Chromium (hexavalent)
Norwalk Water Department
Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).
38
Samples
0
Samples exceeding legal limit (MCL)
25
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | 0.453 ppb | 35 | 23 | ND - 1.70 ppb |
| 2014 | 1.10 ppb | 3 | 2 | ND - 1.80 ppb |
| 2015 | N/A | 0 | 0 | N/A |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | N/A | 0 | 0 | N/A |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.02 ppb
The EWG Health Guideline of 0.02 ppb for chromium (hexavalent) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2013-01-31 | 440-36867-1 | 1.70 ppb |
| 2013-01-31 | 440-36867-7 | 0.0350 ppb |
| 2013-01-31 | 440-36867-21 | 1.60 ppb |
| 2013-01-31 | 440-36867-23 | 1.60 ppb |
| 2013-01-31 | 440-36867-3 | 1.60 ppb |
| 2013-01-31 | 440-36867-19 | 0.520 ppb |
| 2013-01-31 | 440-36867-15 | ND |
| 2013-01-31 | 440-36867-17 | ND |
| 2013-01-31 | 440-36867-11 | 0.0690 ppb |
| 2013-01-31 | 440-36867-5 | 0.0810 ppb |
| 2013-01-31 | 440-36867-9 | ND |
| 2013-04-30 | 440-45114-11 | 0.440 ppb |
| 2013-04-30 | 440-45114-9 | ND |
| 2013-04-30 | 440-45114-7 | ND |
| 2013-04-30 | 440-45114-5 | 0.0880 ppb |
| 2013-04-30 | 440-45114-1 | 0.0990 ppb |
| 2013-04-30 | 440-45114-3 | ND |
| 2013-07-29 | 2869311 | 1.50 ppb |
| 2013-07-29 | 2869300 | 1.50 ppb |
| 2013-07-29 | 2869375 | ND |
| 2013-07-29 | 2869379 | 0.460 ppb |
| 2013-07-29 | 2869371 | 0.0800 ppb |
| 2013-07-29 | 2869347 | ND |
| 2013-07-29 | 2869387 | 1.50 ppb |
| 2013-07-29 | 2869383 | 1.50 ppb |
| 2013-07-29 | 2869391 | ND |
| 2013-07-29 | 2869356 | ND |
| 2013-07-29 | 2869365 | 0.0500 ppb |
| 2013-07-29 | 2869328 | 0.0500 ppb |
| 2013-10-29 | 2922276 | 0.0400 ppb |
| 2013-10-29 | 2922267 | 0.0800 ppb |
| 2013-10-29 | 2922300 | 0.0500 ppb |
| 2013-10-29 | 2922306 | 1.20 ppb |
| 2013-10-29 | 2922293 | ND |
| 2013-10-29 | 2922287 | ND |
| 2014-12-10 | 9588-012-0924 | ND |
| 2014-12-10 | 9588-003-0945 | 1.80 ppb |
| 2014-12-10 | 9588-002-1020 | 1.50 ppb |