Environmental Public Health Division

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Procedure For Taking Bacteriological Samples Of Drinking Water

Owners or managers of public water systems are required by law to submit water samples to an approved laboratory. Individuals wishing to check their private wells may also submit samples to a laboratory. There is a $15.00 – 25.00 fee for each sample submitted. Individuals who are not employed by a public system should not submit samples on that system. They should contact the system office or Harris County Public Health and Environmental Services (HCPHES) regarding complaints and information about the water supply. 

This test is for the coliform organism, which is commonly found in sewage and surface waters. If coliform organisms are found, they indicate that the sample is contaminated with potentially disease causing organisms possibly from sewage, or surface water. This test is only suitable for closed and properly sealed systems. Samples from streams, ponds, unprotected springs, open storage tanks and unsealed wells usually show contamination. It should be noted that samples indicate the condition of the water only at the time the sample is taken. 

Samples must be collected in a Laboratory supplied bottle. An outside faucet (with mouth facing downward) is the preferred place to collect the sample. Samples should not be collected from faucets with leaky washers or valve stems, from drinking fountains, hoses, open pipes or other places that cannot be properly sterilized. 

The tap should be flushed a short time; the mouth of the faucet flamed to dryness (with a propane torch, lighter, etc.) to sterilize it; the water turned back on, and the sample bottle filled to the 100/ml mark. The fingers or any other object should not be permitted to come in contact with the inside of the cap or the lip of the bottle. Accidental contamination is very possible if every precaution is not taken. Do not rinse the bottle or empty it during the process; it contains a chemical used to neutralize chlorine. Replace the cap carefully and tighten. 

A report form is supplied with each bottle. Fill out the form with a black ballpoint pen and take it with the sample to the laboratory. If the sample is taken for a public system, be sure it is identified properly on the report form; otherwise, it will not be recorded on the system’s record. The City of Houston Department of Health and Human Services (HDHHS) has a laboratory located at 2250 Holcombe Blvd. You may also look in the yellow pages under laboratories for other labs in your area. You should receive the results by mail in about one week. Samples containing an insufficient amount of water or samples submitted in bottles other than those furnished by the laboratory will not be examined. 

Samples must arrive at the laboratory within 30 hours after collection.

For further information call:
Environmental Public Health Division
(713) 274-6300

2250 Holcombe
(832) 393-3939





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Last updated:  January 16, 2013 
Harris County Public Health & Environmental Services
2223 West Loop South
Houston, TX 77027
Tel: (713) 439-6000