Culture of Health: Water Borne Disease Outbreak Rainbow Valley Ranch

The department promotes a ‘Culture of Health’ in order to encourage water providers to provide the highest water quality practical and to avoid waterborne disease outbreaks. Generally the department relies on what we call “performance partners” which are operators and suppliers of water to ensure the drinking water is safe. There are times that property owners do not cooperate and it becomes all the more important for the partnership between professionally certified operators and the department to stand firm. In the situation below, which did result in human illness, the contract operator that visited the site was instrumental in helping us understand and discern the facts on the ground. While ultimately the owner chose to sell off a portion of the property to avoid being a regulated public water system, the important realtime information from performance partners in the field helped mitigate the effects of this outbreak. As it stands today, the community should be receiving hauled water from a nearby regulated public water system that is safe to drink, however there is not regulatory oversight of the situation. 

The department values the public health professionals and certified water operators that are the ‘boots on the ground’ helping to protect public health and the environment every day. “If you see something, say something.” It may make all the difference in helping prevent or stop a waterborne disease outbreak.

Outbreak Summary Report:

Rainbow Valley Ranch is a small community and fishing club located in Teller County, Colorado. Before this outbreak, Rainbow Valley Ranch was considered to be a nonpublic water system as they served fewer than 25 people for at least 60 days of the year. Nonpublic water systems are not required to comply with the Safe Drinking Water Act and CDPHE has no regulatory authority over their water system.

According to residents of Rainbow Valley Ranch, people reported illness in April 2022, and CDPHE epidemiologists and WQCD staff worked together to collect and analyze information. Ultimately, CDPHE confirmed this as a confirmed waterborne disease outbreak on July 25, 2022. Four people from multiple households met the case definition of an acute onset of gastrointestinal illness. All four cases were Colorado residents, no one was hospitalized, and all individuals survived the illness.

Epidemiology and Investigation Concluded: Illness was likely Non-Shiga Toxin-Producing Escherichia coli bacteria are found in surface water, like lakes and streams. These bacteria live in the intestines of mammals, and some can cause mild to severe gastrointestinal illnesses.

Summary of Sampling and Gastrointestinal illness:

• 4 sick individuals
• 5 total coliform positive results
• 2 E. coli positive results 

Gastrointestinal Illness: 

Non-Shiga Toxin-Producing Escherichia coli infections can cause gastrointestinal illness with diarrhea and abdominal cramps, among other symptoms. These bacteria occur naturally in the intestinal tract of most animals and people, and can enter surface waters like rivers and

lakes through animal waste. When the people at Rainbow Valley Ranch drank the untreated surface water, the bacteria made them sick. 

Incident Timeline: 

• April 1, 2022
• At least one resident experienced gastrointestinal illness symptoms.
• July 20, 2022
• CDPHE received notification from a tenant at Rainbow Valley Ranch about their drinking water. According to the complainant, the landlord was using untreated lake water for the community’s drinking water and the complainant had diarrhea and blood in their stool. The complainant took a drinking water sample and sent it to the lab, where it was later confirmed as containing E. coli bacteria.
• July 21, 2022
• WQCD performed a site visit, reviewed the source (2 lakes) and treatment processes and collected total coliform samples. WQCD identified a filtration and disinfection system, but the disinfection was not connected to the water and the filtration system was not certified to remove bacteria or viruses. Chlorine results were non-detect.
• In addition, WQCD completed a population count and determined that Rainbow Valley Ranch met the definition of a public water system and would need to comply with the requirements in the Safe Drinking Water Act.
• July 22, 2022
• WQCD received lab results from the total coliform samples showing the presence of total coliform and E. coli. The division issued a boil water advisory to the system, requiring the owner to inform all residents that they must boil their water before using it.
• July 23-24, 2022
• Teller County Public Health and Environment received several other complaints from Rainbow Valley Ranch residents who were experiencing similar gastrointestinal illness symptoms.
• July 25, 2022
• Teller County Public Health and Environment interviewed residents to gather information on symptoms, onset dates, and water quality issues. CDPHE evaluated information and sample results and determined this was a confirmed waterborne disease outbreak. CDPHE required that the owner continue to post the boil water advisory and maintain a 2 ppm chlorine residual until the issue was resolved.
• August 31, 2022
• The owner of Rainbow Valley Ranch reported that she has stopped using the lakes for water and is instead hauling water from a nearby public water system.
• September 7, 2022
• WQCD issued an enforcement order and required the owner to pay a penalty, correct sanitary defects, and hire a certified operator, among other things.
• Late Fall/Early Winter 2022
• The Owner subdivided the property and sold half in order to avoid being a regulated public water system. The fine is still in effect.

➽ Tyson Ingles, Lead Drinking Water Engineer