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EWG's Tap Water Database — 2021 UPDATE

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Cyanide

Cypress Springs SUD N Plant 1 and NE Plant

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.

 

12

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201436.0 ppb21ND - 72.0 ppb
2015ND20ND
2016103.3 ppb2255.5 ppb - 151.0 ppb
201764.5 ppb21ND - 129.0 ppb
201892.1 ppb2285.7 ppb - 98.4 ppb
201921.4 ppb21ND - 42.7 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

Date Lab ID Result
2014-06-18Q1422142006ND
2014-06-18Q142214200772.0 ppb
2015-09-22Q1537064004ND
2015-09-22Q1537064005ND
2016-03-28Q161265001555.5 ppb
2016-03-28Q1612650016151.0 ppb
2017-03-15Q1711217007129.0 ppb
2017-03-15Q1711217008ND
2018-02-21Q180725400498.4 ppb
2018-02-21Q180725401085.7 ppb
2019-03-04Q1909014015ND
2019-03-04Q190901401642.7 ppb