No health-based violations on EPA record since 2016.
Serves about 807 people (269 connections) with surface water bought from City of Houston, Fallbrook Utility District and Harris County MUD 406.
From EPA's record for TX1012913. PurityMap is independent of Harris County MUD 321.
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No health-based violations in the last 10 years, from EPA's SDWIS compliance database.
No lab results for other contaminants (like PFAS) are on file for this system. EPA required that testing from systems serving more than 3,300 people, plus a sample of smaller ones.
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
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Screening: quick check, not lab-grade
Safe Home (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
Turnaround: 5 minutes
What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638 · 2–4 business days after the lab receives it
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.
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Follow this water →Harris County MUD 321's phone number on EPA record is 281-477-4359. Its mailing address is 3200 SOUTHWEST FWY STE 2600, HOUSTON, TX 77027-7537.
According to EPA's record, Harris County MUD 321 uses surface water bought from City of Houston, Fallbrook Utility District and Harris County MUD 406.
No health-based violations on EPA record since 2016. EPA also lists 1 missed or late test or report in 10 years. The record comes from EPA's SDWIS compliance database.
The 90th-percentile lead result in Harris County MUD 321's latest lead and copper round, which ended in December 2024, was 0.7 µg/L, below the federal action level of 15 µg/L.
PurityMap has no verified website for Harris County MUD 321. Its phone number on EPA record is 281-477-4359. Its mailing address on EPA record is 3200 SOUTHWEST FWY STE 2600, HOUSTON, TX 77027-7537. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.