Comments from the Colorado Safe Drinking Water Program regarding the U.S.EPA 

Finished Drinking Water Storage Facility Inspection and Cleaning Public Meeting –

October 15, 2014

As we discussed during our presentation portion of the webinar, Colorado is moving 

forward with a proposed rulemaking regarding storage tank operations and 

maintenance, including periodic and comprehensive storage tank inspections. We 

believe that having a specific, yet flexible, regulatory requirement on this topic is 

more proactive and more transparent, as opposed to relying on the sanitary survey 

process. Sanitary surveys do not include a thorough inspection of all tanks including 

tank entry and cleaning. Also, problems detected during sanitary surveys are by 

definition already problems so that the public has already experienced some higher 

degree of contamination risk to their water supply. We believe that a proactive 

approach that includes thorough inspections and cleaning when needed would be 

better. Also, we believe that if the regulatory agency expects water systems to 

properly maintain storage tanks, then it is more transparent for that expectation to 

be clearly spelled out in a regulation as opposed to relying on the sanitary survey 

process. We do have experience with water system operators actually asking for us to 

cite violations or significant deficiencies to support their efforts to obtain funding 

from decision-makers for needed activities at their water system.

Colorado also wishes to make an additional statement about risk management within 

drinking water distribution systems. We believe that a multiple barrier approach is 

essential to protecting public health within distribution systems. That being said, a 

single federal regulation focusing only on storage tanks may give the mistaken 

impression that tanks are the highest risk area or other known distribution system 

failure points like line breaks and cross connections are somehow less pressing. We 

believe that a comprehensive approach to water quality within distribution systems is 

warranted at all public water systems. A comprehensive approach would dovetail well 

with the concepts of the Revised Total Coliform Rule. 

While the Alamosa and Gideon waterborne disease outbreaks were linked to finished 

water storage tank defects, it is also possible that a robust chorine residual could 

have prevented those outbreaks or reduced their extent and consequences. We 

believe that one of the real lessons from Alamosa is that it probably did not take very 

much animal waste to cause that outbreak. Cross connections, line breaks and other 

distribution system defects not associated with finished water storage tanks also 

provide contamination pathways that cause disease outbreaks. The federal Center for 

Disease Control and Prevention reports hundreds of probable drinking water outbreaks 

from cross connections. 
Since these multiple threats have equal importance and distribution systems need to 

be protected holistically, Colorado is moving forward with a combined rulemaking

approach requiring the following for public water systems:

• Finished water storage tanks must be free from defects.

• Develop and implement maintenance plans for finished water storage tanks 

including periodic and comprehensive inspections, with cleaning as needed.

• Robust cross connection control. 

• Maintain a chlorine residual of 0.2 mg/L throughout distribution. This is 

based on Colorado’s total coliform rule sampling data over the past 21⁄2 

years, which shows 300 percent higher numbers of E. coli positives in 

samples with chlorine residuals below 0.2 mg/L compared to samples with a 

higher residual.

We developed these proposed regulations with considerable stakeholder input. We 

believe that we can implement these rules primarily as modifications and 

clarifications of our current practices and accomplish this without additional funding 

or full time employees (FTE) for the state program. Any federal effort to develop 

regulations about storage tanks needs to be flexible and consider implementation 

activities and funding levels.

We believe that this is the best direction for Colorado to take in implementing the 

recommendations from our Alamosa disease outbreak investigation report to mitigate

waterborne disease outbreak risks within drinking water distribution systems.