Is Larch Corrections Center water safe to drink?

Larch Corrections Center (PWS ID: WA5306461) has 366 recorded violations in the EPA SDWIS database. No PFAS contamination was detected in UCMR5 testing. EPA SDWIS lists this system's service population as 705 people using Groundwater sources.

How many people does Larch Corrections Center serve?

EPA SDWIS reports that Larch Corrections Center serves 705 people (this public water system's service population, not the municipal population of Yacolt or any other city). It is a State-owned system using Groundwater water sources with 496 service connections. The operator address is listed in Yacolt, Washington.

What type of violations does Larch Corrections Center have?

Larch Corrections Center has 366 total violations: 0 health-based violations (MCL exceedances or treatment failures), 366 monitoring/reporting violations, and 0 treatment technique violations. Health-based violations indicate contaminant levels exceeded EPA safe limits.

Has PFAS been detected in Larch Corrections Center water?

No PFAS testing data is available for Larch Corrections Center under the EPA's UCMR5 monitoring program.

What water source does Larch Corrections Center use?

Larch Corrections Center 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.

Where does Larch Corrections Center sit among U.S. public water systems?

According to EPA SDWIS population_served among sitemap-advertised systems (serving 500+), Larch Corrections Center ranks #24,194 of 29,740 by people served, and #621 of 766 in Washington. Ordinals use population_served DESC among systems serving 500+ (the sitemap cohort). See /methodology#corpus-placement.

How does Larch Corrections Center's violation count compare nationally?

Larch Corrections Center has 366 recorded EPA SDWIS violations, fewer than 7% of the 29,740 public water systems serving 500 or more people nationwide (the same sitemap cohort used for the corpus-placement ranking above). 93% of that cohort has fewer violations than Larch Corrections Center. A system can have zero recorded violations and still be actively monitored, and a high violation count often reflects a system that reports thoroughly, not necessarily one with worse water.

States → Washington

Community Water System · PWS WA5306461

Larch Corrections Center

Operator location Yacolt, Washington - 0% of 366 violations are health-based (lower-third health share (≤ 1%)); groundwater source; 705 served per SDWIS.

Compiled by PlainWater · May 15, 2026

705
People served (this PWS) Smaller third of systems: 366
EPA violations (this PWS) Upper third of systems: 0
Health-based (this PWS) Lower third by health-based share: Untested
UCMR5 (this PWS) No UCMR5 result

Follow published updates (RSS)

Larch Corrections Center standing, high SDWIS violation third

0% of 366 recorded violations are health-based - lower-third health share (≤ 1%). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 0% is lower-third health share (≤ 1%). Population rank #24,194 of 29,740 among systems serving 500+.

The verdict

Larch Corrections Center sits in the upper third of the sitemap cohort by violation count (366), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is smaller (705; smaller served population (≤ 999)), so each violation row represents a compact service footprint. Health-based share is only 0% - almost all of this trail is monitoring or reporting. No UCMR5 PFAS test appears for this system in this extract.

#24,194 of 29,740
Population · /systems: #621 of 766
Population · WA: 366
Total EPA violations on record: 0%
Health-based (MCL / treatment failure)

Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.

Water Safety Score

58/100

Larch Corrections Center

Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.

Health-based violations A+

EPA SDWIS health-based violations on record (MCL, MRDL, treatment technique)

Monitoring & reporting violations F

366

Non-health SDWIS violations (monitoring, reporting, and other compliance)

PFAS contamination N/A

Not UCMR5-tested

Highest PFAS compound level detected in UCMR5 testing

System Details

System Type: Community
Owner Type: State
Connections: 496
County: Clark
School/Daycare: No
MCL Violations: 0
Monitoring Violations: 366
Treatment Tech Violations: 0

Violation History

Contaminant violations recorded by EPA.

Contaminant	Category	Count	Latest
cis-1,2-Dichloroethylene	MR	18	2005
DICHLOROMETHANE	MR	18	2005
o-Dichlorobenzene	MR	18	2005
Vinyl chloride	MR	18	2005
1,2-Dichloroethane	MR	18	2005
1,1,2-Trichloroethane	MR	18	2005
CHLOROBENZENE	MR	18	2005
Ethylbenzene	MR	18	2005
p-Dichlorobenzene	MR	18	2005
Trichloroethylene	MR	18	2005
Tetrachloroethylene	MR	18	2005
Toluene	MR	18	2005
Styrene	MR	18	2005
1,2,4-Trichlorobenzene	MR	18	2005
1,1-Dichloroethylene	MR	18	2005
1,1,1-Trichloroethane	MR	18	2005
Carbon tetrachloride	MR	18	2005
1,2-Dichloropropane	MR	18	2005
Benzene	MR	18	2005
trans-1,2-Dichloroethylene	MR	18	2005
Diquat	MR	5	2005
Coliform (TCR)	MR	1	1998

Violation Count vs. the National Corpus

Larch Corrections Center has 366 recorded EPA violations, 93% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 7% carry more. 0% of this system's own violations are health-based (0 of 366), and it ranks #24,194 of 29,740 by population served among that same cohort.

EPA violations vs. the national water-system corpus

Public water systems serving 500+ people (EPA SDWIS)

366 Higher than most more violations than 93% of 29,740 water systems

the national water-system corpus, bucketed by value

Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source EPA SDWIS · 2026-05-15

How many violations vs. how serious, among peer systems

Larch Corrections Center plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.

30 public water systems (500+ people served), EPA SDWIS current release.

How to read this

Each dot is one public water system; the highlighted dot is Larch Corrections Center. A system to the right has more recorded violations; a system higher up has a larger share of those violations classified health-based rather than monitoring or reporting.

Rare but serious: few violations, but most of them are health-based.
Frequent, mostly paperwork: many violations, but mostly monitoring or reporting, not health-based.
Clean record: below-median on both counts, the tinted corner.

View all 30 systems as a list

City of Ballinger: 372 violations, 85% health-based
Nooksack Valley Water Association: 16 violations, 31% health-based
Montgomery Co RWD 12: 7 violations, 29% health-based
Irvin Water District #6: 11 violations, 27% health-based
Ticonderoga WD: 47 violations, 26% health-based
Pine Valley Plantation: 37 violations, 24% health-based
McLouth, City Of: 29 violations, 17% health-based
Kipling Oaks 1: 25 violations, 16% health-based
South Deerfield Water Supply District: 96 violations, 16% health-based
Sunset Ridge Water District: 82 violations, 15% health-based
Orange Water Dept: 136 violations, 14% health-based
Mount Pleasant Water Sys #1: 167 violations, 11% health-based
Lake Gibson Estates: 42 violations, 2% health-based
Benson Culinary Improvement District: 212 violations, 1% health-based
Conemaugh Twp Muni Auth: 567 violations, 1% health-based
Miccosukee Service Plaza: 0 violations, 0% health-based
Brazoria - Fort Bend Counties MUD 3: 0 violations, 0% health-based
Tanglewilde Thompson Place 600: 2 violations, 0% health-based
Center Water Co: 5 violations, 0% health-based
Spring Mills Elem School/Hvs: 9 violations, 0% health-based
Great Bend Industrial Park: 14 violations, 0% health-based
Glen Park Village: 19 violations, 0% health-based
Camp Is-Sho-Da: 22 violations, 0% health-based
Hamilton: 33 violations, 0% health-based
Town of Welaka: 54 violations, 0% health-based
Township of Blairstown Dpw: 61 violations, 0% health-based
McIntosh Water & Fire Pro Authority: 71 violations, 0% health-based
Clarkdale Municipal Water System: 114 violations, 0% health-based
Eureka Water Association: 273 violations, 0% health-based
Larch Corrections Center: 366 violations, 0% health-based (this system)

Health-based violations on Larch Corrections Center

0 health-based rows in the tables above map to MCL or treatment-technique exceedances, verify each contaminant code on the federal SDWIS report for WA5306461.

EPA SDWIS · PWS WA5306461 WA primacy agency

Sources: EPA SDWIS · Washington State Department of Health, Office of Drinking Water

Nationwide peers

366 violations · 705 served: nearest cross-state SDWIS matches.

Cross-state systems with comparable violation load

Nearest cross-state community systems (500+ served) by total SDWIS violations on record.

4 peers

Cross-state systems with smaller service footprints

Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).

4 peers

What to do with Larch Corrections Center

Use this system's EPA-reported record as a starting filter, not a final verdict.

See how every tracked system in Washington compares on the same EPA violation measures. Washington systems
Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
Find and compare another public water system by name or PWSID. Search systems

EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.

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

Compiled by PlainWater, Drinking Water Quality Editorial Process · May 15, 2026

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