Nitrate
Gleanings For The Hungry
Nitrate, a fertilizer chemical, frequently contaminates drinking water due to agricultural and urban runoff, and discharges from municipal wastewater treatment plants and septic tanks. Excessive nitrate in water can cause oxygen deprivation in infants and increase the risk of cancer. Click here to read more about nitrate.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 17.7 ppm | 37 | 37 | 2.20 ppm - 47.0 ppm |
| 2019 | 19.3 ppm | 32 | 31 | ND - 46.0 ppm |
| 2020 | 16.1 ppm | 28 | 25 | ND - 48.0 ppm |
| 2021 | 11.3 ppm | 44 | 42 | ND - 50.0 ppm |
| 2022 | 9.20 ppm | 42 | 41 | ND - 49.0 ppm |
| 2023 | 4.25 ppm | 34 | 32 | ND - 9.30 ppm |
ppm = parts per million
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 0.14 ppm
The EWG health guideline of 0.14 parts per million, or ppm, for nitrate and nitrite is based on the equivalent health guideline for nitrate, as defined in a peer-reviewed scientific study by EWG. This guideline represents a one-in-one-million annual cancer risk level.
EPA Maximum Contaminant
Level (MCL): 10 ppm
The legal limit for nitrate, established in 1962, was developed to protect infants from acute methemoglobinemia, a life-threatening disorder of oxygen transport in the body. This limit does not fully protect against the risk of cancer and harm to the developing fetus.
ppm = parts per million
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-01-18 | CA5402047_021_021-201801181105 | 3.40 ppm |
| 2018-01-18 | CA5402047_018_018-201801181100 | 43.0 ppm |
| 2018-01-18 | CA5402047_017_017-201801181050 | 5.30 ppm |
| 2018-02-08 | CA5402047_021_021-201802081435 | 3.40 ppm |
| 2018-02-08 | CA5402047_018_018-201802081430 | 47.0 ppm |
| 2018-03-20 | CA5402047_017_017-201803201110 | 9.00 ppm |
| 2018-03-20 | CA5402047_018_018-201803201150 | 41.0 ppm |
| 2018-03-20 | CA5402047_021_021-201803201350 | 3.20 ppm |
| 2018-04-24 | CA5402047_017_017-201804241230 | 5.60 ppm |
| 2018-04-24 | CA5402047_018_018-201804241335 | 43.0 ppm |
| 2018-04-24 | CA5402047_021_021-201804241340 | 3.30 ppm |
| 2018-05-11 | CA5402047_018_018-201805110800 | 41.0 ppm |
| 2018-05-11 | CA5402047_021_021-201805110930 | 3.30 ppm |
| 2018-05-11 | CA5402047_017_017-201805110750 | 9.40 ppm |
| 2018-06-22 | CA5402047_018_018-201806221400 | 41.0 ppm |
| 2018-06-22 | CA5402047_017_017-201806221355 | 6.60 ppm |
| 2018-06-22 | CA5402047_021_021-201806221405 | 3.80 ppm |
| 2018-07-04 | CA5402047_018_018-201807041016 | 41.0 ppm |
| 2018-07-04 | CA5402047_017_017-201807041010 | 2.70 ppm |
| 2018-07-04 | CA5402047_021_021-201807041039 | 3.80 ppm |
| 2018-08-09 | CA5402047_017_017-201808091102 | 7.20 ppm |
| 2018-08-09 | CA5402047_018_018-201808091113 | 40.0 ppm |
| 2018-08-09 | CA5402047_021_021-201808091127 | 3.00 ppm |
| 2018-09-20 | CA5402047_021_021-201809201025 | 3.20 ppm |
| 2018-09-20 | CA5402047_017_017-201809201015 | 2.20 ppm |
| 2018-09-20 | CA5402047_018_018-201809201020 | 43.0 ppm |
| 2018-09-24 | CA5402047_017_017-201809241025 | 2.70 ppm |
| 2018-09-24 | CA5402047_018_018-201809241038 | 42.0 ppm |
| 2018-10-09 | CA5402047_017_017-201810091329 | 3.00 ppm |
| 2018-10-09 | CA5402047_018_018-201810091336 | 42.0 ppm |
| 2018-10-09 | CA5402047_021_021-201810091343 | 3.60 ppm |
| 2018-11-05 | CA5402047_018_018-201811051327 | 42.0 ppm |
| 2018-11-05 | CA5402047_021_021-201811051459 | 3.80 ppm |
| 2018-11-05 | CA5402047_017_017-201811051339 | 8.60 ppm |
| 2018-12-05 | CA5402047_021_021-201812051053 | 3.60 ppm |
| 2018-12-05 | CA5402047_017_017-201812051046 | 3.50 ppm |
| 2018-12-05 | CA5402047_018_018-201812051037 | 42.0 ppm |
| 2019-01-08 | CA5402047_018_018-201901080945 | 41.0 ppm |
| 2019-01-08 | CA5402047_021_021-201901081000 | 16.0 ppm |
| 2019-01-08 | CA5402047_017_017-201901080950 | 5.50 ppm |
| 2019-01-15 | CA5402047_021_021-201901151435 | 3.80 ppm |
| 2019-02-05 | CA5402047_017_017-201902051334 | 2.90 ppm |
| 2019-02-05 | CA5402047_018_018-201902051320 | 45.0 ppm |
| 2019-03-11 | CA5402047_018_018-201903111335 | 43.0 ppm |
| 2019-03-11 | CA5402047_017_017-201903111342 | 3.60 ppm |
| 2019-03-11 | CA5402047_021_021-201903111347 | 1.10 ppm |
| 2019-04-11 | CA5402047_021_021-201904111200 | 3.20 ppm |
| 2019-04-11 | CA5402047_017_017-201904111145 | 6.90 ppm |
| 2019-04-11 | CA5402047_018_018-201904111150 | 41.0 ppm |
| 2019-05-08 | CA5402047_017_017-201905081605 | 4.80 ppm |
| 2019-05-08 | CA5402047_018_018-201905081610 | 41.0 ppm |
| 2019-06-11 | CA5402047_018_018-201906111400 | 41.0 ppm |
| 2019-06-11 | CA5402047_017_017-201906111430 | 6.00 ppm |
| 2019-07-12 | CA5402047_021_021-201907121020 | 8.00 ppm |
| 2019-07-12 | CA5402047_017_017-201907121010 | 2.50 ppm |
| 2019-07-12 | CA5402047_018_018-201907121015 | 42.0 ppm |
| 2019-08-19 | CA5402047_021_021-201908191345 | 8.60 ppm |
| 2019-08-19 | CA5402047_017_017-201908191335 | 6.60 ppm |
| 2019-08-19 | CA5402047_018_018-201908191340 | 42.0 ppm |
| 2019-09-26 | CA5402047_017_017-201909261044 | 6.50 ppm |
| 2019-09-26 | CA5402047_021_021-201909261100 | ND |
| 2019-09-26 | CA5402047_018_018-201909261050 | 44.0 ppm |
| 2019-10-31 | CA5402047_017_017-201910311145 | 7.20 ppm |
| 2019-10-31 | CA5402047_018_018-201910311150 | 46.0 ppm |
| 2019-10-31 | CA5402047_021_021-201910311305 | 2.90 ppm |
| 2019-11-27 | CA5402047_017_017-201911271440 | 6.90 ppm |
| 2019-11-27 | CA5402047_018_018-201911271445 | 42.0 ppm |
| 2019-12-19 | CA5402047_018_018-201912191510 | 45.0 ppm |
| 2019-12-19 | CA5402047_017_017-201912191500 | 2.20 ppm |
| 2020-01-29 | CA5402047_017_017-202001291020 | 9.10 ppm |
| 2020-01-29 | CA5402047_018_018-202001291030 | 42.0 ppm |
| 2020-03-23 | CA5402047_018_018-202003231130 | 42.0 ppm |
| 2020-03-23 | CA5402047_017_017-202003231120 | 4.80 ppm |
| 2020-04-15 | CA5402047_017_017-202004151030 | 6.40 ppm |
| 2020-04-15 | CA5402047_018_018-202004151040 | 45.0 ppm |
| 2020-05-15 | CA5402047_018_018-202005150820 | 43.0 ppm |
| 2020-05-15 | CA5402047_022_022-202005150935 | 1.30 ppm |
| 2020-05-15 | CA5402047_017_017-202005150815 | 6.80 ppm |
| 2020-05-22 | CA5402047_022_022-202005221445 | 1.80 ppm |
| 2020-06-15 | CA5402047_017_017-202006151455 | 7.80 ppm |
| 2020-06-15 | CA5402047_022_022-202006151510 | 2.60 ppm |
| 2020-07-15 | CA5402047_017_017-202007151400 | 2.10 ppm |
| 2020-07-15 | CA5402047_022_022-202007151415 | 5.70 ppm |
| 2020-08-05 | CA5402047_017_017-202008051330 | 9.70 ppm |
| 2020-08-05 | CA5402047_022_022-202008051350 | ND |
| 2020-09-22 | CA5402047_018_018-202009221020 | 46.0 ppm |
| 2020-09-22 | CA5402047_017_017-202009221015 | 6.70 ppm |
| 2020-09-22 | CA5402047_022_022-202009221035 | ND |
| 2020-10-19 | CA5402047_022_022-202010191420 | ND |
| 2020-10-19 | CA5402047_018_018-202010191405 | 48.0 ppm |
| 2020-10-19 | CA5402047_017_017-202010191400 | 9.50 ppm |
| 2020-11-10 | CA5402047_018_018-202011101335 | 46.0 ppm |
| 2020-11-10 | CA5402047_017_017-202011101330 | 6.80 ppm |
| 2020-11-10 | CA5402047_022_022-202011101340 | 0.480 ppm |
| 2020-12-17 | CA5402047_017_017-202012171420 | 7.50 ppm |
| 2020-12-17 | CA5402047_018_018-202012171425 | 48.0 ppm |
| 2020-12-28 | CA5402047_022_022-202012281405 | 2.10 ppm |
| 2021-01-19 | CA5402047_018_018-202101191335 | 49.0 ppm |
| 2021-01-19 | CA5402047_022_022-202101191345 | 2.20 ppm |
| 2021-01-19 | CA5402047_017_017-202101191330 | 8.30 ppm |
| 2021-01-19 | CA5402047_021_021-202101191340 | 0.640 ppm |
| 2021-02-17 | CA5402047_017_017-202102171550 | 5.80 ppm |
| 2021-02-17 | CA5402047_021_021-202102171600 | 0.650 ppm |
| 2021-02-17 | CA5402047_022_022-202102171605 | 1.60 ppm |
| 2021-03-16 | CA5402047_017_017-202103161300 | 6.60 ppm |
| 2021-03-16 | CA5402047_021_021-202103161310 | 0.680 ppm |
| 2021-03-16 | CA5402047_022_022-202103161315 | 2.00 ppm |
| 2021-03-16 | CA5402047_018_018-202103161305 | 46.0 ppm |
| 2021-04-21 | CA5402047_017_017-202104211400 | 5.80 ppm |
| 2021-04-21 | CA5402047_018_018-202104211405 | 42.0 ppm |
| 2021-04-21 | CA5402047_021_021-202104211410 | 0.640 ppm |
| 2021-04-21 | CA5402047_022_022-202104211415 | 3.40 ppm |
| 2021-05-07 | CA5402047_017_017-202105071330 | 6.60 ppm |
| 2021-05-07 | CA5402047_021_021-202105071345 | 0.780 ppm |
| 2021-05-07 | CA5402047_018_018-202105071335 | 44.0 ppm |
| 2021-05-07 | CA5402047_022_022-202105071340 | 4.60 ppm |
| 2021-06-24 | CA5402047_017_017-202106241425 | 7.10 ppm |
| 2021-06-24 | CA5402047_022_022-202106241440 | ND |
| 2021-06-24 | CA5402047_021_021-202106241435 | 0.870 ppm |
| 2021-07-21 | CA5402047_022_022-202107211415 | 3.20 ppm |
| 2021-07-21 | CA5402047_017_017-202107211400 | 7.80 ppm |
| 2021-07-21 | CA5402047_018_018-202107211405 | 49.0 ppm |
| 2021-07-21 | CA5402047_021_021-202107211410 | 0.800 ppm |
| 2021-08-30 | CA5402047_018_018-202108301135 | 43.0 ppm |
| 2021-08-30 | CA5402047_021_021-202108301140 | 0.760 ppm |
| 2021-08-30 | CA5402047_022_022-202108301145 | 8.60 ppm |
| 2021-08-30 | CA5402047_017_017-202108301130 | 8.50 ppm |
| 2021-09-20 | CA5402047_017_017-202109201510 | 8.40 ppm |
| 2021-09-20 | CA5402047_022_022-202109201455 | ND |
| 2021-09-20 | CA5402047_021_021-202109201500 | 0.720 ppm |
| 2021-09-20 | CA5402047_018_018-202109201515 | 50.0 ppm |
| 2021-10-27 | CA5402047_017_017-202110271130 | 7.70 ppm |
| 2021-10-27 | CA5402047_022_022-202110271145 | 2.00 ppm |
| 2021-10-27 | CA5402047_021_021-202110271140 | 0.890 ppm |
| 2021-11-10 | CA5402047_021_021-202111101410 | 0.980 ppm |
| 2021-11-10 | CA5402047_022_022-202111101415 | 1.20 ppm |
| 2021-11-10 | CA5402047_017_017-202111101400 | 7.10 ppm |
| 2021-12-23 | CA5402047_021_021-202112230915 | 0.760 ppm |
| 2021-12-23 | CA5402047_022_022-202112230910 | 0.830 ppm |
| 2021-12-23 | CA5402047_017_017-202112230900 | 8.30 ppm |
| 2021-12-23 | CA5402047_018_018-202112230905 | 49.0 ppm |
| 2022-01-25 | CA5402047_022_022-202201251415 | 1.80 ppm |
| 2022-01-25 | CA5402047_021_021-202201251410 | 0.650 ppm |
| 2022-01-25 | CA5402047_017_017-202201251400 | 8.90 ppm |
| 2022-02-23 | CA5402047_022_022-202202231430 | 2.10 ppm |
| 2022-02-23 | CA5402047_017_017-202202231400 | 9.30 ppm |
| 2022-02-23 | CA5402047_018_018-202202231410 | 49.0 ppm |
| 2022-02-23 | CA5402047_021_021-202202231440 | 0.610 ppm |
| 2022-03-17 | CA5402047_018_018-202203171005 | 48.0 ppm |
| 2022-03-17 | CA5402047_022_022-202203171010 | 2.40 ppm |
| 2022-03-17 | CA5402047_017_017-202203171000 | 2.00 ppm |
| 2022-03-17 | CA5402047_021_021-202203171020 | 0.550 ppm |
| 2022-04-12 | CA5402047_017_017-202204121400 | 6.90 ppm |
| 2022-04-12 | CA5402047_018_018-202204121405 | 48.0 ppm |
| 2022-04-12 | CA5402047_021_021-202204121410 | 0.720 ppm |
| 2022-04-12 | CA5402047_022_022-202204121415 | 2.20 ppm |
| 2022-05-27 | CA5402047_022_022-202205271315 | 3.30 ppm |
| 2022-05-27 | CA5402047_017_017-202205271300 | 7.40 ppm |
| 2022-05-27 | CA5402047_021_021-202205271310 | 0.780 ppm |
| 2022-06-29 | CA5402047_017_017-202206290940 | 7.00 ppm |
| 2022-06-29 | CA5402047_022_022-202206290955 | 4.40 ppm |
| 2022-06-29 | CA5402047_021_021-202206290950 | 0.750 ppm |
| 2022-07-25 | CA5402047_022_022-202207251345 | 6.70 ppm |
| 2022-07-25 | CA5402047_021_021-202207251340 | 0.890 ppm |
| 2022-07-25 | CA5402047_017_017-202207251330 | 7.90 ppm |
| 2022-07-25 | CA5402047_018_018-202207251335 | 48.0 ppm |
| 2022-08-23 | CA5402047_017_017-202208231300 | 8.60 ppm |
| 2022-08-23 | CA5402047_021_021-202208231315 | 0.880 ppm |
| 2022-08-23 | CA5402047_022_022-202208231310 | 9.50 ppm |
| 2022-09-28 | CA5402047_022_022-202209281500 | 13.0 ppm |
| 2022-09-28 | CA5402047_017_017-202209281130 | 8.00 ppm |
| 2022-09-28 | CA5402047_021_021-202209281430 | 0.800 ppm |
| 2022-10-05 | CA5402047_022_022-202210051010 | 0.340 ppm |
| 2022-10-31 | CA5402047_021_021-202210310730 | 0.970 ppm |
| 2022-10-31 | CA5402047_022_022-202210310735 | ND |
| 2022-10-31 | CA5402047_017_017-202210310700 | 7.30 ppm |
| 2022-11-21 | CA5402047_017_017-202211211430 | 7.60 ppm |
| 2022-11-21 | CA5402047_021_021-202211211445 | 0.700 ppm |
| 2022-11-21 | CA5402047_018_018-202211211435 | 46.0 ppm |
| 2022-11-21 | CA5402047_022_022-202211211440 | 0.280 ppm |
| 2022-12-19 | CA5402047_022_022-202212191410 | 2.40 ppm |
| 2022-12-19 | CA5402047_017_017-202212191400 | 9.20 ppm |
| 2022-12-19 | CA5402047_021_021-202212191415 | 0.640 ppm |
| 2023-01-27 | CA5402047_022_022-202301271015 | 4.00 ppm |
| 2023-01-27 | CA5402047_017_017-202301271000 | 9.10 ppm |
| 2023-01-27 | CA5402047_021_021-202301271010 | 0.640 ppm |
| 2023-02-22 | CA5402047_017_017-202302221400 | 8.90 ppm |
| 2023-02-22 | CA5402047_022_022-202302221410 | 3.90 ppm |
| 2023-02-22 | CA5402047_021_021-202302221415 | 0.630 ppm |
| 2023-03-31 | CA5402047_017_017-202303311300 | 7.30 ppm |
| 2023-03-31 | CA5402047_021_021-202303311315 | 0.640 ppm |
| 2023-03-31 | CA5402047_022_022-202303311310 | 5.90 ppm |
| 2023-04-24 | CA5402047_017_017-202304241000 | 8.70 ppm |
| 2023-04-24 | CA5402047_021_021-202304241020 | 0.750 ppm |
| 2023-04-24 | CA5402047_022_022-202304241030 | 8.10 ppm |
| 2023-05-30 | CA5402047_022_022-202305301055 | 8.10 ppm |
| 2023-05-30 | CA5402047_017_017-202305301045 | 9.30 ppm |
| 2023-05-30 | CA5402047_021_021-202305301100 | 0.810 ppm |
| 2023-06-19 | CA5402047_022_022-202306191425 | ND |
| 2023-06-19 | CA5402047_017_017-202306191415 | 2.10 ppm |
| 2023-06-19 | CA5402047_021_021-202306191430 | 0.870 ppm |
| 2023-07-27 | CA5402047_017_017-202307271040 | 8.40 ppm |
| 2023-07-27 | CA5402047_021_021-202307271055 | 0.950 ppm |
| 2023-07-27 | CA5402047_022_022-202307271050 | 1.80 ppm |
| 2023-08-23 | CA5402047_021_021-202308231410 | 1.10 ppm |
| 2023-08-23 | CA5402047_022_022-202308231415 | ND |
| 2023-08-23 | CA5402047_017_017-202308231400 | 8.10 ppm |
| 2023-09-28 | CA5402047_017_017-202309281000 | 7.80 ppm |
| 2023-09-28 | CA5402047_021_021-202309281010 | 0.860 ppm |
| 2023-09-28 | CA5402047_022_022-202309281015 | 3.70 ppm |
| 2023-10-30 | CA5402047_021_021-202310301340 | 0.900 ppm |
| 2023-10-30 | CA5402047_017_017-202310301330 | 8.10 ppm |
| 2023-10-30 | CA5402047_022_022-202310301345 | 6.30 ppm |
| 2023-11-27 | CA5402047_021_021-202311271450 | 1.30 ppm |
| 2023-11-27 | CA5402047_022_022-202311271500 | 6.80 ppm |
| 2023-12-27 | CA5402047_021_021-202312271305 | 0.900 ppm |
| 2023-12-27 | CA5402047_022_022-202312271310 | 7.70 ppm |