Alpine E. coli 0157:H7 Outbreak Barbara Barron Drinking Water Program U.S. EPA Region 8
Dec 18, 2015
Alpine E. coli 0157:H7 Outbreak
Barbara BarronDrinking Water ProgramU.S. EPA Region 8
250,000 Gal.
STORAGE
STORAGE
50,000 Gal.
STORAGE
750,000 Gal.
PUMPHOUSE
WELL #2 WELL #1
TO DISTRIBUTION
TO DISTRIBUTION
Intermittent Disinfection
Residentialtaps
Cattle tap
SPRING POND
Municipal WaterSupply - AlpineEstablished 1975
April: Total coliform positiveRepeat samples
negative
May: Total coliform positiveRepeat samples
negative
June: Total coliform positiveRepeat samples
negative
History of BacT Samples in 1998
PRE-OUTBREAK TECHNICAL ASSISTANCE
Site Visit by Contractor
Chlorination Performed
Continuous Chlorination Recommended
250,000 Gal.
STORAGE
STORAGE
50,000 Gal.
STORAGE
750,000 Gal.
PUMP
HOUSE
SPRING
WELL #2 WELL #1
TO DISTRIBUTION Daily TC Sampling
TO DISTRIBUTION
ManualChemicalDisinfection
Cattletap
Shut valve
Residentialtaps
Install firehydrant
Immediate Local Action Under Boil Order
POND
STATE ACTION
Investigation Launched
Assistance Requested from CDC & EPA
Boil Order Continued
Action Under EPA Administrative Order
250,000 Gal.
STORAGE
STORAGE
50,000 Gal.
STORAGE
750,000 Gal.
PUMP HOUSE
Continuous Disinfection
SPRING
WELL #2 WELL #1
TO DISTRIBUTION
TO DISTRIBUTION
Cattletap
Shut valve
Residentialtaps
Install firehydrant
Sever Line
POND
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
P
ond
50K
gal tank
Fence Surrounding Spring Collection Area
Fallen Fence
Cattle Corral First Service Connection
Hose Bibb
Alpine Test Results forClassic Contaminants
ContaminantName
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