The Power of Information

National Drinking Water Database


Contra Costa Water District Utilities - Concord, CA


Serves 200,000 people

Prometryn

Prometryn is an herbicide applied to various food and feed crops, primarily cotton and celery; it has been detected in groundwater in agricultural areas in California.
 
This Drinking Water System
Test Days Exceeding Health GuidelinesDefinition of what this is
0 days
Test Days Exceeding Legal LimitsNumber of days in which the samples taken in that day exceed the Maximum Contaminant Level (Depending on the contaminant and its MCL, that may or may not trigger an MCL violation. Some MCLs are based on averages spanning several months to a year)
0 days
Test DaysNumber of days in which this chemical has reported results in the data we received from the State
18 days
Tests ConductedNumber of individual tests done for this contaminant
22 tests

Testing Summary

ContaminantAverage/
Maximum
Result
Health Limit
Exceeded
Legal Limit
Exceeded

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
PrometrynPrometryn is an herbicide applied to various food and feed crops, primarily cotton and celery; it has been detected in groundwater in agricultural areas in California.0 ppb
0 ppb
No
300 ppb
Legal at any levelThis is the Federal Limit. State Limits may be lower.
NOTE: Each dot in the above graph represents one month.
* Water utilities are noted as exceeding the legal limit if any test is above the maximum contaminant level (MCL). Most MCLs are based on annual averages so exceeding the MCL for one test does not necessarily indicate that the system is out of compliance.

Health Based and Legal Limits for Prometryn

Health Based Limits for Prometryn

StandardDescriptionLevel
Health-Based Screening LevelA benchmark concentration of contaminants in water that may be of potential concern for human health, if exceeded. For noncarcinogens, the HBSL represents the contaminant concentration in drinking water that is not expected to cause any adverse effects over a lifetime of exposure. For carcinogens, the HBSL range represents the contaminant concentration in drinking water that corresponds to an excess estimated lifetime cancer risk of 1 chance in 1 million to 1 chance in 10 thousand. Source: U.S. Geological Survey.300 ppb

Testing Results

Testing DateAverage
Result
Samples taken that dayNumber of Non-DetectsRange of Results
2006-10-040 ppb110 ppb
2006-07-190 ppb110 ppb
2006-04-050 ppb110 ppb
2006-01-180 ppb110 ppb
2006-01-110 ppb110 ppb
2005-10-050 ppb110 ppb
2005-07-060 ppb110 ppb
2005-05-110 ppb110 ppb
2005-04-050 ppb220 ppb
2005-03-210 ppb110 ppb
2005-01-050 ppb110 ppb
2004-10-060 ppb110 ppb
2004-07-140 ppb110 ppb
2004-04-070 ppb110 ppb
2004-03-150 ppb110 ppb
2004-01-070 ppb220 ppb
2004-01-060 ppb220 ppb
2004-01-050 ppb220 ppb