Diesel plant, hydraulic systems and ground contamination put oil into tunnel water. Oil–water separation and activated carbon intercept free, dispersed and dissolved hydrocarbons before discharge.
Tunnel water routinely picks up hydrocarbons from diesel plant, hydraulic and lubrication systems, fuel storage and, on brownfield alignments, contaminated ground. Even small oil concentrations breach discharge consents and foul downstream treatment. A staged barrier — interception of free oil, coalescence of dispersed droplets and adsorption of dissolved hydrocarbons on activated carbon — keeps the discharge clean and protects the receiving water.
A Staged Oil Barrier
Free and dispersed oil is removed first by API-type and coalescing separators; the residual dissolved fraction is then polished on activated carbon. We size the separators for the worst-case oil slug and the carbon for the dissolved load and required limit, with lead/lag vessels and breakthrough monitoring so the discharge stays within consent between media changes.
API and plate separators remove bulk free oil from the stream.
Coalescing media merges dispersed droplets for removal.
Activated carbon adsorbs the dissolved hydrocarbon fraction.
Lead/lag carbon with monitoring holds the discharge limit.
Why a Single Separator Is Not Enough
Oil in tunnel water spans free, dispersed and dissolved fractions, each needing its own barrier.
Free, emulsified and dissolved oil each require a different removal step.
Hydrocarbon consent limits are low, demanding a polishing barrier.
Plant leaks and spills arrive as slugs the system must absorb.
From Contaminated Water to Clean Discharge
Screening and clarification remove solids that would blind the oil barrier.
Coalescing media merges dispersed droplets for capture.
Lead/lag activated carbon polishes dissolved hydrocarbons.
Hydrocarbon analysis confirms compliance before discharge.
Breakthrough monitoring triggers carbon change-outs.
Plant We Build Into This Stage
Coalescing and API separators remove free and dispersed hydrocarbons.
View EquipmentCoarse and fine screens remove debris and protect pumps and downstream plant.
View EquipmentHigh-rate inclined-plate settlers cut suspended solids in a compact footprint.
View EquipmentMultimedia and pressure filters polish settled water to tight TSS limits.
View EquipmentPre-assembled, road-transportable treatment trains that relocate as work advances.
View EquipmentSediment and suspended-solids removal for tunnel construction water.
View EquipmentWhy Choose Reynolds & Bauhm
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