Laboratory Services and Well Water Testing

Collection and Testing of Drinking Water Samples

Water Samples

The Health Department Laboratory Services accepts and tests samples of well water intended for human consumption. These samples must be submitted in sterile treated bottles supplied by the City of Houston Health Department, Harris County Public Health and Environmental Services, the Texas Department of Health, Texas Commission on Environmental Quality (TCEQ) or your local health authority.

For information on well water testing call 713-558-3474 or 281-233-2563.

• Water sampling form - Microsoft Word format
• Water sampling form - Adobe PDF format

Water samples are accepted from 8 a.m. to 4 p.m., Monday through Friday. Sterile treated sample bottles can be picked up from the two laboratory locations.

Water samples are not accepted on Saturdays, Sundays, or holidays. Samples more than 30 hours old when received will not be tested. We do not recommend that samples be mailed to the lab. Samples that are submitted by mail may not arrive within the 30 hour time limit or during the Monday - Friday work week. Mailed samples are also likely to break or leak in transit.

Water is tested for the presence of total coliform bacteria and E.coli. The analysis takes 18 hours to complete.

The fee for water testing is $8 per bottle. Payment by check or money order must accompany the sample. No cash will be accepted at either location.

Collecting the Water Sample

Select a cold water faucet. Remove any screen or other attachment to the faucet, and let the water run for 3 to 5 minutes. Remove the cap from the sample bottle without touching the inside of the cap or the bottle. Fill the bottle above the 100 ml mark within 1/4 inch of the top. Samples with less than 100 ml of water will not be tested. Do not rinse out or overflow the bottle; it contains a chemical used to neutralize chlorine. Replace the cap carefully and tighten. If the sample has excessive chlorine, it is not suitable for analysis. Another sample will have to be submitted.

Fill out the laboratory form, giving complete return address, phone number, county, date, time of collection, and other information requested; print this information using black waterproof ink. Do not photocopy the lab form. A separate form must be filled out for each sample bottle.

Public systems required to submit water sample(s) monthly must indicate their Texas Natural Resource Conservation Commission (TNRCC) water system identification number and sample type (distribution, raw, etc.) in the proper places in the form. This is the only way in which the system will be credited with the sample by the TNRCC.

Deliver the sample and form to the laboratory the same day it is collected or refrigerate and deliver it the next day, within the 30 hour time limit.

Laboratory Reports

We cannot telephone all test results to you; however we will attempt to contact you if your sample is unsatisfactory or was found to have coliform organisms. You may call the Laboratory for your results at the location you submitted the samples.

Reports are mailed to the address you write on the form. You should receive your report within 5 to 7 days. If your report does not arrive within 2 weeks, please contact the Laboratory by telephone.

To locate a report we must have:

( 1 ) The sample number that was given to you when the sample was submitted. Or

(2) The date the sample was submitted AND

(3) The name of the return addressee exactly the way it was written on the form AND

(4) The county the well is located in.

Interpretation of Results

If coliform organisms are not found, the water is bacteriologically safe to drink at the time of sampling. If "total" coliform organisms are found, the sample contains bacteria commonly found in runoff or surface water. If E.coli organisms are found, the sample contains bacteria commonly found in sewage which could include other disease producing bacteria. Any water well found to have coliform organisms should be disinfected according to the directions or treated by a well service company and retested. Water in which either total coliforms or E.coli is found should not be used for drinking, bathing, brushing teeth, cleaning wounds, or washing food which is to be eaten raw. It is advisable to use bottled water until the water supply is reported to be safe to use. However, contaminated water may be boiled for a minimum of 5 minutes before use.

How to disinfect a contaminated well

For questions concerning "Repeat" sampling for public systems receiving a coliform positive report, please contact the TNRCC at 713-767-3650.

For other laboratory services provided by the Houston Department of Health and Human Services, call (713) 558-3400.

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