PlainWater

OAKS WATER USERS ASSOCIATION

PWS ID: SD4602135 · NEW UNDERWOOD, South Dakota 57761

OAKS WATER USERS ASSOCIATION serves 180 people in NEW UNDERWOOD, South Dakota using Groundwater water sources. It has 166 recorded EPA violations, including 8 health-based violations. No PFAS contamination was detected in UCMR5 testing.

Water Quality Snapshot: OAKS WATER USERS ASSOCIATION

OAKS WATER USERS ASSOCIATION is a private-owned community water system that delivers drinking water to 180 residents in NEW UNDERWOOD, South Dakota (Pennington County) through 73 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 166 total violations for this system , of which 8 (5%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 157 monitoring and reporting violations are on file. The most recent violation on record dates to 2015.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 8 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. OAKS WATER USERS ASSOCIATION's 166 violations sit above the South Dakota average. Statewide, 42 of 49 UCMR5-tested systems have reported PFAS detections (85.7%). 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
180
Total Violations
166
Health-Based Violations
8
Water Source
Groundwater

System Details

System Type
Community
Owner Type
Private
Connections
73
County
Pennington
School/Daycare
No
MCL Violations
6
Monitoring Violations
157
Treatment Tech Violations
2

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 8 2001
Coliform (TCR) MCL 6 1999
Lead and Copper Rule MR 4 1994
LASSO MR 3 1993
Atrazine MR 3 1993
Di(2-ethylhexyl) adipate MR 3 1993
Endrin MR 3 1993
BHC-GAMMA MR 3 1993
Chlordane MR 3 1993
Toxaphene MR 3 1993
Simazine MR 3 1993
Aldicarb MR 3 1993
Aldicarb sulfone MR 3 1993
Aldicarb sulfoxide MR 3 1993
OXAMYL MR 3 1993
Dinoseb MR 3 1993
2,4,5-TP MR 3 1993
2,4-D MR 3 1993
1,2-DIBROMO-3-CHLOROPROPANE MR 3 1993
ETHYLENE DIBROMIDE MR 3 1993
Glyphosate MR 3 1993
Diquat MR 3 1993
Nitrate MR 3 1994
Heptachlor MR 3 1993
Picloram MR 3 1993
Heptachlor epoxide MR 3 1993
Benzo(a)pyrene MR 3 1993
HEXACHLOROBENZENE MR 3 1993
Carbofuran MR 3 1993
Endothall MR 3 1993

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 OAKS WATER USERS ASSOCIATION.

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 SD4602135 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
2015 Stage 1 Disinfectants and Disinfection Byproducts Rule TT 2 SDWIS / SD4602135 / 0400
2001 Coliform (TCR) MR 8 SDWIS / SD4602135 / 3100
2001 Gross Alpha, Excl. Radon and U MR 2 SDWIS / SD4602135 / 4000
2001 Combined Radium (-226 and -228) MR 2 SDWIS / SD4602135 / 4010
1999 Coliform (TCR) MCL 6 SDWIS / SD4602135 / 3100
1998 cis-1,2-Dichloroethylene MR 2 SDWIS / SD4602135 / 2380
1998 1,1,1-Trichloroethane MR 2 SDWIS / SD4602135 / 2981
1998 1,2,4-Trichlorobenzene MR 2 SDWIS / SD4602135 / 2378
1998 Xylenes, Total MR 2 SDWIS / SD4602135 / 2955
1998 1,1-Dichloroethylene MR 2 SDWIS / SD4602135 / 2977
1998 Carbon tetrachloride MR 2 SDWIS / SD4602135 / 2982
1998 Styrene MR 2 SDWIS / SD4602135 / 2996
1998 trans-1,2-Dichloroethylene MR 2 SDWIS / SD4602135 / 2979
1998 1,2-Dichloropropane MR 2 SDWIS / SD4602135 / 2983
1998 Benzene MR 2 SDWIS / SD4602135 / 2990

How OAKS WATER USERS ASSOCIATION Compares

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

Metric OAKS WATER USERS ASSOCIATION South Dakota avg Federal benchmark
Total violations 166 86 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 8 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 180 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
Nitrate (as N) 10 mg/L Acute health risk for infants

Frequently Asked Questions

Is OAKS WATER USERS ASSOCIATION water safe to drink?
OAKS WATER USERS ASSOCIATION (PWS ID: SD4602135) has 166 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 180 people using Groundwater sources.
How many people does OAKS WATER USERS ASSOCIATION serve?
OAKS WATER USERS ASSOCIATION serves 180 people in NEW UNDERWOOD, South Dakota. It is a Private-owned system using Groundwater water sources with 73 service connections.
What type of violations does OAKS WATER USERS ASSOCIATION have?
OAKS WATER USERS ASSOCIATION has 166 total violations: 8 health-based violations (MCL exceedances or treatment failures), 157 monitoring/reporting violations, and 2 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in OAKS WATER USERS ASSOCIATION water?
No PFAS testing data is available for OAKS WATER USERS ASSOCIATION under the EPA's UCMR5 monitoring program.
What water source does OAKS WATER USERS ASSOCIATION use?
OAKS WATER USERS ASSOCIATION 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.

Explore PlainWater

Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. This data is provided for informational purposes only.

Related

Data sourced from $official public datasets. See our methodology for details. Retrieved and formatted by Kiznis Studio Editorial