One site. Three different leachates.
Young, intermediate and mature cells drain to the same sump, and each sheds a different solids profile.
Cell age sets the solids character. Young cells shed biological and organic particulate. Intermediate cells shift toward mineral precipitates. Mature and closed cells deliver a fine colloidal fraction that will not settle.
One site drains all three ages into one collection system. Equalization blends them; it does not average them into something stable.
Precipitation sets volume, and loading moves with it. Both variables that define the duty are outside operator control, and they move together in the wrong direction.
The target is moving too. State TSS and turbidity limits have been tightening, and none of it stops at closure — leachate generation continues for decades after the cell stops earning.
Most filtration system don't remove solids - they relocate them.
This is the part of the evaluation that routinely lands outside the equipment comparison, and it is often the larger number.
BACKWASH RETURN
Water, energy and time — plus a concentrated stream returned to the head of the train, competing with influent.
SPENT MEDIA & CARTRIDGES
Wet, heavy, contaminated, handled by a person. Frequency set by suspended solids loads nobody predicted.
CHEMICAL SLUDGE
Coagulation turns a fine fraction into a far larger volume of wet sludge, plus dewatering, hauling and documentation.
The suspended solids spike and the permit exposure are the same event
The rain that raises leachate volume raises solids loading, stressing pretreatment and challenging permit exceedances.
The system under evaluation is not the one running on a Tuesday in July. It is the one running at 2 a.m. on the third night of a storm front, with a reduced crew and a monthly report due. What happens at that hour is a hidden tax — overtime, call-ins, alarm fatigue, and eventually the turnover of the one person who could nurse the filter through a wet week.
Discharge limits have no weather clause. An exceedance during a storm reads identically to one on a clear day, and “the filters blinded” is a finding, not a defense.
So if the honest answer to “does our filtration hold through a spike without manual intervention?” is “usually” — that gap is quantifiable compliance risk. Better to quantify it before an exceedance does.
What to require before you spec a leachate filter
Use this checklist on any vendor, including us. Every item should be answerable with data.
01
Performance at your upper bound, not your average
Ask for performance at the peak TSS your site produces during a wet-weather event, not at the annual mean. If your baseline is 400 mg/L and your storm peak is 3,000, the 400 number tells you nothing about when performance matters most.
02
Whether filtrate is continuous during cleaning
Systems that interrupt output to backwash create a gap in the treated stream. Under a discharge permit that gap is not neutral — it either forces buffering capacity you have to build, or it forces a bypass you have to report.
03
Cleaning frequency — in the unit that matters
“Self-cleaning” is a category, not a specification. The number that predicts behaviour during a spike is how often the screen or media surface is regenerated, and whether that rate is fixed or reactive. A cycle measured in minutes behaves very differently from one measured in fractions of a second when the solids front arrives faster than the trigger.
04
Operator hours per week, from the installed base
An automation claim is unverified until it is expressed in labor hours.
05
Chemical dependency and what it obligates
If stated performance requires coagulant or flocculant, then the quote is incomplete until it includes chemical cost, storage, handling, dose control against a variable stream, and the sludge volume and classification that follow.
06
The quality of water delivered to the next stage
The solids stage is bought to protect what follows it. Specify its output against the feed requirement of your membrane, media or biological stage — including the colloidal fraction, which is what actually fouls a membrane and which a TSS reading will not show you.
07
True water recovery, including cleaning losses
Whatever doesn't leave as filtrate leaves as reject you have to haul or re-treat. Quoted recovery figures often exclude backwash and dump volumes, so the real number is lower than the brochure.
VelRay X is a suspended solids removal stage that holds when the load changes
Engineered against variability
Single-pass filtration across 300–5,000 mg/L TSS, so the design case can be your upper bound.
Screen regeneration at more than 35× per second
Crossflow, tapered slots, active brush cleaning work together to regenerate the screen faster than solids can blind it.
Filtrate flows during regeneration
No gap to buffer, and none to report.
No coagulant, no flocculant
Performance is physical — no dose control, no chemical sludge.
Up to 99% water recovery
Very little leaves as reject, keeping the recycle load off the head of the filtration train.
Frequently asked questions
Send us your leachate data
Give our engineering team your influent characterization, flow rates, and target effluent quality. We'll model VelRay X performance against your actual conditions — including the TSS spikes that break everything else — and walk you through the operator-hour math your team can bring to leadership.