The Revised Total Coliform Rule  has been in the works for years.   Despite the efforts of many  to include potable water tank inspection and cleaning as a requirement those activities remain optional.  Many states are requiring tanks to be inspected and a few like Florida also require cleaning at least once every five years.  However, without federal requirements many states remain without any such rules.  Rules on tank inspection vary from state to state ranging from an annual check list in Texas, to a full licensed engineers report every five years in Florida.

Sediment on the floor of water storage tanks and towers will continue to be a threat to public health.  The Total Coliform Rule (TCR) was published in 1989 and became effective in 1990.   It is worth noting that also in 1990 the EPA SAB  made this statement:

"EPA Science Advisory Board (SAB) cited drinking water contamination as
one of the most important environmental risks and indicated that disease causing
microbial contaminants (i.e.,bacteria, protozoa, and viruses) are probably the
greatest remaining health risk management challenge for drinking water suppliers
(USEPA/SAB, 1990)". 

This quote is found in the  Long Term 1 Enhanced Surface Water Treatment Rule (LT1ESWTR)

And Again Here:

The  EPA is now in the process of collecting information on disinfection by products and pathogens.

On February 13, 2013, EPA published in the Federal Register the revisions to the 1989 TCR.  EPA anticipates greater public health protection under the Revised Total Coliform Rule (RTCR) requirements.  These new requirements will go into full effect April 1, 2016.

Under the RTCR, there is no longer a monthly maximum contaminant level (MCL) violation for multiple total coliform detections.  New revisions require systems that have  indicators of coliform contamination in the distribution system to assess the problem and take corrective action that may reduce cases of illnesses and deaths due to potential fecal contamination and waterborne pathogen exposure. This final rule also updates provisions in other rules that reference analytical methods and other requirements in the 1989 TCR like public notification and ground water rules.

Although the new rule stops short of requiring water tanks to be inspected and cleaned, the following paragraphs at the bottom of the web page “Total Coliform Rule Revisions” suggest that the EPA may still be considering such a requirement in the near future:

In 2000, as part of its recommendations concerning the Long-Term 2 Enhanced Surface Water Treatment Rule and the Stage 2 Disinfection Byproducts Rule, the Stage 2 Microbial/Disinfection Byproducts (M/DBP) Federal Advisory Committee recognized the following points in its Agreement in Principle:

“Finished water storage and distribution systems may have an impact on water quality and may pose risks to public health. Cross-connections and backflow in distribution systems represent a significant public health risk. Water quality problems can be related to infrastructure problems and aging of distribution systems may increase risks of infrastructure problems. Distribution systems are highly complex and there is a significant need for additional information and analysis on the nature and magnitude of risk associated with them.”

The FACA concluded that EPA should review and evaluate available data and research on those aspects of distribution systems that may create or pose risks to public health as a part of the Six-Year Review of the TCR. The FACA also concluded that EPA should initiate a process with stakeholder participation for addressing requirements for cross-connection control and backflow prevention, and distribution systems issues related to significant health risks.


In my mind when indications of  a coliform contamination are found in the distribution system, the first question to be asked to assess the problem is, ‘When was the storage facility last cleaned?’  Bacteria, protozoa and viruses can use sediment on the floor of water storage tanks and towers as a safe habitat. Once that is understood,  assessing the problem by asking when the last tank cleaning was done becomes obvious.

We will continue to monitor updates and re-post any New Revisions found that regard the inspecting and/or cleaning of potable water storage tanks and towers.

See my other blogs at: