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EWG's Tap Water Database — 2021 UPDATE

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Chlorite

City of Weslaco

Chlorite is a disinfection byproduct resulting from water treatment with chlorine dioxide. Chlorite decreases hemoglobin levels and causes other hematologic effects. Read More.

Chlorite also forms when chlorine dioxide is used as a bleaching agent for textiles, paper pulp, flour and oils, and from the use of chlorine dioxide in food and packaging.� In 2009, California published a public health goal of 50 parts per billion for chlorite in drinking water. California state scientists reported that chlorite causes red blood cell damage, affects sperm and thyroid function, and may alter behavior and neurodevelopment of rat pups exposed in the womb.

Click here to read more about disinfection byproducts.

 

219

Samples

1

Samples exceeding legal limit (MCL)

178

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014246.6 ppb3631ND - 835.0 ppb
2015355.6 ppb3633ND - 1,340.0 ppb
2016382.2 ppb3630ND - 810.0 ppb
201789.0 ppb3926ND - 550.0 ppb
2018271.8 ppb3634ND - 935.0 ppb
2019191.8 ppb363624.0 ppb - 428.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 50 ppb

The EWG Health Guideline of 50 ppb for chlorite 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 change in blood chemistry.

EPA Maximum Contaminant
Level (MCL) 1,000 ppb

ppb = parts per billion

All test results

Date Lab ID Result
2014-01-0814-0109-39ND
2014-01-0814-0109-38349.0 ppb
2014-01-0814-0109-40371.0 ppb
2014-02-0414-0205-22285.0 ppb
2014-02-0414-0205-23242.0 ppb
2014-02-0414-0205-24253.0 ppb
2014-03-1214-0313-34835.0 ppb
2014-03-1214-0313-36418.0 ppb
2014-03-1214-0313-35378.0 ppb
2014-04-1714-0418-21310.0 ppb
2014-04-1714-0418-20365.0 ppb
2014-04-1714-0418-19538.0 ppb
2014-05-0814-0512-7464.0 ppb
2014-05-0814-0512-8437.0 ppb
2014-05-0814-0512-9428.0 ppb
2014-06-1214-0613-26220.0 ppb
2014-06-1214-0613-27175.0 ppb
2014-06-1214-0613-2845.0 ppb
2014-07-0714-0708-9203.0 ppb
2014-07-0714-0708-7376.0 ppb
2014-07-0714-0708-8187.0 ppb
2014-08-0714-0811-3190.0 ppb
2014-08-0714-0811-30110.0 ppb
2014-08-0714-0811-29140.0 ppb
2014-09-1014-0911-2870.0 ppb
2014-09-1014-0911-27330.0 ppb
2014-09-1014-0911-26ND
2014-10-0614-1007-37700.0 ppb
2014-10-0614-1007-36ND
2014-10-0614-1007-35ND
2014-11-1314-1114-3142.0 ppb
2014-11-1314-1114-2958.0 ppb
2014-11-1314-1114-30217.0 ppb
2014-12-1014-1211-41ND
2014-12-1014-1211-40200.0 ppb
2014-12-1014-1211-3940.0 ppb
2015-01-0515-0106-9270.0 ppb
2015-01-0515-0106-870.0 ppb
2015-01-0515-0106-7140.0 ppb
2015-02-0315-0204-32140.0 ppb
2015-02-0315-0204-31200.0 ppb
2015-02-0315-0204-33320.0 ppb
2015-03-0415-0306-34100.0 ppb
2015-03-0415-0306-33570.0 ppb
2015-03-0415-0306-32ND
2015-04-0915-0410-18180.0 ppb
2015-04-0915-0410-16660.0 ppb
2015-04-0915-0410-17680.0 ppb
2015-05-1315-0514-161,340.0 ppb
2015-05-1315-0514-18980.0 ppb
2015-05-1315-0514-17370.0 ppb
2015-06-0815-0609-29160.0 ppb
2015-06-0815-0609-27380.0 ppb
2015-06-0815-0609-28360.0 ppb
2015-07-0815-0709-13380.0 ppb
2015-07-0815-0709-15520.0 ppb
2015-07-0815-0709-14280.0 ppb
2015-08-1115-0812-43180.0 ppb
2015-08-1115-0812-45120.0 ppb
2015-08-1115-0812-44170.0 ppb
2015-09-1715-0918-1290.0 ppb
2015-09-1715-0918-3ND
2015-09-1715-0918-2ND
2015-10-1415-1015-19380.0 ppb
2015-10-1415-1015-21300.0 ppb
2015-10-1415-1015-20220.0 ppb
2015-11-1015-1111-31560.0 ppb
2015-11-1015-1111-32480.0 ppb
2015-11-1015-1111-30570.0 ppb
2015-12-0315-1207-19570.0 ppb
2015-12-0315-1207-21580.0 ppb
2015-12-0315-1207-20280.0 ppb
2016-01-1316-0114-7340.0 ppb
2016-01-1316-0114-9250.0 ppb
2016-01-1316-0114-8150.0 ppb
2016-02-1016-0211-22560.0 ppb
2016-02-1016-0211-24400.0 ppb
2016-02-1016-0211-23250.0 ppb
2016-03-0716-0308-25770.0 ppb
2016-03-0716-0308-27710.0 ppb
2016-03-0716-0308-26810.0 ppb
2016-04-1216-0413-42290.0 ppb
2016-04-1216-0413-40360.0 ppb
2016-04-1216-0413-41310.0 ppb
2016-05-1116-0512-25500.0 ppb
2016-05-1116-0512-27350.0 ppb
2016-05-1116-0512-26450.0 ppb
2016-06-1516-0622-100620.0 ppb
2016-06-1516-0622-102520.0 ppb
2016-06-1516-0622-101530.0 ppb
2016-07-2116-0722-2380.0 ppb
2016-07-2116-0722-1560.0 ppb
2016-07-2116-0722-3640.0 ppb
2016-08-1816-0819-8500.0 ppb
2016-08-1816-0819-9500.0 ppb
2016-08-1816-0819-7750.0 ppb
2016-09-2016-0922-7750.0 ppb
2016-09-2016-0922-9600.0 ppb
2016-09-2016-0922-8630.0 ppb
2016-10-1116-1012-2360.0 ppb
2016-10-1116-1012-22130.0 ppb
2016-10-1116-1012-2490.0 ppb
2016-11-0916-1110-24ND
2016-11-0916-1110-22ND
2016-11-0916-1110-23ND
2016-12-1416-1215-10ND
2016-12-1416-1215-12ND
2016-12-1416-1215-11ND
2017-01-1017-0111-2330.0 ppb
2017-01-1017-0111-22220.0 ppb
2017-01-1017-0111-24140.0 ppb
2017-02-1417-0221-180.0 ppb
2017-02-1417-0221-3ND
2017-02-1417-0221-2ND
2017-02-2317-0224-5ND
2017-02-2317-0224-4100.0 ppb
2017-02-2317-0224-6ND
2017-03-0717-0308-2120.0 ppb
2017-03-0717-0308-20ND
2017-03-0717-0308-1970.0 ppb
2017-04-1117-0412-10ND
2017-04-1117-0412-1230.0 ppb
2017-04-1117-0412-11ND
2017-05-0217-0503-19ND
2017-05-0217-0503-17110.0 ppb
2017-05-0217-0503-1860.0 ppb
2017-06-1417-0615-15ND
2017-06-1417-0615-13210.0 ppb
2017-06-1417-0615-1460.0 ppb
2017-07-2117-0724-320.0 ppb
2017-07-2117-0724-160.0 ppb
2017-07-2117-0724-220.0 ppb
2017-08-0917-0811-22ND
2017-08-0917-0811-24ND
2017-08-0917-0811-23ND
2017-09-1417-0915-8470.0 ppb
2017-09-1417-0915-7550.0 ppb
2017-09-1417-0915-9170.0 ppb
2017-10-1117-1012-3070.0 ppb
2017-10-1117-1012-28120.0 ppb
2017-10-1117-1012-29ND
2017-11-1417-1115-24140.0 ppb
2017-11-1417-1115-22220.0 ppb
2017-11-1417-1115-23120.0 ppb
2017-12-1217-1213-15100.0 ppb
2017-12-1217-1213-14180.0 ppb
2017-12-1217-1213-16100.0 ppb
2018-01-0918-0110-18ND
2018-01-0918-0110-16217.0 ppb
2018-01-0918-0110-17ND
2018-02-0818-0209-1046.0 ppb
2018-02-0818-0209-9199.0 ppb
2018-02-0818-0209-8313.0 ppb
2018-03-0618-0307-41670.0 ppb
2018-03-0618-0307-40701.0 ppb
2018-03-0618-0307-42297.0 ppb
2018-04-1118-0412-29360.0 ppb
2018-04-1118-0412-30130.0 ppb
2018-04-1118-0112-28120.0 ppb
2018-05-0918-0510-39131.0 ppb
2018-05-0918-0510-38289.0 ppb
2018-05-0918-0510-37284.0 ppb
2018-06-1218-0613-20149.0 ppb
2018-06-1218-0613-19155.0 ppb
2018-06-1218-0613-21136.0 ppb
2018-07-1718-0718-7348.0 ppb
2018-07-1718-0718-8214.0 ppb
2018-07-1718-0718-9251.0 ppb
2018-08-0818-0809-12915.0 ppb
2018-08-0818-0809-11935.0 ppb
2018-08-0818-0809-10850.0 ppb
2018-09-1118-0912-3784.0 ppb
2018-09-1118-0912-38139.0 ppb
2018-09-1118-0912-39283.0 ppb
2018-10-1118-1018-41114.0 ppb
2018-10-1118-1018-42341.0 ppb
2018-10-1118-1018-4075.0 ppb
2018-11-1918-1126-13388.0 ppb
2018-11-1918-1126-14217.0 ppb
2018-11-1918-1126-15111.0 ppb
2018-12-1818-1219-1176.0 ppb
2018-12-1818-1219-2123.0 ppb
2018-12-1818-1219-323.0 ppb
2019-01-1819-0122-790.0 ppb
2019-01-1819-0122-5176.0 ppb
2019-01-1819-0122-6128.0 ppb
2019-02-1119-0212-9127.0 ppb
2019-02-1119-0212-8216.0 ppb
2019-02-1119-0212-7243.0 ppb
2019-03-1119-0312-11155.0 ppb
2019-03-1119-0312-1268.0 ppb
2019-03-1119-0312-10181.0 ppb
2019-04-0919-0410-392.0 ppb
2019-04-0919-0410-1174.0 ppb
2019-04-0919-0410-2145.0 ppb
2019-05-0719-0508-4236.0 ppb
2019-05-0719-0508-5236.0 ppb
2019-05-0719-0508-6188.0 ppb
2019-06-1019-0611-16268.0 ppb
2019-06-1019-0611-17234.0 ppb
2019-06-1019-0611-18110.0 ppb
2019-07-0919-0710-7248.0 ppb
2019-07-0919-0710-6265.0 ppb
2019-07-0919-0710-833.0 ppb
2019-08-0719-0809-1324.0 ppb
2019-08-0719-0809-1470.0 ppb
2019-08-0719-0809-1574.0 ppb
2019-09-1819-0919-6203.0 ppb
2019-09-1819-0919-5218.0 ppb
2019-09-1819-0919-753.0 ppb
2019-10-1519-1016-2268.0 ppb
2019-10-1519-1016-388.0 ppb
2019-10-1519-1016-1301.0 ppb
2019-11-0719-1108-24152.0 ppb
2019-11-0719-1108-22398.0 ppb
2019-11-0719-1108-23370.0 ppb
2019-12-0319-1204-2383.0 ppb
2019-12-0319-1204-1428.0 ppb
2019-12-0319-1204-3263.0 ppb