Well water in El Paso County: what the data actually shows
Falcon, Peyton, Black Forest, Calhan, Ellicott and Yoder. If you're on a well, every published average is useless to you — and the spread is the whole story.
The range is the finding
A groundwater quality study prepared for the Upper Black Squirrel Creek Ground Water Management District sampled 50 wells for hardness. The results ran from 7 mg/L to 510 mg/L — 0.4 to 29.8 grains per gallon — averaging about 111 mg/L, or 6.5 grains.
Read that again. On the same aquifer, in the same county, one well is softer than Colorado Springs city water and another is harder than Pueblo. Averages cannot help you. Your neighbor's system cannot help you.
Nitrate is the documented concern here
The same study identified nitrate as the contaminant of concern for the basin. Across 148 samples, most fell between 2.5 and 7.5 mg/L, but nine samples exceeded the 10 mg/L federal limit, with a maximum of 72 mg/L.
Nitrate in rural groundwater typically comes from septic systems, livestock and fertilizer. It has no taste, no smell and no color — there is no way to notice it without a test. Infants under six months are the population of concern; that's a conversation for your pediatrician, and it's a good reason to test a well before a baby comes home to it.
What else showed up
| Parameter | Result | Standard |
|---|---|---|
| Iron | Up to 2.8 mg/L; 3 of 43 samples above the secondary standard | 0.3 mg/L (secondary) |
| Total dissolved solids | 165–842 mg/L, average 287; 6 of 77 above standard | 500 mg/L (secondary) |
| Arsenic | Detected in 2 of 18 samples, maximum 0.01 mg/L | 0.01 mg/L |
| Fluoride | 0.3–1.0 mg/L | 2.0 mg/L (secondary) |
| Gross alpha | 0.3–3.6 pCi/L | 15 pCi/L |
Denver Basin bedrock wells are a different animal
If your well is drilled into the Dawson, Denver, Arapahoe or Laramie–Fox Hills aquifers — common in Black Forest, north Falcon and the Monument-area acreage — the U.S. Geological Survey's Denver Basin study found a different profile. Exceedances for total dissolved solids, sulfate, manganese and iron ran roughly 10 to 20 percent of samples. Nitrate, selenium and arsenic exceedances were 1 percent or less, and there were no uranium exceedances.
The standout was radon: concentrations exceeded the lower proposed drinking water standard in more than 90 percent of bedrock samples, though fewer than 5 percent exceeded the higher alternative standard.
What we test at a well appointment
- On site, in front of you: hardness, iron, nitrate, pH and total dissolved solids
- Recommended to a certified lab where warranted: full nitrate confirmation, bacteria, arsenic, uranium, radon and manganese
We'll tell you honestly which of those your situation justifies. A full lab panel on every well is overkill and we're not going to invoice you for theater. But if you have a new baby, a shallow well near a septic field, or staining that suggests iron and manganese, we'll say so.
Sources
El Paso County Groundwater Quality Study, Phase 1, prepared for the Upper Black Squirrel Creek Ground Water Management District. U.S. Geological Survey, Quality of Groundwater in the Denver Basin Aquifer System, Colorado, 2003–5, Scientific Investigations Report 2014-5051.
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All water systems referenced were reported by their utilities as meeting federal and state drinking water standards for the periods cited. Nothing in this article claims any public water supply is unsafe or out of compliance.