Nitrate and nitrite

Honolulu-Windward-Pearl Harbor

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.

MORE ABOUT THIS CONTAMINANT

103

Samples

Samples exceeding legal limit (MCL)

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	N/A	0	0	N/A
2015	N/A	0	0	N/A
2016	0.438 ppm	50	48	ND - 1.80 ppm
2017	0.440 ppm	53	50	ND - 1.60 ppm
2018	N/A	0	0	N/A
2019	N/A	0	0	N/A

ppm = parts per million

State and national drinking water standards and health guidelines

EWG Health Guideline 0.14 ppm

The 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
2016-02-10		0.380 ppm
2016-04-06		1.000 ppm
2016-04-07		0.960 ppm
2016-04-07		0.730 ppm
2016-04-07		0.520 ppm
2016-04-07		0.290 ppm
2016-04-12		0.480 ppm
2016-04-12		0.570 ppm
2016-04-12		0.570 ppm
2016-04-12		0.470 ppm
2016-04-12		0.560 ppm
2016-04-12		0.460 ppm
2016-04-12		0.310 ppm
2016-04-12		0.320 ppm
2016-04-12		0.320 ppm
2016-04-14		0.940 ppm
2016-04-14		0.580 ppm
2016-04-14		0.180 ppm
2016-04-14		0.440 ppm
2016-04-14		0.360 ppm
2016-04-14		0.450 ppm
2016-04-14		0.210 ppm
2016-04-14		0.180 ppm
2016-04-14		0.250 ppm
2016-04-18		0.400 ppm
2016-04-18		0.1000 ppm
2016-04-18		0.410 ppm
2016-04-19		0.350 ppm
2016-04-19		0.220 ppm
2016-04-20		0.180 ppm
2016-04-20		0.170 ppm
2016-04-21		0.530 ppm
2016-04-21		0.320 ppm
2016-04-21		ND
2016-04-21		ND
2016-04-25		0.300 ppm
2016-04-26		0.470 ppm
2016-04-26		0.460 ppm
2016-05-03		0.260 ppm
2016-05-04		0.270 ppm
2016-05-04		0.860 ppm
2016-05-04		0.420 ppm
2016-05-05		0.160 ppm
2016-05-16		0.770 ppm
2016-05-16		0.600 ppm
2016-05-16		0.610 ppm
2016-06-20		0.320 ppm
2016-06-20		0.130 ppm
2016-07-07		1.80 ppm
2016-10-31		0.260 ppm
2017-02-14		1.60 ppm
2017-04-04		0.130 ppm
2017-04-04		0.130 ppm
2017-04-05		0.540 ppm
2017-04-05		0.540 ppm
2017-04-12		0.930 ppm
2017-04-12		1.20 ppm
2017-04-12		0.440 ppm
2017-04-12		0.380 ppm
2017-04-18		0.560 ppm
2017-04-18		0.390 ppm
2017-04-19		ND
2017-04-19		0.220 ppm
2017-04-20		0.520 ppm
2017-04-20		0.410 ppm
2017-04-20		1.60 ppm
2017-04-20		0.430 ppm
2017-04-20		0.450 ppm
2017-04-20		0.290 ppm
2017-04-20		0.270 ppm
2017-04-27		0.630 ppm
2017-05-02		0.200 ppm
2017-05-02		0.180 ppm
2017-05-02		0.120 ppm
2017-05-03		0.450 ppm
2017-05-04		0.520 ppm
2017-05-04		0.900 ppm
2017-05-04		0.700 ppm
2017-05-04		ND
2017-05-04		ND
2017-05-10		0.260 ppm
2017-05-10		0.810 ppm
2017-05-10		0.390 ppm
2017-05-11		0.380 ppm
2017-05-11		0.710 ppm
2017-05-11		0.320 ppm
2017-05-17		0.180 ppm
2017-05-17		0.240 ppm
2017-05-18		0.490 ppm
2017-05-23		0.180 ppm
2017-05-23		0.370 ppm
2017-05-23		0.310 ppm
2017-05-23		0.360 ppm
2017-05-23		0.290 ppm
2017-05-23		0.170 ppm
2017-05-24		0.320 ppm
2017-05-25		0.320 ppm
2017-05-31		0.690 ppm
2017-06-06		0.340 ppm
2017-06-07		0.610 ppm
2017-06-08		0.160 ppm
2017-06-14		0.510 ppm
2017-11-07		0.180 ppm