If you are on a private well not served by a public water system, here is an excellent opportunity to get some baseline testing of your well water at no cost. This testing program is sponsored by the New Mexico Environment Department and the New Mexico Department of Health in cooperation with the City of Santa Fe’s Sangre de Cristo Water Division. The testing includes electrical conductivity, sulfate, pH, nitrate, fluoride, arsenic, iron, and manganese.
The most common health-risk contaminants in our area are arsenic, fluoride, nitrate, and uranium. These contaminants are all regulated in public water systems but there are no comparable regulations for private wells, for which owners are responsible. Nitrate does not occur naturally in this area and elevated nitrate levels are commonly a result of septic-system contamination. The other three members of the quartet are all naturally occurring and are reasonably predictable in geographic occurrence. Their effects on human health (particularly as related to elevated fluoride) are well known.
The highest occurrences of arsenic around Santa Fe occur in what is known as the “northwest quadrant.” Scientists have theorized that arsenic and other metals may come to or near the surface along the Rio Grande Rift, the fault zone through which the modern Rio Grande courses. Arsenic is common in the La Tierra area wells. There is also an area in Eldorado where elevated arsenic levels are commonly reported. Elevated fluoride levels are known from the greater Pojoaque area. Excessive fluoride is well documented to have an adverse effect on teeth and bones.
But the most predictable health-risk contaminant of the four, and one which is not included in this free testing program, and for which you should consider additional contaminant-specific lab testing, is naturally-occurring uranium. If you are a regular reader of this column, you will know that interpretation of uranium isotopes provides convincing evidence that there is no correlation between elevated uranium levels in well water east of the Rio Grande with anthropogenic activities at Los Alamos National Laboratory. Wells situated along the (granitic) Sangre de Cristo mountain front are uranium-prone. The other area where you should absolutely test for uranium in well water is Nambé, where numerous geologic factors (again, all unrelated to LANL) converge to result in the single greatest local concentration of elevated uranium levels — as high as 1,800 parts per billion. (The EPA’s maximum contamination level is 30 parts per billion.)
If you live in a geographic area mentioned above, I recommend that you take advantage of this free testing. It is not a complete test suite; but if nothing else, it will help raise your awareness of the water you are drinking. To find out more about this testing program and sample collection, visit the website https://nmtracking.org/media/cms_page_media/187/Santa%20Fe%20Flyer.pdf and bring your well-water sample to the Genoveva Chavez Community Center on April 22 or 23.
Stephen Wiman holds M.S. and Ph.D. degrees in geology and is a retired petroleum geologist. He also spent 11 years locally in contaminant occurrence and water remediation. He is a member of the City of Santa Fe’s Water Conservation Committee and serves on the Santa Fe Watershed Association board.