Water Quality Testing
Bacteriological and general chemistry testing with a written result you can act on. If something comes back out of range, we'll tell you which stage is responsible.
The short answer
Potable rainwater should be tested at least annually, and any time the taste, smell, or appearance changes. Testing covers bacteriological contamination and general chemistry. A result out of range points to a specific stage of the system — UV, filtration, or first flush — rather than to the water itself.
A failed test is diagnostic, not alarming. The result tells us which stage to look at — a bacteriological hit points at UV or a post-UV entry point, while taste and odor point at carbon. Rainwater itself starts out cleaner than most groundwater in this region.
Before you call
Three questions that narrow it down before any sample goes to a lab.
A sudden change points somewhere different than a gradual one. Sudden usually means something upstream failed; gradual usually means carbon is exhausted.
If it's only hot water, the water heater is the suspect, not the rainwater system. This catches more calls than you'd expect.
A lamp past its life is the most common finding behind a failed bacteriological test, and it gives no warning at the tap.
How we diagnose it
Test results map to specific stages of the system. Here's how we read them.
| Result | Usual cause | What it takes to fix |
|---|---|---|
| Total coliform present | UV underperforming, or entry point after the UV | Verify lamp age and sleeve, then trace post-UV plumbing. |
| E. coli present | Direct contamination path | Stop drinking it, then find the entry point. Usually screens or an open hatch. |
| Taste or odor complaint, clean bacteriology | Carbon exhausted | Carbon cartridge replacement. |
| High turbidity | Sediment stage or first flush failing | Correct filtration, then look upstream at the diverter. |
| Elevated metals | Roof or conveyance material | Identify the source material and assess catchment suitability. |
| Low pH | Normal for rainwater | Usually expected. Treatment only if it's affecting plumbing. |
The visit
Where we sample determines what the result means. Tank, post-filtration, and tap tell you different things, so we choose based on what you're trying to find out.
Sterile technique, correct containers, and same-day delivery. A sample handled badly produces a result nobody can act on.
Not just numbers. You get what each result means and whether anything needs doing.
If something is out of range, we identify the responsible stage and quote the fix before doing any work.
Equipment
Sampling follows lab protocol so results are defensible. We use accredited laboratories rather than field strips for anything you'd act on.
Related
FAQ
Yes. We run bacteriological and general chemistry testing and give you the written results. If something comes back out of range, we will tell you which stage of the system is responsible and what it takes to fix it.
We do. A pre-sale inspection produces a buyer-ready report covering tank condition, filtration, pump, and water quality. Buyers of Hill Country properties increasingly ask for one, and having it in hand keeps the rainwater system from becoming a negotiating point.
About every 420 days. Lamps keep glowing well after their output has dropped below an effective dose, so a lamp that looks fine can be doing nothing at all. The install date is the only reliable indicator.
