Well water in Merrick County, Nebraska
In Merrick County, 60% of 488 tested well samples exceeded the EPA limit for nitrate (10 mg/L), based on public data from Nebraska Groundwater Quality Clearinghouse and USGS Water Quality Portal.
488 individual samples from 118 wells, 1951 to 2025. Data refreshed September 9, 2026.
What individual samples found
Each row summarizes every public sample for that contaminant inside Merrick County. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.
| Contaminant | Samples | Detected | Above limit | Median | Highest | Limit | |
|---|---|---|---|---|---|---|---|
| Nitrate 1951 to 2025 | 488 | 90% | 60% | 12.3 | 61.2 | 10 mg/L EPA limit |
Sampled fewer than 10 times, too few to summarize: Uranium (3), Fluoride (1), Manganese (4), Chloride (3), Radon (2), Iron (2), Sodium (1).
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What this means
The contaminants most often above their limit here are nitrate (60% of 488 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.
Manganese, Chloride, and Iron are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Merrick County
- Nitrate60% of 488 local samples were above the limit.
- Coliform bacteriaRecommended for every private well, every year.
- RadonMedian local reading is 300 pCi/L.
- FluorideDetected in 100% of local samples.
- ManganeseDetected in 100% of local samples.
- ChlorideDetected in 100% of local samples.
- IronDetected in 100% of local samples.
Treatment that fits the local profile
- Nitrate
- Point-of-use reverse osmosis; Anion exchange; Distillation
- Fluoride
- Point-of-use reverse osmosis; Activated alumina; Distillation
- Manganese
- Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
- Chloride
- Point-of-use reverse osmosis; Distillation
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Get your Merrick County water tested at home
A licensed local water treatment company tests your tap water in your home, walks you through the numbers, and quotes treatment only if something needs fixing. Free, about 30 minutes, no obligation. Tell us what you need and we match you with a company that serves Merrick County.
Common questions
How high is radon in well water in Merrick County?
The median radon level across 2 public samples in Merrick County was 300 pCi/L, with a high of 350 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Merrick County?
Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.
Sources
- Nebraska Groundwater Quality Clearinghouse: 484 samples in Merrick County. Groundwater quality results compiled by the Nebraska Department of Environment and Energy, University of Nebraska and Nebraska Department of Agriculture in the Groundwater Quality Clearinghouse, contributed by Natural Resources Districts and state agencies. Retrieved September 9, 2026.
- USGS Water Quality Portal: 20 samples in Merrick County. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.