Northwest Harris County MUD 5 water quality report, rewritten

Serves: 25,425
Connections: 8,475
Water source: Surface water bought from another system
Based in: Houston, TX
County: Harris
Owner: Local government

The 2 ZIP codes it serves

PWSID TX1010884 · EPA data

Read this first

Lithium (above EPA’s health benchmark) was found in 10 of 10 samples, highest 87.4 ppb. Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.

No health-based violations on file since 2016. EPA lists 2 monitoring or reporting violations, which are paperwork and testing lapses rather than water quality findings.

What was found

Highlighted: above the health goal, or EPA’s health benchmark where there is no goal. Circled: above the legal limit in at least one sample, or the action level. Every scale puts that line at its middle.

PFAS and lithium: EPA UCMR 5, samples taken from March 13, 2023 to Feb. 16, 2024. Each blue tick on a scale is one sample where it was found.

Lithium (above EPA’s health benchmark)

Comes from the source

87.4ppb

Highest of 10 samples; found in 10

Health reference level 10

87.4

Above EPA’s health reference level of 10 ppb, a screening level rather than an enforceable limit.

What handles it

No certification claim covers this compound yet.

Also found, with no federal limit

EPA measured these PFAS to learn how often they occur. None has a legal limit or a health goal yet.

Compound	Highest sample	Found in	Certification claim
PFBA	19.2 ppt	1 of 10	None covers it
PFPeA	11.9 ppt	1 of 10	None covers it
PFHxA	6.0 ppt	1 of 10	None covers it

Tested and not found

Below EPA’s minimum reporting level in every sample taken from March 13, 2023 to Feb. 16, 2024. Not found means not measured above that level, which is not the same as zero.

All 27 compounds tested and not found

11Cl-PF3OUdS
4:2 FTS
6:2 FTS
8:2 FTS
9Cl-PF3ONS
ADONA
HFPO-DA (GenX)
Lead
NEtFOSAA
NFDHA
NMeFOSAA
PFBS
PFDA
PFDoA
PFEESA
PFHpA
PFHpS
PFHxS
PFMBA
PFMPA
PFNA
PFOA
PFOS
PFPeS
PFTA
PFTrDA
PFUnA

Violations since 2016

No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.

What this report cannot tell you

Levels of everything else. Federal bulk data carries results for PFAS, lithium, lead and copper, and violations for the rest. Nitrate, arsenic, disinfection byproducts and other levels are in Northwest Harris County MUD 5’s own annual report, which it must send you every year.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
Anything after the latest data. SDWIS data is from 2026 Q2; UCMR 5 samples are from March 13, 2023 to Feb. 16, 2024.

Other Texas utilities

All Texas utilities

Sources

EPA UCMR 5 occurrence data, file of Aug. 27, 2026
EPA SDWA bulk download (SDWIS federal data), 2026 Q2
Limits and goals: each contaminant’s page, with its EPA source.
How this page is built: methodology.

What to do next

Read up on Lithium
What each one does to health, where it comes from, and the certification claim that addresses it.
About Lithium
Get the utility’s own report
Northwest Harris County MUD 5 must send you a water quality report every year. It lists nitrate, arsenic and byproduct levels this page cannot.
How to read it
Test your own tap for lead
Your service line, solder and fixtures decide the lead at your faucet, not the utility’s average.
Lead in your water: what to do
Decide if you want a filter at all
A filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.
NSF/ANSI standards, decoded