Lewiston Tap Water Quality Report
Lewiston's water has 5 contaminants above EPA MCLGs. We recommend using a certified water filter.
No single water system serves most of Lewiston (34,693 residents, Census 2024 estimate). Its large systems are LEWISTON CITY OF (EPA counts 15,001 people served, about 43% of Lewiston's population); PUD #1 OF ASOTIN COUNTY (EPA counts 22,583 people served, about 65% of Lewiston's population); LEWISTON ORCHARDS IRRIGATION DIST (EPA counts 20,000 people served, about 58% of Lewiston's population). EPA's counts may include people served outside Lewiston, so each share is at most that. Check which one bills you: each system's figures are shown separately below.
- LEWISTON CITY OF: 152 contaminants tested, 5 above EPA MCLGs; health-based violations since 2020: 0
- PUD #1 OF ASOTIN COUNTY: 137 contaminants tested, 2 above EPA MCLGs; health-based violations since 2020: 0
- LEWISTON ORCHARDS IRRIGATION DIST: 114 contaminants tested, 2 above EPA MCLGs; health-based violations since 2020: 0
Other systems listed for Lewiston with results above guidelines: RED PHEASANT WATER COMPANY LLC (3 above guidelines), EATON MOBILE HOME COURT (3 above guidelines), PUD #1 OF ASOTIN COUNTY (2 above guidelines), LEWISTON ORCHARDS IRRIGATION DIST (2 above guidelines)
Water systems
3 large systems
Residents (Census 2024)
34,693
Health-based violations since 2020
0
LEWISTON CITY OF. EPA SDWA violation data as of Q2 2026 (downloaded 2026-07-09).
Latest sample on file
May 2022 · LEWISTON CITY OF
Utilities publish newer results in their annual water quality report (Consumer Confidence Report).
Is Lewiston Tap Water Safe to Drink?
We strongly recommend using a certified water filter to reduce exposure: Lewiston's water has 5 contaminants above EPA health-based guidelines. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Lewiston's water.
LEWISTON CITY OF, Lewiston's water system, serves 15,001 people. 6 other systems are listed for Lewiston. Each system's results are listed under its own name, never added to LEWISTON CITY OF's. Water quality testing is conducted regularly and reported to the EPA. The latest sample on file for LEWISTON CITY OF is from May 2022.
In EPA's 2023–2026 UCMR 5 testing, LEWISTON CITY OF measured lithium at up to 43.8 µg/L, which EPA counts as above its health reference level of 10 µg/L. That level is a screening value EPA uses to decide what to study further, not a legal limit, and this result does not change this page's water-quality summary.
Boil water advisories are issued by water systems and state agencies, and they change from day to day. Boil water advisories in Idaho
Lewiston Water Service Areas
What these numbers actually mean for Lewiston, ID
We read Lewiston, ID’s published record and send you a short report — which findings warrant a decision, which to ignore, and what to do about it. Including when the answer is nothing.
- 5 contaminants above EPA MCLGs and 10 contaminants with an EPA health goal detected in some samples (no level on file)
- 140 results on file
- 23 PFAS compounds on record
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Recommended Water Filters for Lewiston
Based on Lewiston's water quality data, these NSF-certified filters are recommended to remove contaminants above EPA MCLGs.
Culligan
ZeroWater
NSF Certified:
Flow Rate
1.9 gpm
Daily Production
1 gpd
Highlights:
- Compact design
- Easy to set up
- Affordable
- NSF-42, NSF-53, NSF-401 certified
Removes 19 contaminants:
+14 more
Strontium, Molybdenum, Fluoride, Uranium, Lead, Total PFAS, Chlorine, 25, Phosphorus, Bicarbonate, Calcium, Carbonate, Magnesium, Sodium
AquaTru
Classic
NSF Certified:
Flow Rate
0.04 gpm
Daily Production
600 gpd
Highlights:
- Best overall contaminant reduction score
- Most performance certifications
- Lifetime warranty
- NSF-42, NSF-53, NSF-58, NSF-401 certified
Removes 23 contaminants:
+18 more
Molybdenum, Barium, Chlorine, Arsenic, 83+ contaminants, Calcium, Chloride, Copper, Magnesium, Nitrate, Phosphorus, Sodium, Sulfate, Total Dissolved Solids, Zinc, Total THMs, Chloroform, Nitrate (as N)
AquaTru
Carafe
NSF Certified:
Flow Rate
0.3 gpm
Daily Production
4 gpd
Highlights:
- Verified PFAS reduction
- Glass collection vessel
- Plug-and-play installation
- NSF-53, NSF-42, NSF-58, NSF-401, NSF-372 certified
Removes 17 contaminants:
+12 more
Arsenic, 83+ contaminants, Copper, Total THMs, Chloroform, Chloride, Sulfate, Nitrate (as N), Molybdenum, Barium, Strontium, Uranium
Waterdrop
A1
NSF Certified:
Flow Rate
0.042 gpm
Daily Production
130 gpd
Highlights:
- Built-in UV sterilization
- Easy maintenance with filter change reminders
- NSF-58 certified
- Hot and cold water dispensing
Removes 12 contaminants:
+7 more
Molybdenum, Sulfate, Strontium, Phosphorus, Chlorine, Barium, Nitrate
Verify Your Water Quality with Independent Testing
With 5 contaminants above EPA MCLGs and 10 contaminants with an EPA health goal detected in some samples (no level on file), independent laboratory testing provides a second opinion and can track changes over time.
SimpleLab
Advanced Home Water Test
$269
Comprehensive water analysis testing over 200 contaminants including bacteria, heavy metals, and chemical compounds.
Tap Score
Advanced Microplastics Test
$829
Cutting-edge testing for microplastics particles in drinking water using advanced laboratory techniques.
Tap Score
Haloacetic Acids (HAA9) Test
$275
Tests for disinfection byproducts formed when chlorine reacts with organic matter in water treatment.
With 5 contaminants above health guidelines, you may want to explore water purification options. Learn how to make distilled water at home for applications like humidifiers, CPAP machines, and baby formula.
What Lewiston's water readings can explain
Utility-reported data for Lewiston includes manganese, turbidity and a chlorine-based disinfectant — the readings behind these common tap water questions. We publish a city-level hardness figure for Lewiston, resolved from its water systems where they report one and estimated from county sampling where they do not. Each page starts with the hot-tap and cold-tap check, then shows what your own water system reported.
On a private well near Lewiston? Public-water results do not apply to private wells. See Nez Perce County well water testing and USGS risk data — modeled arsenic, nitrate, and the tests to run.
Water softener cost and installation in Lewiston
Lewiston's tap water has an estimated 7.1 grains per gallon (122.0 mg/L, county sampling in Nez Perce County) — hard on the USGS scale, the range where scale on fixtures and appliances is the usual complaint.
Water softener cost for an estimated 7.1 gpg water in Lewiston — equipment and local installation labour for your ZIP code, with the sizing arithmetic shown in full. For the national picture first, read what a water softener costs — equipment, installation labour and ten-year ownership, each separated out. For Idaho as a whole, read water softener cost in Idaho — priced against the plumber wage published for the state.
Frequently Asked Questions About Lewiston Tap Water
Lewiston's water has 5 contaminants above EPA MCLGs. We strongly recommend using a certified water filter to reduce exposure to these contaminants. Check our filter recommendations below for NSF-certified options that can remove the specific contaminants found in Lewiston's water.
Spotted something off on this page?
Residents keep our data honest.
This form corrects our data; it does not reach LEWISTON CITY OF. For a problem with your water now (discolored water, no water, low pressure, a leak), contact LEWISTON CITY OF directly.
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