy Dr Louise Weaver, ESR Microbial Inactivation & Removal Filtration Predation Starvation Increase transport times and matrices Sunlight Desiccation Avoid direct deposition

27 Multi-barrier Approach to Safe Drinking Water Protection of source of the water 10 Water treatment Remove Particles Inactivate 20 organisms Secure Distribution system Monitor water quality Response to adverse water test results BV3 BV2 BV1

28 Conclusions Microorganisms are everywhere both good & bad Human sewage/faeces is biggest risk Animal faeces likely to contain pathogens but may differ in quantity and types Drinking water needs a multiple barrier approach Weakness/absence of any one stage needs to recognised and either fixed or compensated for by enhancing other barriers Reduce pathogenic risk in recreational/source waters by increasing opportunities for inactivation or removal of microorganisms

29 Inquiry-into-Havelock-North-Drinking-Water