Viridor is seeking to increase the amount of waste handled by its Runcorn energy from waste facility by 250,000 tonnes per annum.
And the company is also expecting less plastic to be burnt and has revealed that air quality limits have been breached. However, it notes that this was an unreportable incident with no impact on air quality [updated: 23 October].
The facility currently is permitted to take in RDF and a range of household, combustible and industrial wastes for incineration over four moving grate furnaces.
In an application to “substantially vary” its permit, the waste and recycling company has told the Environment Agency that it wants to increase the quantity of permitted waste on site from 850,000 tonnes per annum to 1.1 million tonnes. This would result in 1.04 million tonnes being incinerated, with the remainder being “largely moisture which evaporates from the bunker before the waste is treated”, the company explained.
Viridor reports that the plant is running well and as a consequence it has been possible to increase the rating of the furnaces, allowing them to burn slightly more waste. And, the calorific value of the incoming waste is slightly lower than initially expected and is expected to reduce further, due to improved recycling of plastics.
When planned originally the calorific value had been expected to be approximately 13MJ/kg. But, the incoming waste has been found to have a lower CV than that quoted in the original permit application, at just over 11MJ/kg and, with improved plastics recycling, this is expected to fall further, reaching around 10.5MJ/kg in 2020.
The company is also seeking to change the way its emissions are monitored following breaches of regulations.
It says that there has been “some non-compliance” because occasional short terms peaks in carbon monoxide have had a disproportionate impact on the average. A permit explanation document notes: “These peaks are extremely short lived and will not impact on air quality. They pose no risk to human health or to the environment.”
Consequently to enable Viridor to be “fully compliant” with its permit, the company wants the Agency to change the compliance limit from a half hourly average limit to an alternative 10 minute average limit based on 95% compliance.
Virdor notes that the Environment Agency has agreed to this “alternative method of measurement for Viridor’s EfW facilities at Lakeside, Bolton, Ardley and Trident Park.”
Viridor has also advised [updated 23 October] that compliance limits are established in the Industrial Emissions Directive and allow for the Operator to use either 30 minute or ten minute averages.
In addition, says the permit plans, with reference to the flues in the chimney, “the application seeks to amend the emission limit for carbon monoxide, as discussed and agreed with the Environment Agency and to revise the way in which compliance with the emission standards is assessed so that it applies to an average across each of the four flues within the stack. Neither of these changes will result in any change to the conclusions drawn when the permit was issued and the local air quality will remain fully protected.”
Speaking about the application, Roy Griffin Viridor’s head of operations (north), said: “Since the plant opened in 2015, our team has steadily improved its performance. We are now able to turn more waste into energy, that would otherwise go straight to landfill, and reduce the UK’s reliance on fossil fuels.
“The results of our recent trials of additional throughput have shown that the plant is capable of operating for longer periods of time with fewer maintenance breaks which means that we can maximise the environmental opportunities of the facility. Our aim ultimately is to generate more sustainable energy and send less waste to landfill. By processing more RDF, we are also able to provide more support to the Viridor Environmental Fund for local community projects.”
Comments on the application to vary the permit have been invited by the Environment Agency and are due in at the end of the week (26 October).