On Monday 23 April Cllr Emma Faramarzi and Cllr Toby Elliott visited the Chapel Farm Landfill site operated by Hills Waste Solutions. Emma and Toby were taken around the site and shown the work going into getting to the bottom of the smells in and around Oakhurst, Redhouse, Taw Hill & Ashbrake.
Please find below correspondence from Hills received today by Emma and Toby:
Dear Councillors Faramarzi and Elliott
Chapel Farm landfill site visit 23 April 2013
Thank you for taking the time out to visit our Landfill site at Chapel Farm on 23rd April. Hopefully you found the visit useful and are now better able to understand how the site operates and in particular how we control landfill gas and odours generated at the site.
As we showed you during the site visit, permanent gas wells are routinely installed once a waste cell has been filled and capped with clay. Over the whole site approximately 150 gas wells have been installed. Once installed and connected to the gas extraction system, these wells are commissioned, monitored and maintained and the gas delivered to the on-site gas engines where it is converted to electricity and exported to the national grid. The electricity produced at the site is considered renewable and enough to power in the region of 3,000 homes. In addition to these permanent wells, horizontal sacrificial pipework is also installed within an operational cell to extract any landfill gas that may be generated prior to final capping and permanent gas well installation.
In response to complaints received earlier in the year directly to Hills and through the Environment Agency, some routine site maintenance works were reviewed and undertaken earlier than they would normally occur. This included the sealing of 3 leachate towers, additional clay sealing along an area of the southern boundary of the site and the sealing of an internal flank, and the installation of 11 additional gas wells in the operational area of Cell 22. The works were carried out in phases and were completed by 12th April.
During your visit we talked about the routine monitoring Hills undertakes both on site and at off site locations as part of our Environmental Permit and in response to any complaints the company may receive.
We discussed the typical concentrations of landfill gas (predominantly methane) that can be expected in the vicinity of the site. When taking readings it is not unusual for a vented site gas well to record levels of gas in concentrations in excess of 10,000 ppm (parts per million), however as you move away from the well readings drop significantly to levels in the region of 200ppm at 5 metres away and less than 20ppm up to 10 metres away. In active areas of the site (where the waste is tipped at any given time) gas levels are typically less concentrated and do not normally exceed 1,000 ppm. Recorded levels can be influenced by both atmospheric and meteorological conditions as well as the rate of gas production in that area of the site and the specific composition of waste in any given area.
In recent weeks complaints have been received from locations at distances ranging from between 1-3 Km’s away from the Chapel Farm site boundary. On this basis it is extremely unlikely that any gas that may have left site would be at significantly high enough concentrations to be detected.
You also asked the company to respond to concerns that landfill gas may have detrimental health effects and we refer you to advice issued in 2011 by Public Health England (formally the Health Protection agency) titled “Impact on health of emissions from landfill sites” which concludes that ‘living close to a well-managed landfill site does not pose a significant risk to human health.’
A full copy of the advice can be found at: www.hpa.uk/webc/HPAwebFile/HPAweb_C/1309969974126
The company continues to actively monitoring the situation with respect to potential odours from the Chapel Farm landfill site and to liaise with the Environment Agency. There are further planned engineering works at the site which will result in 18,000m² of permanent capping commencing when the weather is stable enough to allow the works to progress (anticipated June 2013).
We hope that your visit was informative and Hills were able to provide you with the reassurance that Chapel farm is a well-managed site. Should you have any further queries or require any further information please don’t hesitate to contact me.
Landfill Operations Manager, Hills Waste Solutions Limited