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Public Water System Chemical Sampling and Monitoring Frequency

Basic information for public water systems about sampling and monitoring requirements.

Each public water system in Texas must sample for chemical and microbiological contaminants.

Why didn't we get this year's cost estimate letter?

The letters we used to send out in January of each year showed cost estimates that were correct when the letters were prepared, but the estimate for a water system didn't always stay correct as conditions changed during the year.

And you might need to calculate the correct sampling costs for your public water system at any time during the year. So we have put the information you need to calculate sampling costs online.

Sampling costs can change

Many factors used in these estimates can change:

  • New rules can change the sampling requirements for water systems in general.
  • Whenever a water system activates new facilities, sampling schedules will be added for that facility.
  • When a facility is inactivated, the sampling schedules for that facility are ended.
  • Exceedances, the detection of new contaminants, or other changes in your system's water quality can affect your sampling schedules.

Drinking Water Watch lets you estimate your costs at any time

In Texas Drinking Water Watch (DWW), we give you the data you need to calculate the chemical sampling costs for your public water system at any point in the year. Your calculations will be accurate and up to date whenever you need them — not a snapshot based on conditions in January.

If you need help using the information in DWW, please contact the Drinking Water Standards Section at (512) 239-4691

What determines the monitoring schedules for our PWS?

The monitoring frequency is determined by your public water system’s monitoring requirements. These requirements are based on a combination of these factors:

  • Public water system type
    • community (C)
    • nontransient noncommunity (NTNC)
    • transient noncommunity (TNC)
  • Population of the water system from the most recent comprehensive compliance investigation (CCI or survey)
  • Monitoring class (surface, ground, or purchased water)
  • Source water assessments for regulated chemicals
  • The level of chemicals in your water, based on previous sampling

If one or more of these factors change, then the sampling required, the required monitoring frequency, or both may also change.

PWS ID Number

This is the ID number of your public water system in TCEQ records. You can use this number to look up information about your PWS in our Drinking Water Watch (DWW).

How are these samples analyzed?

Samples are analyzed by laboratories at the Department of State Health Services  or Lower Colorado River Authority

Monitoring for Lead and Copper in Distribution

Please visit the Lead and Copper webpage for sampling information.

Monitoring for Coliform in Distribution

Coliform sampling procedures have not changed:

  • Staff or contractors of the public water system collect these samples.
  • PWS customers will not do this sampling.
  • Antea Group (formerly Delta Environmental Consultants, Inc.), will not do this sampling under its TCEQ contract.

You are required to collect these samples and have them analyzed at an accredited lab. The estimated cost of analysis is $25, but your lab may charge more or less than that.

Relevant Rules

In Texas, sampling requirements of the Safe Drinking Water Act and its amendments are regulated through the TCEQ’s rules found in Title 30 of the Texas Administrative Code (30 TAC), Chapter 290, Subchapter F. Other operating rules for public water systems in Texas are found in 30 TAC 290 Subchapter D. You may find copies of these rules online at these locations:

Relevant Guidance

You can find these helpful guidance documents on our Web site:

About Chemical Sampling at Public Water Systems

We make every effort to schedule the least sampling permissible by law, while ensuring that the public’s health is protected. New rules are increasing the number of samples you must collect. Our Drinking Water Standards Section will continue to make every effort to ensure that you are aware of any changes as they occur.

More Questions? Contact Us!

If you have questions please contact us. We want to help you understand the rules so that it is easier for you to comply with them.