Pueblo sewage failure forces water advisories across 150 miles of Colorado’s Arkansas River

A sewage system failure in Pueblo, Colorado discharged 4.2 million gallons of untreated wastewater into the Arkansas River, triggering water contact advisories across a 150-mile stretch of southern Colorado and prompting federal officials to discuss disaster funding options for downstream communities.

The spill, first reported in late August, has forced Colorado Parks and Wildlife to expand its advisory to 10 state wildlife areas and the John Martin Reservoir, warning residents and visitors to avoid all contact with the water. U.S. Senator John Hickenlooper met with local leaders on September 2 to assess the damage and explore federal assistance pathways.

4.2 Million Gallons of Untreated Sewage

Raw sewage contains pathogens that pose immediate health risks to anyone who comes into contact with contaminated water. Untreated wastewater can carry germs such as E. coli and norovirus. According to the EPA, the most common illness from swimming in sewage-polluted water is gastroenteritis, and polluted water can also cause ear, eye, nose and throat infections. The CDC warns that water containing sewage can cause diarrheal disease and wound infections.

The 4.2 million gallon discharge overwhelmed the river's natural dilution capacity, and the contamination plume has now traveled downstream through multiple counties. According to Colorado Parks and Wildlife, the affected areas include Melon Valley, Rocky Ford, Oxbow, Las Animas Fish Hatchery, Purgatoire River, Fort Lyon, John Martin Reservoir State Park, North Gateway Ponds, Granada, Deadman, Midwestern Farms, and Holly state wildlife areas.

Who Is Most at Risk

The advisory warns against swimming, wading, fishing, or any recreational activity involving water contact across the affected region. Children, elderly individuals, and those with compromised immune systems face the highest risk of serious illness from waterborne pathogens.

Agricultural operations that draw irrigation water from the Arkansas River may also face contamination concerns, though state officials have not yet issued specific guidance for farmers. Communities downstream that rely on the river for any portion of their water supply are monitoring the situation closely.

Hickenlooper Meets With Local Leaders on Disaster Funding

Senator Hickenlooper's visit focused on two priorities: immediate assistance for affected communities and longer-term infrastructure improvements to prevent future failures. According to The Pueblo Chieftain, discussions included potential federal disaster funding mechanisms, though no specific commitments have been announced.

Colorado Parks and Wildlife stated the water contact advisory will remain in effect until sampling confirms pathogen levels have returned to safe thresholds. No timeline for lifting the advisory has been provided.

Aging Infrastructure Behind Thousands of Annual Overflows

Aging wastewater infrastructure across the United States fails regularly, often with little public attention until a major discharge occurs. The EPA estimates that sanitary sewer overflows release between 23,000 and 75,000 events annually, discharging billions of gallons of untreated sewage into waterways.

Many municipal sewer systems were built decades ago and have not received the investment needed to handle population growth and extreme weather events. Without significant infrastructure upgrades, communities face continued risk of catastrophic failures like the one now affecting the Arkansas River basin.

What This Means for You

If you're in the affected region:

• Do not swim, wade, fish, or allow pets to enter any water body covered by the advisory, including the 10 state wildlife areas listed by Colorado Parks and Wildlife.
• If you use well water near the Arkansas River, consider testing your water for bacterial contamination, as sewage spills can affect shallow groundwater.
• Monitor Colorado Parks and Wildlife announcements for updates on when the advisory will be lifted.

For general preparedness:

• Residents who rely on private wells near rivers or streams should understand that surface contamination events can migrate into groundwater, particularly in areas with porous soils.

How to Filter Bacteria From Drinking Water

Sewage contamination introduces biological pathogens that require specific treatment methods. Unlike chemical contaminants, bacteria and viruses are living organisms that must be either killed or physically removed from water to make it safe for consumption.

For bacterial contamination like E. coli, effective treatment options include UV purification systems, which destroy pathogens using ultraviolet light, and ceramic or membrane filtration with pore sizes small enough to block bacteria. Boiling water for at least one minute also kills most waterborne pathogens and remains the most accessible emergency option.

For households seeking permanent protection against bacterial contamination, UV systems certified to NSF/ANSI Standard 55 Class A provide whole-house or point-of-use treatment. Our guide to the best UV water purifiers covers systems that meet this standard. For broader filtration needs that address both biological and chemical contaminants, whole-house filtration systems can be configured with UV stages. Private well owners facing recurring contamination concerns may also benefit from understanding filtration options designed specifically for well water.