Short answer: In the records we hold for Modesto, two PFAS, PFOA and PFOS, each had a sample above a 2024 EPA limit (not a violation: the limits are judged on a yearly average, due 2029). Also worth knowing: lithium sits above a screening level, and the water is very hard. 10 substances were detected and 22 were tested and not detected. The water is from City of Modesto, serving 218,915 residents.
5 water systems report serving Modesto. This report uses the largest, MODESTO, CITY OF. Your water bill names your actual supplier. Source: EPA SDWIS 2026Q2.
Surface water
The treatment details are not on record.
Mains, then your building’s service line.
Plumbing inside the building is outside this record.
Two PFAS, PFOA and PFOS, each had a sample above a 2024 EPA limit (not a violation: the limits are judged on a yearly average, due 2029); lithium sits above a screening level, and the water is very hard.
26 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
4.0 ng/L federal MCL (2024): a legal limit. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. EPA health goal (MCLG): 0.
One EPA sample measured 26 ng/L, above the 4 ng/L limit EPA set in 2024. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation.
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58 (PFOA/PFOS)).
8.6 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
4.0 ng/L federal MCL (2024): a legal limit. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation. EPA health goal (MCLG): 0.
One EPA sample measured 8.6 ng/L, above the 4 ng/L limit EPA set in 2024. That limit is judged on a yearly average, and water systems have until 2029 to meet it, so a single sample is not a violation.
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58 (PFOA/PFOS)).
21 µg/L, sampled 2023-11-16 to 2024-08-14. EPA UCMR 5.
10 µg/L EPA health reference level (screening, not a legal limit).
Detected at up to 21 µg/L (above the 10 µg/L EPA health reference level; a screening level, not a legal limit).
Where it enters is not in this record.
Test your own tap first. To reduce it: Depends on the contaminant (The certifier's listing for each named contaminant).
9.3 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
10 ng/L federal MCL (2024): a legal limit. That limit is judged on a yearly average, and water systems have until 2029 to meet it.
Detected at up to 9.3 ng/L (below the 10 ng/L limit EPA set in 2024). That limit is judged on a yearly average, and water systems have until 2029 to meet it.
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHxS named on the listing).
12 µg/L, sampled 2025–2027 monitoring period (still open). EPA SDWIS (Lead & Copper Rule).
15 µg/L federal action level. EPA health goal (MCLG): 0.
The 90th-percentile tap result was 12 µg/L (below the 15 µg/L action level) (monitoring period 2025–2027 still open; result reported so far).
Usually from lead service lines, solder and fixtures inside buildings, after the water leaves treatment.
Test your own tap first. To reduce it: Lead-certified carbon filter, or reverse osmosis (NSF/ANSI 53 (lead)).
4.3 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
2,000 ng/L EPA health advisory (screening, not a legal limit).
Detected at up to 4.3 ng/L (below the 2,000 ng/L EPA health advisory; a screening level, not a legal limit).
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFBS named on the listing).
6.1 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
400,000 ng/L Michigan EGLE state MCL (strictest US state): a state limit.
Detected at up to 6.1 ng/L (below the 400,000 ng/L historical comparison reference).
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHxA named on the listing).
11.6 gpg, sampled 2025. Utility CCR.
Aesthetic, no federal health limit.
199 mg/L as CaCO3 (11.6 grains/gal), very hard. Aesthetic (scale/appliances), not a health finding.
Shows up as scale in kettles, water heaters and fixtures.
Test your own tap first. To reduce it: Ion-exchange water softener (NSF/ANSI 44 (softeners)).
3.6 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
No federal limit is on record for it.
Detected at up to 3.6 ng/L. No federal or state limit exists for this substance; shown for transparency, not graded.
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFHpA named on the listing).
6.7 ng/L, sampled 2023-11-16 to 2024-09-12. EPA UCMR 5.
No federal limit is on record for it.
Detected at up to 6.7 ng/L. No federal or state limit exists for this substance; shown for transparency, not graded.
Comes with the source water; home plumbing does not add it.
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58, with PFPeA named on the listing).
MODESTO, CITY OF (EPA PWSID CA5010010) delivers surface water to 218,915 residents. This report reflects 29 individual PFAS result(s) from the source UCMR5 observations and the latest Lead & Copper Rule 90th-percentile result. The utility's 2025 CCR reports very hard water.
0health-based violations in the last 10 years
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit.
No result is not a pass. Your utility's annual water quality report may list them, and a certified lab test covers your own tap.
The record describes water leaving treatment and samples across the system. Pipes, solder and fixtures inside a building can add lead the record can’t see, especially in older buildings with lead service lines.
Test your waterMeasured in this report
Sampled across the system
Not in this record
Only a tap test measures it
Know what comes from your tap, starting with a first-draw lead sample.
Compare each result with its named reference in our test reader.
Choose a technology certified for what your test found.
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Screening: quick check, not lab-grade
Varify
17 strip readings, including lead, chlorine, fluoride, iron and hardness, plus 2 coliform bacteria tests
What it can't tell you: Strip colors give rough ranges, not lab numbers, and it cannot detect PFAS or arsenic.
When your results arrive, read them here → · Compare every kit we list
| Finding | Reference type | Technology | Certification to check |
|---|---|---|---|
| Perfluorooctanesulfonic acid (PFOS)26 ng/L | Federal MCL | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58 (PFOA/PFOS) |
| Perfluorooctanoic acid (PFOA)8.6 ng/L | Federal MCL | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58 (PFOA/PFOS) |
| Lithium21 µg/L | Screening level | Depends on the contaminant | The certifier's listing for each named contaminant |
| Perfluorohexanesulfonic acid (PFHxS)9.3 ng/L | Federal MCL | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58, with PFHxS named on the listing |
| Lead (90th percentile)12 µg/L | Action level | Lead-certified carbon filter, or reverse osmosis | NSF/ANSI 53 (lead) |
| Perfluorobutanesulfonic acid (PFBS)4.3 ng/L | Screening level | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58, with PFBS named on the listing |
| Perfluorohexanoic acid (PFHxA)6.1 ng/L | State limit | Reverse osmosis, or carbon certified for PFAS | NSF/ANSI 53 or 58, with PFHxA named on the listing |
| Water hardness11.6 gpg | Aesthetic, no health limit | Ion-exchange water softener | NSF/ANSI 44 (softeners) |
★ Best choice: Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200), certified for PFOA, PFOS and lead.
| Pick | Product | Details and price | Certification | Why it’s listed | Link |
|---|---|---|---|---|---|
| ★ Best choice | Under-sinkAquasana Claryum 2-Stage Under-Sink Filter (AQ-5200) | TreatsPFOA, PFOS and leadPrice$$ | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price on Amazon |
| Also good | Under-sinkAquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M) | TreatsPFOA, PFOS and leadPrice$$ | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price at Aquasana |
| Also good | CountertopAquasana Clean Water Machine Countertop Filter (AQ-CWM2) | TreatsPFOA, PFOS and leadPrice$$ | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price at Aquasana |
| Pick | Product | Details and price | Certification | Why it’s listed | Link |
|---|---|---|---|---|---|
| Also good | Reverse osmosisSmartFlow® Reverse Osmosis | TreatsPFOA, PFOS and leadTechnologyReverse osmosisPrice$$$ | Certified for PFOA and PFOS (NSF/ANSI 53 (includes P473), WQA) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price at Aquasana |
| Also good | Under-sinkWaterdrop G3P600 Tankless Reverse-Osmosis System | TreatsPFOA, PFOS and leadPrice$$$ | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price at Waterdrop |
| Also good | Under-sinkWaterdrop G3P800 Tankless Reverse-Osmosis System | TreatsPFOA, PFOS and leadPrice$$$ | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price at Waterdrop |
| Also good | CountertopAquaTru Carafe Countertop Reverse-Osmosis Purifier (AT100) | TreatsPFOA, PFOS and leadPrice$$$ | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price on Amazon |
| Also good | CountertopAquaTru Classic Countertop Reverse-Osmosis Purifier (AT2000) | TreatsPFOA, PFOS and leadPrice$$$ | Certified for PFOA and PFOS (NSF/ANSI 53, IAPMO) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price on Amazon |
| Also good | CountertopPatriot Pure Ultimate Water Filtration System | TreatsPFOA, PFOS and leadPrice$$ | Certified for PFOA and PFOS (NSF/ANSI 53, NSF, IAPMO) | Why it’s listed: its current certification names PFOA and PFOS, found in Modesto’s record.See the evidence | Check price on Amazon |
| Also good | Reverse osmosisiSpring RCC7AK Alkaline Reverse Osmosis SystemUse code REFISPRING at checkout: 10% off your first iSpring order. | TechnologyReverse osmosisPrice$$ | Brand lab-tested for PFAS, not independently certified for PFOA, PFOS, Perfluorobutanesulfonic acid (PFBS), Perfluorohexanoic acid (PFHxA), PFHxS, Perfluoroheptanoic acid (PFHpA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at iSpring |
| Also good | Reverse osmosisiSpring RO5004F Tankless Reverse Osmosis System with UVUse code REFISPRING at checkout: 10% off your first iSpring order. | TechnologyReverse osmosisPrice$$$ | Brand lab-tested for PFAS, not independently certified for PFOA, PFOS, Perfluorobutanesulfonic acid (PFBS), Perfluorohexanoic acid (PFHxA), PFHxS, Perfluoroheptanoic acid (PFHpA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at iSpring |
| Also good | Reverse osmosisWaterdrop X12 Reverse Osmosis System | TechnologyReverse osmosisPrice$$$$ | Brand lab-tested for PFAS, not independently certified for PFOA, PFOS, Perfluorobutanesulfonic acid (PFBS), Perfluorohexanoic acid (PFHxA), PFHxS, Perfluoroheptanoic acid (PFHpA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at Waterdrop |
★ Best choice: HealthShield™, certified for PFOA, PFOS, PFHxS and Perfluoroheptanoic acid (PFHpA).
| Pick | Product | Details and price | Certification | Why it’s listed | Link |
|---|---|---|---|---|---|
| ★ Best choice | Whole-houseHealthShield™ | TreatsPFOA, PFOS, PFHxS and Perfluoroheptanoic acid (PFHpA)Price$$$$ | Certified for PFOA, PFOS, PFHxS and Perfluoroheptanoic acid (PFHpA) (NSF/ANSI 53, WQA) | Why it’s listed: its current certification names PFOA, PFOS, PFHxS and Perfluoroheptanoic acid (PFHpA), found in Modesto’s record.See the evidence | Check price at Aquasana |
| $ Budget pick | Whole-houseiSpring WGB32B-PFKS PFAS & Heavy Metals Whole House FilterUse code REFISPRING at checkout: 10% off your first iSpring order. | Price$$$ | Brand lab-tested for PFAS, not independently certified for PFOA, PFOS, Perfluorobutanesulfonic acid (PFBS), Perfluorohexanoic acid (PFHxA), PFHxS, Perfluoroheptanoic acid (PFHpA) and Perfluoropentanoic acid (PFPeA) | See the evidence | Check price at iSpring |
Also: lead picks → · hard water picks →
Certified filters for lithium →
PurityMap earns a commission from these links. "Best choice" and "Budget pick" go to certified products first; commission never decides them. As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Ask your utility first
Water utilities keep an inventory of service-line materials. Ask City of Modesto whether your address is on it before you replace pipes.
Local help
Call to be connected with a local plumbing provider about lead service lines, repiping or fixture replacement.
Older buildings may have lead service lines, solder or fixtures. Modesto’s record shows lead at 12 µg/L (15 µg/L federal action level). Test first-draw water, then filter if needed.
7 of 29 PFAS tested were detected in Modesto’s record (PFOS 26 ng/L, PFOA 8.6 ng/L and PFHxS 9.3 ng/L, and more); 2 above their limit. If PFAS matters to you, a filter certification names each compound it covers.
Most utilities keep chlorine or chloramine in the pipes. A carbon filter certified for taste and odor reduces either; your utility can tell you which it uses.
Scale is a comfort and appliance issue, not a health one.
Reverse osmosis reduces many dissolved contaminants, including lead and minerals, at a single faucet, with some water sent to drain.
Get one email when Modesto’s record changes.
One email when a new sampling round is published, a result moves above or below its reference, or the system's score changes.PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For Modesto, PFOS 26 ng/L and PFOA 8.6 ng/L were measured in one EPA sample each, above the 4 ng/L limit EPA set in 2024 (not a violation: the limits are judged on a yearly average, due 2029); the lead 90th-percentile result was 12 µg/L against the 15 µg/L action level. MODESTO, CITY OF (PWSID CA5010010) has a Purity Score of 43/100 (confidence: moderate), assessed at the water-system level and computed only from contaminants that were measured. Water can change in your own pipes, so a certified test is the only way to know what comes out of your tap. What we found →
MODESTO, CITY OF (PWS ID CA5010010) is the public water system on record for Modesto, California, serving about 218,915 people. Confirm the utility on your water bill before acting on a specific finding. Water utility →
Surface water (primary source of record in EPA SDWIS). Water utility →
Yes. In EPA's UCMR 5 testing (2023-11-16 to 2024-09-12), PFOS was measured at 26 ng/L in one EPA sample, above the 4 ng/L limit EPA set in 2024 and PFOA was measured at 8.6 ng/L in one EPA sample, above the 4 ng/L limit EPA set in 2024. EPA's 2024 limits are judged on a yearly average, and water systems have until 2029 to meet them, so a single sample is not a violation. PFBS (4.3 ng/L, below the 2,000 ng/L EPA health advisory), PFHxA (6.1 ng/L, below the 400,000 ng/L state limit) and PFHxS (9.3 ng/L, below the 10 ng/L federal limit) were also detected. PFHpA (3.6 ng/L) and PFPeA (6.7 ng/L) were also detected; they have no federal or state limit. Reverse osmosis and filters certified to NSF/ANSI 53 for PFOA/PFOS reduce them at the tap. What we found →
MODESTO, CITY OF's most recent lead 90th-percentile result (2025–2027) was 12 µg/L, below the 15 µg/L action level. That figure comes from sampled homes; lead usually enters from a building's own pipes and fixtures, so only a test at your tap tells you what you drink. Your household →
PurityMap's current record for Modesto holds 32 findings: 4 above a reference, 4 detected within the reference, 2 detected with no limit and 22 not detected. Each finding links to its dated public record; a parameter that was never monitored is shown as pending, not as a pass. Records →
Modesto's water is recorded as 11.6 gpg, very hard. Hardness is an aesthetic and plumbing characteristic, not a health-based limit. Choose your situation →
| Contaminant | Measured | Reference | Sampled | Source |
|---|---|---|---|---|
| Perfluorooctanesulfonic acid (PFOS) | 26 ng/L | 4.0 ng/L federal MCL (2024) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorooctanoic acid (PFOA) | 8.6 ng/L | 4.0 ng/L federal MCL (2024) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Lithium | 21 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Water hardness | 11.6 gpg | Aesthetic, no federal health limit | 2025 | Utility CCR ↗ (opens in a new tab) |
| Perfluorohexanesulfonic acid (PFHxS) | 9.3 ng/L | 10 ng/L federal MCL (2024) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Lead (90th percentile) | 12 µg/L | 15 µg/L federal action level | 2025–2027 | EPA SDWIS (Lead & Copper Rule) ↗ (opens in a new tab) |
| Perfluorobutanesulfonic acid (PFBS) | 4.3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorohexanoic acid (PFHxA) | 6.1 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoroheptanoic acid (PFHpA) | 3.6 ng/L | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoropentanoic acid (PFPeA) | 6.7 ng/L | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L (not detected) | 10 ng/L federal MCL (2024) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorobutanoic acid (PFBA) | < 5 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L (not detected) | 10 ng/L federal MCL (2024) | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L (not detected) | No federal or state limit; shown for transparency | 2023–2024 | EPA UCMR 5 ↗ (opens in a new tab) |
UCMR5 Analytical Results
UCMR5 Analytical Results: MODESTO, CITY OF (CA5010010)
US EPA
State SDWIS Compliance Record
Lead & Copper Rule 90th-percentile: MODESTO, CITY OF (CA5010010)
US EPA SDWIS
Consumer Confidence Report (CCR)
City of Modesto – Modesto System–5010010 (Includes Empire) 2025 Consumer Confidence Report (CCR)
City of Modesto – Modesto System–5010010 (Includes Empire)
Methodology: how we analyze water. Prepared with AI assistance and reviewed by the PurityMap Editorial Team before publication.
EPA SDWIS, EPA UCMR 5 and utility reports, each dated and linked.
Units converted to one basis; a non-detect kept distinct from zero.
Each result tagged by reference type: MCL, action level, screening level or aesthetic.
Every value sits against its own reference, never a blended one.
Measured subjects summarised at the water-system level; an open health-based violation caps the score.
Treatment is matched to what was found; a product is called certified only when its current certification names it.
What the Purity Score means: a summary of this water system’s published record, capped while a health-based violation is open. It is not a test of any tap. MODESTO, CITY OF · PWSID CA5010010 · Purity Score 43/100 (Poor) · Confidence: moderate · Assessed at the water-system level
Full methodology →Start with the hot-or-cold tap check. Where City of Modesto reported something related, it's shown below.
Lead at City of Modesto: 12 µg/L (90th percentile, 2025–2027 monitoring period (still open)). Lead has no taste, so a taste neither shows nor rules it out.