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5302

Investigating the Causes of Total Coliform Positive Samples from Drinking Water Distribution Systems

1.0

Drinking Water

360water, Inc.

Saylor Frye

saylor@360water.com

614-294-3600 Ext.

Partner Website

The purpose of this course is to provide training on the steps to take when investigating the source or cause of a total coliform positive sample that was collected from a public water system’s distribution system. Keep in mind that each water system has regulatory requirements that must be fulfilled when a positive total coliform sample is reported by the laboratory. This course does not address the regulatory requirements but rather gives information with which to find out why a positive total coliform sample was detected. Operators are encouraged to, as much as possible, do more than the regulations require. Operators are encouraged to be proactive in preventing problems from happening or from developing into public health concerns. Upon completion of this course, the operator should have a practical working knowledge of steps to take for investigating the causes of a drinking water sample being reported by a laboratory as testing positive for total coliform bacteria. The operator will develop a better understanding what the indicator may or may not indicate. The operator will be better equipped to talk to the laboratory manager or ask questions about sample collection. The operator will be able to develop an investigative strategy to check for causes in the water system.

Basic thru Intermediate

I Abstract II Objectives III Keywords IV Introduction V Questions to Ask the Laboratory A. Sample Bottle Receiving B. Test Method Changes C. Other Observations VI Questions to Ask the Sample Collector A. Sample Tap Details B. Sample Collection Observations C. Sample Transport Details VII Questions to Ask about the Sample Location A. Type of Facility Accessed B. Facility Plumbing C. Local Street Work VIII Questions to Ask about Water Quality A. Chlorine Residual B. Water Temperature C. Other Tests IX Questions to Ask about the Distribution System A Water Main Configuration and Hydraulics B Local Service Connections C Storage Facilities D Interconnections E Main Breaks and Repairs X Questions to Ask about Water Supply and Water Treatment A Changes in Treatment B Interruptions in Treatment C Changes in Source Water and Conditions XI Summary

All owners and operators for all public water systems, community and non-community should have a working knowledge of how to investigate the possible causes for a total coliform positive sample.

Virtual Asynchronous