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Local water dashboard

Official source aggregation

Water quality in Thorne Bay, AK 99919

A source-transparent look at local hardness, associated public water systems, EPA compliance history, and the measurements that are—and are not—available for Prince Of Wales-Hyder Census Area.

2 reported benchmark flags
Primary matched system
Thorne Bay, City Of
Source water
Surface water
County
Prince Of Wales-Hyder Census Area
Profile updated

At a glance

What the current records say

Hardness

Soft

44.4 PPM · 2.6 GPG

Compliance screen

No active flag

0 active health-based records

Lead 90th percentile

0 mg/L

0% of action level

Utility match

1 system

Serves 470 people system-wide

Hardness meter

How hard is the water?

Soft

Estimated local hardness

USGS hardness classification scale

44.4 PPM

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

Parts per million

44.4

mg/L as CaCO₃ equivalent

Grains per gallon

2.6

1 GPG ≈ 17.1 PPM

What this means at home

At 44.4 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

6

Nearest site

62.4 mi

Observation range

Aug 23, 2017–Jul 22, 2025

Estimate confidence

Low

Median of the latest qualifying hardness observation at each nearby monitoring site. Nearest monitoring location: EULACHON R NR WRANGELL AK (Stream).USGS source documentation ↗

Regional context

Is 99919 typical?

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

Thorne Bay median

44 PPM

About the same

1 indexed ZIP readings · Range 44.4–44.4 PPM

Alaska median

83 PPM

39 PPM lower

18 indexed ZIP readings · Range 36.7–199 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 pass2 fail

Lead (PB90)

0 mg/L

Reported Dec 31, 2024

Copper (CU90)

1.45 mg/L

Reported Dec 31, 2024

Numerical coverage

3 comparable results

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

Lead (90th percentile)

Measured in mg/L

Pass

Local 0

EPA limit 0.015

Local level is 0% of the listed EPA limit.

Copper (90th percentile)

Measured in mg/L

Fail

Local 1.45

EPA limit 1.3

Local level is 112% of the listed EPA limit.

Total Haloacetic Acids (HAA5)

Measured in MG/L

Fail

Local 0.097

EPA limit 0.06

Local level is 162% 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
48
Health-based
1
Active health-based
0
Contaminant or ruleSystemStatusPeriod
Lead and Copper RuleAK2120216UnaddressedJan 1, 2026
Lead and Copper RuleAK2120216UnaddressedJul 1, 2025
TTHMAK2120216ResolvedApr 1, 2025through Jun 30, 2025
Interim Enhanced Surface Water Treatment RuleAK2120216ResolvedMar 1, 2025through Mar 31, 2025
Surface Water Treatment RuleAK2120216ResolvedMar 1, 2025through Mar 31, 2025
Interim Enhanced Surface Water Treatment RuleAK2120216ResolvedFeb 1, 2025through Feb 28, 2025
Surface Water Treatment RuleAK2120216ResolvedFeb 1, 2025through Feb 28, 2025
Surface Water Treatment RuleAK2120216ResolvedJan 1, 2025through Jan 31, 2025
Total Haloacetic Acids (HAA5)AK2120216ResolvedJan 1, 2025through Mar 31, 2025
Interim Enhanced Surface Water Treatment RuleAK2120216ResolvedJan 1, 2025through Jan 31, 2025
TTHMAK2120216ResolvedJan 1, 2025through Mar 31, 2025
Interim Enhanced Surface Water Treatment RuleAK2120216ResolvedDec 1, 2024through Dec 31, 2024
Surface Water Treatment RuleAK2120216ResolvedAug 1, 2024through Aug 31, 2024
Interim Enhanced Surface Water Treatment RuleAK2120216ResolvedAug 1, 2024through Aug 31, 2024
Surface Water Treatment RuleAK2120216ResolvedJan 1, 2024through Jan 31, 2024
NitrateAK2120216ResolvedJan 1, 2024through Dec 31, 2024
Interim Enhanced Surface Water Treatment RuleAK2120216ResolvedJan 1, 2024through Jan 31, 2024
Lead and Copper RuleAK2120216ResolvedJan 1, 2024through Dec 30, 2024
TTHMAK2120216ResolvedOct 1, 2023through Dec 31, 2023
Total Haloacetic Acids (HAA5)AK2120216ResolvedOct 1, 2023through Dec 31, 2023

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 Thorne Bay ZIP 99919 using 44.4 PPM nearby hardness and 3 reported measurement benchmarks.

1 match

Drinking water protection

Under-Sink Reverse Osmosis System

Copper (90th percentile), Total Haloacetic Acids (HAA5) have 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 Thorne Bay

Is tap water safe in Thorne Bay?+

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 44.4 PPM, or 2.6 grains per gallon, classified as soft. This is not a household tap measurement.

Do I need a water softener?+

There is no high-hardness trigger in this profile. Confirm with a tap test before buying equipment.