Water Quality in Houston, TX (77056)
EPA violation data for public water systems serving ZIP code 77056.
Active Health Violations
9 health-based violations found in the past 5 years, with at least one still unresolved. Contaminant levels have exceeded federal safety limits. Consider testing your tap water independently.
More violations than 97% of US ZIP codes.
Based on EPA compliance data. Not a substitute for an official water quality report from your utility.
22,877
Population
170
Water Systems
158
Violations (5yr)
9
Health-Based
Location
Loading map...
Water Systems Serving This Area (170)
City Of Houston
1 health-based Surface water 2,970,543 people served
1 violation (5yr)
· 1 health-based · All resolved
Lead tested: 5 ppb (limit: 15 ppb) ✓
City Of Pasadena
Purchased surface water 152,000 people served
3 violations (5yr)
Lead tested: 3.72 ppb (limit: 15 ppb) ✓
Harris Montgomery Counties Mud 386
Purchased groundwater 18,018 people served
0 violations
Harris County Mud 53
Purchased surface water 17,856 people served
0 violations
Harris County Mud 26
Groundwater 16,518 people served
0 violations
Lead tested: 0.99 ppb (limit: 15 ppb) ✓
Harris County Mud 200 Cranbrook
Purchased surface water 14,868 people served
0 violations
Lead tested: 1.03 ppb (limit: 15 ppb) ✓
Remington Mud 1
Purchased surface water 13,743 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 142
Purchased surface water 11,595 people served
0 violations
Lead tested: 2.5 ppb (limit: 15 ppb) ✓
Harris County Wcid 96
Groundwater 10,530 people served
0 violations
Lead tested: 0.5 ppb (limit: 15 ppb) ✓
Harris County Mud 489
Purchased groundwater 10,476 people served
0 violations
Lead tested: 1.47 ppb (limit: 15 ppb) ✓
Langham Creek Utility District
Purchased surface water 10,377 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Wcid 109
Purchased surface water 10,134 people served
0 violations
Lead tested: 2.36 ppb (limit: 15 ppb) ✓
Harris County Wcid 110
Groundwater 9,807 people served
0 violations
Lead tested: 1.78 ppb (limit: 15 ppb) ✓
Barker Cypress Mud
Purchased surface water 8,976 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Jackrabbit Road Pud
Purchased surface water 8,346 people served
0 violations
Lead tested: 2.88 ppb (limit: 15 ppb) ✓
Harris-Fort Bend Counties Mud 3
All resolved Groundwater 7,971 people served
5 violations (5yr)
· All resolved
Lead tested: 2.34 ppb (limit: 15 ppb) ✓
Blue Ridge West Mud
1 health-based Groundwater 7,545 people served
1 violation (5yr)
· 1 health-based · All resolved
Lead tested: 0.3 ppb (limit: 15 ppb) ✓
Harris County Mud 419
Purchased groundwater 7,389 people served
0 violations
Lead tested: 1.11 ppb (limit: 15 ppb) ✓
Addicks Utility District
Purchased surface water 7,017 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 96
Purchased surface water 6,993 people served
0 violations
Sagemeadow Utility District
Purchased surface water 6,987 people served
0 violations
Brazoria County Mud 6
Purchased groundwater 6,926 people served
0 violations
Lead tested: 0.7 ppb (limit: 15 ppb) ✓
Northwest Harris County Mud 15
Groundwater 6,915 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Montgomery County Mud 119 Spring Trails
Groundwater 6,621 people served
0 violations
Montgomery County Mud 95
All resolved Purchased surface water 6,435 people served
1 violation (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 35
Purchased groundwater 6,297 people served
0 violations
Harris County Mud 400 - East
All resolved Purchased surface water 6,066 people served
1 violation (5yr)
· All resolved
Lead tested: 0.54 ppb (limit: 15 ppb) ✓
Harris County Mud 70
Purchased surface water 5,763 people served
0 violations
Lead tested: 1.88 ppb (limit: 15 ppb) ✓
Harris County Mud 239
Groundwater 5,583 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 34
Purchased surface water 5,523 people served
0 violations
Mount Houston Road Mud
Groundwater 5,346 people served
0 violations
Lead tested: 0.5 ppb (limit: 15 ppb) ✓
Westador Mud
Purchased surface water 5,337 people served
0 violations
Lead tested: 2 ppb (limit: 15 ppb) ✓
Harris County Mud 400 - West
Purchased surface water 5,217 people served
0 violations
Lead tested: 1.68 ppb (limit: 15 ppb) ✓
Montgomery County Mud 94
Groundwater 5,184 people served
0 violations
Harris County Mud 276
Purchased surface water 5,094 people served
0 violations
Northwest Harris County Mud 32
All resolved Groundwater 5,016 people served
1 violation (5yr)
· All resolved
Lead tested: 1.56 ppb (limit: 15 ppb) ✓
Ricewood Mud
Groundwater 4,989 people served
0 violations
Lead tested: 2.24 ppb (limit: 15 ppb) ✓
Harris County Mud 360
Groundwater 4,707 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris Fort Bend Counties Mud 5
Groundwater 4,641 people served
0 violations
Lead tested: 4 ppb (limit: 15 ppb) ✓
Harris County Mud 130
All resolved Purchased surface water 4,572 people served
2 violations (5yr)
· All resolved
Harris County Mud 344
Purchased surface water 4,518 people served
1 violation (5yr)
Lead tested: 2.4 ppb (limit: 15 ppb) ✓
Harris County Mud 370
All resolved Purchased surface water 4,452 people served
2 violations (5yr)
· All resolved
Lead tested: 1.83 ppb (limit: 15 ppb) ✓
Plantation Mud
Groundwater 4,263 people served
0 violations
Lead tested: 2 ppb (limit: 15 ppb) ✓
Harris County Mud 166
Purchased surface water 4,239 people served
0 violations
Harris County Mud 536
Groundwater 4,188 people served
0 violations
Lead tested: 0.1 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 41
All resolved Purchased surface water 4,179 people served
43 violations (5yr)
· All resolved
Lead tested: 3.17 ppb (limit: 15 ppb) ✓
Harris County Mud 342
Purchased groundwater 4,035 people served
0 violations
Lead tested: 0.7 ppb (limit: 15 ppb) ✓
Harris County Mud 183
Purchased surface water 3,981 people served
0 violations
Lead tested: 2.1 ppb (limit: 15 ppb) ✓
Cypress Klein Utility District Wimbleton
Groundwater 3,960 people served
0 violations
Lead tested: 2.93 ppb (limit: 15 ppb) ✓
Westlake Mud 1
Groundwater 3,909 people served
0 violations
Lead tested: 0.92 ppb (limit: 15 ppb) ✓
Northgate Crossing Mud 1
Groundwater 3,906 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Grand Lakes Mud 4
Purchased surface water 3,867 people served
0 violations
Harris County Mud 345
Groundwater 3,843 people served
0 violations
Northwest Freeway Mud
Groundwater 3,678 people served
0 violations
Fort Bend County Mud 229
Groundwater 3,666 people served
0 violations
Lead tested: 1.33 ppb (limit: 15 ppb) ✓
Harris County Mud 281
Groundwater 3,573 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 149
Groundwater 3,543 people served
0 violations
Lead tested: 7.79 ppb (limit: 15 ppb) ✓
Harris County Mud 257
All resolved Purchased surface water 3,501 people served
1 violation (5yr)
· All resolved
Lead tested: 3 ppb (limit: 15 ppb) ✓
Harris County Wcid 132
Purchased surface water 3,501 people served
0 violations
Harris County Mud 249
Groundwater 3,420 people served
0 violations
Lead tested: 2.03 ppb (limit: 15 ppb) ✓
Fort Bend County Fwsd 1
Groundwater 3,309 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 282
Purchased groundwater 3,237 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Grand Lakes Mud 1
Purchased surface water 3,219 people served
0 violations
Northwest Harris County Mud 22
Purchased surface water 3,156 people served
0 violations
Lead tested: 0.62 ppb (limit: 15 ppb) ✓
Harris County Wcid Fondren Road
All resolved Purchased surface water 3,144 people served
2 violations (5yr)
· All resolved
Lead tested: 4 ppb (limit: 15 ppb) ✓
Wood Trace Mud 1
All resolved Groundwater 3,084 people served
1 violation (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Green Trails Mud
Groundwater 2,982 people served
0 violations
Lead tested: 3.72 ppb (limit: 15 ppb) ✓
Harris County Mud 399
Purchased groundwater 2,967 people served
0 violations
Harris County Mud 280
Purchased groundwater 2,898 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 434
Groundwater 2,859 people served
0 violations
Lead tested: 0.69 ppb (limit: 15 ppb) ✓
Morton Road Mud
All resolved Purchased surface water 2,817 people served
4 violations (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Montgomery County Mud 98
Purchased surface water 2,766 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 389
Groundwater 2,676 people served
0 violations
Lead tested: 0.82 ppb (limit: 15 ppb) ✓
Spring West Mud
Groundwater 2,639 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Montgomery County Mud 84
Purchased groundwater 2,553 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 215
Groundwater 2,541 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 341
All resolved Purchased surface water 2,421 people served
2 violations (5yr)
· All resolved
Harris Montgomery Counties Mud 386 May V
Purchased surface water 2,364 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Montgomery County Mud 96
Groundwater 2,334 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 44
Groundwater 2,301 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Kirkmont Mud
Purchased surface water 2,289 people served
0 violations
Lead tested: 3.4 ppb (limit: 15 ppb) ✓
Montgomery County Mud 83
Groundwater 2,208 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Grand Lakes Mud 2
Purchased surface water 2,076 people served
0 violations
Audubon Mud 1
Groundwater 2,049 people served
0 violations
Lead tested: 0.64 ppb (limit: 15 ppb) ✓
Sedona Lakes Mud 1
Groundwater 1,977 people served
0 violations
Harris County Mud 494
Purchased groundwater 1,944 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 220
Groundwater 1,812 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Longhorn Town Utility District
Groundwater 1,788 people served
0 violations
Lead tested: 1.55 ppb (limit: 15 ppb) ✓
Generation Park Management District
All resolved Purchased surface water 1,687 people served
2 violations (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 552
All resolved Purchased surface water 1,683 people served
14 violations (5yr)
· All resolved
Lead tested: 0.92 ppb (limit: 15 ppb) ✓
Willow Point Mud
Groundwater 1,668 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Northwest Harris County Mud 28
Purchased surface water 1,605 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 205
Purchased groundwater 1,560 people served
0 violations
Lead tested: 0.38 ppb (limit: 15 ppb) ✓
Harris County Mud 36
Groundwater 1,464 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 537
Purchased surface water 1,416 people served
0 violations
Montgomery County Mud 152a
Purchased groundwater 1,344 people served
0 violations
Harris County Mud 490
All resolved Purchased surface water 1,293 people served
1 violation (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 551
All resolved Purchased surface water 1,269 people served
1 violation (5yr)
· All resolved
Fort Bend County Mud 145 Rio Vista
Purchased groundwater 1,263 people served
0 violations
Lead tested: 0.66 ppb (limit: 15 ppb) ✓
Charleston Mud
Groundwater 1,212 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
West Harris County Mud 16
Purchased surface water 1,175 people served
3 violations (5yr)
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 122
Purchased surface water 1,158 people served
0 violations
Lead tested: 2.58 ppb (limit: 15 ppb) ✓
Harris County Mud 570c
Purchased groundwater 1,113 people served
0 violations
Corinthian Point Mud 2
Groundwater 1,086 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Baker Road Mud
Purchased groundwater 1,062 people served
0 violations
Lead tested: 0.84 ppb (limit: 15 ppb) ✓
Montgomery County Mud 141
2 health-based Purchased groundwater 978 people served
2 violations (5yr)
· 2 health-based · All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 576
Purchased groundwater 822 people served
0 violations
Big Sky Mud
All resolved Groundwater 813 people served
1 violation (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 132
Purchased surface water 795 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Fort Bend County Wcid 3
Groundwater 648 people served
0 violations
Lead tested: 3.1 ppb (limit: 15 ppb) ✓
Montgomery County Mud 42
All resolved Purchased groundwater 630 people served
2 violations (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Harris County Mud 569
Purchased groundwater 549 people served
0 violations
Lead tested: 0.5 ppb (limit: 15 ppb) ✓
Harris County Mud 170
Groundwater 500 people served
0 violations
Lead tested: 1.47 ppb (limit: 15 ppb) ✓
Fort Bend County Mud 66
Purchased surface water 495 people served
0 violations
Cigna Tower
Purchased groundwater 350 people served
0 violations
Camfield Mud
Purchased surface water 350 people served
0 violations
Advanced Rv Park
All resolved Purchased surface water 327 people served
1 violation (5yr)
· All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Montgomery County Mud 172
All resolved Groundwater 264 people served
1 violation (5yr)
· All resolved
Harris County Mud 493
Purchased surface water 255 people served
0 violations
Chambers County Improvement District 2
Purchased surface water 250 people served
0 violations
Lead tested: 0.4 ppb (limit: 15 ppb) ✓
Chambers County Mud 3
Purchased surface water 234 people served
0 violations
Bridgets Basket
Groundwater 225 people served
0 violations
Montgomery County Mud 158
Purchased groundwater 219 people served
0 violations
King Ranch Santa Gertrudis District
Groundwater 212 people served
0 violations
Lead tested: 0.27 ppb (limit: 15 ppb) ✓
Dollar General Bandera Store 21901
Groundwater 210 people served
0 violations
Waller County Mud 34c
All resolved Groundwater 141 people served
1 violation (5yr)
· All resolved
Lead tested: 1.77 ppb (limit: 15 ppb) ✓
Channel Oaks Water System
Groundwater 135 people served
7 violations (5yr)
Lead tested: 2.92 ppb (limit: 15 ppb) ✓
Kocide Chemical Corp - Deer Park
Groundwater 135 people served
0 violations
Fort Bend County Mud 216
Purchased groundwater 133 people served
0 violations
Lead tested: 1.11 ppb (limit: 15 ppb) ✓
Leaning Oak Mobile Home Park
1 health-based Groundwater 105 people served
5 violations (5yr)
· 1 health-based · All resolved
Lead tested: 2.26 ppb (limit: 15 ppb) ✓
Binning'S Bldg Products
Groundwater 100 people served
0 violations
Tampa Warehouse
Groundwater 100 people served
0 violations
Westfield Full Gospel Church
Groundwater 100 people served
0 violations
Harris County Mud 359
Groundwater 85 people served
0 violations
Willow Ridge Estates Utilities Inc
Groundwater 81 people served
0 violations
Oak Acres Mobile Home Park
1 health-based Groundwater 80 people served
13 violations (5yr)
· 1 health-based
Lead tested: 1.9 ppb (limit: 15 ppb) ✓
Montgomery County Mud 144
Groundwater 60 people served
0 violations
Lead tested: 0 ppb (limit: 15 ppb) ✓
Chambers County Improvement District 3
Purchased surface water 60 people served
0 violations
Lead tested: 2.7 ppb (limit: 15 ppb) ✓
Mechanical Systems A C V
Groundwater 60 people served
0 violations
King Ranch Laureles Division
Groundwater 60 people served
0 violations
Guerras Ballroom
Groundwater 50 people served
0 violations
Audubon Mud 2
Purchased groundwater 45 people served
0 violations
Kendall County Wcid 3a
Purchased surface water 45 people served
1 violation (5yr)
Hi-Crush Augusta
Groundwater 40 people served
0 violations
Westlake Royal Roofing
2 health-based Groundwater 40 people served
4 violations (5yr)
· 2 health-based · All resolved
Lead tested: 0 ppb (limit: 15 ppb) ✓
Westlake Royal Roofing Plant 1
All resolved Groundwater 35 people served
5 violations (5yr)
· All resolved
Lead tested: 1 ppb (limit: 15 ppb) ✓
King Ranch Norias
Groundwater 34 people served
1 violation (5yr)
Lead tested: 0.7 ppb (limit: 15 ppb) ✓
Pennypatch Properties
All resolved Groundwater 31 people served
15 violations (5yr)
· All resolved
Am Natural Gas Prod Co Blue Ma
Purchased surface water 25 people served
0 violations
Cities Svc Oil Co Atlas Ii
Purchased groundwater 25 people served
0 violations
Westlake Royal Roofing Plant 2
All resolved Groundwater 25 people served
5 violations (5yr)
· All resolved
Lead tested: 3 ppb (limit: 15 ppb) ✓
Am Natural Gas Prod Co Souther
Purchased surface water 25 people served
0 violations
Harris County Mud 491
Purchased groundwater 25 people served
0 violations
Cities Svc Oil Co Draco
Purchased groundwater 25 people served
0 violations
Galveston Co Mud 14
Groundwater 25 people served
0 violations
Burney Road Mud
Groundwater 1 people served
0 violations
Montgomery County Mud 126
Purchased groundwater 0
0 violations
Montgomery County Mud 152c
Groundwater 0
0 violations
Chaplines Mobile Home Park
Groundwater 0
0 violations
Harris County Mud 387
Groundwater 0
0 violations
Central Harris County Regional Water Aut
1 health-based Purchased surface water 0
2 violations (5yr)
· 1 health-based · All resolved
Harbor Island Terminal Northwest
Purchased surface water 0
0 violations
Harris County Mud 418
Purchased surface water 0
0 violations
Wise County Power Plant
Groundwater 0
0 violations
Camp Strake Bsa
Groundwater 0
0 violations
Montgomery County Mud 40
Purchased surface water 0
0 violations
Weatherford International Nw Loop 338 Od
Groundwater 0
0 violations
Weatherford International Spencer Rd
Groundwater 0
0 violations
Harris County Mud 570d
Groundwater 0
0 violations
Fort Bend County Mud 68
Purchased groundwater 0
0 violations
Contaminants Found
Lead and Copper RuleHealth-Based
Lead and copper testing requirement. Lead exposure can cause developmental harm in children.
16 violations
Has active
LEAD AND COPPER RULE REVISIONSHealth-Based
6 violations
All resolved
Gross Alpha, Excl. Radon and UHealth-Based
2 violations
All resolved
Interim Enhanced Surface Water Treatment RuleHealth-Based
1 violation
All resolved
Public NoticeMonitoring
23 violations
Has active
Revised Total Coliform RuleMonitoring
Missed testing deadlines — not a detection of bacteria.
20 violations
All resolved
E. COLIMonitoring
7 violations
All resolved
Consumer Confidence RuleMonitoring
Annual water quality report delivery requirement.
5 violations
All resolved
NitrateMonitoring
At high levels, nitrate can cause blue baby syndrome in infants.
4 violations
All resolved
p-DichlorobenzeneMonitoring
2 violations
All resolved
1,1,2-TrichloroethaneMonitoring
2 violations
All resolved
EthylbenzeneMonitoring
2 violations
All resolved
BenzeneMonitoring
2 violations
All resolved
trans-1,2-DichloroethyleneMonitoring
2 violations
All resolved
TolueneMonitoring
2 violations
All resolved
1,2-DichloroethaneMonitoring
2 violations
All resolved
Xylenes, TotalMonitoring
2 violations
All resolved
CHLOROBENZENEMonitoring
2 violations
All resolved
1,2-DichloropropaneMonitoring
2 violations
All resolved
o-DichlorobenzeneMonitoring
2 violations
All resolved
DICHLOROMETHANEMonitoring
2 violations
All resolved
Vinyl chlorideMonitoring
2 violations
All resolved
Carbon tetrachlorideMonitoring
2 violations
All resolved
TrichloroethyleneMonitoring
2 violations
All resolved
1,1,1-TrichloroethaneMonitoring
2 violations
All resolved
1,1-DichloroethyleneMonitoring
2 violations
All resolved
1,2,4-TrichlorobenzeneMonitoring
2 violations
All resolved
cis-1,2-DichloroethyleneMonitoring
2 violations
All resolved
TetrachloroethyleneMonitoring
2 violations
All resolved
StyreneMonitoring
2 violations
All resolved
TTHMMonitoring
2 violations
All resolved
Total Haloacetic Acids (HAA5)Monitoring
2 violations
All resolved
2,4,5-TPMonitoring
1 violation
All resolved
PicloramMonitoring
1 violation
All resolved
DinosebMonitoring
1 violation
All resolved
2,4-DMonitoring
1 violation
All resolved
DalaponMonitoring
1 violation
All resolved
Combined UraniumMonitoring
1 violation
All resolved
Combined Radium (-226 and -228)Monitoring
1 violation
All resolved
CYANIDEMonitoring
1 violation
All resolved
NitriteMonitoring
Similar to nitrate — harmful to infants at high levels.
1 violation
All resolved
ChlorineMonitoring
Used to disinfect water — generally safe at regulated levels.
1 violation
All resolved
Lead & Copper Levels
Lead (Pb)
Within limit0.92 ppb measured
Action level: 15 ppb
Sampled: Jul 2025
How Does This Compare?
Houston (77056) has more violations than 97% of US ZIP codes. The national average is 18.87 violations per ZIP over 5 years. This ZIP has 158.
Fewer violations 97th percentile More violations
Recommended Water Filters
Based on health-based violations detected in your area, these filter types are commonly used to address similar contaminants. Consult your water utility's Consumer Confidence Report for the most current data.
Reverse Osmosis System
Highly effective at removing heavy metals, dissolved solids, and a wide range of contaminants. Recommended for homes with lead or arsenic concerns.
Targets:Lead, Copper, Arsenic, Mercury, Cadmium
Look for:NSF/ANSI 58 certified
Always look for filters certified by NSF International for the specific contaminants you want to remove. This is general educational information, not an endorsement of any specific product.