Unregistered Water Systems Can Pose a Risk to Public Health
In spring of 2021 the department learned that a small mountain resort was open to the public and serving untreated groundwater under the direct influence of surface water (GWUDI). The water supplier was aware of its lack of treatment and had historically been in contact with the department but failed to notify us upon reopening to the public. Inadequately treated GWUDI can contain disease-causing organisms and other contaminants with acute health effects. It is the supplier’s responsibility to put public health first by contacting the department prior to serving water and ensure that, if applicable, it is in compliance with the safe drinking water regulations. Please read on to discover how the involved parties responded to the situation in order to best protect public health and how other water providers can do the same.
The supplier had historically been classified as a regulated public drinking water system serving groundwater under the influence of surface water. After submitting documentation that the resort was no longer open to the public, the water system remained unregulated for several years. Aware of the regulatory requirements and their lack of filtration and disinfection treatment, the supplier reopened its resort to the public. Upon receipt of this information, the department issued a boil water advisory to be immediately distributed throughout the resort due to the increased risk associated with untreated GWUDI. The department also issued a violation for their failure to provide adequate treatment.
As the situation evolved, water samples were collected and shown to contain coliforms which are organisms known to exist in the digestive tracts of animals. Coliforms can indicate the presence of microbial contaminants with acute health effects such as viruses, bacteria, and protozoa. The purpose of filtration and disinfection treatment is to inactivate and remove such organisms before they can cause harm. Some unregistered water suppliers have treatment installed, however it may not be meeting the minimum removal and/or inactivation requirements needed to protect public health. That is one of the reasons that each new public water system’s treatment system is reviewed by the department.
While under a boil water advisory, the resort chose to temporarily close and immediately began working with a certified operator to install chemical disinfection. Within 11 days, a chlorinator was installed, operational, and providing disinfection at the required interim level. Following the installation, multiple sample results confirmed that coliform was no longer active in the water and now, several months later, the supplier is on track to have a filtration system installed as required under Regulation 11’s Surface Water Rule. As we have worked towards an acceptable resolution, the water supplier has been cooperative and has worked quickly to return to compliance.
Unregistered water suppliers can pose a serious threat to public health by exposing the public to potentially harmful pathogens if the appropriate treatment systems are not installed and properly operated. Even suppliers that have some form of treatment may not be meeting the minimum removal and/or inactivation requirements needed to protect public health. These scenarios create conditions that could lead to waterborne disease outbreaks. If you are a water supplier or operator in Colorado, thank you for joining us in our mission to protect public health. If you are aware of any unregistered systems in Colorado, the department requests that you contact the compliance specialist for your region and work with them to determine whether the system meets the criteria of a public water system. Together we can ensure that the water meets safe drinking water standards and better serve the citizens and visitors of Colorado.
➽ Jamie Duvall, Drinking Water Compliance Specialist
