Constructed Wetlands for the Treatment of Landfill Leachates

Constructed wetlands are proving to be the best natural treatment system for landfill leachates.Most of the contaminants in landfill leachates are degraded in treatment wetlands. Potential for long-term sustainability and significant cost savings are attractive features of this eco-technology.Documentation of the experience in this use of constructed wetlands has been limited. Constructed Wetlands for the Treatment of Landfill Leachates is the first compilation of the results of research from North America and Europe. Originally presented at an international symposium, this collection of papers offers the most recent research findings from the leading researchers in this new and innovative natural treatment system.Specific issues addressed in the text include:oleachate characteristics, and the potential for treatability by constructed wetlandsowetland treatment, processes and transformationouse of constructed wetlands in cold climatic conditionsoassessment of the tolerance of wetland plants to the toxicity of leachatesorole of plants in the treatments of leachatesointegrated wetland systemsoperformance of different wetland treatment systemsocost comparisons of wetland technology vs. traditional treatment technologiesThe potential for environmental contamination due to leachates from landfills is increasing, and there is an urgent need to find ways and means to treat leachates in a sustainable way Constructed Wetlands for the Treatment of Landfill Leachates will provide an invaluable source of information on the subject for scientists, engineers, practitioners, policy makers, and regulatory officials.

Price: $129.95

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Avoiding Failure of Leachate Collection and Cap Drainage Systems (Pollution Technology Review No. 138)

A guide to the control of leachate, including failure mechanisms, design, construction, inspection, maintenance and repair.

Price: $139.95

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Cranston tells Resource Recovery to pay its bills - Providence Journal

CRANSTON — The Rhode Island Resource Recovery Corporation has until Sept. 27 to settle a $2-million debt in back charges or the city will initiate legal action, members of the City Council’s public works committee said Thursday.

Council members say the owner and operator of the state Central Landfill in Johnston snubbed settlement attempts for months.

“They can’t continue to put their heads in the sand and act like we don’t exist,” Council President John E. Lanni Jr. said.

Friday, Michael J. OConnell, the corporation’s executive director, said Resource Recovery was actually waiting for city officials to contact them.

“Our predicament is that we have requested information from them, and we haven’t got anything back from them, which is why we can’t respond,” OConnell said.

On July 20, the city billed Resource Recovery for $2,096,598.31 in back charges, saying the corporation failed to treat its leachate or pay its share of expensive upgrades. The invoice includes $437,254.52 in operating and maintenance costs associated with the excess loading dating to 2005, and $1,659,343.78 for the corporation’s pro-rated share of the city’s costs of upgrading the plant based on a permit change that year. It does not include possible administrative costs.

City officials also say Resource Recovery allowed three businesses in its Johnston industrial park to illegally tie into Cranston’s sewer service. That violation carries penalties of $25,000 per day per business, city officials say.

City Solicitor Evan Kirshenbaum and Councilman Mario Aceto, the committee’s chairman, have said the city tried to negotiate a resolution for the past year, but agency officials stalled in scheduling another meeting. City officials later learned from a newspaper article that Resource Recovery was planning to build a sewer line to connect into a Narragansett Bay Commission sewage intake.

The Providence Journal filed an open records request on July 30 asking for copies of public documents, including the corporation’s annual budget, along with any supporting documentation and description of the corporation’s leachate pretreatment system or payment-in-lieu of pretreatment and any sewer agreement with the city to extend service to the corporation’s industrial park.

The deadline to respond was Sept. 14.

Friday, OConnell said the corporation’s lawyer was reviewing the documents to see which, if any, would be released “because this is a likely lawsuit in the near term.”

Also Thursday night, the council finance committee voted to unseal the minutes of several closed-door discussions on how much Johnson & Wales University is to pay the city in taxes for 12 lots, roughly 20 acres of waterfront land, on its Harborside Campus.

In 2005, the city rezoned the land and amended its Comprehensive Plan to allow the university to build 12 dormitories and a community building and management facility.

The campus, which includes 84 buildings on the Providence side, was built by a nonprofit agency, which leases the buildings to the university. That raised the question of whether the project was tax-exempt.

Rather than seek clarification, the university and the city reached a 20-year agreement that city officials say was never signed, under which the city was to get $95,000 annually for the first 10 years and $104,500 for the next 10 years.

The “memorandum of understanding” called for the city to collect most of that money from the state in the form of a payment in lieu of taxes and Johnson & Wales to cover any difference between the state compensation and the agreed-upon figure. If the property was later deemed to be taxable, the university agreed to pay the appropriate tax.

This year, Finance Director Robert F. Strom said, Cranston received $4.2 million in PILOT money from the state, which includes payment for the 12 university parcels and 20 state lots. Strom estimated the state’s payment for Johnson & Wales was $150,000 to $160,000.

The university land, Strom said, is currently assessed at $4.8 million, and the buildings at $21 million.

marmenta@projo.com

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Fulton continues to work on landfill violations - Fulton Sun

He said the city also has completed supplemental environmental performance projects, which he described as "essentially an additional penalty designed to improve the situation, including a methane capture system. Slivka also addressed a concern from Ready regarding what happens when the landfill closes in May 2011.

"We will have a financial assurance instrument in place," he said.

"Essentially saying 'Here's this money to fix violation issues if it happens."

Fulton Director of Administration Bill Johnson said the city actually has been subject to more inspections since announcing its intention to close the landfill.

"DNR has an interest in ensuring we close it properly," Johnson said.

Regarding odor issues, Slivka said the Department of Natural Resources has been out to test air quality on a number of occasions -- as recently as the week of Sept. 6 -- and never found a problem.

"On odor violations, our litmus test is 7 to 1 dissolution," Slivka said. "We've gone out there a number of times and it's never been higher than 2 to 1."

Johnson addressed the most recent violations for exposed litter.

"This is not an excuse, but we are approaching our closure date, and there was an attempt to spread trash thinner over a wider area to even out the land," Johnson said, noting that process also included having to haul in more dirt. "The idea sounded good to use the trash to fill in, but it just didn't work out the way we thought.

"We did it, it was wrong, and we won't be doing it anymore."

As for methane levels, he said one supplemental environmental performance project currently in the works involves putting in a 10,000 gallon tank to pump water that flows down into the methane collection wells out of the landfill.

"This will allow our methane extraction wells to function better," Johnson said. "Hopefully by drawing the methane down into the wells it will stop it from migrating."

Another just-completed project is a storm water sediment pond "that will give sediment in the storm water time to settle out before water leaves the site."

Although Slivka said he could not give a number regarding how much the city has been fined for these violations, he did say DNR recently sent an agreement in principal regarding settlement.

"We're certainly sympathetic to Mrs. Ready, but we feel like we have been out there and we have been on the city's back," Slivka said.

Johnson acknowledged the city has received that agreement, noting DNR is proposing a fine of $10,000 as well as an additional $5,403 to pay for investigative costs.

Johnson said he is scheduled to meet with Department of Natural Resources officials later this week, and noted the agreement in principle will be presented to the Fulton City Council at its Sept. 28 meeting.

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Dumping water into bay could be Mercury clean-up solution - UpperMichigansSource.com

CMS would filter the water to remove 90 percent of mercury, but some ask if that's enough

PETOSKEY, MI -- CMS Land Company believes they've found a local solution to the Leachate problem at Bay Harbor and East Park, but it's being met with some serious concern.

What to do with the contaminated water from the former Penn-Dixie Cement Plant near Petoskey?

That has been the question, and for four years, the water has been shipped to a deep-well injection site.

But CMS Land Company says something else needs to be done, and they believe they've found the solution.

But this solution could mean small quantities of Mercury being diluted into the Great Lakes.

For five years it has worked like this...collect the run-off water that contains mercury from the contaminated land underneath Bay Harbor and East Park, neutralize it in this building, and then ship the result, an average of 150-thousand gallons per day, to a deep-injection well-site more than 50 miles away to Johannesburg.  C-M-S Land Company has been in charge, and now, they say it's their belief they've found a better *local solution to take care of the local problem.

"We're proposing to build a $4 million state-of-the-art facility to treat the water that we collect here using the best available technology and then release that water back to Lake Michigan," said CMS Land Company Area Manager Tim Petrosky.

The main contaminant of concern is Mercury.  The facility will remove 90 percent or more from the water.  That water would then be mixed with clean water to meet environmental criteria before going back in the lake.

"The requirements are very, very stringent, in fact, the release criteria for mercury to the lake is 1.3 parts per trillion," said Petrosky.

Here's an analogy of the parts per trillion guideline.  It'd be like placing one drop of contaminated liquid in all of the water of 20 Olympic-sized swimming pools combined.

But Doctor Grenetta Thomassey of the Tip of the Mitt Watershed Council says this amount *may seem benign...it could be detrimental, which is why the council doesn't support this solution.

“You mix it with water, and let it go into Little Traverse Bay, and then you come back and you mix it with water, and let it go into Little Traverse Bay, and basically what you got is that exact same amount of mercury all ending up in Little Traverse Bay, so we're not in favor of that, no," said Thomassey.

CMS has submitted an application to the Department of Natural Resources and Environment. 

“We look really carefully at mercury because it is one of the few contaminants that is known as a bio-cumulative compound, meaning that it builds up in the environment over a period of time, so we look at that very carefully," said Bob Wagner, the Lake Huron Regional Director of the DNRE.

“We think it's the best solution to environmental, safety, and economic perspective," said Petrosky.

“This is a bad deal.  So we are not interested in anything going into Little Traverse Bay if it can be prevented," said Thomassee.

The DNRE will review the application and if the proposed treatment meets the guidelines, they'll issue a draft permit sometime in October or November.  After that, they'll seek public comment.

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Damu inspects waste plant work at Sonsoddo - Times of India

MARGAO: Fatorda MLA Damodar Naik accompanied by the chief officer of the Margao Municipal Council (MMC) inspected the Sonsoddo site on Tuesday morning to take stock of the status of the work of the garbage treatment plant carried out by Fomento-IL&FS.

Chief executive officer of Fomento, Sridhar Kamat, was also present on the occasion.

The BJP legislator voiced his displeasure over the failure of Fomento to put in place any adequate measures to control flow of leachate from the site onto the roads. The explanation offered by Kamat that the heavy rains impeded the leachate control work at the site failed to convince Naik who demanded that the situation be brought under control within two days.

Later speaking to reporters, Naik said that he had received several complaints from the residents of the area about leachate from Sonsoddo flowing onto the streets since the last several days. "It's over seven months that the site was handed over to Fomento by the MMC and it is yet to control leachate flow.

The situation is leading to contamination of wells in the vicinity and will turn out to be a health hazard if the leachate flow is not brought under control immediately," Naik said.

MMC councillors Narayan Fondekar, Raju Shirodkar, Ciriaca Rodrigues, municipal engineer Surendra Naik and sanitary inspector Viraj Arabekar were present for the inspection.

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Landfills pose a health risk - Malaysia Star

MOST people object to having a landfill near their houses. We generate rubbish but once it enters the dustbins or recycling bin, we want nothing more to do with it.

The main reason is fear of possible health problems arising from contact with pollutants escaping from waste management sites, but the problem is set to grow over the next decade due to our throwaway lifestyle.

Each year, we produce more than nine million tons of household waste, but only recycle 3% of it. There is no positive sign that waste generation is decreasing. As a result, a large number of former mines and quarries have been lined with water-proof material and filled with rubbish. As suburbia spreads and brown field sites are developed, more Malaysian families than ever before are living close to landfill sites.

In landfill sites, bacteria break down food and other organic materials, producing potentially pollution liquids and gases such as ammonia, acids and heavy metals, mixed into a nasty cocktail called leachate.

All these contaminants are cause for concern if they end up in natural

water-courser and drinking water supplies. Many such cases have been recorded lately in Malaysia.

Leachate can destroy the well balanced eco-system and is very harmful to human. It is clear that poorly managed landfill will lead to serious environmental problem such as the recent incidence of raw water pollution caused by leachate seepage from a landfill.

Hence, leachate management becomes an important issue in deciding which strategy to apply in any planning process involving the closure of dumps and siting and development of landfills. The main objective of any leachate management will be to ensure that landfill waste does not impose any unacceptable short term or long term risks to the environment or to public health.

ETHAYA RAJAN MOKANATAS,

Kuala Lumpur.

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Largest Membrane Leachate Plant Handover - Water and Wastewater

Enschede, The Netherlands -- Two years ago, ISTAÇ (Istanbul Metropolitan Municipality Environmental Protection and Waste Materials Valuation Industry) and Norit X-Flow embarked on one of the most remarkable wastewater treatment projects of its time; the treatment of leachate from the Istanbul landfill in Odayeri and Kömürcüoda. The installation became the largest membrane leachate plant in the world and involves the most advanced water treatment technology available.

The ISTAÇ Leachate Treatment project represents one of the most challenging filtration projects globally, based upon its size, environmental conditions , and continuous growth rates. The solution had to be robust, future proof and deliver consistently the highest effluent quality levels to ensure the environmental integrity of the region. says Jürgen von Hollen, Managing Director of Norit X-Flow.

After approximately two years of operation and treating up to 3500 m3 of landfill water percolate on a daily basis the conclusion is that the plant meets its specifications and contractual requirements for discharge of the treated effluent. ISTAÇ and Norit X-Flow celebrated the official handover and the successful partnership on August 17, 2010.

Water percolating through landfills for solid waste results in leachate, which may contain undesirable or toxic chemicals. The ISTAÇ landfill is constructed to prevent leachate contamination of groundwater or surface waters. The landfill percolate containing high amounts of COD, BOD, TSS and Nitrogen is collected and treated by Norit's membrane bioreactor (MBR) technology which makes it possible to discharge this water directly into the Black Sea, a process that is in line with both current and future drainage standards.

Beside its state of the art MBR technology, the wastewater treatment plants in Istanbul uses a combination of two advanced Norit X-Flow technologies: a biological process applied in conjunction with ultrafiltration followed by nanofiltration.

The collected leachate is first subjected to primary clarification and afterwards transferred to a bioreactor unit for biological treatment. In the bioreactor COD, BOD and Nitrogen compounds are eliminated. Subsequently the Norit X-Flow Crossflow membrane system, placed outside of the bioreactor, separates sludge, solid waste on suspension and some amount of COD. Lastly, the Norit NF installation eliminates the remaining COD, organic micro polluters, heavy metals and other compounds (humic acids, color) to a water quality conform current and future discharge standards.

Mr. Akguel, Managing Director of ISTAÇ adds ?The success of the project beyond the technological solution can be attributed to the project partnership approach adopted by both ISTAÇ and Norit X-Flow both at the operational level, but equally important at the management level to ensure that full commitment and prioritization was given to this project. Our continuous partnership will ensure that this installation is the benchmark for landfill leachate plants for years to come.?

Source: http://www.x-flow.com/

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Leachate from disused site costs ratepayers New Zealand - Northern Advocate

Give us your thoughts on this story.

A Hakaru resident is angry that leachate from a disused landfill is costing Kaipara ratepayers thousands of dollars a year to have it collected and transported from the site.

Derek Mason said the leachate volumes have doubled since the site ceased operating as a landfill and blames poor construction advice, which included no sidewall liners, as a reason for the ongoing problems.

Mr Mason said the Hakaru landfill site, between Mangawhai and Kaiwaka, has been controversial since it was opened in 1995 and was not wanted by the community who had always preferred a transfer station.

The landfill served the Kaiwaka, Mangawhai and Maungaturoto area east of Doctors Hill Rd. Mr Mason said the Kaipara District Council estimated refuse volumes to the landfill of 20,000cu m yearly made a transfer station an unviable option but these volumes had not eventuated.

The council walked away from a proposed site at Franklin Rd, Paparoa, after it realised it was going to be too costly, he said.

Mr Mason, who is a member of the Hakaru Landfill Committee, claimed it cost ratepayers $127,000 per annum to have the leachate carted off site, which was "wasteful spending".

The total volume of refuse collected over the 10 years the site had operated was only 25,000cu m, he said.

"The whole operation has been flawed from the beginning," Mr Mason said.

He estimated the landfill had cost ratepayers $2 million to subsidise its operation.

The committee's view was that the quarry face, where the landfill is sited, would have to be dug out to reduce leachate.

Mr Mason said this would remove about 25 per cent of the compacted landfill. Rather than a costly onsite treatment system, it would be more cost effective to dig out the entire landfill.

Submissions on the matter were heard during the 2010-11 annual plan process.

Council spokeswoman Claire Lichtwark-McInnes said the council agreed there was a problem with the Hakaru landfill and the ongoing costs to remove leachate. In 2007, the council had opted to close the landfill and operate a transfer station at the site.

Mrs Lichtwark-McInnes said the leachate removal did come at a cost to the whole district and was funded from the general rate. Closed landfills throughout the district all had ongoing costs which were covered district-wide, she said. At edition time, she was unable to confirm the costs.

A report to council on the landfill said "the submitters' concerns were valid and the matter needed to be addressed".

Mrs Lichtwark-McInnes said the council had agreed to allocate $25,000 to look at options for the future management of the Hakaru landfill.

Investigations would be completed this year. Options include the removal of all waste, identifying the waste sources to the landfill, drainage of the base around the walls and the building of an onsite leachate treatment system.

The committee regards the treatment system too expensive and considers the removal of all compacted refuse the best option.

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Barr Environmental Explains the Background to the Garlaff Leachate Treatment Plant Project

The following is based upon an article about the latest Enviros designed and commissioned Leachate Treatment Plant, published in the July 2009 Edition of the Community Newsletter published by Barr:

Rain falling on the waste in a landfill is held within the plastic lining the waste sits on, which is intended to stop the rainfall entering the soil and rock beneath.

As site operator Barr Environmental needs to pump it out of the waste and treat it as per their SEPA waste permit. Till last year the leachate from the waste at Garlaff was treated in an open lagoon system close to the site entrance. While this plant still worked it was built many years back and wasn't able to treat the leachate to the highest standards now feasible. This old plant has been substituted by a state of the art treatment system beside Cell two of the rubbish heap.

The new plant is one of the most recent systems in the United Kingdom and was designed by leading leachate professionals Enviros. The consultants have designed over one hundred plants around the globe to treat this kind of waste water and have advised the UK govt and in particular the DEFRA government department in the Best Available Techniques (BAT) available for this kind of leachate treatment.

The plant is entirely automated and computer controlled and can nicely treat all of the leachate the landfill site produces every day. The system was built by Barr Surfacing & Civil Engineering and largely invisible from outside of the site as four fifth's of the plant is built below ground, rather like a below ground multi-storey car park.

The leachate is pumped from the rubbish heap from a series of wells in the waste to an large holding tank in the plant. There were some concerns about odour from this tank. So, all the tanks have been sealed at the top to stop any smells entering the air round the site before the leachate starts to be dealt with.

The main treatment tank is aerated and the leachate treated using the natural microbes in the sludge in the tank in the same way a sewage plant works. These microbes are specifically evolved to treat the ammonium rich liquid to provide a clean liquid that is fit for discharge to the brook.

The plant has been engineered to the most recent standards with a high efficiency energy rating that's achieved by insulating the tank with earth around it and transferring the heat from the aerators into the treatment liquid. Keeping up the leachate temperature through the winter at about 25 degrees C creates the ideal conditions for fast decrease in the pollutants within the aeration tank.

Still working with nature the final part of the treatment process uses natural reedbeds on site to shine and take away the last traces of solids and nitrogen.

The reedbeds have proven to be a helpful habitat as well to wildlife. They will quickly become home to many insects and the tiny birds that eat them.

Barr have been so happy with this new leachate plant that they have just built its twin at their other landfill site, at Auchencarroch in West Dunbartonshire, Scotland. Together these plants are the biggest and most modern leachate plants to ever be built in Scotland and controlled by one company.

The plants will operate for no less than the next 30-40 years till the leachate has been fully treated on the site and no longer is required to be removed.

Environment Agency UK Issues Guidance on Environmental Permitting for "Orphan" Leachate Treatment Plants

Earlier this month (July 2009) the EA's Modernising Waste Regulation Panel issued a Regulatory Position Statement about Environmental Permits for Waste Treatment Plants.

This has updated a previous pair of statements on this subject which we found hard to interpret, and which were issued a least a year ago.

Under the original EU Directive based PPC Regs. and UK permitting rules it appeared that in due course all leachate treatment plants greater than 50 tonnes per day (50 cubic metres per day) capacity would have to be officially issued with a permit by the Agency. This would be the case even if the plant had been in existence for many years and was clearly complying with its watercourse (or sewer) discharge consent and not causing any environmental problems at all.

From the start this seemed absurd, and an enormous cost and bureaucratic burden on the operators of these plants, without anyone really being clear what benefit would result.

As time progressed and the Environment Agency concentrated on prioritising the most important treatment processes and all new landfills, we all wondered when they would catch up with this and start contacting the operators of these so called "orphan" sites.

Now, finally it seems that most if not all leachate treatment plant owners and operators that do not already have an Environmental Permit, or have been required to submit for one, for their leachate treatment plant can relax about this.

The position statement says:

The Environment Agency’s position:

We will not pursue an environmental permit application for an IPPC directive waste treatment activity where all the following conditions are met:

• the treatment plant is subject to a consent issued under the Water Industry Act or the Water Resources Act;

• the plant only treats waste/waste water produced on-site and does not import it from other sites;

• management of the activity ensures that the risk of pollution incidents from the site, including nuisance, remains low;

• relevant operational records are kept for a period of four years and made available to Environment Agency officers when requested.

However, if you do own or operate a leachate treatment plant on what would usually be a closed landfill, you should not rely on this posting alone, and you really should visit the EA's web site and read it for yourself at the WTP Orphan page/pdf.

However, here is a thought to end this post. How many closed landfill leachate treatment plant operators have a full 4 years of data properly archived and ready for inspection, if requested. I wonder!?

WRG Arpley Landfill Passes 1/2 Million Tonnes of Leachate Treated

From the WRG Newsletter

During early 2008, WRG’s Arpley leachate treatment plant passed a total of 500,000m3 of leachate treated. Since it was commissioned in October 2001, the plant has been treating very strong leachates which routinely contain greater than 2000mg/l of ammoniacal-N, to standards which allow safe discharge of effluent into the River Mersey.

When WRG took over Arpley Landfill in the spring of 1999, leachate was not under control. Although heads of leachate on the liner were limited to a maximum depth of 1 metre, levels were typically 7 or 8 metres, and well out of compliance. A key part of site remediation was investment of more than £1 million in a dedicated pneumatic leachate collection system, to automatically manage leachate levels in nearly 100 boreholes. From the start of 2001 leachates then began to be tankered off-site for treatment, at rates of up to 10,000m3 per month.

This allowed detailed pilot-scale treatability trials to be carried out by Enviros, to enable an optimum treatment scheme to be developed, which would represent the largest load of contaminants to be treated at any landfill site in the UK. WRG were no stranger to leachate treatment. In 1994, working with Enviros, a large leachate treatment plant had previously been designed and commissioned at Buckden Landfill near to Huntingdon, where a discharge consent into the sensitive River Great Ouse demands that rainbow trout shall be unharmed after 96 hours exposure to the final effluent. That plant continues to perform well, nearly 15 years later.

The treatment process adopted at Arpley (Plate 1) includes aerobic biological treatment of up to 450m3 of leachate each day, in three identical large Sequencing Batch Reactors. The SBR process has been pioneered for leachate treatment by Enviros, and shown to provide very stable and robust treatment of the very high ammonia and COD values which characterise leachates from large landfills. Effluent from the SBRs then passes through a Dissolved Air Flotation (DAF) process, which removes any remaining suspended solids. The treated leachate receives final “polishing” by passage through the root zone of extensive engineered reed beds, before being discharged safely into the River Mersey which flows beside the site.

WRG and Enviros worked closely with the Environment Agency to plan and implement the leachate treatment solution, and by 2004 leachate levels had been brought back into compliance with the site licence in every monitoring borehole. The plant remains a key part of controlled landfilling at Arpley, and continues to treat leachates at typical rates of 8,000 to 9,000 cubic metres per month.

Operation of all functions of the plant is completely automated. A programmable logic controller (PLC) provides maximum reliability, and the plant operator interfaces with this using a PC. Many dozens of failsafe systems, alarms, and telemetry links provide enormous security of operation. Experiences at Arpley have also formed the basis for many other large leachate treatment plants around the world. For example, Taman Beringin is a very large landfill located close to the centre of the city of Kuala Lumpur, in Malaysia. Remediation of the site has included a new leachate treatment plant (see Plate 2). It achieves very high effluent quality standards, which allow discharge of treated leachate to be made into a nearby watercourse.

As environmental standards at landfill sites are raised around the world, the ability to treat leachates reliably, and to high standards, remains critical, and WRG and Enviros are presently designing several new plants that will be commissioned during 2009.

Enviros is a UK-based full-service environmental consultancy, with an international reputation in wastes management. In the specialised field of landfill leachate management, the company has unique expertise, having worked on every continent except Antarctica, and has designed and commissioned more than 80 full-scale
leachate treatment plants throughout the World.

Can Landfill Leachate be Treated by Anaerobic Digestion?

Every now and again the question of whether landfill leachate can be effectively treated by Anaerobic Digestion is raised.

My reply is yes, and in fact, it has already happened in the landfill before you usually see most leachate. After an initial aerobic (acetogenic) stage, modern landfills in effect become anaerobic digesters themselves. Once this has occurred the leachate produced has already been subjected to a form of anaerobic digestion, so there is little additional treatment which an AD Plant can provide to these mature leachates once leachate is removed from the landfill.

In a modern Municipal Solid Waste (MSW) landfill. as it is filled, each cell or area within it, will within 6 months to one year, or, at the most eighteen months, not only become airless, but methanogenic (methane producing). Once this happens, the decomposition process taking place in the landfill is broadly similar to, but slower than, that which occurs in an anaerobic digester.

So, modern lined and well regulated landfills these days do, almost without exception, produce a mature methanogenic leachate.

As a result the use of Anaerobic Digestion to treat landfill leachate is not normally a good choice and the use of the Anaerobic Digestion process to treat landfill leachate is not very effective. This can be readily deduced just by thinking about the processes which leachate undergoes within a landfill. The big problem with using AD on a mature leachate would be the lack of significant reduction of ammoniacal nitrogen in the discharge, and ammoniacal nitrogen is one of the most important contaminants to remove, for reduced toxity to water life.

However, the opposite does work. Now think of using aerobic reactors to treat Anaerobic Digestion concentrates, if these concentrates cannot for any reason be disposed as a fertiliser product and thus have to be treated as a waste material.

So, leachate treatment plant aerobic biological reactors can be used very effectively to treat AD liquid digestate, if that "product" ends up proving to be unsaleable locally. Indeed, on site aerobic digestate treatment might be essential in these circumstances if no sewage treatment works was available to accept tanker loads of liquid from an AD Plant.

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!

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.

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.

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 .

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.

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....

Leachate Treatment Issues and Site Closure at a US Site

Landfill wants leachate treatment services, township wants land
By Rodney L. Sherman, Clarion News Editor

FARMINGTON TWP. – County Environmental of Clarion, operators of the landfill in Farmington Township , is seeking a favor from the township and supervisor Ed Heasley wants to close the door on any future expansion of the facility.

It’s possible both goals could be met with one agreement.

County Environmental , also know as County Landfill Inc., is beginning its efforts to close the landfill next year. Company representatives attended the Nov. 7 meeting of the Farmington Township Board of Supervisors to outline their plans for the closing.

One of the ongoing problems at the landfill involves treatment of the leachate produced by the landfill. County Environmental has been unable to resolve problems at its treatment plant and recently was fined $225,149 for exceeding pollution limits established by the landfill’s federal wastewater discharge permit. More here ....