Testing New Wells for Coliform Bacteria HELPING ENSURE

Testing New Wells for Coliform Bacteria HELPING ENSURE DRINKING WATER SAFETY

Why Test Well Water for Coliform Bacteria? Ensure Safety of Drinking Water Maintain Consumer Confidence in Groundwater

Waterborne Pathogen Exposure Routes INGESTION AEROSOL INHALATION FOOD DERMAL CONTACT

What are Coliform Bacteria? AEROBIC AND FACULTATIVE ANAEROBIC GRAM-NEGATIVE NONSPORE-FORMING ROD-SHAPED FERMENTS LACTOSE WITH GAS PRODUCTION WITHIN 48 HOURS @ 35 DEGREES CELSIUS MEMBRANE FILTER ANALYSIS

Coliform Bacteria are Indicator Organisms Positive coliform test indicates potential presence of pathogenic (disease-causing) microbes Testing for pathogens requires large volumes of water and complex lab procedures Coliforms are found in greater numbers than pathogens E. coli bacteria live longer than fecal coliforms Coliform testing is easier, more economical and safer than pathogen testing.

TOTAL COLIFORMS FECAL COLIFORMS E. COLI PATHOGENIC E. COLI

Sources of Coliform Bacteria INTESTINES OF WARM-BLOODED ANIMALS SOIL & VEGETATION SURFACE WATER & FLOODWATER ON-SITE SEWAGE SYSTEMS & SEWERLINE LEAKS GROUNDWATER AGRICULTURAL WASTE RUNOFF

Etiologies of Waterborne Illness Outbreaks (1991 – 2002) LEGIONELLA 3% CAMPYLOBACTERIOSIS 3% SHIGELLOSIS 4% OTHER DISEASES 6% ACUTE GASTROINTESTINAL ILLNESS (AGI), UNIDENTIFIED 38% AGI – E. COLI 0157: H 7 5% AGI – NOROVIRUS 6% CRYPTOSPORIDIOSIS 7% GIARDIASIS 12% CHEMICAL POISONING 16%

Burden of Illness Pyramid (From: Journal of Water and Health, Estimating Disease Risks Associated With Drinking Water Microbial Exposures, Vol. 4, Supplement 2, 2006) Deaths Persons who are hospitalized Persons who visit physician or health care facility Persons who exhibit symptoms Person is exposed to pathogen in water and becomes infected

Cryptosporidium WATERBORNE PATHOGENS E. coli ACUTE GASTROENTERITIS SYMPTOMS: STOMACH CRAMPS DIARRHEA NAUSEA VOMITING Symptomatic Host FEVER

Cryptosporidium WATERBORNE PATHOGENS E. coli FECAL TO ORAL TRANSFER OF PATHOGEN Asymptomatic Host Secondary Host

MICHIGAN GROUNDWATER IS GENERALLY FREE OF: • COLIFORM BACTERIA • DISEASE-CAUSING MICROBES Exceptions: Shallow carbonate bedrock (Karst) Very shallow coarse sand & gravel Faulty well construction Unplugged abandoned wells

Unsealed, Abandoned Well Causes Bacteria Problems for Noncommunity Public Water-Supply Well Reported by Minnesota Dept. of Health, Minnesota Well Management News Fall 2006 / Winter 2007, Volume 26, No. 2 PERSISTENT COLIFORMS IN NCPWS (>2 YRS. ) (24 YR. OLD WELL - 57 FT. DEEP - 4 IN. CASING) REPEAT WELL DISINFECTIONS UNSUCCESSFUL INVESTIGATION OF FACILITY HISTORY FOLLOWED BY METAL DETECTOR SEARCH BY MDH - ABANDONED WELL WITHIN 10 FT. OF ACTIVE WELL IS SUSPECTED EXCAVATION FINDS OLD WELL UNCAPPED 7 FT. BELOW GRADE, 10 FT FROM ACTIVE WELL - UNSEALED – SAND & DEBRIS FROM 35 FT. TO BOTTOM OF 60 FT. WELL STATIC WATER LEVEL SAME AS ACTIVE WELL – HYDRAULIC CONNECTION BETWEEN WELLS AFTER OLD WELL PROPERLY PLUGGED – CONSISTENT NEGATIVE COLIFORM BACTERIA SAMPLES

Potential Sources of Microbial Contamination from Well Drilling Practices OBTAINING DRILLING WATER FROM SURFACE WATER SOURCE USING BIODEGRADABLE DRILLING FLUID OR LOST CIRCULATION ADDITIVES IRON BACTERIA IN SURFACE WATER

Introducing Contaminants During Well Construction FAILURE TO MAINTAIN MINIMUM 10 PPM CHLORINE RESIDUAL IN DRILLING WATER TRANSFERRING CONTAMINANTS FROM GROUND SURFACE INTO WELL BOREHOLE ENCOURAGE DRILLERS TO USE TEST STRIPS

DOWNWARD LEAKAGE AROUND UNGROUTED CASING INFILTRATION OF SURFACE CONTAMINANTS CONTAMINANT PLUME STATIC WATER LEVEL UNSEALED ANNULAR SPACE AROUND CASING DOWNWARD LEAKAGE UNCONFINED AQUIFER

GROUT PIPE UNSEALED ANNULUS BETWEEN CASING & BOREHOLE DIRECT PATHWAY TO AQUIFER IF LEFT UNGROUTED OR IMPROPERLY GROUTED

Would this temporary cap keep contaminants out of the well?

Sanitary & Preventive Practices During Well Completion CLEAN DRILLING TOOLS BETWEEN WELLS TO PREVENT CROSS-CONTAMINATION KEEP WELL COMPONENTS ELEVATED OFF GROUND…. . USE SANITARY HANDLING PRACTICES

SANITARY WELL COMPLETION PRACTICES PROPER WELL CONSTRUCTION MATERIALS TRAINED PROFESSIONAL WATER WELL CONTRACTORS COMPONENTS OF A TARGET AQUIFER HAS AMPLE YIELD & SAFE WATER SAFE & RELIABLE WATER WELL SUFFICIENT SEPARATION FROM CONTAMINATION SOURCES ROUTINE MONITORING OF WATER QUALITY PROPER WATER SYSTEM MAINTENANCE

DEFICIENT WELL HEAD (CRACKED WELL CAP OR OPEN VENT) OLD WELLS WITH CORRODED WELL CASING SHALLOW DEPTH (OR SHORT CASING IN BEDROCK) POOR CONSTRUCTION (UNSEALED ANNULUS OR DUG WELL) WELLS MOST VUNERABLE TO MICROBIAL CONTAMINATION FLOODING, BURIED WELL HEAD OR SUBMERGED IN WELL PIT TOO CLOSE TO SEPTIC SYSTEM, AGRIC. RUNOFF OR ABANDONED WELL SEWER LINE BREAK, SEWAGE OVERFLOW OR CROSSCONNECTION

LHD Water Sampling Activities COLLECT BACTI SAMPLES OR PROVIDE SAMPLE BOTTLES TO WELL DRILLER OR OWNER USE WELL PERMIT PROGRAM TO NOTIFY WELL OWNER OF NEED TO COLLECT SAMPLE TRACK TEST RESULTS TO ENSURE ALL NEW WELLS ARE TESTED PROMPT FOLLOW-UP ON POSITIVE COLIFORM RESULTS, ESPECIALLY E. COLI POSITIVES WITHHOLD ISSUANCE OF WELL APPROVAL UNTIL SAFE BACTERIOLOGICAL SAMPLES ARE ATTAINED

Why Should Well Contractors Collect Bacteriological Water Samples? • • Reduce public health risk Enhance industry professionalism Validate quality of contractors’ work Reduce contractor liability

Why Should Well Contractors Collect Bacteriological Water Samples? • Improve customer confidence in groundwater • Reduce customer anxiety over positive test results • Gain better understanding of public health within water well industry

Why Should Well Contractors Collect Bacteriological Water Samples? • Current practice leaves customers with sense of purchasing incomplete product • Contractor knows when water system is complete and ready for sampling. • Well owners are unfamiliar with sampling protocol – prone to false positives.

Why Should Well Contractors Collect Bacteriological Water Samples? • Contractor ownership of sampling protocol • Fewer disputes over sampling location and technique • Reduction of complaints over validity of sample results • Encourages more sanitary drilling practices

WORK WITH LOCAL BUILDING CODE OFFICIAL WATER SUPPLY APPROVAL BY LHD BUILDING INSPECTOR CERTIFICATE OF OCCUPANCY