Know Your Environment. Protect Your Health.

Nitrate and nitrite

San Antonio Water Company

Nitrate and nitrite enter water from fertilizer runoff, septic tanks and urban runoff. These contaminants can cause oxygen deprivation for infants and increase the risk of cancer. Nitrite is significantly more toxic than nitrate. Click here to read more about nitrate.

 

20

Samples

0

Samples exceeding legal limit (MCL)

17

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20182.54 ppm86ND - 10.00 ppm
20198.30 ppm118.30 ppm
20204.20 ppm114.20 ppm
20213.79 ppm109ND - 10.00 ppm
2022N/A00N/A
2023N/A00N/A

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

ppm = parts per million

All test results

Date Lab ID Result
2018-07-20CA3610085_004_004-20180720113510.00 ppm
2018-07-20CA3610085_016_016-201807201030ND
2018-07-20CA3610085_017_017-2018072009201.60 ppm
2018-07-20CA3610085_013_013-2018072009002.10 ppm
2018-07-20CA3610085_018_018-2018072009461.90 ppm
2018-07-20CA3610085_002_002-2018072009511.40 ppm
2018-07-20CA3610085_003_003-2018072011563.30 ppm
2018-07-20CA3610085_001_001-201807201100ND
2019-01-04CA3610085_011_011-2019010409538.30 ppm
2020-04-07CA3610085_021_021-2020040710204.20 ppm
2021-07-20CA3610085_017_017-2021072009431.50 ppm
2021-07-20CA3610085_001_001-202107201036ND
2021-07-20CA3610085_018_018-2021072011302.30 ppm
2021-07-20CA3610085_003_003-2021072010133.50 ppm
2021-07-20CA3610085_013_013-2021072009542.60 ppm
2021-07-20CA3610085_011_011-2021072008428.40 ppm
2021-07-20CA3610085_002_002-2021072011245.60 ppm
2021-07-27CA3610085_021_021-2021072712453.60 ppm
2021-07-27CA3610085_004_004-20210727090810.00 ppm
2021-07-27CA3610085_016_016-2021072708100.410 ppm