Septic system replacement in Victoria, tank and bed
When both halves have reached the end, replacing them as one job is cheaper and faster than two separate projects, because the soil work, the permit and the machine time are shared.
A bed that failed because solids reached it can often be rebuilt in or beside the same footprint once the tank problem is fixed. A bed that failed because the soil there was never suitable, or because the water table rises into it seasonally, will fail again in the same place no matter how well it is built.
That is why the soil work is repeated rather than inherited from the original permit, which may be decades old and may predate a neighbouring development that changed the drainage. The perc test is done fresh.
Where the site genuinely cannot support a conventional bed at any location, an aerobic treatment unit discharges cleaner effluent and needs less area. Full pricing by type is on septic system cost.
Full replacement
How it works
How a full replacement runs
Fresh soil evaluation
New test pits and rate, because the original permit may be decades old and the site's drainage may have changed.
Design, permit, reserve area
System sized and drawn, permit filed, and a reserve area identified and protected for whatever comes after this one.
Decommission and build
Old tank pumped and removed or filled, old bed taken out of service, then the new tank and bed built to drawing.
Inspect, grade, seed
Open-trench inspection, backfill in lifts, final grade and seed, with the approved paperwork handed over.
The reserve area is worth protecting
Every bed is temporary, including the new one
A well-built bed on decent soil lasts twenty to thirty years, which means somebody will replace it again. The cheapest possible version of that future job is one where a suitable, undisturbed area has been kept clear for it.
So part of a replacement is identifying that reserve area and telling you plainly what must not happen on it: no vehicles, no sheds, no patios, no deep-rooted planting. Compaction closes the soil pores a bed depends on and it is not reversible, which is also the rule for the bed you are building now, set out on drain field.
The other half of making it last is the tank. Solids reaching the new bed will kill it as fast as they killed the old one, so the pumping schedule and the effluent filter matter more after a replacement, not less.
Re-tested, not inheritedSoil
Identified and markedReserve area
Removed or filledOld tank
Installation services
Other installation work
From a single tank swap to a full build on a difficult site.
Get that tested rather than taking it on a quote. A tipped distribution box or a collapsed outlet tee produces the same symptoms as total failure. See septic repair before accepting a replacement.
Sometimes, if the failure was caused by solids rather than by unsuitable soil. Fresh test pits decide it, because rebuilding in ground that was never right repeats the failure.
It is driven by soil, access, system type and imported fill. A conventional bed on good soil sits at the bottom of the range and an engineered system on clay at the top. See septic system cost.
Usually not at all. The old system generally stays in service until the new one is ready to cut over, and where that is not possible we tell you the gap before starting.
It is taken out of service and left in place. Excavating a failed bed is rarely necessary and disturbs ground you may want as reserve area later.
Twenty to thirty years for the bed is typical where the tank is pumped on a measured interval. Neglect the tank and the same bed can be gone in under fifteen.
