Austin Water's annual report and its monthly summaries answer different questions, and a filter decision uses both. The 2025 Water Quality Report gives a full year of results for the whole system, including the disinfectant measured out in the pipes, while the monthly summaries give the latest month's averages from each of the three treatment plants. Read with the year and sampling point of each figure in mind, the two documents show which part of Austin's water a carbon filter, a kitchen reverse osmosis (RO) system or a whole-house system would be working on, and a separate utility page shows whether any notice is currently in effect.
The earlier guide to water filter brands for Austin homes covers the brands. Austin Water's figures are quoted here as published, with the year and unit beside each one.
Confirming the Report Belongs to Your Address
The first check is the name on the water bill. Austin Water's annual report carries the identifier "Austin Water Public Water System ID: 2270001" on its cover, and that ID is the system the whole report describes. A bill from Austin Water ties the household to this report; a bill from another utility points to that utility's own report.
The report also states where the water comes from. Austin Water draws surface water from the Lower Colorado River as it flows through Lake Travis and Lake Austin, and treats it at three plants, named in the report as Handcox, Davis and Ullrich. Those plant names come up again in the monthly summaries, which is where the two documents connect.
Austin Water posts both on its water quality reports page, with the 2025 report at the top and earlier years back to 2021 listed below it.
What "Sampled in 2025" Covers
The tables in the 2025 report carry the heading "Sampled in 2025 unless noted differently," and the exceptions are marked row by row. The lead and copper rows, for instance, carry a 2024 date, because that testing is conducted at customer taps every three years. Reading the year beside each row keeps a 2024 result from being mistaken for a 2025 one.
The second thing to note is where a row was measured. The report groups its results under headings such as "Regulated at the Treatment Plant" and "Regulated in the Distribution System." Chloramines, the disinfectant Austin Water uses, sit in the distribution group, which means the figures describe water out in the pipe network on its way to homes. The monthly summaries, by contrast, are organized by treatment plant. The same item can therefore show different numbers in the two documents without either one being off.
The Numbers That Bear on a Filter Choice
The chloramine level, total hardness and the monthly total solids figure are the entries on Austin's reports that bear most on a filter choice. This table sets the 2025 annual figures beside the September 2026 monthly summary, the latest month posted as of November 3, 2026.
| Item | 2025 annual report (whole system) | September 2026 monthly summary (by treatment plant) | What it points to |
|---|---|---|---|
| Chloramines | Distribution system: low 0.06, high 3.1, average 2.3 ppm | Total chloramines, monthly average: Davis 2.98, Ullrich 2.80, Handcox 2.96 mg/L | Taste and odor from the disinfectant, a job for activated carbon |
| Total hardness (as CaCO3) | Low 70, high 126, average 93 ppm (4.1, 7.4 and 5.4 grains per gallon) | Monthly average: Davis 69, Ullrich 73, Handcox 68 mg/L | Scale on fixtures and appliances, a whole-house decision |
| Total solids | Not listed in the annual table | Monthly average: Davis 142, Ullrich 137, Handcox 150 mg/L | A broad measure of the material carried in the water leaving each plant |
The monthly sheet also gives a maximum and a minimum for each plant, which shows how much a number moves within a month. In September 2026, total hardness at the Ullrich plant ran from 70 to 82 mg/L, at Davis from 65 to 72 and at Handcox from 66 to 72, all inside the 70 to 126 ppm range the annual report gives for 2025 or just under its low end. Total chloramines stayed between 2.70 and 3.15 mg/L across the three plants. The annual figures for 2025 and the monthly figures for September 2026 come from different years and different sampling points, so each is read with its own label and the two are not merged into one range.
Units line up more easily than they appear: for water, mg/L and ppm describe the same quantity, and the annual report converts hardness into grains per gallon using its stated rule that one grain per gallon equals about 17.1 ppm.
Total solids, as the monthly summary reports it, counts all the material carried in a water sample, and total dissolved solids (TDS) is the dissolved share of it, so the two figures are related without being the same measurement. Chloramine taste is a carbon question; the Water Quality Association describes activated carbon as "the most effective nonchemical method for removing chloramines," and the chloramine filter brands guide compares products built for it. Hardness is the measure tied to mineral scale on fixtures and appliances, and how a household handles scale across the house is a separate decision from drinking-water filtration. For the kitchen tap, the relevant technology is reverse osmosis, which the U.S. EPA lists as effective for removing total dissolved solids and other inorganic substances.
Where a Kitchen RO Fits These Numbers
For drinking and cooking water, a kitchen RO system lowers total dissolved solids (TDS) at the tap, and a faucet with its own display shows that reading at the household's own sink. Austin's reports describe the system and its plants over a year or a month, while a faucet reading describes the water leaving one kitchen's filter each time it runs, so the two kinds of numbers sit well together.
At the kitchen faucet, a kitchen RO system adds a reading of its own to what Austin publishes: the purified water's TDS. It appears alongside the remaining filter life on the smart faucet of the Viomi V8 PRO, a tankless RO system, and the Viomi app adds TDS before and after filtration. The touchscreen on the Viomi M1 shows the tap water's TDS and the purified water's TDS together, which puts the change through the filter in a single glance at the kitchen tap. For a closer look at what a TDS figure includes and how it is measured, see the guide to TDS and water quality.
Checking for Current Notices
Annual and monthly reports look back at water that has already been delivered. Current notices are posted separately, on Austin Water's emergency information page. On November 3, 2026, that page stated that no boil water notice was in effect for Austin Water customers, and that any future notice would be posted there and shared through local news media and the utility's official channels. The same page carries the utility's cold weather tips and drought information, and on that date it listed Austin as under Conservation Stage water restrictions. When a notice is in effect, the utility's instructions are the ones to follow.
FAQ
Why does the monthly summary list three treatment plants?
Austin Water treats its water at three plants, Davis, Ullrich and Handcox, and the monthly summary reports averages, maximums and minimums for each one separately. The annual report, by contrast, gives system-wide figures, and for chloramines it reports samples from the distribution system.
Why do the monthly numbers differ from the annual report?
They describe different places and periods. The monthly summary reports averages for each treatment plant over one month, while the annual report covers the whole year and, for chloramines, samples taken in the distribution system. Some items, such as total solids, appear only in the monthly summary.
How often does Austin Water post new summaries?
Austin Water posts both monthly and quarterly summaries. The September 2026 monthly summary covers samples collected from September 1 to September 30, 2026, and the third-quarter 2026 summary covers July through September.
Can I compare this year's numbers with older Austin reports?
Comparisons work best between like entries: the same item, the same unit and the same sampling point, such as distribution-system chloramines from one annual report to the next. A monthly plant average and an annual distribution-system range answer different questions, so they sit beside each other with their labels instead of being treated as one series.
Will an RO faucet's TDS reading match the number in the summary?
It measures something different. The summary lists total solids at the treatment plant, while an RO faucet's display shows the TDS of water after filtration in the home. A display that shows tap TDS as well, like the one on the Viomi M1, gives a before-and-after pair for the same sink.
Reading Austin's Numbers With Their Labels
The most useful habit with Austin's reports is keeping each figure's year, sampling point and unit beside it. Read that way, a September 2026 plant average and a 2025 distribution-system range can sit side by side without being merged into one number, and the household knows which document to open the next time a question about the water comes up.
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