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Community Water System · PWS SD4600411

Timber Lake

Timber Lake, South Dakota 57656 - drinking water served from groundwater sources to 499 people, tracked in EPA SDWIS and UCMR5.

499
People served
207
EPA violations
2
Health-based
Untested
UCMR5 result

The verdict

EPA records 207 drinking-water violations at Timber Lake, 1% of them health-based - above the South Dakota per-system average.

207
Total EPA violations on record
1%
Health-based (MCL / treatment failure)
499
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Timber Lake

Timber Lake is a local-owned community water system that delivers drinking water to 499 residents in Timber Lake, South Dakota (Dewey County) through 210 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 207 total violations for this system , of which 2 (1%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 202 monitoring and reporting violations are on file. The most recent violation on record dates to 2012.

The most frequently cited contaminant at this system is Vinyl chloride, recorded in 4 violations (MR). This system has not yet been sampled under EPA's UCMR5 PFAS monitoring program, so no PFAS detection data is available here.

Across South Dakota, EPA tracks 654 public water systems serving 915,901 people, with 56,254 cumulative violations and 8,399 health-based violations on record. About 92% of systems in the state carry at least one violation, and state-wide the average per system is 86 violations. Statewide, 42 of 49 UCMR5-tested systems have reported PFAS detections (85.7%).

Timber Lake's 207 violations sit above the South Dakota average.

All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

Population Served
499
Total Violations
207
Health-Based Violations
2
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Local
Connections
210
County
Dewey
School/Daycare
No
MCL Violations
0
Monitoring Violations
202
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Vinyl chloride MR 4 2012
1,1,1-Trichloroethane MR 4 2012
Tetrachloroethylene MR 4 2012
DICHLOROMETHANE MR 4 2012
1,2,4-Trichlorobenzene MR 4 2012
Xylenes, Total MR 4 2012
1,1-Dichloroethylene MR 4 2012
Carbon tetrachloride MR 4 2012
Styrene MR 4 2012
o-Dichlorobenzene MR 4 2012
1,2-Dichloropropane MR 4 2012
1,2-Dichloroethane MR 4 2012
Toluene MR 4 2012
LASSO MR 4 2011
Heptachlor epoxide MR 4 2011
Atrazine MR 4 2011
Benzo(a)pyrene MR 4 2011
Di(2-ethylhexyl) phthalate MR 4 2011
Endrin MR 4 2011
HEXACHLOROBENZENE MR 4 2011
BHC-GAMMA MR 4 2011
Chlordane MR 4 2011
Toxaphene MR 4 2011
Simazine MR 4 2011
2,4,5-TP MR 4 2011
Pentachlorophenol MR 4 2011
Picloram MR 4 2011
1,2-DIBROMO-3-CHLOROPROPANE MR 4 2011
ETHYLENE DIBROMIDE MR 4 2011
Glyphosate MR 4 2011

Verify This Water System

The figures above are aggregated from EPA's public databases. To verify the underlying records, or to file a complaint, request a Consumer Confidence Report, or check current monitoring status, go directly to the federal and state regulators that enforce the Safe Drinking Water Act for Timber Lake.

Federal Source of Truth

EPA SDWIS, Federal Reports

EPA's Safe Drinking Water Information System (SDWIS) holds the federal compliance record for every regulated public water system. Open the system-level report by PWS ID:

View PWS ID SD4600411 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

South Dakota Drinking Water Authority

South Dakota's primacy agency administers the Safe Drinking Water Act locally. Search EPA SDWIS for the current state contact, or use the state's public health or environment department portal.

Find SD regulator via EPA SDWIS

Violation Timeline

Each row links to the EPA SDWIS public record for verification. Cross-reference the contaminant code on EPA's federal report to see violation dates, return-to-compliance status, and enforcement actions.

Year (latest) Contaminant Category Count EPA Record
2012 Vinyl chloride MR 4 SDWIS / SD4600411 / 2976
2012 1,1,1-Trichloroethane MR 4 SDWIS / SD4600411 / 2981
2012 Tetrachloroethylene MR 4 SDWIS / SD4600411 / 2987
2012 DICHLOROMETHANE MR 4 SDWIS / SD4600411 / 2964
2012 1,2,4-Trichlorobenzene MR 4 SDWIS / SD4600411 / 2378
2012 Xylenes, Total MR 4 SDWIS / SD4600411 / 2955
2012 1,1-Dichloroethylene MR 4 SDWIS / SD4600411 / 2977
2012 Carbon tetrachloride MR 4 SDWIS / SD4600411 / 2982
2012 Styrene MR 4 SDWIS / SD4600411 / 2996
2012 o-Dichlorobenzene MR 4 SDWIS / SD4600411 / 2968
2012 1,2-Dichloropropane MR 4 SDWIS / SD4600411 / 2983
2012 1,2-Dichloroethane MR 4 SDWIS / SD4600411 / 2980
2012 Toluene MR 4 SDWIS / SD4600411 / 2991
2012 cis-1,2-Dichloroethylene MR 4 SDWIS / SD4600411 / 2380
2012 Ethylbenzene MR 4 SDWIS / SD4600411 / 2992

How Timber Lake Compares

Cross-reference this system's record against state averages and the federal MCL framework for context.

Metric Timber Lake South Dakota avg Federal benchmark
Total violations 207 86 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 2 12.8 Indicates a contaminant exceeded a federal MCL
PFAS detection None 85.7% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 499 1,400 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 654 regulated public water systems in South Dakota.

Federal MCL reference, Safe Drinking Water Act thresholds ▼
Contaminant Federal MCL / Action Level Note
Lead 0 mg/L (Action Level: 0.015 mg/L) Lead and Copper Rule treatment technique
Arsenic 0.010 mg/L (10 ppb) Health-based MCL since 2006
Total Coliform Treatment technique (RTCR) Indicator organism, monitoring trigger
PFOA / PFOS (PFAS) 4.0 ppt each (final 2024 rule) Compliance deadline 2029 (EPA proposed extending to 2031, not yet final as of May 2026)
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is Timber Lake water safe to drink? ▼
Timber Lake (PWS ID: SD4600411) has 207 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 499 people using Groundwater sources.
How many people does Timber Lake serve? ▼
Timber Lake serves 499 people in Timber Lake, South Dakota. It is a Local-owned system using Groundwater water sources with 210 service connections.
What type of violations does Timber Lake have? ▼
Timber Lake has 207 total violations: 2 health-based violations (MCL exceedances or treatment failures), 202 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Timber Lake water? ▼
No PFAS testing data is available for Timber Lake under the EPA's UCMR5 monitoring program.
What water source does Timber Lake use? ▼
Timber Lake uses Groundwater as its primary water source. It is classified as a Community Water System (CWS), serving residential populations year-round.
Where does this data come from? ▼
All data comes from the EPA Safe Drinking Water Information System (SDWIS) and the UCMR5 PFAS monitoring program. SDWIS tracks compliance for all public water systems regulated under the Safe Drinking Water Act.
Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Read our methodology - how this data is sourced, computed, and verified.

Data sourced from EPA SDWIS and UCMR5 PFAS monitoring data. See our methodology for details. Retrieved and formatted by PlainWater Editorial

Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. This system's figures are rendered directly from EPA SDWIS data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.