Borehole water often looks clear from the tap yet carries dissolved iron and manganese, sub-micron colloidal particles, hardness and sometimes pathogens — each of which fouls reverse-osmosis membranes, scales boilers or breaches potable limits. We assess the actual water and engineer the treatment train that turns a raw borehole into a reliable supply.
Aeration and catalytic multimedia filtration that removes dissolved Fe and Mn.
SDI reduction and fine-particle removal that stops membrane fouling.
Disinfection, hardness and compliance for drinking-water boreholes.
The oxidation step that makes dissolved iron, manganese and gases filterable.
Every common borehole contaminant explained — what it is and what it costs.
Softening, antiscalant or RO to stop scale in boilers, RO and cooling.
Boreholes and groundwater abstractions are among the most cost-effective water sources available, but raw groundwater rarely meets the quality a process, boiler, membrane plant or potable network requires. Dissolved iron and manganese, hardness, sulphides, dissolved gases, fine colloidal turbidity and occasional microbial contamination all sit hidden in water that can look perfectly clear at the wellhead. Reynolds & Bauhm start every project with a full analysis of the actual borehole — flow, chemistry and seasonal variation — rather than a generic package, because the right train for high-iron groundwater is very different from one sized for hardness or RO pre-treatment. From that basis we design, build and commission the complete treatment train — aeration and oxidation, multimedia or catalytic filtration, softening, disinfection and RO protection as required — so the supply is dependable, compliant and protects everything downstream.
Eight in-depth guides — the problems, the aeration step, each treatment stage and the pitfalls.
Iron, manganese, hardness, CO₂, H₂S, ammonia, colloids and bacteria — what each does and why.
Read MoreWhen you need one, the types, and how the oxidation step is sized.
Read MoreCatalytic media filtration after oxidation — the core of most plants.
Read MoreSoftening, antiscalant or RO — matched to the end use.
Read MoreSDI reduction and UF that stop membrane fouling.
Read MoreUV and chlorination barriers for a safe potable supply.
Read MoreThe complete drinking-water borehole train.
Read MoreWhy borehole plants fail — and how to avoid it.
Read MoreThe contaminants that matter are the ones you cannot see
Groundwater is often anoxic, so iron and manganese arrive dissolved (Fe²⁺, Mn²⁺) and invisible. They only precipitate — as orange and black deposits — once exposed to air downstream, staining fixtures, fouling membranes and coating heat-transfer surfaces.
Iron & Manganese RemovalBorehole turbidity is frequently dominated by 1–3 µm colloids — far below the cut of a conventional sand filter. They pass straight through coarse media and drive the Silt Density Index (SDI) that fouls reverse-osmosis membranes.
Colloids & SDI ControlCalcium and magnesium hardness, often with elevated alkalinity, scales boilers, cooling systems and RO membranes — needing softening or antiscalant depending on the end use.
Hardness & SofteningEven a deep borehole can carry bacteria or be vulnerable to ingress. A potable supply needs disinfection and a barrier philosophy to meet drinking-water standards reliably.
Disinfection & ComplianceThe most common — and most expensive — borehole mistake is to install a plain quartz or sand filter and expect clean water. It fails on both counts. First, a granular sand bed captures particles down to roughly 10–20 µm, but borehole turbidity is dominated by 1–3 µm colloids that pass straight through, so the SDI barely moves and the RO keeps fouling. Second, sand does nothing to dissolved iron and manganese: Fe²⁺ and Mn²⁺ are in solution, not suspension, so there is nothing for the filter to strain — they must first be oxidised to an insoluble floc. The correct train therefore always pairs an oxidation step (aeration, sometimes with a catalyst or oxidant) with the right media: catalytic manganese-dioxide media to drive and hold Fe/Mn removal, and a genuinely fine polishing stage — ultrafiltration where an SDI ≤ 3 is required for RO. Diagnose the water first, then choose the media; never the other way round.
A staged train, each stage matched to a measured contaminant
Atmospheric or pressurised aeration raises dissolved oxygen and oxidises Fe²⁺ to Fe³⁺ floc; where manganese or ammonia are present, a catalyst or oxidant is added. This is the step plain filtration omits.
A multimedia bed — anthracite over catalytic manganese-dioxide media over sand — both filters the iron floc and catalytically removes residual Fe and Mn, all in one pressure vessel with air-scour backwash.
Where the water feeds RO, a fine polishing stage — ultrafiltration — removes the sub-micron colloids that granular media cannot, bringing SDI below the membrane’s limit.
Hardness is managed by ion-exchange softening or dosed antiscalant, sized to the end use — boiler, cooling, RO or potable.
UV disinfection, or chlorination with a contact main, provides the microbiological barrier required for a potable or hygienic process supply.
The polished water meets its duty — reverse osmosis for high-purity or boiler feed, direct supply for potable or process water — with the upstream train protecting it.
Representative trains we arrange for different end uses — the actual design follows a treatability assessment of your water
Arrangement: aeration column → catalytic multimedia filters (Fe/Mn) → ultrafiltration (SDI ≤ 3) → antiscalant → reverse osmosis → boiler. Protects the RO from the dissolved iron and sub-micron colloids that are the usual cause of premature membrane fouling on borehole supplies.
RO Pre-TreatmentArrangement: aeration → catalytic Fe/Mn filtration → polishing filtration → UV disinfection → supply. Brings iron, manganese and turbidity within drinking-water limits and adds a disinfection barrier for a compliant private or community supply.
Potable SupplyArrangement: aeration → multimedia filtration → softening or side-stream filtration. Removes the iron and turbidity that stain product, foul nozzles and build deposits in cooling circuits, with hardness control matched to the duty.
Cooling Water FiltrationArrangement: enhanced aeration / oxidant dosing → first-stage catalytic filtration → second-stage polishing filtration. For strongly ferruginous or manganiferous boreholes where a single pass cannot reach target — staged catalytic media carries the load.
Fe/Mn RemovalWe set out tiered arrangements against the same measured water, so the trade-offs are explicit
The minimum train that actually solves the measured problem — oxidation plus catalytic multimedia filtration — rather than a single filter that looks cheaper but fixes nothing.
The balanced arrangement: staged catalytic filtration plus the polishing or UF stage the end use needs, sized with backwash, instrumentation and a sensible safety margin.
Full resilience: duty/standby, online water-quality analysers, disinfection, design documentation and commissioning — a plant engineered to run unattended and stay in compliance.
Every arrangement is sized against a treatability assessment of your actual borehole — the figures above are representative, not a substitute for that analysis.
The heart of almost every borehole plant we build
Catalytic manganese-dioxide media that drives and holds Fe/Mn removal after oxidation.
Read MoreAnthracite / sand / catalytic media beds that combine coarse and fine filtration in one vessel.
Read MoreMultimedia and ultrafiltration arranged specifically to protect downstream RO membranes.
Read MoreSurface loading, bed depth, backwash and media selection for the duty.
Read MoreThe oxidation step that makes dissolved iron and manganese filterable.
Read MoreUltrafiltration for sub-micron particle and SDI reduction ahead of RO.
Read MoreProtecting boilers and RO from borehole iron and turbidity.
Read MoreWhere borehole treatment fits the wider process-water train.
Read MoreGo deeper into the technologies behind a borehole plant.
The fundamentals of how aeration adds oxygen and drives iron and manganese oxidation.
Read ArticleCascade, packed, spray and pressure aerators — how each type works.
Read ArticleSurface loading, bed depth, media selection and backwash for the duty.
Read ArticleHow ultrafiltration removes the sub-micron colloids that drive SDI.
Read ArticleHow multimedia and UF are arranged to protect downstream RO membranes.
Read ArticleTreating the ammonia and nitrogen sometimes found in borehole water.
Read ArticleClarification and filtration for compliant potable water.
Read ArticleAeration and destratification of raw-water reservoirs feeding a supply.
Read ArticleReynolds & Bauhm assesses the actual borehole water, identifies what is really driving the problem — dissolved iron, sub-micron colloids, hardness or pathogens — and arranges the multimedia and membrane train that fixes it, with essential, recommended and premium options costed against the same analysis.
Our expertise spans multiple industries with sector-specific water treatment solutions.