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EPA system TX1700001 · Texas

City of Conroe: Lithium at or above EPA's 10 ppb health reference level

System ID TX1700001; community water system; Texas; source: purchased surface water; serves 113,912 people via 56,627 connections; status: active

In focus113,912people served, EPA registry
Public records. Clearer context.
Highest result against its EPA referenceLithium
Lithium: 138 ppb; health reference level 10 ppb. highest single sample.138 ppbhealth reference level: 10 ppb

highest single sample; sampled January 2025–October 2025. Source: EPA UCMR 5 final release, August 2026.

City of Conroe is a local-government-owned community water system in Texas serving about 113,912 people, matched to 6 ZIP codes.

< 4.0 ppt
PFOA, highest complete-set average
42 samples, none above the reporting level
MCL 4.0 ppt · not detected above the reporting level
< 4.0 ppt
PFOS, highest complete-set average
42 samples, none above the reporting level
MCL 4.0 ppt · not detected above the reporting level
138 ppb
Lithium, highest single sample
34 of 43 samples above the reporting level
health reference level 10 ppb · at or above the health reference level
0 / 29
PFAS found above the reporting level
1,265 results, 16 entry points
0 at or above an MCL on the average basis
0 ppb
Lead 90th percentile
period ending Dec 31, 2025
action level 15 ppb · below the action level
0
health-based violations since Sep 3, 2016
0 violations in total

What EPA says about what was found

  • Lithium EPA's health reference level is derived from a 2008 provisional toxicity value based on effects seen at therapeutic lithium doses; EPA notes the assessment is provisional. EPA source

Quoted from EPA assessments. This site adds no health claims of its own.

PFAS and lithium: what EPA's national survey found

EPA tested this water for 30 substances and found 1. Lithium reached 138 ppb; EPA's health reference level, which is guidance and not a limit, is 10 ppb.

Between January 2025 and October 2025, EPA's UCMR 5 program tested 1,265 samples from 16 sampling locations for 30 contaminants (29 PFAS plus lithium). 1 were detected above the reporting level in at least one sample. Lithium reached 138 ppb in a single sample, at or above the health reference level of 10 ppb, which is non-regulatory.

Result EPA comparesNot detected, shown at the reporting levelEPA reference value, at the middle of each row's scale
ContaminantResult against the EPA referenceResultStatus
Lithiumhighest single sample
138 ppb
at or above the health reference level
Show the 29 contaminants not detected above the reporting level
11Cl-PF3OUdSnot detected · reporting level 5.0 ppt
< 5.0 ppt
not detected above the reporting level
4:2 FTSnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
6:2 FTSnot detected · reporting level 5.0 ppt
< 5.0 ppt
not detected above the reporting level
8:2 FTSnot detected · reporting level 5.0 ppt
< 5.0 ppt
not detected above the reporting level
9Cl-PF3ONSnot detected · reporting level 2.0 ppt
< 2.0 ppt
not detected above the reporting level
ADONAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
HFPO-DA (GenX)not detected · reporting level 5.0 ppt
< 5.0 ppt
not detected above the reporting level
NEtFOSAAnot detected · reporting level 5.0 ppt
< 5.0 ppt
not detected above the reporting level
NFDHAnot detected · reporting level 20.0 ppt
< 20.0 ppt
not detected above the reporting level
NMeFOSAAnot detected · reporting level 6.0 ppt
< 6.0 ppt
not detected above the reporting level
PFBAnot detected · reporting level 5.0 ppt
< 5.0 ppt
not detected above the reporting level
PFBSnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFDAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFDoAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFEESAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFHpAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFHpSnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFHxAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFHxSnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFMBAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFMPAnot detected · reporting level 4.0 ppt
< 4.0 ppt
not detected above the reporting level
PFNAnot detected · reporting level 4.0 ppt
< 4.0 ppt
not detected above the reporting level
PFOAnot detected · reporting level 4.0 ppt
< 4.0 ppt
not detected above the reporting level
PFOSnot detected · reporting level 4.0 ppt
< 4.0 ppt
not detected above the reporting level
PFPeAnot detected · reporting level 3.0 ppt
< 3.0 ppt
not detected above the reporting level
PFPeSnot detected · reporting level 4.0 ppt
< 4.0 ppt
not detected above the reporting level
PFTAnot detected · reporting level 8.0 ppt
< 8.0 ppt
not detected above the reporting level
PFTrDAnot detected · reporting level 7.0 ppt
< 7.0 ppt
not detected above the reporting level
PFUnAnot detected · reporting level 2.0 ppt
< 2.0 ppt
not detected above the reporting level
Full table: samples, detections, highest single sample, complete-set average and sampling dates for all 30 contaminants
ContaminantSamplesDetectionsHighest single sampleComplete-set average (results used)EPA referenceStatusSampled
Lithium4334138 ppb49.2 ppb (2 of 2)10 ppb health reference level · compared on the highest sampleat or above the health reference levelJanuary 2025 – October 2025
11Cl-PF3OUdS420< 5.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
4:2 FTS420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
6:2 FTS420< 5.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
8:2 FTS420< 5.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
9Cl-PF3ONS420< 2.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
ADONA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
HFPO-DA (GenX)420< 5.0 ppt10.0 ppt MCL (rescission proposed) · compared on the complete-set averagenot detected above the reporting levelJanuary 2025 – October 2025
NEtFOSAA430< 5.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
NFDHA420< 20.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
NMeFOSAA430< 6.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFBA420< 5.0 ppt6,000 ppt screening level · compared on the highest samplenot detected above the reporting levelJanuary 2025 – October 2025
PFBS420< 3.0 ppt2,000 ppt health-based water concentration · compared on the highest samplenot detected above the reporting levelJanuary 2025 – October 2025
PFDA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFDoA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFEESA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFHpA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFHpS420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFHxA420< 3.0 ppt3,000 ppt screening level · compared on the highest samplenot detected above the reporting levelJanuary 2025 – October 2025
PFHxS420< 3.0 ppt10.0 ppt MCL (rescission proposed) · compared on the complete-set averagenot detected above the reporting levelJanuary 2025 – October 2025
PFMBA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFMPA420< 4.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFNA420< 4.0 ppt10.0 ppt MCL (rescission proposed) · compared on the complete-set averagenot detected above the reporting levelJanuary 2025 – October 2025
PFOA420< 4.0 ppt4.0 ppt MCL · compared on the complete-set averagenot detected above the reporting levelJanuary 2025 – October 2025
PFOS420< 4.0 ppt4.0 ppt MCL · compared on the complete-set averagenot detected above the reporting levelJanuary 2025 – October 2025
PFPeA420< 3.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFPeS420< 4.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFTA430< 8.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFTrDA430< 7.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
PFUnA420< 2.0 pptnone setnot detected above the reporting levelJanuary 2025 – October 2025
UCMR 5 is a one-time national monitoring survey. Its results do not indicate compliance or non-compliance with the PFAS Maximum Contaminant Levels, which are enforced on running annual averages and take effect in 2029 (EPA has proposed allowing extensions to 2031). A single result above a limit on this page is a measurement, not a violation.

Sampling-point average: mean of a location's two (ground water) or four (surface water) UCMR 5 results with non-detects counted as zero, EPA's method for comparing UCMR 5 data to the PFAS MCLs. EPA rounds to the reference value's significant digits before deciding whether an average is "greater than" an MCL (PFOA/PFOS averages count as above 4.0 ng/L only from 4.05 ng/L; lithium results count as above the 10 ppb reference only from 15 ppb). This site does not apply that rounding: "at or above" here means the measured value is numerically at or above the reference.

Every detection by sampling location (34 results)
DateSampling locationSource waterContaminantResultReporting level
Jan 2, 2025Sample Tap Wells 4, 3 & 17ground waterLithium48.1 ppb9 ppb
Jan 2, 2025Sample Tap Well 5ground waterLithium43.2 ppb9 ppb
Jan 2, 2025Sample Tap Well 6mixed ground and surface waterLithium36.5 ppb9 ppb
Jan 2, 2025Sample Tap Well 7ground waterLithium16.2 ppb9 ppb
Jan 2, 2025Sample Tap Wells 12 & 13ground waterLithium50.8 ppb9 ppb
Jan 2, 2025Sample Tap Well 15mixed ground and surface waterLithium24.3 ppb9 ppb
Jan 2, 2025Sample Tap Well 18ground waterLithium39.8 ppb9 ppb
Jan 2, 2025Sample Tap # 20mixed ground and surface waterLithium45.9 ppb9 ppb
Jan 2, 2025Sample Tap Well 19ground waterLithium40.8 ppb9 ppb
Jan 2, 2025Sample Tap Well 22mixed ground and surface waterLithium27.6 ppb9 ppb
Jan 2, 2025Sample Tap Well 23ground waterLithium45.9 ppb9 ppb
Jan 2, 2025Sample Tap Well 25ground waterLithium50.8 ppb9 ppb
Jan 2, 2025Sample Tap Well 26ground waterLithium42.2 ppb9 ppb
Apr 28, 2025Sample Tap Well 6mixed ground and surface waterLithium42.9 ppb9 ppb
Apr 28, 2025Sample Tap Well 14mixed ground and surface waterLithium30 ppb9 ppb
Apr 28, 2025Sample Tap Well 15mixed ground and surface waterLithium27.7 ppb9 ppb
Apr 28, 2025Sample Tap Well 21mixed ground and surface waterLithium15 ppb9 ppb
Jul 10, 2025Sample Tap Well 24ground waterLithium138 ppb9 ppb
Jul 10, 2025Sample Tap Wells 4, 3 & 17ground waterLithium44.9 ppb9 ppb
Jul 10, 2025Sample Tap Well 5ground waterLithium42.8 ppb9 ppb
Jul 10, 2025Sample Tap Well 6mixed ground and surface waterLithium20.5 ppb9 ppb
Jul 10, 2025Sample Tap Well 7ground waterLithium48.8 ppb9 ppb
Jul 10, 2025Sample Tap Wells 12 & 13ground waterLithium33.6 ppb9 ppb
Jul 10, 2025Sample Tap Well 14mixed ground and surface waterLithium39.7 ppb9 ppb
Jul 10, 2025Sample Tap Well 15mixed ground and surface waterLithium27.4 ppb9 ppb
Jul 10, 2025Sample Tap Well 18ground waterLithium47 ppb9 ppb
Jul 10, 2025Sample Tap # 20mixed ground and surface waterLithium38.5 ppb9 ppb
Jul 10, 2025Sample Tap Well 19ground waterLithium40.9 ppb9 ppb
Jul 10, 2025Sample Tap Well 21mixed ground and surface waterLithium9.9 ppb9 ppb
Jul 10, 2025Sample Tap Well 22mixed ground and surface waterLithium17.2 ppb9 ppb
Jul 10, 2025Sample Tap Well 23ground waterLithium43.4 ppb9 ppb
Jul 10, 2025Sample Tap Well 25ground waterLithium47.5 ppb9 ppb
Jul 10, 2025Sample Tap Well 26ground waterLithium40.2 ppb9 ppb
Oct 9, 2025Sample Tap Well 22mixed ground and surface waterLithium11.3 ppb9 ppb

Utility-reported context (UCMR 5 questionnaire, aggregated across sampling events): PFAS previously found at this system: no at 44 of 44 sampling events; potential PFAS sources nearby: no at 44 of 44 sampling events.

Lead at customer taps

In the latest completed monitoring period, ending Dec 31, 2025, 9 in 10 sampled homes had lead at or below 0 ppb, below the 15 ppb action level that triggers utility action. None of the 17 periods on record reached it.

Action level 15 ppb015Jan 1, 1999 – Dec 31, 2001: 6.9 ppbJan 1, 2005 – Dec 31, 2007: 6.3 ppbJan 1, 2007 – Dec 31, 2009: 5.1 ppbJan 1, 2008 – Dec 31, 2010: 4.0 ppbJan 1, 2010 – Dec 31, 2012: 3.0 ppbJan 1, 2013 – Dec 31, 2015: 1.6 ppbJan 1, 2017 – Jun 30, 2017: 2.7 ppbJul 1, 2017 – Dec 31, 2017: 4.7 ppbJan 1, 2020 – Jun 30, 2020: 8.5 ppbJan 1, 2021 – Dec 31, 2021: 1.4 ppbJan 1, 2022 – Dec 31, 2022: 1.2 ppbJan 1, 2023 – Dec 31, 2025: 0 ppbDec 31, 2001Dec 31, 20250 ppb

In the most recent completed lead monitoring period, ending Dec 31, 2025, the 90th-percentile lead result at customer taps was 0 ppb, below the action level of 15 ppb (17 monitoring periods on record, none at the action level). The 90th percentile is the value that 9 in 10 sampled homes were at or below. Values are in parts per billion (ppb).

Monitoring periodMetal90th percentileAction levelStatus
Jan 1, 2023 – Dec 31, 2025Lead0 ppb15 ppbbelow the action level
Jan 1, 2022 – Dec 31, 2022Lead1.2 ppb15 ppbbelow the action level
Jan 1, 2021 – Dec 31, 2021Lead1.4 ppb15 ppbbelow the action level
Jan 1, 2020 – Jun 30, 2020Lead8.5 ppb15 ppbbelow the action level
Jul 1, 2017 – Dec 31, 2017Lead4.7 ppb15 ppbbelow the action level
Jan 1, 2017 – Jun 30, 2017Lead2.7 ppb15 ppbbelow the action level
Jan 1, 2013 – Dec 31, 2015Lead1.6 ppb15 ppbbelow the action level
Jan 1, 2010 – Dec 31, 2012Lead3.0 ppb15 ppbbelow the action level
Jan 1, 2008 – Dec 31, 2010Lead4.0 ppb15 ppbbelow the action level
Jan 1, 2007 – Dec 31, 2009Lead5.1 ppb15 ppbbelow the action level
Jan 1, 2005 – Dec 31, 2007Lead6.3 ppb15 ppbbelow the action level
Jan 1, 1999 – Dec 31, 2001Lead6.9 ppb15 ppbbelow the action level
Show all 17 monitoring periods on record
Monitoring periodMetal90th percentileAction levelStatus
Jan 1, 2023 – Dec 31, 2025Lead0 ppb15 ppbbelow the action level
Jan 1, 2022 – Dec 31, 2022Lead1.2 ppb15 ppbbelow the action level
Jan 1, 2021 – Dec 31, 2021Lead1.4 ppb15 ppbbelow the action level
Jan 1, 2020 – Jun 30, 2020Lead8.5 ppb15 ppbbelow the action level
Jul 1, 2017 – Dec 31, 2017Lead4.7 ppb15 ppbbelow the action level
Jan 1, 2017 – Jun 30, 2017Lead2.7 ppb15 ppbbelow the action level
Jan 1, 2013 – Dec 31, 2015Lead1.6 ppb15 ppbbelow the action level
Jan 1, 2010 – Dec 31, 2012Lead3.0 ppb15 ppbbelow the action level
Jan 1, 2008 – Dec 31, 2010Lead4.0 ppb15 ppbbelow the action level
Jan 1, 2007 – Dec 31, 2009Lead5.1 ppb15 ppbbelow the action level
Jan 1, 2005 – Dec 31, 2007Lead6.3 ppb15 ppbbelow the action level
Jan 1, 1999 – Dec 31, 2001Lead6.9 ppb15 ppbbelow the action level
Jan 1, 1996 – Dec 31, 1998Lead4.1 ppb15 ppbbelow the action level
Jan 1, 1995 – Dec 31, 1995Lead2 ppb15 ppbbelow the action level
Jan 1, 1994 – Dec 31, 1994Lead4.5 ppb15 ppbbelow the action level
Jan 1, 1993 – Jun 30, 1993Lead6.9 ppb15 ppbbelow the action level
Jul 1, 1992 – Dec 31, 1992Lead12.4 ppb15 ppbbelow the action level

Drinking water violations since Sep 3, 2016

EPA lists no drinking-water violations for this utility since Sep 3, 2016.

EPA's SDWIS database lists no drinking water violations for this utility since Sep 3, 2016.

None on file.

Sanitary surveys and site visits

Most recent state inspection: Oct 1, 2025 (sanitary survey); 2 visits since Sep 3, 2021.

What you can do about these results

Lithium: what reduces it

Lithium reached 138 ppb in a single sample, at or above EPA's non-regulatory 10 ppb health reference level.

No NSF/ANSI certification claim exists for lithium. Reverse osmosis systems reduce dissolved minerals generally; we do not recommend a specific product for lithium.

ZIP codes served

Sources

Data vintage: EPA UCMR 5 occurrence data, samples collected 2023-01-03 – 2026-06-17, final release, August 2026 (file dated Aug 28, 2026); EPA SDWIS via ECHO, 2026Q2 extract (file dated Jul 9, 2026); EPA service-area boundaries v3.0; Census 2020 ZCTAs. Page generated 2026-09-03.

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