Short answer: In the 2023–2025 records we hold for Riverside, no listed result is above a legal limit. Also worth knowing: the water is very hard. 7 substances were detected and 26 were tested and not detected. The water is from Riverside Public Utilities, serving 302,776 residents.
Plumbing inside the building is outside this record.
At a glance
Riverside water in four numbers
85/100 · GoodConfidence: highPurity ScoreRIVERSIDE, CITY OF · PWSID CA3310031
7Detected1 above a reference
1Above a referenceof 33 records
0Health-based violationslast 10 years · EPA SDWIS
No measured result is above a legal limit; the water is very hard.
What we found
7 detected results, by distance from their limit
Each bar runs to the named reference; the tick marks it. Open a row for five layers: measured, compared, meaning, where it matters, what to do.
PFOSPerfluorooctanesulfonic acid (PFOS)Within reference · Federal MCL4.0 ng/L federal MCL (2024)4ng/L▾
① · Measured
4 ng/L, sampled 2023-02-07 to 2023-11-20. EPA UCMR 5.
② · Compared
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. EPA health goal (MCLG): 0.
③ · Meaning
Detected at up to 4 ng/L (below 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.
④ · Where it matters
Comes with the source water; home plumbing does not add it.
⑤ · What to do
Test your own tap first. To reduce it: Reverse osmosis, or carbon certified for PFAS (NSF/ANSI 53 or 58 (PFOA/PFOS)).
RIVERSIDE, CITY OF (EPA PWSID CA3310031) delivers surface water to 302,776 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 2024 CCR reports very hard water and chlorine disinfection.
Track record
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.
Your household
Your tap can differ from the city record
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.
Affiliate linksPurityMap 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
★ Best choice: Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200), certified for PFOS and lead.
Reverse osmosisiSpring RCC7AK Alkaline Reverse Osmosis SystemiSpring · It treats only the water from its own faucet and sends part of the water to the drain; the NSF listing for the plain RCC7AK covers dissolved solids, not lead or PFAS.Use code REFISPRING at checkout: 10% off your first iSpring order.
Reverse osmosisiSpring RO5004F Tankless Reverse Osmosis System with UViSpring · Its PFAS and lead reduction claims are iSpring's own, with no third-party certification named for this model, and it treats only the water at its own faucet.Use code REFISPRING at checkout: 10% off your first iSpring order.
Reverse osmosisWaterdrop X12 Reverse Osmosis SystemWaterdrop · Its IAPMO NSF/ANSI 58 certification covers TDS reduction only, so its PFAS and lead claims rest on Waterdrop's own SGS lab testing.
Whole-houseiSpring WGB32B-PFKS PFAS & Heavy Metals Whole House FilteriSpring · It does not reduce total dissolved solids or soften hard water, and its PFAS result comes from SGS lab testing rather than an NSF/ANSI certification.Use code REFISPRING at checkout: 10% off your first iSpring order.
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
Find out if your building has a lead service line
Water utilities keep an inventory of service-line materials. Ask Riverside Public Utilities whether your address is on it before you replace pipes.
Your path: I live in an older buildingLead from plumbing is the main question
Older buildings may have lead service lines, solder or fixtures. Riverside’s record shows lead at 1 µg/L (15 µg/L federal action level). Test first-draw water, then filter if needed.
3 of 29 PFAS tested were detected in Riverside’s record (PFOS 4 ng/L, PFHxA 4.1 ng/L and PFPeA 6.7 ng/L). If PFAS matters to you, a filter certification names each compound it covers.
Look forNSF/ANSI 53 or 58, with each compound you care about named on the listing
PurityMap does not give a safe/unsafe verdict; it shows what the public records measured. For Riverside, PFAS were detected below their limits, and PFPeA 6.7 ng/L with no federal or state limit; the lead 90th-percentile result was 1 µg/L against the 15 µg/L action level. RIVERSIDE, CITY OF (PWSID CA3310031) has a Purity Score of 85/100 (confidence: high), 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 →
Who provides tap water in Riverside?+
RIVERSIDE, CITY OF (PWS ID CA3310031) is the public water system on record for Riverside, California, serving about 302,776 people. Confirm the utility on your water bill before acting on a specific finding. Water utility →
Where does Riverside get its drinking water?+
Surface water (primary source of record in EPA SDWIS). Water utility →
Are PFAS "forever chemicals" in Riverside's water?+
In EPA's UCMR 5 testing (2023-02-07 to 2023-11-20), PFHxA was detected at 4.1 ng/L, below the 400,000 ng/L state limit and PFOS was detected at 4 ng/L, below the 4 ng/L federal limit. PFPeA (6.7 ng/L) was also detected; it has no federal or state limit. What we found →
Is there lead in Riverside's tap water?+
RIVERSIDE, CITY OF's most recent lead 90th-percentile result (2023–2025) was 1 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 →
What does the latest Riverside water report show?+
PurityMap's current record for Riverside holds 33 findings: 1 above a reference, 5 detected within the reference, 1 detected with no limit and 26 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 →
Is Riverside's water hard?+
Riverside's water is recorded as 11.3 gpg, very hard. Hardness is an aesthetic and plumbing characteristic, not a health-based limit. Choose your situation →
EPA SDWIS, EPA UCMR 5 and utility reports, each dated and linked.
02Normalize
Units converted to one basis; a non-detect kept distinct from zero.
03Classify
Each result tagged by reference type: MCL, action level, screening level or aesthetic.
04Compare to the named reference
Every value sits against its own reference, never a blended one.
05Score
Measured subjects summarised at the water-system level; an open health-based violation caps the score.
06Match treatment
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. RIVERSIDE, CITY OF · PWSID CA3310031 · Purity Score 85/100 (Good) · Confidence: high · Assessed at the water-system level
Lead at Riverside Public Utilities: 1 µg/L (90th percentile, 2023–2025 monitoring period). Lead has no taste, so a taste neither shows nor rules it out.
ZIP codes in Riverside
A ZIP code is a postal area, not a water service area. Your water bill names your supplier.