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  • Mark Hearon

5 Important Parts of a Sample Schedule

Last week, in 7 Powerful Steps to Win at Sampling Schedules, we showed a lot of tables. Like, a lot of tables. Each table contained more labeled columns than were honestly necessary to tell the story.

Unfortunately, this left some of our readers wanting some additional explanation. This week, we're going to take a quick spin through the 5 most important parts of a sample schedule. Specifically. we'll take a closer look at the information contained within the Expanded Sample Schedules/FANLs/Plans link of the Texas Drinking Water Watch utility.

Feel free to follow along with the expanded view of the Group Non-TCR Sample Schedules table for the City of Lewisville.


Facility indicates where a water sample comes from. The facility column can be filled with several codes. Some of the most common include the following:

  • Distribution system (DS)

  • Entry point (EP)

  • Treatment plant (TP)

The navigation menu at the top of the Texas Drinking Water Watch landing page for queried water systems
Click for an expanded view.

If you're wondering which facilities your city or utility has, it's fairly easy to find out. For example, if your city or utility doesn't have a treatment plant, code TP won't be a valid facility entry on your sample schedule. To learn which facility codes apply to your city or utility, reference the Sample Points link found above Sample Schedules/FANLs/Plans on the main landing page for your water system.


While reading an expanded sample schedule, you'll likely come across code DS01 in the facility column. DS01 is a generic code for a distribution system. When the TCEQ requires you to collect a sample from DS01, it could be from any set sample site within your distribution system.

Consult your sample points for specific sampling location information.

Begin End Date

Admittedly, there's not much to add here as the data is rather straightforward. Start sampling on X date and end sampling on X date unless the end date is continuous. In this case, sampling never ends.

However, there's one caveat to be aware of: the end date can and does change over time. To avoid unnecessary sampling activities, check the end date often. Your team will thank you when they aren't working overtime.

Seasonal (Seas.)

Seasonal sampling is arguably the most important data field because it has the greatest potential for variability. The TCEQ uses the Seas. column to denote specific windows for sampling activity. Any sampling activity that takes place outside of the specified seasonal window is invalid.

The Group Non-TCR Sample schedules table from Texas Drinking Water Watch
Click for an expanded view.

In the example above, lead and copper samples must be collected between 06/01 and 09/30. Additional context can be found in the Analyte Group > Analyte column to the right of the Seas. column.


the TCEQ records a seasonal window of June 1 - September 30, 2024, in the example above. If you're wondering why there's no year associated with the June 1 date, it's because the TCEQ assumes you understand the month of June which precedes the September 30, 2024 end date is also in 2024. Although it's a fair assumption, we still find it unclear.

If the TCEQ is reading this, add the year to both the start and end date. It's four extra keystrokes.

Requirements (Req’s)

The Req's column denotes how many samples should be collected and how often. Data in this column is usually displayed in the following manner (highlighted on right).

Begin End Date


Init. MP Begin Dt


07-01-2013 | Continuous



04-01-2012 | Continuous



01-01-2019 | Continuous

6/1 - 9-30


50 RT/3Y

In the example Req's column, RT stands for routine sample. Ergo, 1 RT/MN is 1 routine sample per month. The next is 8 per quarter, and the last is 50 total samples every 3 years.

Analyte Group

While this is a restatement of which samples need to be collected on the simple sample schedule, this expanded schedule expands the data to include:

  • the specific analytes within the group.

  • the current monitoring period.

  • the number of samples the TCEQ has received.

  • a satisfaction status (e.g., Yes or No).


It's quite common to see a plethora of "Yes" notations on the Schedule Satisfied column after completing a round of sampling. I checked this list after a contract lab completed our metals samples and noticed that chromium was the only one with "No" while the rest said Yes. Sometimes, a "No" can hide quite well in a slew of "Yes" notations.

I called the contractor and they found an error in their upload that left the chromium sample out. Thankfully, they fixed it right away and we avoided the fun process of refuting a violation with the TCEQ.

The Wrap

The beauty of writing about water operator life and the TCEQ is there's always another layer of the onion to peel back. In this case, it's adding additional context that couldn't be included in last week's article without making it a ponderous profanation to the eyes. With this addition, reading your expanded sample schedule is less likely to break your flow.


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