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Alpine E. coli 0157:H7 Outbreak. Barbara Barron Drinking Water Program U.S. EPA Region 8. Municipal Water Supply - Alpine Established 1975. SPRING. POND. 250,000 Gal. STORAGE. 50,000 Gal. WELL #1. WELL #2. STORAGE. Cattle tap. Residential taps. PUMP HOUSE. TO DISTRIBUTION.
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Alpine E. coli 0157:H7 Outbreak Barbara Barron Drinking Water Program U.S. EPA Region 8
Municipal Water Supply - Alpine Established 1975 SPRING POND 250,000 Gal. STORAGE 50,000 Gal. WELL #1 WELL #2 STORAGE Cattle tap Residential taps PUMP HOUSE TODISTRIBUTION IntermittentDisinfection STORAGE 750,000 Gal. TO DISTRIBUTION
History of BacT Samples in 1998 April: Total coliform positive Repeat samples negative May:Total coliform positive Repeat samples negative June: Total coliform positive Repeat samplesnegative
PRE-OUTBREAK TECHNICAL ASSISTANCE • Site Visit by Contractor • Chlorination Performed • Continuous Chlorination Recommended
STORAGE POND SPRING Immediate Local Action Under Boil Order STORAGE 50,000 Gal. 250,000 Gal. Manual Chemical Disinfection WELL #2 WELL #1 Shut valve Cattle tap Install fire hydrant Residential taps PUMP HOUSE TO DISTRIBUTION STORAGE 750,000 Gal. TO DISTRIBUTION Daily TC Sampling
STATE ACTION • Boil Order Continued • Investigation Launched • Assistance Requested from CDC & EPA
SPRING POND STORAGE 50,000 Gal. Action Under EPA Administrative Order Shut valve WELL #1 WELL #2 Cattle tap Install fire hydrant STORAGE Sever Line 250,000 Gal. Residential taps PUMP HOUSE Continuous Disinfection TO DISTRIBUTION STORAGE 750,000 Gal. TO DISTRIBUTION
EXAMINING SPRING BOX Analytical Findings Spring Pond: Total Coliform + Fecal Coliform + Enterococcus species + Clostridium perfringens + Storage Tank: Total Coliform + E. coli + Enterococcus species + Clostridium perfringens +
CHANCE OF ACQUIRING INFECTION CDC Data for Exposure Period 6/25/98 - 7/01/98 • Residents who drank Alpine water vs. residents who did not drink Alpine water • Visitors who drank Alpine water vs. visitors who did not drink Alpine water • 99.99% certainty that municipal water supply was source of outbreak Eight times more likely to acquire infection Fourteen times more likely to acquire infection
Little Jenny Pond/Mill Creek Spring Pond 50K gal tank
Fallen Fence Fence Surrounding Spring Collection Area
Cattle Corral First Service Connection Hose Bibb
Alpine Test Results for Classic Contaminants Contaminant Name Test Date Result Inorganics 12/06/93 Within limits Pesticides 11/10/97 Not Detected Radionuclides 11/10/97 Not Detected Nitrate/Nitrite 11/10/97 Not Detected Volatile Organics 12/06/93 Not Detected Unregulated 11/10/97 Not Detected Pb/Cu 01/01/98
Where Do We Go From Here? Direct Implementation Program A. Sanitary Survey Triage B. Develop 24hr. Emergency Protocol C. Strengthen Ties with State Agencies D. Pilot SWP Program at Alpine E. Enhance Internal Procedures F. Continuing Technical Assistance to Alpine