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Local water dashboard

Official source aggregation

Water quality in Doon, IA 51235

A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Lyon County.

1 reported benchmark flag
Primary matched system
Lyon-Sioux Rws-Doon
Source water
Groundwater
County
Lyon County
Profile updated

At a glance

What the current records say

Hardness

Very Hard

460.5 PPM · 26.9 GPG

Compliance screen

No active flag

0 active health-based records

Lead 90th percentile

0.004 mg/L

27% of action level

Utility match

2 systems

Serves 1,765 people system-wide

Hardness meter

How hard is the water?

Very Hard

Estimated local hardness

USGS hardness classification scale

460.5 PPM

Soft
0–59Moderate
60–120Hard
121–180Very hard
181+

Parts per million

460.5

mg/L as CaCO₃ equivalent

Grains per gallon

26.9

1 GPG ≈ 17.1 PPM

What this means at home

At 460.5 PPM, mineral scale can build up on fixtures and heating elements, reduce soap lather, and leave visible spotting. Hardness is primarily an aesthetic and appliance concern—not itself a tap-water safety rating.

USGS sites used

14

Nearest site

62 mi

Observation range

Aug 9, 2016–Apr 15, 2026

Estimate confidence

Low

Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: 29N 7E 35DC (D-J3) (Well).USGS source documentation ↗

Regional context

Is 51235 typical?

These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.

Doon median

461 PPM

About the same

1 indexed ZIP readings · Range 460.5–460.5 PPM

Iowa median

281 PPM

180 PPM higher

721 indexed ZIP readings · Range 182–834 PPM

EPA benchmark screen

Contaminant snapshot

Available numerical results from associated SDWIS community water systems, compared with the applicable action level or federal MCL. Federal measured-value coverage is incomplete.

1 pass1 fail

Lead (PB90)

0.004 mg/L

Reported Dec 31, 2024

Copper (CU90)

1.6 mg/L

Reported Jun 30, 1996

Numerical coverage

2 comparable results

Missing values remain blank; absence is not treated as a pass.

Lead (90th percentile)

Measured in mg/L

Pass

Local 0.004

EPA limit 0.015

Local level is 27% of the listed EPA limit.

Copper (90th percentile)

Measured in mg/L

Fail

Local 1.6

EPA limit 1.3

Local level is 123% of the listed EPA limit.

Share of EPA benchmark

100% line = listed limit

EPA SDWIS compliance

Reported violation history

Open EPA source documentation ↗
2026Q2
All records
1
Health-based
0
Active health-based
0
Contaminant or ruleSystemStatusPeriod
Revised Total Coliform RuleIA6015047ResolvedDec 1, 2022through Dec 31, 2022

No reported violation does not prove that every contaminant was tested or absent; SDWIS measured values are incomplete and lag state records.

Solutions matcher

Your personalized water action plan

Matched to Doon ZIP 51235 using 460.5 PPM nearby hardness and 2 reported measurement benchmarks.

2 matches

Scale protection

High-Capacity Whole House Water Softener

460.5 PPM is 4× the high-hardness trigger used by this matcher.

Designed to reduce scale on fixtures, water heaters, glassware, and plumbing throughout the home.

Compare whole-house systems

Drinking water protection

Under-Sink Reverse Osmosis System

Copper (90th percentile) has a measured benchmark flag or active health-based SDWIS record in this profile.

A certified multi-stage RO system targets a broader range of dissolved contaminants at the kitchen tap.

Explore under-sink filtration

Affiliate disclosure: we may earn a commission from qualifying purchases, at no added cost to you. Product matching is educational and does not replace certified water testing.

Frequently asked

Water questions for Doon

Is tap water safe in Doon?+

EPA ECHO shows no active health-based violation for the associated systems in this reporting snapshot. This does not prove every contaminant is absent; federal records can lag and household plumbing can change tap conditions.

How hard is the water?+

Nearby USGS observations produce an estimate of 460.5 PPM, or 26.9 grains per gallon, classified as very hard. This is not a household tap measurement.

Do I need a water softener?+

At 460.5 PPM, a correctly sized whole-house softener can reduce scale and hard-water spotting. It does not replace contaminant filtration.