Manganese
Norwalk Water Department
Manganese is a naturally occurring element that is common in food and drinking water. Excessive manganese exposures may impair children's attention, memory and intellectual capacity. Click here to read more about manganese.
41
Samples
0
Samples exceeding legal limit (MCL)
1
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2013 | N/A | 0 | 0 | N/A |
| 2014 | 14.7 ppb | 6 | 3 | ND - 33.0 ppb |
| 2015 | 29.3 ppb | 3 | 3 | 28.0 ppb - 31.0 ppb |
| 2016 | 30.5 ppb | 4 | 4 | 24.0 ppb - 37.0 ppb |
| 2017 | 20.2 ppb | 6 | 4 | ND - 34.0 ppb |
| 2018 | N/A | 0 | 0 | N/A |
| 2019 | 18.8 ppb | 4 | 3 | ND - 26.0 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 100 ppb
The EWG Health Guideline of 100 ppb for manganese was defined by the state of Minnesota as a health risk limit, the concentration of a contaminant that can be consumed with little or no risk to health. This health guideline protects against harm to the brain and nervous system.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-02-19 | 9588-012-0930 | ND |
| 2014-04-29 | 9588-012-0950 | 29.0 ppb |
| 2014-07-23 | 9588-003-1010 | ND |
| 2014-07-23 | 9588-002-1025 | ND |
| 2014-07-23 | 9588-012-0945 | 26.0 ppb |
| 2014-12-10 | 9588-012-0924 | 33.0 ppb |
| 2015-03-25 | 9588-012-0926 | 29.0 ppb |
| 2015-04-23 | 9588-012-0947 | 28.0 ppb |
| 2015-07-30 | 9588-012-0928 | 31.0 ppb |
| 2016-03-24 | 9588-012-0940 | 33.0 ppb |
| 2016-06-09 | 9588-012-0909 | 24.0 ppb |
| 2016-07-20 | 9588-012-0915 | 28.0 ppb |
| 2016-10-12 | 9588-012-0914 | 37.0 ppb |
| 2017-01-18 | 9588-012-0900 | 33.0 ppb |
| 2017-04-17 | 9588-012-0910 | 27.0 ppb |
| 2017-07-24 | 9588-012-0923 | 27.0 ppb |
| 2017-07-24 | 9588-003-0955 | ND |
| 2017-07-24 | 9588-002-1028 | ND |
| 2017-10-18 | 9588-012-0914 | 34.0 ppb |
| 2019-05-24 | 9588-012-0920 | 25.0 ppb |
| 2019-07-25 | 9588-002-1035 | ND |
| 2019-07-25 | 9588-012-0930 | 26.0 ppb |
| 2019-10-25 | 9588-012-0930 | 24.0 ppb |
| 2020-02-12 | 0B07005-04 | 130.0 ppb |
| 2020-02-12 | 0B07005-06 | 23.0 ppb |
| 2020-02-12 | 0B07005-05 | 0.490 ppb |
| 2020-02-12 | 0B07005-03 | 3.60 ppb |
| 2020-02-12 | 0B07005-01 | ND |
| 2020-05-21 | 0E05002-01 | 1.40 ppb |
| 2020-05-21 | 0E05002-02 | 1.30 ppb |
| 2020-05-21 | 0E05002-03 | ND |
| 2020-06-23 | 0F15003-01 | 2.10 ppb |
| 2020-08-27 | 0H19002-04 | 2.20 ppb |
| 2020-08-27 | 0H19002-01 | 2.70 ppb |
| 2020-08-27 | 0H19002-02 | 5.10 ppb |
| 2020-08-27 | 0H19002-05 | ND |
| 2020-08-27 | 0H19002-03 | 2.80 ppb |
| 2020-11-12 | 0K11001-01 | 1.40 ppb |
| 2020-11-12 | 0K11001-02 | 1.40 ppb |
| 2020-11-12 | 0K11001-03 | 1.30 ppb |
| 2020-11-12 | 0K10003-01 | 23.0 ppb |