Diquat
City of Flagstaff
Diquat is a herbicide used on potato crops and aquatic weeds.
30
Samples
0
Samples exceeding legal limit (MCL)
0
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 | ND | 2 | 0 | ND |
| 2015 | ND | 18 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 2 | 0 | ND |
| 2019 | ND | 8 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 6 ppb
The EWG Health Guideline of 6 ppb for diquat 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 cataracts.
EPA Maximum Contaminant
Level (MCL) 20 ppb
The legal limit for diquat, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-08-27 | 201408300317S | ND |
| 2014-10-06 | 201410070846S | ND |
| 2015-04-14 | 201504150294S | ND |
| 2015-07-08 | 20150709265S | ND |
| 2015-07-08 | 20150709264S | ND |
| 2015-07-08 | 20150709263S | ND |
| 2015-07-09 | 201507100128S | ND |
| 2015-07-09 | 201507100126S | ND |
| 2015-07-09 | 201507100124S | ND |
| 2015-07-30 | 201507310184S | ND |
| 2015-08-27 | 201508280194S | ND |
| 2015-09-10 | 201509120269S | ND |
| 2015-10-07 | 201510080415S | ND |
| 2015-10-07 | 201510080483S | ND |
| 2015-10-07 | 201510080461S | ND |
| 2015-10-20 | 201510070069S | ND |
| 2015-10-21 | 201510070066S | ND |
| 2015-10-22 | 201510070067S | ND |
| 2015-10-26 | 201510070060S | ND |
| 2015-11-12 | 201510070068S | ND |
| 2018-06-11 | 201806120451S | ND |
| 2018-09-11 | 201809130645S | ND |
| 2019-01-23 | 201901240323S | ND |
| 2019-01-23 | 201901240321S | ND |
| 2019-03-12 | 201903130529S | ND |
| 2019-03-12 | 201903130527S | ND |
| 2019-07-22 | 201907230337S | ND |
| 2019-07-22 | 201907230199S | ND |
| 2019-09-25 | 201909260284S | ND |
| 2019-09-25 | 201909260285S | ND |