Borehole treatment plants fail more often than any other small water plant — not because the technology is hard, but because the water is misjudged and the wrong train is installed. This page sets out the real-world problems with treating borehole water: the design mistakes, the operating headaches and the things that quietly degrade performance, so you can avoid them before they cost you a re-build.
Most failures are designed in before commissioning.
The number-one mistake: a sand/multimedia filter installed without an aeration/oxidation step. Dissolved Fe/Mn pass straight through and precipitate downstream. The filter changes nothing.
Manganese oxidises far slower than iron and needs higher pH or catalytic media. A plant sized for iron alone fails its manganese limit (0.05 mg/L) within weeks.
Sand captures ~10–20 µm; borehole turbidity is 1–3 µm colloids that drive SDI. Without ultrafiltration, the RO keeps fouling.
Designing from a single old water report — or none. Borehole chemistry varies with season, draw-down and depth; the plant must be sized on representative data.
The headaches that appear once the plant is running.
| Problem | Cause | Prevention / fix |
|---|---|---|
| Media blinding / short runs | Floc forming inside the filter, or overload | Oxidise & contact upstream; correct backwash & air scour |
| Manganese breakthrough | pH too low, media exhausted, insufficient contact | pH correction, catalytic media, oxidant trim |
| RO fouling persists | SDI still high — colloids not removed | Add UF polishing to reach SDI ≤ 3 |
| Scaling on RO/boiler | Hardness not managed | Softening or antiscalant |
| Biofouling / regrowth | Iron bacteria, no disinfection barrier | Disinfection, periodic sanitisation |
| Backwash water disposal | Fe/Mn-rich backwash needs handling | Settlement/thickening, consented discharge |
| Seasonal quality swings | Aquifer level & chemistry change | Design margin, online monitoring, control trim |
| Corrosion of pipework | Aggressive low-pH / high-CO₂ water | CO₂ stripping & pH correction |
Diagnose the water, then choose the train — never the other way round. A plant matched to a real analysis runs reliably; one matched to a catalogue picture fails. See the correct staged train on the treatment hub.
We diagnose why it’s failing — missing oxidation, wrong media, manganese breakthrough, SDI, scaling or biofouling — and put right the train so it meets target reliably.
Our expertise spans multiple industries with sector-specific water treatment solutions.