Glyphosate
City of San Luis
Glyphosate is the weedkiller marketed as Roundup. The state of California classifies glyphosate as a chemical known to cause cancer. Read More.
Glyphosate is classified as a probable human carcinogen by the International Agency for Research on Cancer and has been linked to increased risk of non-Hodgkin’s lymphoma in people. Exposure to glyphosate during pregnancy may affect fetal development.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | ND | 4 | 0 | ND |
| 2015 | ND | 12 | 0 | ND |
| 2016 | N/A | 0 | 0 | N/A |
| 2017 | N/A | 0 | 0 | N/A |
| 2018 | ND | 6 | 0 | ND |
| 2019 | ND | 6 | 0 | ND |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 5 ppb
The EWG Health Guideline of 5 ppb for glyphosate was defined by EWG as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
EPA Maximum Contaminant
Level (MCL) 700 ppb
The legal limit for glyphosate, established in 1992, was based on a toxicity study in laboratory animals conducted in the 1980s. This limit does not account for the cancer risks of glyphosate and does not include any additional consideration of children’s health.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2014-02-13 | 479281-005D | ND |
| 2014-02-13 | 479281-005C | ND |
| 2014-02-13 | 479281-005B | ND |
| 2014-02-13 | 479281-005A | ND |
| 2015-05-20 | 201505210191SC | ND |
| 2015-05-20 | 201505210191SB | ND |
| 2015-05-20 | 201505210191SA | ND |
| 2015-05-20 | 201505210177SC | ND |
| 2015-05-20 | 201505210177SB | ND |
| 2015-05-20 | 201505210177SA | ND |
| 2015-11-18 | 201511190130SC | ND |
| 2015-11-18 | 201511190132SC | ND |
| 2015-11-18 | 201511190132SB | ND |
| 2015-11-18 | 201511190132SA | ND |
| 2015-11-18 | 201511190130SB | ND |
| 2015-11-18 | 201511190130SA | ND |
| 2018-03-27 | 201803280607SC | ND |
| 2018-03-27 | 201803280607SB | ND |
| 2018-03-27 | 201803280607SA | ND |
| 2018-03-28 | 201803280608SC | ND |
| 2018-03-28 | 201803280608SB | ND |
| 2018-03-28 | 201803280608SA | ND |
| 2019-03-12 | 201903130096SA | ND |
| 2019-03-12 | 201903130098SC | ND |
| 2019-03-12 | 201903130098SB | ND |
| 2019-03-12 | 201903130098SA | ND |
| 2019-03-12 | 201903130096SC | ND |
| 2019-03-12 | 201903130096SB | ND |