The Stringent EA Controls Which Limit UK Landfill Gas Emissions to Minimize the Emission of Carbon Dioxide thought to be a Cause of Climate Change
The UK waste management industry is required to control landfill gas emissions to a high standard. The Environment Agency (EA) ensures that all licensed or permitted landfill sites which contain landfill gas are regulated to ensure that emissions are kept to a minimum. This is enforced either under the pollution prevention and control (PPC) regime, or the earlier waste management licensing system which continues to apply to older sites.
In addition to the measures described here which have now largely completed on landfills throughout the United Kingdom to reduce methane emissions, operators will now have to tackle long neglected issues related to trace landfill gas compounds and combustion by-products.
The process, which commenced in line with increasing public awareness of air quality issues around landfills, is also popular in the eyes of the public in the UK, for the reduction in the amount of carbon dioxide emitted and the hoped for reduction in the “greenhouse gas effect”, achieved by these measures.
What is surprising in the opinion of the author, however, is the continued absence of a well organised programme to tackle closed landfill sites which pre-date licensing laws, which remain significant in terms of their landfill gas emissions. In fact most owners of these old sites are local authorities, and these are becoming increasingly aware of the need for emissions control, so most old sites in public ownership do now have landfill gas flaring provisions.
Today, operational landfill sites taking biodegradable waste in the UK, and throughout Europe, are routinely fitted with active gas extraction and migration controls are built inot the lining designs. Landfill gas generation is usually a very profitable activity in the UK with a number of government incentives available to the operators, to encourage renewable energy generation, and a readiness from the grid operators to accept the electricity into their systems.
As a result ever increasing quantities of landfill gas is being burnt in power generation plants.
The advances have helped to tackle some of the hazards of landfill gas, such as explosion risks by ensuring that the gas is pumped out under suction and thus is unable to migrate, and have also significantly reduced the industry's contribution to greenhouse gas emissions. However, the process has also created a new set of lesser but still worrying environmental problems – in the shape of emissions from flares and engines.
Emissions from flares and gas engines
These emissions were unregulated in the UK until 2003 when new regulations were implemented and the discharges are now monitored to flare type.
The landfill research community – with funding from both the Environment Agency and operators – has made big strides in characterising the range of emissions from typical equipment and standards have now been agreed and set.
In 2003 Environment Agency officials put the proportion of open to enclosed flares at around 50:50. However, since that time operators and owners have invested in enclosed combustion chamber flare models which are emissions regulations compliant. Flares in all but the oldest sites, which predate the requirements for licensing have been replaced by newer compliant models, and the ratio is now heavily in favour of compliant installations.
That's the situation in respect of flaring the landfill gas that is being collected, but much of the gas produced by a landfill is either:
But, how effectively is landfill gas is being collected combusted to avoid methane discharges and its energy recovered? The Agency's local area regulation offices make regular visits to all currently licensed and sites which hold permits, but the Agency has no data at the national level to say how many sites are fitted with flares or gas utilisation equipment. The Agency has even less information when it comes to sites that closed before 1994, because these sites fall outside the waste licensing regime.
The EU Landfill Directive requires that landfill gas be collected from all sites receiving biodegradable waste, and that this gas must be treated. Landfill Operators of all open permitted landfill sites also must comply with the principals of Best Available Techniques (BAT) as required by the PPC Regulations. Put simply – If the gas cannot be used to produce energy, it must be flared.
Importantly, the Directive also stipulates that the collection, treatment and use of landfill gas must be carried out in a manner “which minimises damage to or deterioration of the environment and risk to human health.”
The Agency has now largely completed the huge task in bringing the landfill sector into the PPC permitting regime which was will be complete by the middle of 2007, and will by then have been undertaken over a four year period which commenced in 2003.
The time is approaching when we will begin to see large numbers of new flares on landfills, and many appearing generators as well as a result.
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