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Dry Creek Rancheria

PWS ID: 090600127 · Geyserville, 09 95441

Dry Creek Rancheria serves 2,200 people in Geyserville, 09 using Groundwater water sources. It has 122 recorded EPA violations, including 4 health-based violations. PFAS "forever chemicals" were detected in UCMR5 testing (1 compound found).

Water Quality Snapshot: Dry Creek Rancheria

Dry Creek Rancheria is a native american-owned non-transient non-community water system that delivers drinking water to 2,200 residents in Geyserville, 09 through 3 service connections. Its water is drawn from groundwater sources. EPA's Safe Drinking Water Information System records 122 total violations for this system , of which 4 (3%) are health-based — meaning a contaminant exceeded an EPA Maximum Contaminant Level or a required treatment technique failed. A further 44 monitoring and reporting violations are on file. The most recent violation on record dates to 2025.

The most frequently cited contaminant at this system is Coliform (TCR), recorded in 11 violations (MR). Under EPA's UCMR5 PFAS monitoring program, 1 PFAS compound was detected in samples collected from this system, with a maximum reported concentration of 16.4 ppt. PFAS are persistent synthetic chemicals linked to health effects at very low exposure levels.

Across 09, EPA tracks 323 public water systems serving 555,721 people, with 48,296 cumulative violations and 3,354 health-based violations on record. About 97% of systems in the state carry at least one violation, and state-wide the average per system is 149.5 violations. Dry Creek Rancheria's 122 violations sit below the 09 average. Statewide, 30 of 41 UCMR5-tested systems have reported PFAS detections (73.2%). All figures above are sourced directly from EPA SDWIS and UCMR5 public data releases and are updated as EPA publishes new reporting cycles.

PFAS Detected

1 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.

Population Served
2,200
Total Violations
122
Health-Based Violations
4
Water Source
Groundwater

System Details

System Type
Non-Transient Non-Community
Owner Type
Native American
Connections
3
School/Daycare
No
MCL Violations
4
Monitoring Violations
44
Treatment Tech Violations
0

Violation History

Contaminant violations recorded by EPA.

Contaminant Category Count Latest
Coliform (TCR) MR 11 2014
Nitrate MR 4 2013
Coliform (TCR) MCL 4 2011
Consumer Confidence Rule Other 3 2002
Xylenes, Total MR 2 2021
Lead and Copper Rule MR 2 1996
Arsenic MR 1 2001
Cadmium MR 1 2001
CYANIDE MR 1 1998
Fluoride MR 1 2001
Mercury MR 1 2001
Selenium MR 1 2001
Antimony, Total MR 1 2001
Beryllium, Total MR 1 2001
Di(2-ethylhexyl) adipate MR 1 2017
Pentachlorophenol MR 1 2017
2,4-D MR 1 2017
Benzo(a)pyrene MR 1 2017
1,2-DIBROMO-3-CHLOROPROPANE MR 1 1996
Chlorine MR 1 2025
Revised Total Coliform Rule MON 1 2018
Public Notice Other 1 2018
Picloram MR 1 2017
Methoxychlor MR 1 2017
Dinoseb MR 1 2017
E. COLI MR 1 2019
Barium MR 1 2001
2,4,5-TP MR 1 2017
Dalapon MR 1 2017
Chromium MR 1 2001

PFAS Testing Results (UCMR5)

Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 2 of 60 samples detected PFAS.

Contaminant Date Result MRL Status
PFUnA 7/22/2025 <0.002 µg/L 0.002 µg/L Not Detected
PFHxA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFDA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 7/22/2025 <0.008 µg/L 0.008 µg/L Not Detected
PFOA 7/22/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFOS 7/22/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFDoA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
11Cl-PF3OUdS 7/22/2025 <0.005 µg/L 0.005 µg/L Not Detected
ADONA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFTrDA 7/22/2025 <0.007 µg/L 0.007 µg/L Not Detected
NEtFOSAA 7/22/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFNA 7/22/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFMPA 7/22/2025 <0.004 µg/L 0.004 µg/L Not Detected
NMeFOSAA 7/22/2025 <0.006 µg/L 0.006 µg/L Not Detected
9Cl-PF3ONS 7/22/2025 <0.002 µg/L 0.002 µg/L Not Detected
PFHxS 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHpS 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 7/22/2025 <0.004 µg/L 0.004 µg/L Not Detected
NFDHA 7/22/2025 <0.02 µg/L 0.02 µg/L Not Detected
PFEESA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
8:2 FTS 7/22/2025 <0.005 µg/L 0.005 µg/L Not Detected
4:2 FTS 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
6:2 FTS 7/22/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFBA 7/22/2025 <0.005 µg/L 0.005 µg/L Not Detected
HFPO-DA 7/22/2025 <0.005 µg/L 0.005 µg/L Not Detected
lithium 7/22/2025 11.8000 µg/L 9 µg/L Detected
PFMBA 7/22/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFOS 1/6/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFNA 1/6/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFHxS 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFHpA 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFBS 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
NMeFOSAA 1/6/2025 <0.006 µg/L 0.006 µg/L Not Detected
NEtFOSAA 1/6/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFTrDA 1/6/2025 <0.007 µg/L 0.007 µg/L Not Detected
lithium 1/6/2025 16.4000 µg/L 9 µg/L Detected
PFOA 1/6/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFPeA 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFTA 1/6/2025 <0.008 µg/L 0.008 µg/L Not Detected
NFDHA 1/6/2025 <0.02 µg/L 0.02 µg/L Not Detected
8:2 FTS 1/6/2025 <0.005 µg/L 0.005 µg/L Not Detected
PFDA 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFPeS 1/6/2025 <0.004 µg/L 0.004 µg/L Not Detected
PFEESA 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFMBA 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected
PFMPA 1/6/2025 <0.004 µg/L 0.004 µg/L Not Detected
4:2 FTS 1/6/2025 <0.003 µg/L 0.003 µg/L Not Detected

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 Dry Creek Rancheria.

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 090600127 on SDWIS

Source: EPA SDWIS Federal Reports Search

State Regulator

09 Drinking Water Authority

09'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 09 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
2025 Chlorine MR 1 SDWIS / 090600127 / 0999
2021 Xylenes, Total MR 2 SDWIS / 090600127 / 2955
2019 E. COLI MR 1 SDWIS / 090600127 / 3014
2018 Revised Total Coliform Rule MON 1 SDWIS / 090600127 / 8000
2018 Public Notice Other 1 SDWIS / 090600127 / 7500
2017 Di(2-ethylhexyl) adipate MR 1 SDWIS / 090600127 / 2035
2017 Pentachlorophenol MR 1 SDWIS / 090600127 / 2326
2017 2,4-D MR 1 SDWIS / 090600127 / 2105
2017 Benzo(a)pyrene MR 1 SDWIS / 090600127 / 2306
2017 Picloram MR 1 SDWIS / 090600127 / 2040
2017 Methoxychlor MR 1 SDWIS / 090600127 / 2015
2017 Dinoseb MR 1 SDWIS / 090600127 / 2041
2017 2,4,5-TP MR 1 SDWIS / 090600127 / 2110
2017 Dalapon MR 1 SDWIS / 090600127 / 2031
2017 Di(2-ethylhexyl) phthalate MR 1 SDWIS / 090600127 / 2039

How Dry Creek Rancheria Compares

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

Metric Dry Creek Rancheria 09 avg Federal benchmark
Total violations 122 149.5 SDWA compliance — any non-zero count is a recorded breach
Health-based violations 4 10.4 Indicates a contaminant exceeded a federal MCL
PFAS detection 1 compound 73.2% EPA final rule (2024): PFOA/PFOS MCL = 4.0 ppt
Population served 2,200 1,720 Sizing context for compliance burden

Sources: EPA SDWIS and EPA National Primary Drinking Water Regulations (40 CFR Part 141). State averages computed across 323 regulated public water systems in 09.

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 Dry Creek Rancheria water safe to drink? ▼
Dry Creek Rancheria (PWS ID: 090600127) has 122 recorded violations in the EPA SDWIS database. PFAS contamination has been detected in UCMR5 testing, with 1 PFAS compound found. This system serves 2,200 people using Groundwater sources.
How many people does Dry Creek Rancheria serve? ▼
Dry Creek Rancheria serves 2,200 people in Geyserville, 09. It is a Native American-owned system using Groundwater water sources with 3 service connections.
What type of violations does Dry Creek Rancheria have? ▼
Dry Creek Rancheria has 122 total violations: 4 health-based violations (MCL exceedances or treatment failures), 44 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.
Has PFAS been detected in Dry Creek Rancheria water? ▼
Yes. UCMR5 testing detected 1 PFAS compound in Dry Creek Rancheria's water supply: lithium. PFAS are persistent "forever chemicals" that do not break down in the environment.
What water source does Dry Creek Rancheria use? ▼
Dry Creek Rancheria 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.

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Data Sources: EPA Safe Drinking Water Information System (SDWIS), Q4 2025. PFAS data from EPA UCMR5 monitoring program (2023-2025). This data is provided for informational purposes only.

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

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