Moss Filters installed in Hereford
Case reference EIR2024/00890
Published 24 May 2024
Request
I would like to request the following information regarding the moss filters installed in Hereford:
1.The location of each of the moss filters together with the dates when they became operational.
2.The purchase price of each filter.
3.The running/maintenance cost of each filter for each year they have been operational.
4.The mass of carbon dioxide (NOT volume) removed by each filter each year.
5. Where and how the carbon dioxide has been disposed of.
Response
I would like to request the following information regarding the moss filters installed in Hereford:
1.The location of each of the moss filters together with the dates when they became operational.
CT 309 adjacent to The Courtyard, Edgar Street - operational 08.06.23
CT 310 Eign Gate adjacent to Trekitt - operational 15.06.22
CT311 Eign Street bus stop - operational 09.06.23
2.The purchase price of each filter.
CT 309 - £40,374.54
CT 310 - £43,911.27
C 311 - £34,291.35
3.The running/maintenance cost of each filter for each year they have been operational.
Running/maintenance for all 3 units including labour, capital replacement parts, replacement of moss mats and reporting/monitoring data for 60 months = £61,048.
4.The mass of carbon dioxide (NOT volume) removed by each filter each year.
The moss filter units utilise CO₂ (like any plant) and have been estimated to produce a reduction of approximately 342kg per year (on a moss filter footprint of 9m2). The CO₂ is not removed and disposed of, but is used by the moss in the unit during photosynthesis producing O₂ as a by-product.
Air pollution can be caused by solid particles such as soot or gases like Nitrogen Dioxide (NO₂). Particulate matter makes up a large part of air pollution in a city, it consist of particles of less than 10µm. The moss filters up to 82% of fine particulate matter from the ambient air. The total mass filtered out of the air volume since commissioning (calculated following DIN EN ISO 16890) is as follows:
CT311 142.1g
CT 309 140.2g
CT 310 298.3g
I.e. a total reduction in particulate matter of 580.6g of fine particulate matter.
Please see the following link to view the information in more detail on the Herefordshire Council website:
Moss filters - Herefordshire Council
5. Where and how the carbon dioxide has been disposed of.
Carbon dioxide is not disposed of, it is used by the moss, during photosynthesis, with water and nutrients to produce glucose and oxygen.
Documents
This is Herefordshire Council's response to a freedom of information (FOI) or environmental information regulations (EIR) request.
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