Enviros Queried - Can You Treat Our Leachate?

In the past few weeks we have recieved a series of enquiries from landfill operators and water treatment plant contractors/operators, and they have raised a common question, which made us think it worth discussing here.

That recurring question is:

Can You Treat Our Leachate?

and, this is followed by, a comment suggesting that even if we design a plant it might not work.

These enquirers say things like:

We cannot afford to appoint you and for your plant not to work.

After further discussion we have been finding that they have been promised a working leachate treatment plant by an otherwise apparently competent water treatment engineer/ contactor/ operator, and it simply has not worked. By "not worked" this usually means that in some important water quality parameter the plant has failed to treat the substance sufficiently to meet the regulatory requirement.

This is truly a strange concept to us, that anyone offering to design a water treatment process, or any other process for that matter, spends the Client's money and builds a plant, and then is unable to get the plant to work and walks away.

In any other industry the perpetrators of such a debacle would surely have been "run out of town" by now! Or else the lawyers would be involved.

We would just like to say to our readers the following:-

We have only experienced less than half a dozen landfills around the world in the last 20 years which were not treatable by biological methods.

When we find a landfill leachate which we think is unusual and may be hard to treat, we will always carry out a simple treatability trial pilot study to test for the viability of biological treatment using a represetative sample of that leachate, before we commit to treatment.

If in the rare event we were unable to assure ourselves and all involved that we would be able to treat, we would not go forward into the construction stage. (However, we do have about 80 leachate plants to our designs working currently numbering the largest and most difficult anywhere.)

When the waste (which I am assuming will be a primarily Municipal Solid Waste) contains heavy metals high salinity etc, the biomass may take longer to acclimatise, but almost always will become established.

I will mention salinity again, because it brings us to another feature of these enquiries, and that is that many of these sites have RO Plants installed.

If the salt content would be above the maximum watercourse discharge concentration after biological treatment, we would consider installing an RO Plant, but only after biological treatment for any permanent installation.

Reverse Osmosis seldom makes sense as a main "treatment method" for landfill leachates, because biological treatment is normally cheaper than RO and importantly it does actually treat the waste.

Reverse Osmosis does not "treat" anything in the sense of coverting a contaminant from a toxic or damaging form to another chemical form, which is less so or even completely harmless, in the way biological treatment does.

We have been solving these problems for clients for the past 20 years or so, and our successful track record speaks for us.

So, if you are considering approaching the Enviros leachate team to ask us to assist with your project, please be assured that we are not in the business of providing plants that do not work!