Bacteriological Testing

Quick Links

Public vs. Private Systems

Types of Users

You may wonder what type of system you are testing. We hope this outline will be clear.

Public Users

You have a public water system if you have a water system ID number. Public Water Systers (PWS) may include, but are not limited to:

  • Cities
  • Schools
  • Grocery Stores
  • Hotels/Motels
  • Retreat/Encampment Sites

Private Users

You are an individual customer if you do not have a water system ID number.

Other Users

This may include bottled or vended water.

Water Sampling

Collecting a Water Sample

All tests submitted must be collected in a container approved by the testing laboratory. Collect the sample from an outside faucet (for homes), not a kitchen or bathroom faucet, if possible.

  • Make sure the faucet is above ground and free of grass, shrubbery, and debris.
  • Flush the faucet for several minutes.
  • Check the chlorine residual and enter it on the form if the sample is from a chlorinated water source.
  • Heat the faucet with a torch or wash it with a strong bleach solution to kill any bacteria that might be present. Heating the faucet is the preferred method.
  • Do not rinse the bottle or pour out the white powder. It is present to neutralize the chlorine residual so it does not interfere with the test.
  • Adjust the stream of water to the size of a pencil.
  • Without touching the inner neck of the bottle or lid, fill above the 100 mL mark to the curve of the neck of the bottle. Note: this is a recent change.
  • Keep the sample out of direct sunlight and as cool as possible until taking it to the lab.
  • IMPORTANT: Sample must be brought to the LAB on ICE

Paper Work for the Water Sample

Samples must be accompanied by a completed TCEQ-approved Microbial Reporting Form.

  • Enter the system name and ID number (PWS only).
  • Fill out the return address portion of the form to indicate where the results are to be sent.
  • Enter the date and time of collection.
  • Enter the point of collection (site, location, or town) and county.
  • Enter the name and phone number of the collector.
  • Indicate what type of system the sample represents.
  • Enter the chlorine residual if from a chlorinated source or recently chlorinated site.
  • DO NOT write on the grayed area of the form. This is for Laboratory Use Only
Note: ALL Public Water Systems (PWS) are required to have a chlorine residual. if the sample is from a PWS and the form does not have a chlorine residual listed, the sample will not be processed. You can view the new form and an explanation of some changes by following this link. Please contact the laboratory with any questions about the Mircobial Reporting Form

Submitting the Sample

  • Submit the sample to the lab as soon as soon after collection as possible. These are time sensitive samples.
  • The $20 per sample fee is due upon submitting the sample.
  • The lab has ultimate authority to reject any sample due to incorrect sampling procedures, formes filled out improperly, samples too old for analysis, or other circumstances.
  • In the event that a sample is invalidated, a repeat sample will be requested
    • A $20 credit will be given only if the sample was paid and not set up for analysis.
  • When repeat sampling is required due to a positive result, the repeat testing will cost the standard $20 per sample fee.
  • Results will be mailed to the submitting party. Requests to have test results faxed or picked up should be made when samples are brought to the lab.
Please direct other lab inquiries to lab personnel.