The Power of Information

National Drinking Water Database

California Water Service-S San Francisco Utilities - San Jose, CA

Serves 54,060 people


Dimethoate is an organophosphate insecticide used on crops and in livestock.
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
10 days
Tests ConductedNumber of individual tests done for this contaminant
12 tests

Testing Summary

Health Limit
Legal Limit

Testing History

-Tested      -Detected      -Over Health Guidelines      -Over Legal Limit*
DimethoateDimethoate is an organophosphate insecticide used on crops and in livestock.0 ppb
0 ppb
2 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 Dimethoate

Health Based Limits for Dimethoate

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.2 ppb

Testing Results

Testing DateAverage
Samples taken that dayNumber of Non-DetectsRange of Results
2009-03-100 ppb110 ppb
2009-01-220 ppb110 ppb
2008-12-300 ppb220 ppb
2008-10-220 ppb110 ppb
2008-06-250 ppb220 ppb
2008-06-240 ppb110 ppb
2007-07-300 ppb110 ppb
2007-03-130 ppb110 ppb
2004-07-270 ppb110 ppb
2004-04-200 ppb110 ppb