Water quality tests at 60 wells across the Animas Valley showed about half had elevated levels of contamination.
San Juan Basin Public Health plans to test 100 wells as part of its long-term water-quality monitoring work in the Animas River Basin. The monitoring is funded by the state, Surface and Drinking Water Manager Brian Devine said.
“From the perspective of public health, how are people going to be exposed to water-quality problems? Well, it’s through their drinking water. That’s the actual biggest risk. So, we fought to get this project in the monitoring,” he said.
The work started in October, and it likely will finish in April.
Tests have not revealed any geographic patterns in the contamination, which emphasizes the importance of having individual wells tested, a news release said.
Privately owned wells are not regulated by any agency, and their quality is the responsibility of the owner.
Iron and manganese were the most common contaminants, present in about 40 to 50 percent of the wells. These metals will harm appliances, plumbing and stain fixtures, but they are not generally a health concern, Devine said. Residents also can see and smell high levels of iron.
“Everyone that has high iron knows it already,” he said.
Three wells had levels of lead or arsenic above the national health standards, and most of the wells had detectable levels of both metals, a news release said.
A third of the wells had coliform bacteria and three wells had E. coli. It is possible bacteria was present in the outdoor spigot where the sample was collected, and not the wells themselves.
Because ingesting bacteria is the quickest way to get sick from your drinking water, the health department gives well owners information on how to kill the microscopic bugs.
While E. coli is the most-concerning, coliform bacteria can indicate that other families of bacteria are present, Devine said.
No link was found between bacteria in wells and animal pens or manure, but health officials recommend well sites be kept clean.
Devine also found low levels of nitrates and chemicals that come from fertilizer, elevated fluoride and high pH in wells.
Most wells tested had some kind of water-filtration system, but many didn’t know what contaminants it filtered nor had they done maintenance on them.
“They are obviously very high use, and like every high use product it requires maintenance,” he said.
The testing stemmed from Environmental Protection Agency findings.
After the Gold King Mine spill, the federal agency tested private wells for metals, and tests found between 5 to 10 percent of the wells had elevated levels of metals. The health department doesn’t believe the spill changed metal levels in wells because the findings were in line with historic measurement, Devine said.
“Their tests were a mix of at-the-tap, at-the-wellheads or in between. It was really useful for telling us that we needed to be aware of this issue and follow up on it, but it wasn’t very useful for drawing any conclusions about water in the valley,” he said.
It is possible more testing might find some geographical correlation between types of contamination.
Devine used La Plata County maps to identify homeowners likely not on regulated water systems and sent out letters to invite them to participate in the free study.
A few available slots remain in the study, and those who are interested in having a well tested can call 335-2052.
Well water quality is variable throughout La Plata County, and Devine recommends well owners test their water once a year because water contaminants change, and not all filters address all issues.
Well water tests can cost $100 to $200.
mshinn@durangoherald.com
