For over a decade, residents of Austin's Colony, a neighborhood in an unincorporated area of southeast Austin outside of the city service area, have voiced concern about their tap water's intermittent discoloration and extreme hardness.
In a recent study published in the journal PLOS Water , researchers from The University of Texas at Austin took a closer look at the water quality from April 2024–October 2025, working with residents and the community group PODER to collect information and water samples from across the neighborhood.
The study revealed evidence of contamination, with some samples exceeding state regulatory standards for lead, arsenic and other contaminants. However, the contamination appears to happen after the water — which is supplied from three different sources by a private water company — is mixed together in the neighborhood's water system.
This suggests that interactions between the neighborhood's water sources and its plumbing could be causing contamination to gradually build up and sporadically slough off into the water before it hits the faucet.
"If you test the source, it's going to be fine in terms of contaminants," said the study's lead author David Bahamón-Pinzón, a research coordinator at the UT Jackson School of Geosciences. "The problem is when you look at the household [tap water]."
The researchers analyzed 81 water samples from the neighborhood, with most coming from eight households. Three of these samples were discolored, and eight of them — including all three of the discolored samples — had levels of various contaminants, including lead and arsenic that exceeded state standards.
Of the eight total samples with high contaminant levels, three of them had lead levels that exceeded the Texas standard of 15 parts per billion (ppb), and another three had levels that exceeded the World Health Organization's standard of 10 ppb.
The water for Austin's Colony comes from three sources: wells in the Austin's Colony neighborhood, wells in the city of Manor, and wells that tap the Carrizo-Wilcox Aquifer in Burleson County. At their sources, the water meets regulatory standards based on data from the Texas Commission on Environmental Quality. The water also met state standards at the neighborhood's water entry points.
But once in the neighborhood's plumbing system, the water from these different sources mix together. The researchers determined that most households receive a mix of two or three water sources depending on where they are located. They also found that the lead, manganese and iron contaminants were suspended as particles in the water, which suggests corrosion of pipeline buildup.
This process of water mixing, contaminant buildup and corrosion could explain the sporadic nature of the discolored water that residents have been experiencing for years.
In addition to the contaminants, the researchers also determined that Austin's Colony and Manor wells are sources of hard water, with both having high calcium and magnesium levels. Hard water issues could be mitigated by reducing water use from these sources and using more water from the Carrizo-Wilcox Aquifer, which has lower levels of these elements.
The researchers found that household water treatment systems were effective at removing the contaminants and the minerals associated with hard water. However, these systems can be expensive, and many households lack them. Out of the 100 households surveyed in the study, 70 said they had experienced discolored water, and 71 have a water treatment system. The survey captured only a small slice of the nearly 8,000 people who live in Austin's Colony.
Resident Bianca Guerrero, who assisted with sample collection and community organizing, said the research helps validate the water issues that she and other community members have been dealing with for years.
"With this paper finally coming out, one that's academic and peer-reviewed, we finally have something that carries some weight," she said. "Our words and what we're going through should carry weight, but we're not going to get anywhere unless we have something that's based on science."
Bahamón-Pinzón said that Austin's Colony residents were critical collaborators throughout the research process, from sample collection to community involvement.
"The community members are not just a research subject, but they're also participants. They play an active role in the process," he said. "This research is a participatory approach in collaboration between the university, the community organization, and the residents."
The study was conducted as part of the UT BRIDGES program, which is based out of the Jackson School's Environmental Science Institute and brings together UT faculty members and Austin community members for research projects that can benefit local residents.
Susana Almaza, the director of PODER, said that the community group initially tried to conduct their own water sampling, but that it proved to be too expensive. She said that working with UT BRIDGES has helped the community get data that can help inform action.
"The community can now take that research and move to the next step, whether that's looking at legislation, looking at policy," she said. "We have something that we can take on and move forward."
Study co-author Kelly Haragan, the director of the Environmental Clinic at the UT School of Law, said that she and students involved with the clinic are helping community members explore different strategies.
"There are obvious gaps in the regulatory system where it's not protective enough in situations like this," she said. "There are different avenues for addressing the problem — from filing complaints, to drafting legislation, to litigation — and the community will have to decide which they want to pursue."
The research was funded by the National Science Foundation, the Cynthia and George Mitchell Foundation, and the Jackson School of Geosciences.
