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Non-Transient Non-Community Water System · PWS CO0202300

Great Sand Dunes Hq

Mosca, Colorado 81146 - drinking water served from groundwater sources to 1,400 people, tracked in EPA SDWIS and UCMR5.

1,400
People served
52
EPA violations
4
Health-based
Untested
UCMR5 result

The verdict

EPA records 52 drinking-water violations at Great Sand Dunes Hq, 8% of them health-based - below the Colorado per-system average.

52
Total EPA violations on record
8%
Health-based (MCL / treatment failure)
1,400
People served by this system
N/A
PFAS compounds detected (UCMR5)

Water Quality Snapshot: Great Sand Dunes Hq

Great Sand Dunes Hq is a federal-owned non-transient non-community water system that delivers drinking water to 1,400 residents in Mosca, Colorado (Alamosa County) through 16 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 52 total violations for this system , of which 4 (8%) are health-based, meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 45 monitoring and reporting violations are on file. The most recent violation on record dates to 2024.

The most frequently cited contaminant at this system is Lead and Copper Rule, recorded in 12 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 Colorado, EPA tracks 2,193 public water systems serving 7,473,456 people, with 238,796 cumulative violations and 30,589 health-based violations on record. About 93% of systems in the state carry at least one violation, and state-wide the average per system is 108.9 violations. Statewide, 98 of 163 UCMR5-tested systems have reported PFAS detections (60.1%).

Great Sand Dunes Hq's 52 violations sit below the Colorado 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
1,400
Total Violations
52
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Non-Transient Non-Community
Owner Type
Federal
Connections
16
County
Alamosa
School/Daycare
No
MCL Violations
0
Monitoring Violations
45
Treatment Tech Violations
4

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Lead and Copper Rule MR 12 2020
Revised Total Coliform Rule MON 6 2021
Coliform (TCR) MR 6 2008
Stage 1 Disinfectants and Disinfection Byproducts Rule TT 4 2024
Barium MR 3 2002
Total Polychlorinated Biphenyls (PCB) MR 3 2011
Chlorine MR 3 2019
Total Haloacetic Acids (HAA5) MR 3 2019
Di(2-ethylhexyl) phthalate MR 3 2024
Antimony, Total MR 3 2002
TTHM MR 3 2019
Public Notice Other 2 2020

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 Great Sand Dunes Hq.

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 CO0202300 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

Colorado Drinking Water Authority

Colorado Department of Public Health and Environment, Water Quality Control is the primacy agency that licenses and inspects Great Sand Dunes Hq under EPA-delegated authority.

Open CO regulator portal

Source: Colorado Department of Public Health and Environment, Water Quality Control

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
2024 Stage 1 Disinfectants and Disinfection Byproducts Rule TT 4 SDWIS / CO0202300 / 0400
2024 Di(2-ethylhexyl) phthalate MR 3 SDWIS / CO0202300 / 2039
2021 Revised Total Coliform Rule MON 6 SDWIS / CO0202300 / 8000
2020 Lead and Copper Rule MR 12 SDWIS / CO0202300 / 5000
2020 Public Notice Other 2 SDWIS / CO0202300 / 7500
2019 Chlorine MR 3 SDWIS / CO0202300 / 0999
2019 Total Haloacetic Acids (HAA5) MR 3 SDWIS / CO0202300 / 2456
2019 TTHM MR 3 SDWIS / CO0202300 / 2950
2011 Total Polychlorinated Biphenyls (PCB) MR 3 SDWIS / CO0202300 / 2383
2008 Coliform (TCR) MR 6 SDWIS / CO0202300 / 3100
2002 Barium MR 3 SDWIS / CO0202300 / 1010
2002 Antimony, Total MR 3 SDWIS / CO0202300 / 1074

How Great Sand Dunes Hq Compares

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

Metric Great Sand Dunes Hq Colorado avg Federal benchmark
Total violations 52 108.9 SDWA compliance, any non-zero count is a recorded breach
Health-based violations 4 13.9 Indicates a contaminant exceeded a federal MCL
PFAS detection None 60.1% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 1,400 3,408 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 2,193 regulated public water systems in Colorado.

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 Great Sand Dunes Hq water safe to drink? ▼
Great Sand Dunes Hq (PWS ID: CO0202300) has 52 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. This system serves 1,400 people using Groundwater sources.
How many people does Great Sand Dunes Hq serve? ▼
Great Sand Dunes Hq serves 1,400 people in Mosca, Colorado. It is a Federal-owned system using Groundwater water sources with 16 service connections.
What type of violations does Great Sand Dunes Hq have? ▼
Great Sand Dunes Hq has 52 total violations: 4 health-based violations (MCL exceedances or treatment failures), 45 monitoring/reporting violations, and 4 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Great Sand Dunes Hq water? ▼
No PFAS testing data is available for Great Sand Dunes Hq under the EPA's UCMR5 monitoring program.
What water source does Great Sand Dunes Hq use? ▼
Great Sand Dunes Hq uses Groundwater as its primary water source. It is classified as a Non-Transient Non-Community Water System, serving the same people for at least 6 months per year.
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.