Tapcensus

Wales Water System

Community water system in Wales, Nome Census Area, Alaska, serving 173 people from ground water. 9 rules violated in the past three years, 2 still unresolved. Owned by tribal government.

People served 173 ground water
Rules violated, past 3 years 9 one rule can carry several violations
Unresolved 2 rules currently in violation, EPA data updated Oct 7, 2026
Quarters with violations 12 of the last 12 quarters

Quarterly compliance history

SQ3
2023
SQ4
2023
SQ1
2024
SQ2
2024
SQ3
2024
SQ4
2024
SQ1
2025
SQ2
2025
SQ3
2025
SQ4
2025
SQ1
2026
SQ2
2026
UQ3
2026
–No violation identified VViolation identified SSerious violator (EPA enforcement priority) UUndetermined Oldest quarter on the left. Quarters 1 to 12 are the twelve most recent official quarters at EPA's last data refresh; the 13th is the quarter in progress at that refresh, which EPA reports as undetermined.

Currently in violation

EPA data updated Oct 7, 2026

Stage 2 Disinfectants and Disinfection Byproducts Rule

Monitoring and Reporting

4 violations, Oct 2024 to Dec 2026 · 2 contaminants

EPA rule code 220 · 4 violations recorded, 2 still open

Monitoring and Reporting: 4 violations, 2 still open, Oct 2024 to open. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

Contaminants on the record: Total Haloacetic Acids (HAA5), TTHM (Total Trihalomethanes).

Lead and Copper Rule

Monitoring and Reporting

3 violations, Jan 2024 to open

EPA rule code 350 · 3 violations recorded, 2 still open

Monitoring and Reporting: 3 violations, 2 still open, Jan 2024 to open. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

What the rule requires: The 1991 LCR uses action levels rather than MCLs: if the 90th percentile of high-risk tap samples exceeds 15 ppb lead or 1.3 mg/L copper, the system must take escalating corrective actions. Violations typically indicate failure to maintain adequate corrosion control — the treatment that keeps lead from leaching out of pipes, solder, and fixtures.

About this rule

Also violated in the past three years

Jul to Sep 2023 to Jul to Sep 2026

Revised Total Coliform Rule

Monitoring Violation

5 violations, May 2024 to May 2026

EPA rule code 111 · 5 violations recorded

Monitoring Violation: 5 violations, May 2024 to May 2026. The system did not complete required monitoring. This does not show that a contaminant was found.

What the rule requires: The 2013 RTCR (effective 2016) replaced the original TCR. It triggers automatic E. coli testing whenever total coliform is found. A single E. coli-positive sample is an acute MCL violation. It also requires systems exceeding 5% total coliform-positive samples to conduct a formal assessment and correct any deficiencies, helping prevent contamination before it escalates.

About this rule

Ground Water Rule

Monitoring and ReportingTreatment Technique Violation Health-based

4 violations, Jun 2022 to Jun 2026 · 2 contaminants

EPA rule code 140 · 4 violations recorded, 3 health-based

Treatment Technique Violation, health-based: 3 violations, Jun 2022 to Jan 2024. The system did not carry out a required treatment process or corrective action.

Monitoring and Reporting: 1 violation, Jun 2026 to Jun 2026. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

Contaminants on the record: Groundwater Rule (GWR), E. coli (Escherichia coli).

Groundwater Rule (GWR), health effects: Protects against enteric viruses, which can contaminate groundwater via cracked well casings, failing septic systems, or animal waste. Viruses persist longer in groundwater than in surface water. Hepatitis A and norovirus are the primary pathogens of concern. Limit: Treatment technique: 4-log virus treatment required when source water has fecal indicators or significant sanitary deficiencies

E. coli (Escherichia coli), health effects: Most E. coli strains cause diarrheal illness. Some strains (e.g., O157:H7) produce toxins causing severe bloody diarrhea, hemolytic uremic syndrome (HUS — a form of kidney failure), and death — especially in children under 5 and the elderly. Even non-pathogenic strains in drinking water indicate that disease-causing organisms may also be present. Limit: Zero (one confirmed positive sample = acute MCL violation)

Stage 1 Disinfectants and Disinfection Byproducts Rule

Monitoring and Reporting

1 violation, Apr 2026 to May 2026 · Chlorine (MRDL)

EPA rule code 210 · 1 violation recorded

Monitoring and Reporting: 1 violation, Apr 2026 to May 2026. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

Contaminant on the record: Chlorine (MRDL).

Volatile Organic Chemicals

Monitoring and Reporting

21 violations, Jan 2024 to Jul 2025 · 21 contaminants

EPA rule code 310 · 21 violations recorded

Monitoring and Reporting: 21 violations, Jan 2024 to Jul 2025. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

Contaminants on the record: 1,2,4-Trichlorobenzene, cis-1,2-Dichloroethylene, Xylenes, Total, Dichloromethane (Methylene Chloride), o-Dichlorobenzene, p-Dichlorobenzene, Vinyl Chloride, 1,1-Dichloroethylene, trans-1,2-Dichloroethylene, 1,2-Dichloroethane, 1,1,1-Trichloroethane, Carbon Tetrachloride, 1,2-Dichloropropane, Trichloroethylene (TCE), 1,1,2-Trichloroethane, Tetrachloroethylene (PCE), Chlorobenzene, Benzene, Toluene, Ethylbenzene, Styrene.

Nitrate Rule

Monitoring and Reporting

1 violation, Jan 2024 to Jul 2025

EPA rule code 331 · 1 violation recorded

Monitoring and Reporting: 1 violation, Jan 2024 to Jul 2025. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

What the rule requires: Nitrate (NO₃) is the most common chemical contaminant in US groundwater, entering from fertilizers, septic systems, and animal waste. It is odorless and tasteless — the only way to know if it's present is to test.

About this rule

Radionuclides and Revised Rad Rule

Maximum Contaminant Level ViolationMonitoring and Reporting Health-based

13 violations, Jul 2023 to Jun 2026 · 3 contaminants · 2 measured values

EPA rule code 340 · 13 violations recorded, 2 health-based

Maximum Contaminant Level Violation, health-based: 2 violations, Oct 2023 to Sep 2025. A sample exceeded the maximum contaminant level EPA allows in drinking water.

Monitoring and Reporting: 11 violations, Jul 2023 to Jun 2026. The system did not complete required monitoring, or did not report the results on time. This does not show that a contaminant was found.

Measured
Combined Uranium 37 UG/L

Limit 30 UG/L · Jul to Sep 2025

Combined Uranium 40 UG/L

Limit 30 UG/L · Oct to Dec 2023

Contaminants on the record: Gross Alpha, Excl. Radon and U, Combined Uranium, Combined Radium (-226 and -228).

Gross Alpha, Excl. Radon and U, health effects: Alpha-emitting radionuclides accumulate in bone and soft tissue, delivering sustained internal radiation doses that increase lifetime cancer risk. There is no established safe threshold for ionizing radiation. Individual contributors such as radium-226 and polonium-210 have their own MCLs; gross alpha serves as a cost-effective screening tool that triggers more specific radionuclide analysis when exceeded. Limit: 15 pCi/L (excluding radon and uranium)

Combined Uranium, health effects: Uranium poses both radiological and chemical health risks. Chronic exposure is primarily associated with kidney damage due to its chemical toxicity as a heavy metal. The radiological risk — increased cancer probability — is also present but secondary to the nephrotoxic concern at drinking water concentrations. There is no safe threshold for radiation exposure. Limit: 0.030 mg/L (30 µg/L)

Combined Radium (-226 and -228), health effects: Radium is a bone-seeking radionuclide that accumulates in skeletal tissue after ingestion. Long-term exposure increases the risk of bone cancer and leukemia. There is no safe threshold for ionizing radiation — the MCL is set at a level balancing risk reduction with treatment feasibility. Children are particularly vulnerable due to higher rates of bone growth and calcium uptake. Limit: 5 pCi/L (combined Ra-226 and Ra-228)

Public Notice Rule and Revised PN Rule

Other Violation

3 violations, Apr 2024 to Dec 2024 · Public Notification Rule

EPA rule code 410 · 3 violations recorded

Other Violation: 3 violations, Apr 2024 to Dec 2024. A requirement other than monitoring, reporting, or a contaminant limit, such as public notice or the annual water quality report.

Contaminant on the record: Public Notification Rule.

Lead and copper at the tap

The 90th percentile of the tap samples the system collected in its latest monitoring period, against EPA's action level. Levels vary between homes.

Lead 0.0017 mg/L

Action level 0.015 mg/L · Jan 2023 to Dec 2025

Copper 1.64 mg/L

Action level 1.3 mg/L · Jul to Dec 2007

About this data

Rules violated and the list above come from EPA's SDWIS violation records, one row per violation and contaminant, grouped by the rule each row belongs to. A violation counts when its non-compliance period ended on or after Jul 1, 2023, the start of the thirteen quarters ECHO's three-year figures cover, or is still open; it is unresolved when it was still open at EPA's data refresh on Oct 7, 2026. EPA's rule code 500, "Not Regulated", is left out, as in ECHO's counts. Each rule's violation count is EPA's, and one rule can carry several: a missed monitoring round for a group of contaminants is one violation per contaminant and period. Category names are EPA's violation categories.

ECHO's own summary count of rules violated agrees with this grouping for 98.8% of active systems nationally, and its count of rules being violated for 98.7%; where they differ, the figures here follow the rows listed.

A measured value shown with a rule is the sample result EPA recorded with that violation (SDWIS viol_measure), against the limit EPA recorded on the same row (state_mcl), both in EPA's unit as written; violations without a recorded value, such as missed monitoring, show none. Other measured contaminant levels are not part of this record; each system publishes them in its annual Consumer Confidence Report.

Lead and copper are the newest 90th-percentile results in EPA's SDWA data download (LCR_SAMPLES, codes PB90 and CU90): for each monitoring period a system reports the 90th-percentile value of its tap samples, which EPA compares with its action level of 0.015 mg/L for lead and 1.3 mg/L for copper (40 CFR 141.80). A result is not a measurement of any one tap.

Service area from EPA's Public Water System Service Area Boundaries dataset: Random Forest method, Federal agency. The system's location is the centre of the service area EPA publishes for the system.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Alaska records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet.