Sunday, November 02, 2008

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!

Wednesday, June 18, 2008

Last Chance to Book for Leachate Monitoring Course

The next Chartered Institution of Waste Management (UK) Leachate Monitoring course is on 25 Jun 2008, so if you act today there is just about time to register.

This is a One day (non-residential) course held in Shrewsbury, Shropshire, UK.

If you are you involved in the monitoring or the control of leachate from landfills this will be useful to you.

Do you really understand what leachate is and how to effectively monitor it?

This course will provide an understanding of what leachate is, its composition, and appropriate monitoring requirements you should implement.

The course includes practical demonstrations of using a range of leachate sampling and testing equipment.

The course will also provide an introduction to the treatment of leachate.

What’s in it for me?

By the end of the course you will be able to:

• Explain the basic principles of leachate generation
• Identify key contaminants and their risks
• Explain the requirements of monitoring programmes and their objectives
• Identify the range of monitoring equipment used during leachate monitoring and understand how they are used
• Know what current technical guidance documents are available
• Know how to interpret the data generated in order to identify problems and ensure appropriate actions can be determined and taken
• Explain some typical leachate treatment systems and be aware of the monitoring requirements of them.

Who is it for?

Technical staff working in landfill site operations, or design and regulation, with day to day responsibility for the monitoring of leachate generated by landfills or the monitoring of leachate treatment facilities.

Your Leachate News Blogmaster Steve Last will be tutor for the sessions on, "What is Leachate?" and "Leachate Treatment".

For more information, and booking, visit the CIWM web site Leachate Monitoring Course page.

Monday, June 09, 2008

Enviros Commissions 3rd Leachate Treatment Plant in South Africa


Enviros Consulting landfill leachate treatment experts have successfully completed the commissioning of the new Leachate Treatment Plant for eThekwini Municipality's solid waste Disposal department (Durban Solid Waste - DSW).

The plant is treating leachate collected from the Buffelsdraai Landfill, which is a large new landfill located to the north west of the city. The site opened in May 2006 and receives the waste-stream that was originally accepted by the now closed La Mercy landfill site. The site will also accept waste previously disposed at other DSW landfills, including the large Bisasar Road Landfill.

The leachate treatment plant is planned to be completed in two stages with a treatment capacity of approximately 200 cubic metres per day, of which half has now been installed and commissioned.

The plant is the third biological treatment plant using a nitrification process similar to the many other Enviros plants, which Enviros has designed and commissioned in South Africa. It follows the commissioning of the Vissershok Leachate Treatment Plant (Cape Town City Council) and the Mariannhill Leachate Teatment Plant (Durban Solid Waste).

The leachate treatment plant protects the local river from contamination by leachate, which would if not treated, pollute the watercourse. Even if present at extremely low levels untreated leachate can cause taste problems in water later abstracted and treated for potable (drinking) water supplies.

The plant includes a reed bed for final water quality polishing, and will provide water for irrigation and for dust suppression.

Friday, March 14, 2008

New UK Environment Agency Statement on Leachate Irrigation

There has been a gap in the information provided by the UK environment Agency since last year when the BAT Guidance for leachate treatment was publised on the web site www.environment-agency.gov.uk .

The whole area of leachate treatment by irrigation, which is still practised in the UK at a few landfill sites, and which is used to a much greater extent in Europe generally, was until now without any guidance.

To a certain extent that gap has been closed by the position statement published in February, which can be read here.

The regulatory position statement covers the application of treated landfill leachate to short rotation coppice (SRC), but the principles described would presumably also apply to other forms of irrigation (eg grass plot).

In other EU countries, including Scandinavia (which is normally seen as exemplary in their application of environmental controls), the rules are much more relaxed as follows:-

- They allow untreated leachate to be irrigated to short rotation coppice (SRC)

- They allow irrigation not only during soil-moisture deficit periods, but also in many cases when there is not a soil-moisture deficit, so in Europe such schemes entail run-off during irrigation from the irrigated area during wet weather.

- They do not require the base of the irrigated area of treated landfill leachate to short rotation coppice (SRC) to be engineered and to have a barrier to prevent any loss to groundwater, as this is prohibitively expensive for such an otherwise inherently low cost process.

The question has to be asked that if the UK Environment Agency (EA) consider that the EU regulations such as the EU Groundwater Directive, and the EU Landfill and Waste Management Directives require them to take this position, why are not the other EU states applying equal stringency?

Finally, the position statement makes no reference to the dilute leachate which emerges from many old landfill sites in large volumes, where often a lack of original engineering design allows the leachate to become extensively diluted by groundwater.

These old leachates are often very dilute in nature, yet still environmentally damaging, and the techniques which would be applicable under BAT to these would hardly be those which would be applicable for a strong leachate from a WM Licensed or Permitted site. Yet there is still no UK EA guidance on BAT for these examples of leachate.

In my view the effect of this interpretation of the EU regulations will be that the potential opportunity for the nutrients from leachate, which could otherwise be used to water and fertilise extensive use of willow coppicing, much of which in turn could be used for biomass energy production, will be lost.

If it can be done elsewhere, as it is being done, with proper scientific monitoring and control, it should be possible to do this within the UK.

We would be pleased to receive your views - comment on the leachate blog or email me steve.last[at]virgin.net with your views, which if suitable and with your permission, we would like to publish. See also www.leachate-irrigation.com .

Friday, February 15, 2008

Leachate Monitoring (plus treatment) Course

One Day Course 27 Feb 2008

Course Title: Leachate Monitoring (plus treatment)

A one day (non-residential)course

Location: Shrewsbury, Shropshire, UK

Are you involved in the monitoring or the control of leachate from landfills? Do you really understand what leachate is and how to effectively monitor it?

This course will provide an understanding of what leachate is, its composition, appropriate monitoring requirements including practical demonstrations of using a range of equipment. The course will also provide an introduction to the treatment of leachate.

What’s in it for me?

By the end of the course you will be able to:

• Explain the basic principles of leachate generation
• Identify key contaminants and their risks
• Explain the requirements of monitoring programmes and their objectives
• Know what current technical guidance documents are available
• Use the data generated to identify problems to ensure appropriate actions can be determined
• Identify a range of monitoring equipment and understand how they are to be used
• Explain some typical leachate treatment systems and be aware of the monitoring requirements of them.

Who is it for?

Technical staff working in landfill site operations, or design and regulation, with day to day responsibility for the monitoring of leachate generated by landfills or the monitoring of leachate treatment facilities.

For more information and booking visit the CIWM web site here.

Sunday, February 10, 2008

Waste Management Inc. Virginia USA - Leachate Spill Settlement

State's largest landfill fined for garbage juice spill

Originally Posted to: Environment News Virginia

By Scott Harper, The Virginian-Pilot, © February 12, 2008

The owner of the state's largest landfill, in Sussex County, has agreed to pay a $14,250 fine for an environmental accident in 2006, when some 8,000 gallons of garbage juice - known as leachate - spilled into wetlands.

It is the first time that the Atlantic Waste Disposal Inc. landfill, owned by trash-giant Waste Management Inc., has been in trouble with the state Department of Environmental Quality, according to records and officials.

Under the terms of a proposed settlement, the company would pay the fine, assess any environmental harm from the spill and adopt better monitoring of ammonia and other pollutants that might wash off its massive landfill and taint neighboring lands and waters.

Spread across more than 1,300 acres near Waverly, on the western outskirts of Hampton Roads, the private facility accepts the most trash of any landfill in Virginia, said Bill Hayden, a state environmental department spokesman.

Under its state permit, the Atlantic Waste Disposal site can take out-of-state garbage, in-state trash, sludge, scrap metal and industrial debris - but not medical waste, asbestos or hazar dous waste.

It is one of several landfills constructed in the 1990s east of Interstate 95 that have made Virginia the second-largest importer of household garbage in the country. Pennsylvania is No. 1.
According to the proposed written settlement, the accident occurred Nov. 9, 2006. The leachate was being pumped into a tanker truck, but the driver fell asleep and some 8,000 gallons overflowed onto the ground, said Michael P. Kearns, district manager for Atlantic Waste Disposal Inc.

"He woke up and there was stuff running all over the place," Kearns said. "He came and told us right away."

The juice ran off a loading pad, into a drainage ditch and settled in nearby wetlands, which are considered "waters of the state" because of their environmental importance, according to the settlement.

The company immediately contacted state environmental officials, as required by law, and a cleanup began, said Jennifer Hoeffner, a state enforcement specialist overseeing the case. More....