Engineering design for contaminated-site dewatering: contaminant characterisation, multi-barrier treatment trains, carbon and precipitation, discharge compliance.
The application overview — scope, treatment process and benefits.
On-site pilot trials confirm performance and set dosing and media-change rates.
Pre-assembled, relocatable treatment equipment for construction sites.
The parent hub for construction and quarry dewatering treatment.
Treatment design for contaminated ground stands or falls on characterisation: you cannot specify barriers without knowing the contaminants, their concentrations and how they will change as dewatering mobilises the plume. This guide covers characterisation, multi-barrier selection, pilot testing and verification against strict discharge or reinjection limits.
Characterise Before You Specify
We begin with the site investigation and a sampling campaign to fix the contaminant classes, their concentrations and the discharge or reinjection limits. Barriers are then selected per contaminant — physical for solids and free oil, chemical for metals, adsorptive or oxidative for dissolved organics — and arranged so each protects the next. A pilot trial confirms removal and sets media-change and dosing rates before full build.
Classes and concentrations fixed from the GI and a targeted sampling campaign.
One barrier per contaminant class, sequenced to protect downstream media.
On-site pilot confirms removal and sets media life and dose rates.
Matching Treatment to Pollutant
Typical contaminant–barrier pairings for brownfield dewatering.
| Contaminant | Primary Barrier | Polishing |
|---|---|---|
| Free / dispersed oil | Oil–water separation | Activated carbon |
| Dissolved hydrocarbons | Activated carbon (GAC) | Filtration |
| Heavy metals | Precipitation / electrocoagulation | Media filtration |
| Chlorinated solvents | GAC / advanced oxidation | Polishing GAC |
| Suspended solids | Coagulation + clarification | Filtration |
| Ammonia / nutrients | site-specific | Biological / ion exchange |
Unit Operations In Sequence
Buffers the variable contaminant load for steady downstream dosing.
Clarification and oil–water separation remove gross solids and free oil.
Precipitation or EC removes dissolved metals; sludge thickened for disposal.
Lead/lag GAC adsorbs dissolved hydrocarbons and solvents.
Filtration and pH trim to the discharge limit.
Final sampling confirms compliance before discharge or reinjection.
Proving Trace-Level Removal
Specified for This Duty
Coalescing and API-type separators remove free and dispersed oils ahead of biological or carbon polishing.
View EquipmentHydroxide and sulphide precipitation removes dissolved heavy metals to low microgram-per-litre limits.
View EquipmentSacrificial-electrode EC removes emulsified oils, metals and fine colloids without bulk chemical storage.
View EquipmentGAC adsorption captures hydrocarbons, solvents and emerging organic contaminants from groundwater.
View EquipmentMultimedia and pressure filters polish settled water down to low single-figure NTU for tight consents.
View EquipmentFilter presses and thickeners turn settled solids into a stackable cake for economical off-site disposal.
View EquipmentBack to the Application
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