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Joe Brown PhD PE

Small water supplies under the microscope: a case study on water quality and health from rural Alabama. Joe Brown PhD PE Lecturer, Department of Disease Control, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, University of London

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Joe Brown PhD PE

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  1. Small water supplies under the microscope: a case study on water quality and health from rural Alabama Joe Brown PhD PE Lecturer, Department of Disease Control, Faculty of Infectious & Tropical Diseases, London School of Hygiene & Tropical Medicine, University of London joe.brown@lshtm.ac.uk

  2. Acknowledgements Funding: US EPA (STAR) Students: Olivia Johns and Maxwell Izenberg (LSHTM) Study participants, Alabama Pauline Johnson and group (UA) Julie Olson and group (UA) Christine Stauber (GSU) Christine Moe and group (Emory) Rick Gelting and group (CDC) Shadi Eskaf (UNC) Engineers Without Borders (UA) HERO & Pam Dorr Samory Pruitt and CCBP (UA)

  3. Alabama

  4. Gasteyer and Vaswani 2004 From 2000 census data

  5. Southeast’s $50 Billion drinking water capital needs estimate Source: EPA 2007, Drinking Water Infrastructure Needs Survey Assessment, Shadi Eskaf EFC-UNC.

  6. Rural water supplies • More than 94 percent of the nation’s 156,000 public water systems serve <3,300 persons • Disproportionate share of outbreaks related to microbial contamination • Face a variety of challenges: • Wide service areas and disperse populations • O & M challenges • Meeting regulatory requirements

  7. Southeast’s 8,700 community water systems serve 58.5 Million People Source: EPA’s 2011 SDWIS data analyzed by the Environmental Finance Center at the University of North Carolina, Shadi Eskaf

  8. PWS Violations Alabama 1997-2012 > 8x > 40x 197x L Talebi

  9. Alabama’s Black Belt region • Common demographic and socio-economic characteristics • High poverty • High unemployment • Decreasing population • High percentage of minorities • Common themes • Decaying infrastructure • Poor access to basic services and health care • High percentage of vulnerable people (the young, elderly and infirm, HIV+)

  10. Results from scoping assessment • In collaboration with HERO • Customer complaints: outages, cloudy or smelly water • High cost to connect and tariffs • Post-meter leakages • Services disconnected • Alternatives are potentially unsafe water sources (i.e. shallow wells near failing septic systems) • Poor septic access and apparent function

  11. Phase 1: pilot study • Pilot cross-sectional study of 300 households in Hale County to examine: • (i) drinking water quality at the household level (both private wells and county public supply), • (ii) possible associations between water infrastructure characteristics and drinking water quality, and • (iii) risk of Highly Credible Gastrointestinal Illness (HCGI)

  12. Data collection overview • One survey on water use, basic demographics, health, and access to and perception of infrastructure • All households submitted a water quality sample at the time of the visit • Some households submitted two samples • Analysis for fecal coliform, turbidity, pH, and total and free chlorine • Membrane filtration, EPA 1904/Standard Methods • pH and Cl measured at point of sampling, colorimetric tests • Turbidity

  13. Not in the Job description

  14. Results overview • 8% of system samples positive for FC • 30% of well samples positive for FC • No Cl in >35% of samples from the county water supply system • Cl presence associated with FC • Frequently intermittent service: 8% of households • 18% of households had no onsite sanitation • Wells more likely to be contaminated

  15. Results overview, continued • 12 cases of GI illness among 507 people: 2.4% 7-day prevalence • High risk • Individualswhose drinking water was found to contain ≥ 1 cfu/100 ml of FC were 4 times as likely to have also reported HCGI in the previous 7 days as those whose water sample was negative for FC (<1 cfu/100 ml) • (OR 4.0, 95% CI 1.2 – 14)

  16. WELL WATER WITH SIGNIFICANTLY HIGHER FC WELL PROBLEMS ASSOCIATED WITH FC Cl RESIDUALS ASSOCIATED WITH LESS FC

  17. ODDS OF HCGI ARE 4x HIGHER IF WATER SAMPLE IS POSITIVE FOR FECAL COLIFORM

  18. Summary: Alabama, Phase 1 • Systems and wells at risk for microbiological contamination • Onsite sanitation a (potentially big) problem • High prevalence of gastro-intestinal illness • Suggestive evidence that water may play a role • Need for assistance with DBP rules

  19. Phase 2: Current study • Water Infrastructure Sustainability and Health in Alabama's Black Belt • Advancing Public Health Protection through Water Infrastructure Sustainability (EPA-G2009-STAR-F1) • 2011 – 2015, 14 water systems, 3 counties

  20. Goals: Phase 2 • 1. Assess system performance and water quality • Fecal indicators and pathogens • 2. GI illness associations • Directly measured (epidemiology) • Modeled using QMRA • 3. Identify possible transmission pathways • 4. Identify risk mitigation strategies • Working with operators

  21. Methods • Household-level water quality data • Microbiological indicators, pressure, Cl, pH, turbidity • Health GI measures • HCGI health diaries & interviews • Salivary antibody assay pilot • Pathogens and indicators from concentrated ultrafiltration samples • Cryptosporidium, Giardia, E. histolytica, norovirus, rotavirus, adenovirus, Enterococcus, E. coli, Campy, Salmonella • Other system-level data • System modeling • Operation and maintenance • Infrastructure characteristics

  22. Methods, continued • Survey of 900 randomly selected connected households (300 in each county) • Health outcomes • Grab vs flamed drinking water samples • Septic access and function • Perceptions and water use • Ongoing surveillance • Selection of sampling sites • Selected households, key system points • Up to 10 sample points per system • Dead-end ultrafiltration

  23. Selecting sampling points Turbidity – cross-sectional TC– cross-sectional

  24. System data • Flow modeling • O&M records • Existing monitoring data • Offering PDHs to operators

  25. Onsite sanitation • Surveys of OSS function and access • Public records vs survey • Previous study: 90% of septic systems in the Black Belt were failing (ADPH 1997) • Microbial source tracking of E. coli isolates • Household-level samples, drainfield samples, system samples • Partner study: household well samples • Technology innovation for underserved communities • Urgent need

  26. COURTESY OF R GELTING + CDC

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