Menu

EWG's Tap Water Database — 2019 UPDATE

Donate

Cyanide

City of Rockport

NOTE: City of Rockport purchases water from San Patricio Municipal Water District which is required to test for cyanide. Sample information shown below was taken by San Patricio Municipal Water District.

Cyanide is a toxic chemical that causes central nervous system and thyroid toxicity. Water contamination is generally the result of metal mining and chemical industry waste, runoff from agriculture and road salts used for melting ice.

 

4

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013N/A00N/A
201450.0 ppb1150.0 ppb
2015ND10ND
2016ND10ND
201740.0 ppb1140.0 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 150 ppb

The EWG Health Guideline of 150 ppb for cyanide 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 harm to the brain and nervous system.

EPA Maximum Contaminant
Level (MCL) 200 ppb

The legal limit for cyanide, established in 1992, was based on a 1955 toxicity study conducted in laboratory animals. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

NOTE: City of Rockport purchases water from San Patricio Municipal Water District which is required to test for cyanide. Sample information shown below was taken by San Patricio Municipal Water District.

Date Lab ID Result
2014-04-24AC5164350.0 ppb
2015-02-25AC81817ND
2016-03-16AD28968ND
2017-03-09AD7426640.0 ppb