Colilert Quantitray - Total Coliform: Count (MPN)

The Colilert Quantitray test determines the count of coliform bacteria or E.coli present in drinking water, non-potable, and agricultural samples.

Water containing 1 or more coliform colony forming units per 100 mL results in a positive Colilert and is considered unsafe for human consumption. This is the EPA and Washington State Department of Health safe drinking water tolerance level. 


Colilert results are available 24 hours after the test is started. 



Colilert - Total Coliform: E.coli Presence/Absence (P/A)

The Colilert test determines if there are any coliform bacteria or E.coli present in drinking water samples.


Water containing 1 or more coliform colony forming units per 100 mL results in a positive Colilert and is considered unsafe for human consumption. This is the EPA and Washington State Department of Health safe drinking water tolerance level.


Colilert results are available 24 hours after the test is started.



Nitrate - Nitrate Electrode Method

The nitrate electrode responds to nitrate ion activity in water between 0.14 and 1400mg nitrate nitrogen per liter. The Maximum Contaminate Level allowed by the Washington State Department of Health is 10mg/L and water containing greater than this is considered unsafe for human consumption. High risk individuals such as infants and adults with depressed immune systems are recommended to drink only water below 5.0 mg/L nitrate nitrogen.


Nitrate analysis are typically completed within 24 hours, depending on sample volume. 

We are currently certified to perform coliform (MPN and P/A) and nitrate testing on drinking water and coliform counts in non-potable water.


These include a presence/absences test for coliforms and E.coli, quantitative levels for coliforms and E.coli, and quantitative levels for nitrate-nitrogen. 

Water Analysis