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States → South Dakota

Transient Non-Community Water System · PWS SD4600568

Guadalajara Mexican Restaurant

Spearfish, South Dakota 57783 - drinking water served from groundwater sources to 630 people, tracked in EPA SDWIS and UCMR5.

630
People served
129
EPA violations
15
Health-based
Untested
UCMR5 result

The verdict

EPA records 129 drinking-water violations at Guadalajara Mexican Restaurant, 12% of them health-based - above the South Dakota per-system average.

129
Total EPA violations on record
12%
Health-based (MCL / treatment failure)
630
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Guadalajara Mexican Restaurant

Guadalajara Mexican Restaurant is a private-owned transient non-community water system that delivers drinking water to 630 residents in Spearfish, South Dakota (Lawrence County) through 1 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 129 total violations for this system , of which 15 (12%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 78 monitoring and reporting violations are on file. The most recent violation on record dates to 2021.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 61 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%).

Guadalajara Mexican Restaurant's 129 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
630
Total Violations
129
Health-Based Violations
15
Water Source
Groundwater

System Details

System Type
Transient Non-Community
Owner Type
Private
Connections
1
County
Lawrence
School/Daycare
No
MCL Violations
15
Monitoring Violations
78
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 61 2004
Coliform (TCR) MCL 15 2015
Nitrate MR 8 2004
E. COLI MR 6 2021
Coliform (TCR) Other 6 2000
Public Notice Other 3 2005
Revised Total Coliform Rule MON 3 2018

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 Guadalajara Mexican Restaurant.

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 SD4600568 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
2021 E. COLI MR 6 SDWIS / SD4600568 / 3014
2018 Revised Total Coliform Rule MON 3 SDWIS / SD4600568 / 8000
2015 Coliform (TCR) MCL 15 SDWIS / SD4600568 / 3100
2005 Public Notice Other 3 SDWIS / SD4600568 / 7500
2004 Coliform (TCR) MR 61 SDWIS / SD4600568 / 3100
2004 Nitrate MR 8 SDWIS / SD4600568 / 1040
2000 Coliform (TCR) Other 6 SDWIS / SD4600568 / 3100

How Guadalajara Mexican Restaurant Compares

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

Metric Guadalajara Mexican Restaurant South Dakota avg Federal benchmark
Total violations 129 86 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 15 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 630 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 Guadalajara Mexican Restaurant water safe to drink? ▼
Guadalajara Mexican Restaurant (PWS ID: SD4600568) has 129 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 630 people using Groundwater sources.
How many people does Guadalajara Mexican Restaurant serve? ▼
Guadalajara Mexican Restaurant serves 630 people in Spearfish, South Dakota. It is a Private-owned system using Groundwater water sources with 1 service connections.
What type of violations does Guadalajara Mexican Restaurant have? ▼
Guadalajara Mexican Restaurant has 129 total violations: 15 health-based violations (MCL exceedances or treatment failures), 78 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Guadalajara Mexican Restaurant water? ▼
No PFAS testing data is available for Guadalajara Mexican Restaurant under the EPA's UCMR5 monitoring program.
What water source does Guadalajara Mexican Restaurant use? ▼
Guadalajara Mexican Restaurant uses Groundwater as its primary water source. It is classified as a Transient Non-Community Water System, serving transient populations.
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.