Understanding Total Coliform and E. coli Testing – Why It’s Essential for Safe Drinking Water

May 21, 2025

4 min read

Understanding Total Coliform and E. coli Testing – Why It’s Essential for Safe Drinking Water

Safe drinking water is a fundamental public health priority, and ensuring it is free from harmful bacteria is non-negotiable. Whether you’re a homeowner relying on a private well, a school administrator ensuring student safety, or a property owner dealing with the aftermath of a flood—testing for Total Coliforms and E. coli is one of the most critical assessments you can perform. At PITS Environmental, we offer laboratory-grade water testing services that meet both regulatory and health protection standards.

What Are Total Coliforms and E. coli?

Total Coliforms are a broad class of bacteria found naturally in the environment, including soil and vegetation. While not all coliforms are harmful, their presence indicates that a pathway exists for contaminants—potentially including harmful pathogens—to enter your water supply.

E. coli (Escherichia coli) is a specific subset of coliform bacteria that originates from human and animal fecal waste. The presence of E. coli in drinking water is a direct indication of recent fecal contamination and the possible presence of dangerous pathogens such as viruses, protozoa, and other bacteria.

Why Testing Is Mandatory in Certain Cases

Private Wells

Private well owners are responsible for their own water safety. Unlike municipal water supplies, which are regularly tested, private wells can easily become contaminated without obvious warning signs. Annual testing for Total Coliforms and E. coli is recommended—and often required when selling or buying a home.

School Water Testing

Children are particularly vulnerable to waterborne illnesses. That’s why local and state health departments often require routine bacterial testing in schools. A single contaminated faucet or fountain can pose a serious health risk if Total Coliforms or E. coli are present.

Post-Flood Events

Floodwaters can carry sewage, animal waste, and other contaminants into drinking water supplies. After any flooding event, it’s imperative to test water systems—especially wells—for bacterial contamination. Even minor floods can cause groundwater infiltration and system breaches.

Real Estate Transactions and Regulatory Compliance

When buying or selling property—particularly those with private water systems—testing for bacterial contamination is usually required by lenders, insurers, and state health departments.

Federal and State Requirements

  • EPA National Primary Drinking Water Regulations (NPDWRs): The EPA sets the Maximum Contaminant Level (MCL) for Total Coliforms at zero. Under the Revised Total Coliform Rule (RTCR), any detection of E. coli constitutes a violation.

  • New York State (NYSDOH): Requires routine Total Coliform/E. coli testing for all public water systems. Private wells used in property transactions or school compliance must meet the same zero-tolerance standard.

  • New Jersey (NJDEP): Requires quarterly (or more frequent) microbiological testing for non-community water systems. Post-flood testing and school water system compliance fall under NJ Safe Drinking Water Act regulations, aligned with EPA standards.

Turnaround Time: Results typically available within 24–48 hours. 

What Do the Results Mean?

  • Negative for Total Coliform and E. coli: Your water is considered bacteriologically safe.
  • Positive for Total Coliform, Negative for E. coli: Your water may be compromised—further investigation is required.
  • Positive for E. coli: Immediate action is necessary—do not consume the water until remediation is completed and retesting shows clear results.

What to Do If Contamination Is Found

  • Disinfect the well or plumbing system (commonly done with chlorination)

  • Inspect for system breaches or structural issues

  • Install treatment systems like UV disinfection or filtration

  • Retest after remediation to confirm safety

Why Choose PITS Environmental for Your Water Testing?

  • NELAP-accredited testing procedures

  • Fast, reliable turnaround

  • Expert guidance on corrective actions

  • Customized services for homes, schools, and commercial properties

We understand the urgency and importance of safe drinking water. Our team works closely with homeowners, school officials, environmental engineers, and real estate professionals to deliver testing you can trust.

Final Thoughts

Don’t wait for symptoms of contamination to take action. Whether you’re maintaining your private well, reopening a school after a break, or recovering from a flood—testing for Total Coliforms and E. coli is a small step that offers major peace of mind.

Contact PITS Environmental today to schedule your water test and ensure the safety of your drinking water.

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