The UK Urban NO2 Network (UUNN) 2024

Description

The UUNN was first established in January 2020 and has expanded since to respond to evidence needs and is currently operating at ~299 sites. <br/>The primary aim of the UUNN is the provision of additional NO2 monitoring data for inclusion within the national UK compliance assessment. Previously the national assessment of NO2 has comprised of a UK-wide automatic monitoring network; the Automatic Urban and Rural Network (AURN), and national scale modelling; the Pollution Climate Mapping (PCM) model.<br/>UUNN monitors were sited specifically to target areas where modelling had indicated an exceedance of the annual mean NO2 limit value, and where concentrations predicted by the PCM model and by local modelling completed by a relevant local authority were not in good agreement. <br/>The two requirements to identify specific road links for UUNN measurements within these areas were originally as follows:<br/>▪ Where the PCM model and/or modelling completed by a relevant local authority had predicted an exceedance of the NO2 annual Lot 1: This opportunity is advertised by Defra group Commercial (DgC) on behalf of the Environment Agency (EA) and the Joint Air Quality Unit (JAQU).<br/>The Environment Agency work to create better places for people and wildlife and support sustainable development. EA is an executive non-departmental body, sponsored by the Department for Environment, Food and Rural Affairs. For further information please visit Environment Agency - GOV.UK (Environment Agency - GOV.UK (www.gov.uk).<br/>The aim of the UK Urban NO2 Network (UUNN) is to provide additional local NO2 measurement data for inclusion within the national UK compliance assessment for NO2. Data from the UUNN supplements the established assessment, comprised of data from the Automatic Urban and Rural Network (AURN) and air quality modelling. The programme of work is led by (Joint Air Quality Unit) JAQU and the Environment Agency (EA). For the purposes of the Terms and Conditions, the Environment Agency is the Buyer. This contract is for management of the UUNN on behalf of Defra and the EA. The Contract is for 3 years with 2 x 1-year extensions, with a 3-month handover / mobilisation period.<br/>The UUNN is an air quality monitoring network that provides measurements of NO2 concentrations at urban traffic sites. Measurement data is used to assess compliance against the annual mean limit value for NO2 set out in the Air Quality Standards Regulations (AQSR) 2010 (40μg/m³). The AQSR provide detailed siting criteria for assessment of ambient air quality and the location of sampling points for the measurement of air pollutants in ambient air. The network has become the critical data for zones where this annual mean limit is exceeded, and the data is now embedded as part of the ongoing assessment of UK-air compliance. Data capture and date integrity is therefore critical to delivery.<br/>The UUNN was first established in January 2020 and has expanded since to respond to evidence needs and is currently operating at ~299 sites. The network is envisaged to operate between 200 – 600 sites over the next few years and has budgeted for circa 300 sites a year at present, but this may be subject to change.<br/>Monitoring is completed using Palmes-type diffusion tubes which are modified to improve data quality. The tubes are deployed in triplicate at each monitoring location to reduce the level of uncertainty and therefore increase the level of accuracy associated with each measured concentration. The Supplier must ensure tubes at each monitoring location are changed according to the UUNN monitoring calendar. The Supplier must also manage a redeployment exercise to decommission and establish new sites on the network at the start of each year as guided by the Authority.<br/>UUNN monitors were sited specifically to target areas where modelling had indicated an exceedance of the annual mean NO2 limit value, and where concentrations predicted by the PCM model and by local modelling completed by a relevant local authority were not in good agreement.<br/>The two requirements to identify specific road links for UUNN measurements within these areas were originally as follows:<br/>▪ Where the PCM model and/or modelling completed by a relevant local authority had predicted an exceedance of the NO2 annual mean limit value of 40μg/m3 in 2020 and/or 2021.<br/>▪ Where the difference between the PCM model and modelling completed by a relevant local authority is larger than 20%.<br/>Now the network has moved from an initial improvement work package to an ongoing tool for enhanced NO2 assessment and is foreseen to be part of our NO2 assessments work notably on high traffic road links for the foreseeable future. This procurement helps support the Environment Agency’s corporate strategy. Environment Agency: EA2025 creating a better place - GOV.UK (www.gov.uk) – provides the Environment Agency’s commitment to measure healthy air to protect the environment and people.