Utility-reported hardness
Unavailable
Ask your provider or test your tap
Local water dashboard
Official source aggregationWater quality in Hermosa, SD 57744
Regional hardness evidence, possible serving systems, EPA compliance history, and the measurements that are—and are not—available for Custer County.
1 active health-based record(s) across possible systems
- Largest possible serving system
- Hermosa-Old System
- Source water
- Groundwater
- County
- Custer County
- Profile updated
Your tap water
What does the utility report?
Match the utility name to your water bill. These results describe the utility’s water, not a test at your home. A ZIP can include several water systems.
Utility hardness unavailable in this index
Nearby river or groundwater samples cannot tell us the hardness coming out of your tap. Ask your water provider for total hardness as CaCO₃, or test it at home.
Find an official utility report →At a glance
What the current records say
EPA quarter 2026Q2
All possible systems
Review needed
1 active health-based record
Measurements by utility
Each result belongs to a specific system.
Utility match
4 systems
Serves 420 people system-wide
Match the name on your water bill
Your utility’s measurements and compliance records
These are possible serving systems. A record for one system does not apply to every home in this ZIP. Confirm your provider before interpreting a measurement or notice. Federal records can lag current utility notices.
EPA snapshot: 2026Q2. Historical window begins Jan 1, 2021.
Hermosa-Old System
SD4600154 · Groundwater · 420 people served system-wide
EPA SDWIS explicitly lists this ZIP in the system's served geography.
No active health-based record in this imported snapshot
Find this utility’s official report →Measurements (1)
An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.
Lead (90th percentile)
EPA SDWIS Lead and Copper Rule samples
- Reported level
- 0.007 mg/L
- Action level
- 0.015 mg/L
47% of the listed benchmark
Monitoring period: Jan 1, 2023 to Dec 31, 2023
Violation history (4)
| Rule | Status | Period |
|---|---|---|
| Revised Total Coliform Rule | Resolved | Apr 1, 2025 to Apr 30, 2025 |
| Combined Uranium | Resolved | Oct 1, 2021 to Dec 31, 2021 |
| Combined Radium (-226 and -228) | Resolved | Oct 1, 2021 to Dec 31, 2021 |
| Gross Alpha, Excl. Radon and U | Resolved | Oct 1, 2021 to Dec 31, 2021 |
Hermosa Water Users Association
SD4602180 · Groundwater · 108 people served system-wide
EPA SDWIS explicitly lists this ZIP in the system's served geography.
No active health-based record in this imported snapshot
Find this utility’s official report →Measurements (1)
An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.
Lead (90th percentile)
EPA SDWIS Lead and Copper Rule samples
- Reported level
- 0.002 mg/L
- Action level
- 0.015 mg/L
13% of the listed benchmark
Monitoring period: Jan 1, 2025 to Dec 31, 2025
Violation history (1)
| Rule | Status | Period |
|---|---|---|
| Lead and Copper Rule | Resolved | Jul 1, 2021 to Dec 23, 2021 |
Heartland Country Ranchettes
SD4602235 · Groundwater · 95 people served system-wide
EPA SDWIS explicitly lists this ZIP in the system's served geography.
No active health-based record in this imported snapshot
Find this utility’s official report →Measurements (1)
An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.
Lead (90th percentile)
EPA SDWIS Lead and Copper Rule samples
- Reported level
- 0.001 mg/L
- Action level
- 0.015 mg/L
7% of the listed benchmark
Monitoring period: Jan 1, 2025 to Dec 31, 2025
Violation history (0)
No record returned in this imported window. This is not a guarantee of tap-water safety.
North Hermosa Wud
SD4600329 · Groundwater · 40 people served system-wide
EPA SDWIS explicitly lists this ZIP in the system's served geography.
1 reported active health-based record(s) for this system
Find this utility’s official report →Measurements (1)
An action level is a regulatory trigger, not a pass/fail health boundary. A reported zero is the value in the source record and does not establish that lead is absent at your tap.
Lead (90th percentile)
EPA SDWIS Lead and Copper Rule samples
- Reported level
- 0.001 mg/L
- Action level
- 0.015 mg/L
7% of the listed benchmark
Monitoring period: Jan 1, 2025 to Jun 30, 2025
Violation history (3)
| Rule | Status | Period |
|---|---|---|
| Public Notice | Unaddressed | Dec 13, 2025 |
| Stage 1 Disinfectants and Disinfection Byproducts RuleHealth-based | Unaddressed | Feb 1, 2025 |
| Revised Total Coliform Rule | Resolved | Sep 1, 2024 to Sep 30, 2024 |
Hardness meter
What does nearby environmental evidence show?
688
PPM as CaCO₃
Very Hard
PPM
688
GPG
40.2
Regional environmental evidence
USGS hardness classification scale
688 PPM
Soft
0–60Moderate
61–120Hard
121–180Very hard
181+
0–60Moderate
61–120Hard
121–180Very hard
181+
Parts per million
688
mg/L as CaCO₃ equivalent
Grains per gallon
40.2
1 GPG ≈ 17.1 PPM
How to use regional evidence
These samples describe nearby environmental water. They cannot establish whether your tap water is soft or hard. Use a utility result or a tap test for appliance settings and treatment sizing.
USGS sites used
13
Nearest site
21.4 mi
Observation range
Jul 23, 2020–Nov 20, 2024
Regional evidence confidence
Moderate
Median of the latest source-type-aligned hardness observation at each monitoring site within 25 miles. Nearest monitoring location: 002S06E18BD (Burnpit well) (Well).USGS source documentation ↗Evidence tier: Regional environmental evidence. This value is not used as proof of the serving utility's treated-water hardness.
Regional context
Is 57744 typical?
These comparisons use other indexed ZIP estimates, not utility tap samples. They help show local context without replacing a household test.
Hermosa median
688 PPM
About the same1 indexed ZIP readings · Range 688–688 PPM
South Dakota median
688 PPM
About the same66 indexed ZIP readings · Range 8.3–1770 PPM
Evidence-first next steps
Confirm the problem before choosing treatment
This profile can help you ask the right question. It cannot select equipment for a property without a current result from the serving utility or the tap.
Confirm the serving system
ZIP boundaries and utility service areas do not perfectly match. Verify the system on a water bill before relying on system-wide records.
Read the current utility report
An active health-based record is present. Follow the utility's current notice and public-health instructions.
Find an official utility report →Test for the decision you face
Use a tap hardness test before sizing a softener. For health concerns, use a certified laboratory and the correct sampling protocol.
Convert your hardness test result →Frequently asked
Water questions for Hermosa
Is tap water safe in Hermosa?+
EPA ECHO reports 1 active health-based violation among the associated community water systems. Review the affected utility's current notice and Consumer Confidence Report.
How hard is the water?+
Utility-reported hardness is unavailable in this index. Regional samples do not establish tap-water hardness. Ask your provider or test your tap.
Do I need a water softener?+
Confirm hardness at your tap and consider actual scale or spotting before choosing treatment. Regional environmental values cannot determine whether you need a softener. A softener addresses hardness, not every contaminant.