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.

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.

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 Safari Visitors Avoid Showers to See Seven Leachate Plants in 2 Days

Everyone kept dry for the Enviros Leachate Safari, which visited 7 plants, and clocked up 700 miles of driving.

Leachate Treatment Plants operated by Viridor Waste Management, Waste Recycling Group (WRG), and the Greater Manchester Waste Disposal Authority were viewed, by the 34 waste management, regulatory officer, consultant, and student, attendees.

The trip provided an informal and enjoyable opportunity for the dissemination of information on the subject.

The celebratory (25 years of Leachate Treatment for Enviros) dinner, which was held at the historic oak panelled "Draper's Hall" in the centre of Shrewsbury, proved popular - where the wine cellar proved to contain some remarkably fine wines.

The trip confirmed that biological leachate treatment is being used very effectively and reliably at a large number of landfills in the UK.

The stars of the tour were definately the daily operators of each plant. They were clearly pleased to show off their plants, with pride, and enthusiasm.