Skip to content

Water Quality Technical Report — LA SALLE, IL

PWSID
IL0990300
Population
9,700
Source
Groundwater
Data Period
Last Updated

A note from the author — I'm Jacob Thorwolf. WaterAdvantage.org is a personal project of mine, separate from my day job as an Account Executive at Bottleless Nation, a commercial water filtration company. If you request a consultation through any form on this site, it comes to me or a colleague at BN. More about this project →

Summary

LA SALLE serves approximately 9,700 people in LA SALLE, Illinois. Based on contaminant analyses from EPA ECHO, EPA UCMR5, the most recent monitoring readings are within federal EPA standards (MCL), but this system has active MCL violations on record for 1 contaminant. 1 contaminant exceeds health-based guidelines. The most significant finding is Lead (90th Percentile) at 0.00903 mg/L, which is 45.2x the health guideline. Data is drawn from source-level compliance monitoring and covers 2016 through 2025. Results reflect conditions at the point of collection (wells, treatment plants), not necessarily at the tap.

Key Findings

Understanding the two thresholds

EPA Legal Limit (MCL)

The highest level of a contaminant allowed by federal law. Utilities that exceed this threshold face enforcement action. Limits balance health risk against the cost of treatment, so they are not always set at levels considered safe by independent researchers.

Health Guideline

The level below which independent researchers (CalEPA, WHO, EWG) believe there is no known health risk. Guidelines are not legally enforceable but are typically stricter than legal limits — often by 10x or more for contaminants like arsenic and lead.

A reading can be below the EPA limit (legally compliant) while still exceeding health guidelines (above levels considered safe by independent researchers).

EPA Violation Records

The following violation records exist in EPA's federal compliance database for this system. We do not have corresponding monitoring data for these contaminants in our database.

Total TrihalomethanesHistorical

Recorded: 7/1/2022 — 9/30/2022

Total TrihalomethanesHistorical

Recorded: 4/1/2022 — 6/30/2022

Total TrihalomethanesHistorical

Recorded: 1/1/2022 — 3/31/2022

Total TrihalomethanesHistorical

Recorded: 10/1/2017 — 12/31/2017

Total TrihalomethanesHistorical

Recorded: 7/1/2017 — 9/30/2017

Total TrihalomethanesHistorical

Recorded: 4/1/2017 — 6/30/2017

Exceeds Health Guidelines

These contaminants were detected below the EPA legal limit but above a health-based guideline from a public health agency (CalEPA OEHHA, WHO, or similar). Health guidelines are non-enforceable research-backed targets that are often stricter than the legal limit.

Detected contaminants
ContaminantResultUnitHealth GuidelineEPA Legal LimitSourceSample Date
Lead (90th Percentile)
Developmental delays in children, kidney damage, high blood pressure. There is no safe level of lead exposure.
9.03ug/L0.215
Pending rule: LCRI 2024Action level drops from 15 → 10 µg/L effective 2027; full lead service line replacement within 10 years (EPA Lead & Copper Rule Improvements, October 2024)
EPA ECHO

PFAS

Per- and polyfluoroalkyl substances (PFAS) are a group of manufactured chemicals that persist in the environment and accumulate in the human body. The EPA set enforceable limits for six PFAS compounds in April 2024, with a compliance deadline of 2029. PFAS compounds measured above EPA standards appear in the Above Federal Standard section above.

Detected contaminants
ContaminantResultUnitHealth GuidelineEPA Legal LimitSourceSample Date
Lithium20ug/LEPA UCMR5
PFBA (Perfluorobutanoic Acid)
Shorter-chain PFAS with faster elimination. Thyroid effects in animal studies.
6.7ng/LNot publishedNot regulatedEPA UCMR5
PFBS (Perfluorobutane Sulfonate)
Thyroid effects, reproductive and developmental effects, kidney effects.
3.1ng/LNot publishedRegulated via Hazard Index (HBWC 2,000 ng/L)EPA UCMR5

Microplastics

Microplastics have been documented in raw and treated drinking water worldwide, but federal regulations do not currently require testing — so there is no data specific to this system. Standardized methods and rules are in progress.

Other Potential Contaminants

Not detecting a contaminant does not prove it isn't present — it only means the laboratory didn't test for it, or tested below the reporting limit. Many substances of emerging concern are not routinely monitored because federal regulations haven't caught up to the science.

Compliance History

Formal EPA and DNR compliance events on record for this utility. Includes all events from the last 10 years plus any unresolved violations regardless of age. Health-based violations are legally enforceable thresholds that were exceeded; procedural events are monitoring or reporting lapses that don't indicate contamination by themselves.

6 health-based5 procedural
Total Trihalomethanes (TTHMs)0.087 MG/LHealth-based
MCL Violation

Jul 1, 2022 – Sep 30, 2022

Total Trihalomethanes (TTHMs)0.095 MG/LHealth-based
MCL Violation

Apr 1, 2022 – Jun 30, 2022

Total Trihalomethanes (TTHMs)0.086 MG/LHealth-based
MCL Violation

Jan 1, 2022 – Mar 31, 2022

Total Trihalomethanes (TTHMs)0.088 MG/LHealth-based
MCL Violation

Oct 1, 2017 – Dec 31, 2017

Total Trihalomethanes (TTHMs)0.101 MG/LHealth-based
MCL Violation

Jul 1, 2017 – Sep 30, 2017

Total Trihalomethanes (TTHMs)0.088 MG/LHealth-based
MCL Violation

Apr 1, 2017 – Jun 30, 2017

Haloacetic Acids (HAA5)
Consumer Confidence Report

Oct 1, 2025 – Dec 31, 2025

Lead and Copper Rule
Monitoring (RTCR)

Jun 1, 2024 – Jun 30, 2024

Turbidity
Consumer Confidence Report

Apr 1, 2024 – Jun 30, 2024

Total Coliform
Public Notification (Tier 2)

Oct 1, 2023 – ongoing

E. coli (RTCR)
Administrative

Feb 23, 2006 – ongoing

Source: EPA ECHO enforcement and violation records (via Envirofacts / SDWIS Federal Reports).

Routine Maintenance

Nothing in this system's current readings crosses a legal limit or a health guideline. Water systems still change over time, so the following is a baseline of habits worth keeping.

Frequently Asked Questions

What contaminants are in LA SALLE water?

Based on available public monitoring data, 31 contaminants have been tested in LA SALLE's water supply. 4 were detected above reporting limits. The most notable detections include Lead (90th Percentile), PFBS (Perfluorobutane Sulfonate), PFBA (Perfluorobutanoic Acid). This data comes from source-level compliance monitoring at wells and treatment plants.

Does LA SALLE water meet EPA standards?

The most recent monitoring readings are within federal EPA standards (MCL), but this system has active MCL violations on record for 1 contaminant. MCL violations can result from compliance calculations (averaging across wells or quarters) that differ from individual sample readings. See the Compliance History section for details.

Is LA SALLE, IL water safe to drink?

Based on source-level compliance monitoring, the most recent readings are within federal standards, but this system has active MCL violations on record for 1 contaminant. However, compliance monitoring tests water at wells and treatment plants, not at individual taps. An on-site test is the only way to know what reaches your tap, as conditions can vary based on plumbing, blending, and distribution.

Does LA SALLE water have PFAS?

Yes, PFAS compounds have been detected in source monitoring for LA SALLE's water supply: PFBS (Perfluorobutane Sulfonate) (0.0031 ug/L), PFBA (Perfluorobutanoic Acid) (0.0067 ug/L), Lithium (20 ug/L). PFAS are a group of manufactured chemicals that do not break down in the environment. The EPA set enforceable limits for several PFAS compounds in 2024.

Does LA SALLE water have lead?

No. LA SALLE's most recent Lead and Copper Rule testing found a 90th-percentile lead level of 0.00903 mg/L, which is below the EPA action level of 0.015 mg/L. That means at the systemwide level, lead is not exceeding the enforcement threshold. Lead levels can still vary significantly by individual building — older homes and schools with legacy plumbing can have much higher readings than the system average.

Cross-check against the official record

This report is our read of the public monitoring data. Every Illinoisutility also publishes an annual Consumer Confidence Report (CCR) — a plain-language summary written by the utility itself, usually mailed with a water bill or posted on the utility's website. If anything in this report surprises you, request LA SALLE's latest CCR directly from the utility, or browse the underlying compliance data published by Illinois EPA.

Data Sources and Methodology

EPA ECHO Lead & Copper Rule

90th percentile measurements from EPA Enforcement and Compliance History Online. Based on tap-level sampling at high-risk sites.

EPA UCMR5

Unregulated Contaminant Monitoring Rule, Fifth cycle. Per-analyte PFAS results from utility-level sampling.

Definitions

Maximum Contaminant Level (MCL)
The highest level of a contaminant allowed in drinking water, set by the EPA. MCLs are legally enforceable standards.
Maximum Contaminant Level Goal (MCLG)
The level of a contaminant below which there is no known or expected health risk. MCLGs are non-enforceable public health goals.
Action Level
The concentration of a contaminant which, if exceeded, triggers treatment or other requirements. Used for lead and copper.
Health Advisory
Non-enforceable guidelines set by the EPA providing information on contaminants that can cause health effects at certain exposure levels.
Total Dissolved Solids (TDS)
A measure of all dissolved minerals, salts, and organic matter in water, expressed in mg/L (ppm). Not a health hazard but affects taste and indicates overall mineral content.
PFAS
Per- and polyfluoroalkyl substances. A group of manufactured chemicals that do not break down in the environment. The EPA set enforceable limits for several PFAS compounds in 2024.
Non-Detect (ND)
The contaminant was tested for but not found above the laboratory's reporting limit. This does not mean zero — it means below the detection threshold.
VOCs (Volatile Organic Compounds)
Chemicals that evaporate easily and can contaminate groundwater. Sources include gasoline, industrial solvents, and dry cleaning fluids. Some are regulated by the EPA; many are monitored but not yet regulated.

Download Data

Cite This Report

WaterAdvantage. "Water Quality Technical Report: LA SALLE, IL (IL0990300)." WaterAdvantage.org, 2026-09-06. https://www.wateradvantage.org/report/IL0990300/detail

Curious about filtration for your home or facility? I work at Bottleless Nation during the day and I'm happy to take a look. Submit the form below and I or a colleague will reach out — the consultation is free, and if it turns into a sale, I earn a commission.

Get a free filtration consultation