Is Katy, Texas tap water safe?

91 water systems report serving Katy. Your water depends on which one serves your address. Check your bill if unsure. This list is matched from the ZIP codes in this place, so it may include nearby systems.

A

Harris County MUD 165

Serves 40,503 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

City of Katy

Serves 25,253 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Cimarron MUD

Serves 19,338 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Harris County MUD 71

Serves 17,079 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Harris County MUD 167

Serves 16,761 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Harris County MUD 105

Serves 14,925 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
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Harris County MUD 157

Serves 13,062 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 142

Serves 11,595 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Harris County MUD 81

Serves 11,475 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 58

Serves 10,629 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 182

Serves 10,498 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
B

Langham Creek Utility District

Serves 10,377 people · Surface water · Full report →
No health-based violations in the last 5 years; 5 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Fort Bend County MUD 151

Serves 10,233 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Harris County MUD 495

Serves 9,882 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
B

Harris-Fort Bend Counties MUD 3

Serves 9,297 people · Groundwater · Full report →
No health-based violations in the last 5 years; 5 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Mason Creek Utility District

Serves 8,900 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Harris County MUD 536

Serves 8,070 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Northwest Harris County MUD 12

Serves 7,764 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Weston MUD

Serves 7,647 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Harris County MUD 449

Serves 7,179 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
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Nottingham Country MUD

Serves 7,095 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

West Harris County MUD 2 Chase

Serves 6,921 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; 1 not yet resolved; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Harris County MUD 287

Serves 6,864 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Harris County MUD 64

Serves 6,726 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Memorial MUD

Serves 6,615 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Interstate MUD

Serves 6,591 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Harris County MUD 65

Serves 6,330 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Fort Bend County MUD 35

Serves 6,297 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Cinco MUD 14

Serves 6,192 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Cinco Southwest MUD 4

Serves 6,093 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Harris County MUD 457

Serves 5,967 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
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Cinco MUD 8

Serves 5,613 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Harris County MUD 239

Serves 5,583 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Cinco Southwest MUD 2

Serves 5,496 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Fulshear MUD 3a

Serves 5,421 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

Rolling Creek Utility District

Serves 5,388 people · Surface water · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Fort Bend County MUD 34

Serves 5,367 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Fort Bend County MUD 57

Serves 5,335 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
A

Cornerstones MUD

Serves 5,331 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
B

Mayde Creek MUD

Serves 5,301 people · Surface water · Full report →
1 health-based violation in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

West Harris County MUD 7

Serves 5,289 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Harris County MUD 127

Serves 5,247 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Cinco Southwest MUD 3 Daycare

Serves 5,187 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Ricewood MUD

Serves 4,908 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Harris County MUD 432

Serves 4,782 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
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Cinco MUD 2

Serves 4,743 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Harris Fort Bend Counties MUD 5

Serves 4,641 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Harris County MUD 284

Serves 4,506 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

Clay Road MUD

Serves 4,443 people · Surface water · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2024).
A

Cinco MUD 7

Serves 4,239 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
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West Memorial MUD

Serves 4,182 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2023).
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Harris-Waller Counties MUD 5

Serves 4,098 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Grand Lakes MUD 4

Serves 3,867 people · Surface water · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Cinco MUD 9

Serves 3,828 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Harris Fort Bend Counties MUD 1

Serves 3,812 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
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Fry Road MUD

Serves 3,711 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 185

Serves 3,663 people · Groundwater · Full report →
No health-based violations in the last 5 years; 3 monitoring/reporting violations; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

West Harris County MUD 5

Serves 3,591 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

Harris County MUD 62

Serves 3,519 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Willow Creek Farms MUD

Serves 3,453 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Fort Bend County MUD 122

Serves 3,366 people · Surface water · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

West Harris County MUD 17

Serves 3,354 people · Groundwater · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

Grand Lakes MUD 1

Serves 3,219 people · Surface water · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
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Fort Bend County MUD 130

Serves 3,150 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Cinco MUD 6

Serves 3,048 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Morton Road MUD

Serves 2,817 people · Surface water · Full report →
No health-based violations in the last 5 years; 4 monitoring/reporting violations; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

Cinco MUD 10

Serves 2,583 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 124

Serves 2,544 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Cinco MUD 3

Serves 2,517 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Castlewood MUD

Serves 2,505 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
B

Cinco MUD 5

Serves 2,460 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Cinco MUD 12

Serves 2,274 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Grand Lakes MUD 2

Serves 2,076 people · Surface water · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Harris County MUD 61

Serves 2,016 people · Groundwater · Full report →
No health-based violations in the last 5 years; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 156

Serves 1,719 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Harris County MUD 538

Serves 1,710 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

Willow Point MUD

Serves 1,668 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Fort Bend County MUD 37

Serves 1,662 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Freeman Ranch

Serves 1,308 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Western Pines MHP

Serves 1,170 people · Groundwater · Full report →
No health-based violations in the last 5 years; 3 monitoring/reporting violations; PFAS tested (UCMR 5), none above federal limits; Lead 90th percentile below the action level (2025).
A

Lakehouse Water Plant

Serves 1,071 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Cinco MUD 1

Serves 945 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2026).
A

Hunter Place

Serves 606 people · Groundwater · Full report →
No health-based violations in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Cinco Southwest MUD 1

Serves 513 people · Surface water · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
A

Peek Road Utilities

Serves 480 people · Groundwater · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; 1 not yet resolved; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2022).
A

Waller County MUD 35

Serves 411 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2025).
A

Lake Pointe Estates

Serves 285 people · Groundwater · Full report →
No health-based violations in the last 5 years; 2 monitoring/reporting violations; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
C

Harris County Leadership Academy

Serves 125 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 53 monitoring/reporting violations; 2 not yet resolved; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2023).
C

Peek Road Mobile Home Park

Serves 63 people · Groundwater · Full report →
1 health-based violation in the last 5 years; 35 monitoring/reporting violations; 1 not yet resolved; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2024).
A

August Lakes WSC

Serves 45 people · Groundwater · Full report →
No health-based violations in the last 5 years; No UCMR 5 PFAS results on file; Lead 90th percentile below the action level (2026).
B

Central Harris County Regional Water Aut

Population not reported (often a wholesaler) · Surface water · Full report →
1 health-based violation in the last 5 years; 1 monitoring/reporting violation; No UCMR 5 PFAS results on file.