What was tested, and what was not.
The direct potable reuse project was monitored heavily. Turbidity, pathogens, disinfectant residuals, regulated chemicals and disinfection byproducts were all measured, often continuously, with automatic shutdown triggers.
NDMA was not among them.
The monitoring that existed was real.
TCEQ's Enclosure B monitoring diagram maps every required sampling point through the system. This was not a project without oversight. That is what makes the omission worth examining.
On the required sampling diagram
- Wastewater effluent turbidity
- Wastewater effluent E. coli
- Microfiltration integrity
- Chloramine contact zones
- Reverse-osmosis performance
- Blending
- Finished water
- Regulated chemicals at the entry point
- Trihalomethanes and haloacetic acids
Absent from that diagram
- NDMA
- NPYR
- Any other nitrosamine
NDMA was analyzed elsewhere — in feasibility and planning work before the project, and in 2015 pilot research on RO permeate. None of that was operational monitoring of the finished water. Details below.
Shutdown triggers were set for the parameters that were monitored. Above 24 NTU turbidity, for example, the wastewater pumps shut down automatically. The monitoring in place was capable of stopping the process. It was measuring other things.
NDMA was raised five times before and during the project.
This is not a case of a contaminant nobody thought of. It was named in writing, by a regulator and by a treatment vendor, before full-scale operation began.
TCEQ stars NDMA and NPYR
TCEQ's reuse monitoring recommendations mark NDMA and NPYR (EPA Method 521) as "highly recommended for sampling."
Recommended — not requiredTrojanUV raises NDMA directly with the City
TrojanUV writes to the City about NDMA passage through reverse osmosis, citing California's 10 ng/L notification level, and asks whether the City has looked at NDMA levels leaving River Road.
Question put to the City in writingNDMA and NPYR enter the verification protocol
Both compounds appear in TCEQ's verification protocol as parameters the City volunteered to monitor.
In the protocolThey are deleted at the City's request
NDMA and NPYR are removed from the verification protocol. The request came from the City.
Removed from the protocolTCEQ recommends quarterly monitoring again
TCEQ's Enclosure G again recommends quarterly NDMA and NPYR monitoring, marked "highly recommended for sampling." Not required.
Recommended a second time — not requiredThe City has answered this question directly.
In response to a public information request, the City of Wichita Falls addressed whether nitrosamine monitoring was required and whether it was carried out.
TCEQ “highly recommended those for sampling, but did not require them.”
The City “did NOT do any internal testing for those unregulated contaminants during the DPR.”
City of Wichita Falls, public information request response, November 2025. Emphasis as it appears in the original.
This is not an allegation and it is not in dispute. It is the City's own account, in writing, of what was and was not done.
A twelve-month gap that cannot be filled.
No routine NDMA monitoring of the finished drinking water was performed during the twelve months of DPR operation. The City has said so directly. That is the gap.
NDMA was analyzed on more than one occasion in Wichita Falls — during the feasibility and planning work that preceded the project, including testing of wastewater effluent, and again in 2015 during treatment research conducted by Garver Engineering at the Cypress Water Treatment Plant with a TrojanUV pilot reactor. That 2015 study was commissioned by WateReuse Texas and sampled Wichita Falls reverse-osmosis permeate — water drawn from part way through the treatment process.
Each of these was study work: evaluating a proposed process, or researching how well treatment steps removed the compound. None of it was ongoing operational monitoring of the finished drinking water, and none of it was required.
That distinction is the point. NDMA was looked for, by people who knew to look for it, and found. It still did not become something the City measured in the water it delivered.
Whatever concentration reached the distribution system during 2014 and 2015, there is no record of it, and the water itself is long gone. A test not run then cannot be run now.
Wichita Falls operates an indirect potable reuse system today. The water flowing through it right now can be sampled and analyzed by EPA Method 521 — the same method TCEQ named in 2012.
That is the one question from this record that still has an available answer.
What this page claims, and what it does not.
It does not claim a violation. There is no federal maximum contaminant level for NDMA and no Texas requirement to monitor for it. The City was not obligated to sample for nitrosamines, and declining to do so broke no rule.
It does not claim the water was unsafe. No measurement exists from that period, which means no one can say what the concentrations were — including me. An absent measurement is not a high result.
It does not claim anyone acted in bad faith. The records show what was recommended, what was volunteered, what was withdrawn and what was operated. Why those decisions were made is not something these documents establish, and this page does not guess at it.
What it does claim is narrow. A compound was identified in advance by a state regulator and by a treatment vendor, was analyzed during feasibility and planning work, was briefly placed in the verification testing protocol, was taken back out at the City's request, was recommended a second time, was found again in reverse-osmosis permeate when a research pilot looked for it, and was never part of routine operational monitoring of the finished drinking water during direct potable reuse. Each of those steps is documented.
And one record is still outstanding. The laboratory that analyzed the 2015 pilot samples has confirmed it still holds those reports, but has said they can be released only to the engineering firm that submitted them. The underlying results have been requested and not yet obtained. They are described here as not in hand, not as non-existent.
How these records are sourced and handled →Read the record yourself.
The documents referenced on this page — Enclosure B, Enclosure G, the 2012 TCEQ recommendations, the 2013 TrojanUV correspondence, the verification protocol and the City's 2025 response — are in the source library.