EPA ID TX0150018 · checked 16 Oct 2026
San Antonio tap water: what EPA testing found
San Antonio Water System (EPA record: SAN ANTONIO WATER SYSTEM) serves 2,643,729 people in TX from surface water purchased. It also sells water to other utilities.
What the data shows
PFAS found, below EPA’s limits (PFBS, PFBA, PFPeA)
3 PFAS compounds reached EPA’s reporting level in at least one sample; no sampling point averaged above a limit.
What fits: Pick a filter whose listing certifies PFOA/PFOS (or total PFAS) reduction under NSF/ANSI 53 or 58. Under-sink reverse osmosis units and some carbon filters and pitchers carry it; the certification for the exact model is what counts, not the filter type.
Certified — IAPMO listing, checked 16 Oct 2026- Culligan with ZeroWater Technology 10 Cup PitcherPitcher filter · ZEROP10
- PUR PLUS Lead Reducing Pitcher & Dispenser Replacement FilterPitcher filter · PPF951K
- ZeroWater 5-Stage Replacement FilterPitcher filter · ZR-017
- Culligan Scout 2.25 Gallon Gravity Countertop System with MaxClear…Countertop dispenser · MCSP
- PUR Faucet Filtration System, VerticalFaucet-mount filter · FM-3333B
- PUR PLUS Faucet Filtration System – Horizontal, ChromeFaucet-mount filter · PFM400H
- AquaTru Classic Countertop Reverse Osmosis Water PurifierCountertop reverse osmosis · AT2000
- Aquasana Claryum Direct Connect Under Sink Water FilterUnder-sink filter · AQ-MF-1
- Culligan EZ-Change Under Sink Drinking Water Filtration SystemUnder-sink filter · US-EZ-4
- APEC Water Tankless RO System 4 Stage Water Filter, 1000 GPD Reverse…Under-sink reverse osmosis · ROTL-A1000
- Waterdrop 800 GPD Tankless Reverse Osmosis System - Waterdrop G3P800Under-sink reverse osmosis · WD-G3P800
- Waterdrop G3P600 Reverse Osmosis System - Waterdrop G3P600Under-sink reverse osmosis · WD-G3P600
Brand says certified — not found in IAPMO’s listing; check NSF- Aquasana Clean Water MachineCountertop dispenser · AQ-CWM2-B · check NSF’s listing yourself
- Aquasana Claryum 2-Stage Under Sink Water FilterUnder-sink filter · AQ-6200 · check NSF’s listing yourself
- Aquasana Claryum 3-Stage Max Flow Under Sink Water FilterUnder-sink filter · AQ-6300M · check NSF’s listing yourself
- Aquasana Claryum 3-Stage Under Sink Water FilterUnder-sink filter · AQ-6300 · check NSF’s listing yourself
- A. O. Smith High Efficiency Reverse Osmosis SystemUnder-sink reverse osmosis · AOS-HERO-CHR · check NSF’s listing yourself
- Aquasana SmartFlow Reverse Osmosis Water FilterUnder-sink reverse osmosis · AQ-SFRO2 · check NSF’s listing yourself
- Culligan Aquasential Smart Reverse Osmosis Drinking Water…Under-sink reverse osmosis · Aquasential Smart RO · check NSF’s listing yourself
- Waterdrop Instant Hot Water Dispenser, Reverse Osmosis System, K6Under-sink reverse osmosis · WD-K6-W · check NSF’s listing yourself
- Waterdrop X Series Reverse Osmosis System, X12Under-sink reverse osmosis · WD-X12 · check NSF’s listing yourself
- Aquasana HealthShield Whole House Water Filtration SystemWhole-house filter · WH-HS · check NSF’s listing yourself
NSF’s and WQA’s listings can’t be checked automatically; each product page also links to WQA’s.
Lithium above EPA’s screening level (there is no legal limit)
Highest result 25.5 µg/L; EPA’s health reference level for screening is 10 µg/L.
What fits: EPA has no lithium limit, and no NSF/ANSI standard has a lithium reduction claim, so no home filter is certified for lithium.
Lead from home plumbing (not in this data)
UCMR 5 does not test for lead, and lead usually enters water from service lines and plumbing inside buildings. Your utility’s lead service line inventory says whether your address is served by a lead line.
What fits: Lead comes from lead service lines, solder and fixtures inside buildings, not usually from the treatment plant. Use a filter certified for lead reduction (NSF/ANSI 53 or 58) at the tap you drink from.
Certified — IAPMO listing, checked 16 Oct 2026- Brita Elite Replacement Filter, formerly Longlast+Pitcher filter · OB06
- Culligan with ZeroWater Technology 10 Cup PitcherPitcher filter · ZEROP10
- PUR PLUS Lead Reducing Pitcher & Dispenser Replacement FilterPitcher filter · PPF951K
- ZeroWater 5-Stage Replacement FilterPitcher filter · ZR-017
- Culligan Scout 2.25 Gallon Gravity Countertop System with MaxClear…Countertop dispenser · MCSP
- PUR Faucet Filtration System, VerticalFaucet-mount filter · FM-3333B
- PUR PLUS Faucet Filtration System – Horizontal, ChromeFaucet-mount filter · PFM400H
- AquaTru Classic Countertop Reverse Osmosis Water PurifierCountertop reverse osmosis · AT2000
- Aquasana Claryum Direct Connect Under Sink Water FilterUnder-sink filter · AQ-MF-1
- Culligan EZ-Change Under Sink Drinking Water Filtration SystemUnder-sink filter · US-EZ-4
- Waterdrop 800 GPD Tankless Reverse Osmosis System - Waterdrop G3P800Under-sink reverse osmosis · WD-G3P800
- Waterdrop G3P600 Reverse Osmosis System - Waterdrop G3P600Under-sink reverse osmosis · WD-G3P600
Brand says certified — not found in IAPMO’s listing; check NSF- LifeStraw Home 7-Cup Glass Water Filter PitcherPitcher filter · LSH7SPC101 · check NSF’s listing yourself
- Aquasana Clean Water MachineCountertop dispenser · AQ-CWM2-B · check NSF’s listing yourself
- Brita Elite Advanced Water Filter Faucet System with Brita…Faucet-mount filter · FF-100 · check NSF’s listing yourself
- Brita Hub Countertop Water Filter System with Brita Hub FilterCountertop filter · 87340 · check NSF’s listing yourself
- Aquasana Claryum 2-Stage Under Sink Water FilterUnder-sink filter · AQ-6200 · check NSF’s listing yourself
- Aquasana Claryum 3-Stage Max Flow Under Sink Water FilterUnder-sink filter · AQ-6300M · check NSF’s listing yourself
- Aquasana Claryum 3-Stage Under Sink Water FilterUnder-sink filter · AQ-6300 · check NSF’s listing yourself
- A. O. Smith High Efficiency Reverse Osmosis SystemUnder-sink reverse osmosis · AOS-HERO-CHR · check NSF’s listing yourself
- APEC Water Tankless RO System 4 Stage Water Filter, 1000 GPD Reverse…Under-sink reverse osmosis · ROTL-A1000 · check NSF’s listing yourself
- APEC Water Ultimate 5-Stage 90 GPD High Output Reverse Osmosis Water…Under-sink reverse osmosis · RO-90 · check NSF’s listing yourself
- Aquasana SmartFlow Reverse Osmosis Water FilterUnder-sink reverse osmosis · AQ-SFRO2 · check NSF’s listing yourself
- Culligan Aquasential Smart Reverse Osmosis Drinking Water…Under-sink reverse osmosis · Aquasential Smart RO · check NSF’s listing yourself
- iSpring RCC7AK, NSF Certified 75 GPD, Alkaline 6-Stage Reverse…Under-sink reverse osmosis · RCC7AK · check NSF’s listing yourself
- Waterdrop X Series Reverse Osmosis System, X12Under-sink reverse osmosis · WD-X12 · check NSF’s listing yourself
NSF’s and WQA’s listings can’t be checked automatically; each product page also links to WQA’s.
PFAS and lithium (EPA UCMR 5)
2,730 results from 44 sampling points, 8 May 2023 to 16 Jun 2026. Averages count results below EPA’s reporting level as zero, as the PFAS rule does. Every number links to EPA’s UCMR 5 Data Finder (search PWSID TX0150018). Limits: EPA PFAS rule.
| Contaminant | Detected in | Highest result | Average | EPA limit |
|---|---|---|---|---|
| PFOA | 0 of 91 | not detected | 0 ng/L | 4 ng/L |
| PFOS | 0 of 91 | not detected | 0 ng/L | 4 ng/L |
| PFHxS | 0 of 91 | not detected | 0 ng/L | 10 ng/L* |
| PFNA | 0 of 91 | not detected | 0 ng/L | 10 ng/L* |
| HFPO-DA | 0 of 91 | not detected | 0 ng/L | 10 ng/L* |
| PFBS | 2 of 91 | 3.8 ng/L | 0.08 ng/L | none |
| PFBA | 3 of 91 | 9.2 ng/L | 0.25 ng/L | none |
| PFPeA | 1 of 91 | 3.2 ng/L | 0.04 ng/L | none |
| Lithium | 38 of 91 | 25.5 µg/L | 6.63 µg/L | none (screening level 10 µg/L) |
* PFHxS, PFNA and HFPO-DA limits (and the PFAS hazard index) are in the rule, but EPA proposed on 20 May 2026 to rescind them; not final as of 16 Oct 2026. UCMR 5 results are screening data, not compliance results: compliance uses quarterly running averages from 2029. Source file: EPA UCMR 5 occurrence data (dated 15 Oct 2026).
Health-based violations since 2016
None in EPA’s SDWIS data.
Source: EPA SDWIS via Envirofacts and the ECHO report for TX0150018, retrieved 16 Oct 2026.
Hardness
20 grains per gallon (top of the utility's typical range 15.0-20.0 gpg, undated), from the utility’s water report checked 16 Oct 2026. Size a softener for this water.
Places and ZIP codes served
San Antonio, Boerne, Adkins, Converse, Elmendorf, Helotes, Jbsa Ft Sam Houston, Jbsa Lackland, Mico, Poteet, Schertz, Somerset, Von Ormy.
78006 78015 78023 78056 78065 78069 78073 78101 78109 78112 78154 78201 78202 78203 78204 78205 78207 78208 78209 78210 78211 78212 78213 78214 78215 78216 78217 78218 78219 78220 78221 78222 78223 78224 78225 78226 78227 78228 78229 78230 78231 78232 78233 78234 78235 78236 78237 78238 78239 78240 78242 78244 78245 78247 78248 78249 78250 78251 78252 78253 78254 78255 78256 78257 78258 78259 78260 78261 78263 78264 78266 78284 78288
ZIP codes the system reported to EPA for UCMR 5; place names from GeoNames (CC BY 4.0). A ZIP code can be split between systems.