Cahaba Water Co.
The numbers, from the utility's own report.
Every figure below is quoted from the Central Alabama Water (formerly Birmingham Water Works) 2026 Annual Water Quality Report, covering 2025 monitoring data, and you can read the report yourself. This page is Central Alabama Water. If your bill comes from Pelham, Alabaster or Trussville, the numbers are different.
There is no single Birmingham hardness number.
Published total hardness runs 38 to 224 mg/L across the system — roughly 2.2 to 13.1 grains per gallon. That one range crosses four of the five standard classification bands: slightly hard at the bottom, very hard at the top. Which end describes your house depends on which of the four filter plants supplies it and where you sit in the distribution system.
You will see a single figure quoted for the whole metro — "15.2 grains per gallon," or simply "extremely hard." No one number can stand in for a range this wide, and 15.2 sits above the highest hardness reading in the utility's own report. The useful answer is the published range, plus a measurement at your own tap.
A water softener isn't automatic in Birmingham. Hardness varies by water source and location, so we test your home's water before recommending one. If the number is low, we'll tell you. If the hardness level and your goals justify softening, we'll size the system accordingly.
The musty water in spring is real. It's geosmin.
In May 2024, homes across Homewood, Vestavia Hills, Mountain Brook and North Hoover reported water that tasted earthy and musty. Central Alabama Water identified the cause: geosmin, a natural compound produced by algae in the reservoirs.
It's harmless — it's the same compound that gives beets and fresh soil their smell, and humans can detect it at a handful of parts per trillion. It's also seasonal and recurring, because surface water does this in spring.
What fixes it: at the drinking tap, reverse osmosis reliably does. A whole-home carbon filter reduces it only partially at full household flow, because contact time is short. That's an inconvenient thing for us to say, and it's true.
Free chlorine, within limits.
Disinfection byproducts form when chlorine reacts with natural organic matter — an unavoidable consequence of disinfecting surface water, and far preferable to not disinfecting it. Activated carbon reduces both chlorine and its byproducts.
Detected, below the limit, and worth being precise about.
PFOA and PFOS are detectable in Birmingham water, at levels below the EPA limit of 4.0 ppt
Compliant is the accurate word for it, and it is the one we use. Anything stronger would overstate what these figures say.
Softeners and whole-home carbon are the wrong tools for PFAS — the case for those sits with hardness, taste and chlorine, which is where we make it
The parameters that need no equipment.
| Parameter | Result | Our read |
|---|---|---|
| Lead | 90th percentile 0.003 mg/L (action level 0.015)Tap sampling June - September 2023, range ND - 0.033, with one sample above the action level. | A plumbing question rather than a source-water one. Where lead shows up it comes from a service line or the pipe inside the house — specific to an address, which is why the utility samples at taps and why testing yours is the only way to know. |
| Iron | Not detected | Iron treatment is a well-water answer. On this supply the report lists iron among the parameters it did not detect, so there is nothing for a filter to take out. |
| Manganese | ND - 0.003 mg/L (limit 0.05) | Well inside the limit. |
| Turbidity | Highest single measurement 0.5 NTUThe standard is a treatment technique: at least 95% of samples below 0.3. 99.7% of samples met it. | The filtration is doing its job. Sediment cartridges are a well and private-supply tool, not something municipal water here calls for. |
| Nitrate | ND - 0.59 mg/L (limit 10) | Well inside the limit. |
| Combined radium | 0.4 pCi/L (limit 5) | Well inside the limit. |
| VOCs, pesticides, PCBs | Not detected | Dozens of parameters on the standard list, every one of them reported as not detected. |
Birmingham municipal water is, by the numbers, good water. Central Alabama Water reports meeting every state and federal regulation for 2025. What we sell improves taste, odor and chlorine, reduces hardness where the measured number warrants it, and — at the drinking tap — addresses contaminants the RO is certified for. That is the whole of the case, and it is enough.
Two cases with their own numbers.
Trussville is served by its own utilities board, drawing on wells rather than rivers and lakes. Different sources, different report, different numbers. We read that report before recommending anything there — the figures are on our Trussville page.
A well is tested only as often as its owner tests it. Hardness, iron, sulfur and bacteriological risk are all common on wells in this region and absent on municipal supply. A well gets a proper lab test first — then, and only then, a recommendation.
Find out where your house falls
Published hardness runs from 2.2 to 13.1 grains per gallon. A free mailed test tells you which end of that your house is on, and whether softening earns its place.