Loading water data...
Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
EPA records for CRYSTAL LAKE • Updated September 2026
Grade B — based on EPA compliance records, lead testing and PFAS monitoring
CRYSTAL LAKE is in good standing with EPA, with only minor deductions for monitoring paperwork, low-level PFAS or historical readings near a limit.
Yes — by EPA's records Crystal Lake, IL tap water is safe to drink and earns a B. The grade rests on lead at 7.7 ppb (90th percentile) — under the 15 ppb action level but above 5 ppb and low-level PFAS (PFBS, PFPeA) detected below federal limits. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
Yes — by EPA's records Crystal Lake, IL tap water is safe to drink and earns a B. The grade rests on lead at 7.7 ppb (90th percentile) — under the 15 ppb action level but above 5 ppb and low-level PFAS (PFBS, PFPeA) detected below federal limits. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
CRYSTAL LAKE's most recent Lead and Copper Rule result (2025-07-01 to 2025-12-31) was 7.7 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2024-12-03 to 2025-11-03) detected PFBS, PFPeA, all below federal MCLs. Reverse osmosis and certified activated-carbon filters reduce PFAS.
CRYSTAL LAKE has 12 violations on file since 2016: 0 health-based in the last five years and 12 monitoring or reporting violations in that window. Monitoring violations are paperwork lapses, not measured contamination.
CRYSTAL LAKE reports groundwater as its primary source and serves about 40,661 people (EPA PWSID IL1110150).
Optional but sensible. The findings on this page are below federal limits; an NSF-certified pitcher or under-sink filter handles lead, PFAS and improves taste.
Compare filter options for your Crystal Lake tap water
Lead was found at 7.7 ppb (90th percentile) in Crystal Lake's latest tap sampling — below the action level, but there is no safe level of lead.
Unsure which contaminants to treat? Compare home kits and certified lab testing before buying.
Amazon. We may earn a commission, at no extra cost to you.
CRYSTAL LAKE · SDWIS records since 2016 · 5-year window starts 2021-09-13
EPA records no health-based violations for this system in the last five years. The 12 violations on file in that window are monitoring or reporting paperwork issues, not measured contaminant exceedances.
| Violation | Category | Compliance period | Status |
|---|---|---|---|
| Monitoring, RegularHexachlorocyclopentadiene | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularDi(2-ethylhexyl) phthalate | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularAtrazine | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularDi(2-ethylhexyl) adipate | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularEndrin | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularLASSO | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularHeptachlor epoxide | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularHEXACHLOROBENZENE | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularSimazine | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularBHC-GAMMA | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularMethoxychlor | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
| Monitoring, RegularHeptachlor | Monitoring & reporting | 2026-01-01 → 2026-03-31 | Archived |
Source: ECHO SDWA bulk download (SDWA_VIOLATIONS_ENFORCEMENT.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-13)
EPA Lead and Copper Rule 90th-percentile results reported by CRYSTAL LAKE
Below the action level, but detectable. In the most recent monitoring period on file (2025-07-01 to 2025-12-31), 90% of the homes CRYSTAL LAKE sampled had lead at or below 7.7 ppb.
EPA's action level is 15 ppb (dropping to 10 ppb under the 2024 Lead and Copper Rule Improvements). There is no safe level of lead; the 90th-percentile figure describes the system, not your tap — homes with lead service lines or pre-1986 plumbing can be higher.
| Monitoring period | Lead 90th percentile | vs 15 ppb action level |
|---|---|---|
| 2025-01-01 → 2025-12-31 | 4.3 ppb | Well below the 15 ppb action level |
| 2025-01-01 → 2025-12-31 | 1.3 ppb | Well below the 15 ppb action level |
| 2025-07-01 → 2025-12-31 | 7.7 ppb | Below the action level, but detectable |
| 2025-01-01 → 2025-06-30 | 9.3 ppb | Below the action level, but detectable |
| 2024-07-01 → 2024-12-31 | 12 ppb | Below the action level, but detectable |
| 2024-01-01 → 2024-06-30 | 4.7 ppb | Well below the 15 ppb action level |
| 2023-07-01 → 2023-12-31 | 7.4 ppb | Below the action level, but detectable |
| 2023-01-01 → 2023-06-30 | 5.6 ppb | Below the action level, but detectable |
| 2022-07-01 → 2022-12-31 | 5.3 ppb | Below the action level, but detectable |
| 2022-01-01 → 2022-06-30 | 5.1 ppb | Below the action level, but detectable |
| 2018-01-01 → 2020-12-31 | 3.77 ppb | Well below the 15 ppb action level |
| 2015-01-01 → 2017-12-31 | 0 ppb | Well below the 15 ppb action level |
Source: ECHO SDWA bulk download (SDWA_LCR_SAMPLES.csv, SDWIS 2026Q2, file dated 2026-07-09, fetched 2026-09-13)
EPA UCMR5 monitoring, 2024-12-03 to 2025-11-03 · 290 PFAS results at entry points to the distribution system
PFBS, PFPeA detected at low levels; no compound was at or above its federal MCL. Detections below the MCL are common in surface-water systems and are reported here exactly as EPA published them.
| Compound | Detects / samples | Max (ppt) | Reporting limit | EPA MCL |
|---|---|---|---|---|
| PFOA | 0 / 10 | < 4 | 4 ppt | 4 ppt |
| PFOS | 0 / 10 | < 4 | 4 ppt | 4 ppt |
| PFHxS | 0 / 10 | < 3 | 3 ppt | 10 ppt |
| PFNA | 0 / 10 | < 4 | 4 ppt | 10 ppt |
| HFPO-DA | 0 / 10 | < 5 | 5 ppt | 10 ppt |
| PFBS | 1 / 10 | 4.6 | 3 ppt | hazard index only |
| PFPeA | 1 / 10 | 4.5 | 3 ppt | hazard index only |
“< 4 ppt” means below the laboratory reporting limit, not zero. ppt = parts per trillion (ng/L). Results are for finished water leaving the treatment plant.
What PFAS are and how to remove them → · Best filters for PFAS →
Source: UCMR5 occurrence data, EPA Data Summary July 2026 (UCMR5_All.txt)
EPA Six-Year Review 4 compliance samples for CRYSTAL LAKE · finished water only · dated data, released 2024
These are the regulated-contaminant samples CRYSTAL LAKE reported to its state between 2012 and 2019 — the most recent nationwide sample-level dataset EPA has published. Radium-226/228 is flagged below; the status column explains why. Treat this as history, not today's tap water.
| Contaminant | Samples | Average | Max | EPA limit | Status |
|---|---|---|---|---|---|
| Arsenic | 150 detects | 0 µg/L | ND | 10 µg/LMCL | Not detected |
| Nitrate (as N) | 400 detects | 0 mg/L | ND | 10 mg/LMCL | Not detected |
| Fluoride | 15 | 0.857 mg/L | 1.08 mg/L | 4 mg/LMCL | Within MCL |
| Chromium (total) | 150 detects | 0 µg/L | ND | 100 µg/LMCL | Not detected |
| Radium-226/228 | 2821 detects | 1.334 pCi/L | 5.51 pCi/L | 5 pCi/LMCL | 1 of 28 samples over MCL |
| Total trihalomethanes (TTHM) | 88 | 33.732 µg/L | 75.8 µg/L | 80 µg/LMCL (LRAA) | Within MCL |
| Haloacetic acids (HAA5) | 88 | 7.807 µg/L | 31.2 µg/L | 60 µg/LMCL (LRAA) | Within MCL |
| Lead (tap samples) | 6011 detects | 3.22 µg/L | 41 µg/L | 15 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
| Copper (tap samples) | 6052 detects | 321.3 µg/L | 1730 µg/L | 1300 µg/Laction level (90th percentile) | Reported, not scored (compliance is on the 90th percentile) |
Averages count non-detects as zero. TTHM and HAA5 limits are locational running annual averages, so a single high sample is not a violation — we grade those on the average only. Lead and copper rows are individual tap samples and are shown for context; compliance (and our score) uses the 90th-percentile result above. LRAA = locational running annual average; ND = not detected.
Source: SYR4 Six-Year Review compliance monitoring data 2012–2019 (released 2024-03)
A point-of-use (under-sink) system typically runs $200-$600 installed; whole-house treatment $1,000-$3,000+ depending on flow and what has to come out. Tell us where you are and a certified water-treatment installer serving Crystal Lake will follow up - no obligation.
CRYSTAL LAKE · 13,787 service lines inventoried · Q2 2026 snapshot
CRYSTAL LAKE reports 560 service lines that are lead or galvanized-requiring-replacement (4.1% of the lines it has inventoried), plus 1,109 lines whose material is still unknown. A lead service line is the pipe between the water main and a building, so treated water can pick up lead after it leaves the plant — which city-level testing does not capture. Under EPA's Lead and Copper Rule Improvements, utilities must replace lead lines within 10 years starting in 2027.
Source: EPA SDWIS Service Line Inventory (Q2 2026) · PWS ID IL1110150 · See all Illinois lead service lines. We may earn a commission from filters and test kits, at no extra cost to you.
Groundwater systems draw from wells; naturally occurring arsenic, nitrate, radium and uranium are the readings to watch, along with PFAS near industrial or military sites.
How to test your tap water and the treatment options that actually fit Crystal Lake homes
The most reliable way to know what is actually coming out of your tap is a certified mail-in lab test. City-wide EPA data (like the report above) reflects the water leaving the treatment plant, but contaminants such as lead and copper can be picked up from your own service line and household plumbing — so the water at your Crystal Lake faucet can differ from the system average. A state-certified lab measures dozens of contaminants at once with results you can trust; you can also find one near you through the EPA's certified-lab list at epa.gov/dwlabcert. Hardware-store test strips are cheaper and instant, but they only screen for a few basics (chlorine, hardness, pH, and a rough lead pass/fail) and are far less accurate — treat them as a first look, not a diagnosis.
Match the treatment to what your test finds. Reverse osmosis (RO) removes the widest range of contaminants — lead, arsenic, nitrate, PFAS, and dissolved solids — which makes an under-sink reverse osmosis system the most thorough choice for Crystal Lake households with heavy-metal or PFAS concerns. If your main issue is taste, odor, or chlorine, an activated carbon filter (pitcher, faucet, or under-sink) is simpler and cheaper and handles chlorine and many organic compounds well, though carbon alone does not remove arsenic, nitrate, or most PFAS. NSF-certified pitchers rated for lead reduction are the easiest way to start today while you decide on a permanent setup.
We may earn a commission from testing kits and filters purchased through these links, at no extra cost to you.
What Crystal Lake residents measured at their own tap (ZIPs 60012, 60014). All reader results →
Reader submissions are unverified and shown separately from EPA data. They reflect one tap on one day, not the utility's compliance record.
No reader results for Crystal Lake yet - yours would be the first. A hardness or TDS number from a $10 strip kit is enough to start the map.
Help build the first reader-sourced water map. Enter whatever your test strip, TDS pen or lab report shows - one number is enough.
Crystal Lake ranks #47 of 56 graded Illinois cities.
Deep-dive guides for the specific contaminants EPA data flagged in Crystal Lake's water, with removal options for each.
Yes — by EPA's records Crystal Lake, IL tap water is safe to drink and earns a B. The grade rests on lead at 7.7 ppb (90th percentile) — under the 15 ppb action level but above 5 ppb and low-level PFAS (PFBS, PFPeA) detected below federal limits. Lead from your own service line or plumbing is the main risk city-level data cannot see, so homes built before 1986 should still test at the tap.
CRYSTAL LAKE's most recent Lead and Copper Rule result (2025-07-01 to 2025-12-31) was 7.7 ppb at the 90th percentile, below EPA's 15 ppb action level. Because lead usually comes from service lines and household plumbing, homes built before 1986 should still test at the tap.
Yes. EPA's UCMR5 sampling (2024-12-03 to 2025-11-03) detected PFBS, PFPeA, all below federal MCLs. Reverse osmosis and certified activated-carbon filters reduce PFAS.
CRYSTAL LAKE has 12 violations on file since 2016: 0 health-based in the last five years and 12 monitoring or reporting violations in that window. Monitoring violations are paperwork lapses, not measured contamination.
CRYSTAL LAKE reports groundwater as its primary source and serves about 40,661 people (EPA PWSID IL1110150).
Optional but sensible. The findings on this page are below federal limits; an NSF-certified pitcher or under-sink filter handles lead, PFAS and improves taste.
Lead was found at 7.7 ppb (90th percentile) in Crystal Lake's latest tap sampling — below the action level, but there is no safe level of lead.
Most Popular for Lead
ZeroWater 10-Cup Pitcher
NSF 53 certified to reduce lead & chromium — no installation, the easiest way to start protecting your water today.
Check Price on AmazonCompare direct from Waterdrop
Filters rated for lead reduction
Waterdrop's lead collection — every filter here is selected for lead reduction, so you can compare options rated for this exact problem.
Shop Filters Rated for Lead →Whole-Home Filtration System
Whole-house system — treats every tap at the source
For consistently poor water, a whole-home system filters every faucet, shower, and appliance — the permanent, install-once fix that goes beyond a single point-of-use filter.
Explore Whole-Home SystemsNot sure what filter you need?
Test your tap water first, so you filter for what's actually in it.
Shop Home Water Test Kits →We may earn a commission from Amazon and Waterdrop when you purchase through our links, at no extra cost to you.
Based on contaminants detected in your water, these resources may be helpful:
Find the right filter for your Crystal Lake water quality needs:
Tap water is one piece of the picture — our sister sites cover the rest for Crystal Lake, IL.
County radon prediction and EPA zone for homes around Crystal Lake.
Arsenic and nitrate risk for homes on a well instead of city water.
Understand your water better with our in-depth guides on contaminants, filtration, and water safety.