Know Your Environment. Protect Your Health.

Cyanide

CTWC - Shoreline Region-Guilford System

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.

 

25

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2018ND20ND
2019ND40ND
2020ND60ND
2021ND20ND
2022ND30ND
2023ND80ND

ppb = parts per billion

State, National, and Health Guidelines for Drinking Water

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
2018-03-30CA11463IOCRND
2018-03-30CA11466IOC1ND
2019-01-30IOC1 200520057ND
2019-02-27IOCR 200523002ND
2019-06-24IOC1 200537625ND
2019-07-10IOC1 200539998ND
2020-01-20IOC1 200563509ND
2020-01-21IOC1 200563516ND
2020-01-28IOC1 200564212ND
2020-02-11IOC1 200565799ND
2020-02-11IOCR 200565797ND
2020-02-25IOC1 200567275ND
2021-09-30I300072093 300072097ND
2021-09-30R300072099 300072104ND
2022-08-15CM05636ND
2022-08-29CM17830ND
2022-08-29CM17831ND
2023-02-13CN41858ND
2023-02-13CN41859ND
2023-09-12CO95874ND
2023-09-12CO95875ND
2023-09-12CO95877ND
2023-10-12CP23629ND
2023-11-28CP55320ND
2023-11-29CP56434ND