Lead in well water
1in4
private wells tested in New Madrid County, Missouri had lead above the limit, the highest share of any county, according to Missouri DHSS private well sampling summaries.
Lead in well water almost always comes from household plumbing and older fixtures, not the aquifer, and corrosive (low pH) well water makes it worse. There is no safe level for children; it harms brain development.
- EPA limit
- 15 ug/L (EPA action level (40 CFR 141.80); 2024 rule lowers to 10 ug/L in 2027)
- Missouri level
- 15 ug/L
- CAS number
- 7439-92-1
Check your lead number
Type the value from your lab report. It is compared to the EPA limit, the same way the full interpretation does it.
Test your own well for lead
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says.
Systems that remove lead
Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For lead
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For lead
Acid neutralizing filter
whole-house, at the point of entry, about $1,200
Raises pH so plumbing stops leaching lead and copper.
For lead
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
Rather have it installed and sized for your well? Book a free in-home water test with a licensed local company.
Where lead is worst, by homeowner tests
Counties ranked by the share of private wells above the state guidance level in tests homeowners sent to the state lab. Shares combine town summaries, weighted by wells tested.
| County | Above state level | Wells tested | Highest |
|---|---|---|---|
| New Madrid County, Missouri | 112 | ||
| Venango County, Pennsylvania | 80 | 180 ug/L | |
| Hickory County, Missouri | 31 | ||
| York County, Pennsylvania | 211 | 201 ug/L | |
| Coos County, New Hampshire | 346 | 721 ug/L | |
| Cheshire County, New Hampshire | 375 | 205 ug/L | |
| Jefferson County, Pennsylvania | 77 | 192 ug/L | |
| Forest County, Pennsylvania | 54 | 171 ug/L | |
| Carbon County, Pennsylvania | 48 | 108 ug/L | |
| Clarion County, Pennsylvania | 95 | 238 ug/L | |
| Sullivan County, New Hampshire | 543 | 892 ug/L | |
| Wyoming County, Pennsylvania | 46 | 170 ug/L | |
| Elk County, Pennsylvania | 40 | 242 ug/L | |
| Hillsborough County, New Hampshire | 1,580 | 31,200 ug/L | |
| Beaver County, Pennsylvania | 48 | 56 ug/L |
By individual samples
Counties with at least 30 individual samples in public monitoring data, against the EPA limit.
| County | Above EPA limit | Samples | Detected | Median |
|---|---|---|---|---|
| Ramsey County, North Dakota | 80 | 88% | 0 ug/L | |
| Eddy County, New Mexico | 94 | 90% | 0.51 ug/L | |
| Meade County, Kentucky | 63 | 49% | 0 ug/L | |
| Vernon County, Louisiana | 39 | 69% | 0.294 ug/L | |
| Benson County, North Dakota | 208 | 77% | 0 ug/L | |
| St. Francois County, Missouri | 113 | 86% | 1.05 ug/L | |
| Marion County, Oregon | 103 | 100% | 4.74 ug/L | |
| Fulton County, Illinois | 255 | 60% | 0 ug/L | |
| Ashland County, Wisconsin | 50 | 76% | 6.5 ug/L | |
| Juab County, Utah | 37 | 49% | 0 ug/L | |
| Westchester County, New York | 72 | 85% | 1.17 ug/L | |
| Rice County, Minnesota | 107 | 33% | 0 ug/L | |
| Chouteau County, Montana | 32 | 88% | 0 ug/L | |
| Shoshone County, Idaho | 7,181 | 99% | 3 ug/L | |
| Tillamook County, Oregon | 75 | 100% | 2.05 ug/L |
How to test
Use a state-certified lab and a proper sampling bottle; hardware-store strips cannot measure lead at the levels that matter. Collect from the kitchen tap before any treatment, and again after treatment if you install it.
How to treat
- Point-of-use reverse osmosis
- Certified lead-removal carbon filter
- Neutralizing filter to raise pH and stop leaching