Information about Mountsorrel Quarry can be found on this webpage.

The Mountsorrel Dust Management and Monitoring Plan (Sept 2022) can be found below:

Our PM10 'Partisol' monitor initially started reporting data on 26th October 2011, however due to experiencing reliability issues with the analyser during 2022 this unit has now been removed from service. The replacement 'Zephyr' analyser, which has been positioned at the same location, provides the further capability of monitoring concentrations of PM2.5 in addition to that of PM10 initially monitored.

Partisol data through to the end of 2021 can be download here:

Annual Zephyr data is available from 2022 in the following documents with the current 'Year-to-date' output(s) from the monitor being updated and published here on a monthly basis, summarised in the table beneath.  

It is often the case that 24-hour episodes of raised PM10 levels observed at the Mountsorrel location coincide with increased concentrations also being recorded at the Automatic Urban and Rural Network (AURN) samplers in Leicester and Nottingham. This is an indicator that some elevated results might be regional and 'transboundary' in nature and therefore not likely to be associated with operations at Mountsorrel Quarry.   The above documents also present graphs to compare the data obtained from these samplers.  Note that there is currently no data available from 30th January for the Nottingham montitor.

2024 Summary (to 30th April) Number

No. of 24-hour PM10 exceedences (01/01/24 to 30/04/24)

[No more than 35 exceedance of 50 µgm-3 permitted per annum]

No. of valid samples 118
Data capture rate (%) 97.5

Comparison against the National Air Quality Objectives (NAQOs)

Annual mean concentration AQO [PM2.5] = 20 µgm-3
Annual mean concentration AQO [PM10]  = 40 µgm-3

5.65 [PM2.5]

9.48 [PM10]

PM10 Exceedences in previous years

  • 2023: 00 from 100% data capture (avg. conc. = 10.64 µg/m-3) *subject to Defra ratification*
  • 2022: 03 from 100% data capture (avg. conc. = 14.54 µg/m-3)
  • 2021: 07 from 245 valid samples = equivalent of 10 for full year  (avg. conc. = 19.95 µg/m-3)
  • 2020: 05 from 088 valid samples = equivalent of 21 for full year  (avg. conc. = 23.50 µg/m-3)
  • 2019: 09 from 200 valid samples = equivalent of 17 for full year  (avg. conc. = 22.60 µg/m-3) 
  • 2018: 15 from 199 valid samples = equivalent of 28 for full year  (avg. conc. = 24.66 µg/m-3)
  • 2017: 15 from 238 valid samples = equivalent of 23 for full year  (avg. conc. = 24.84 µg/m-3)
  • 2016: 21 from 268 valid samples = equivalent of 29 for full year  (avg. conc. = 24.65 µg/m-3)
  • 2015: 26 from 279 valid samples = equivalent of 34 for full year  (avg. conc. = 27.09 µg/m-3)
  • 2014: 26 from 296 valid samples = equivalent of 33 for full year  (avg. conc. = 25.50 µg/m-3)
  • 2013: 18 from 299 valid samples = equivalent of 22 for full year  (avg. conc. = 24.10 µg/m-3)
  • 2012: 16 from 339 valid samples = equivalent of 18 for full year  (avg. conc. = 22.96 µg/m-3)

Results obtained during our study in 2009/10 (against which results the Air Quality Management Area was declared) showed 60 exceedences in a corresponding period of time from 313 valid sampling days, the equivalent to 70 exceedences per annum.  The annual average concentration for this period was 33.18 µg/m-3.

Results to date would suggest that there has been a significant reduction in the average concentration of PM10 at the sampling site (which is considered to be a worse case position) when compared to results prior to the declaration of the Air Quality Management Area (AQMA).

Mountsorrel Quarry information events

As the operators of Mountsorrel Quarry, Tarmac has been preparing a planning application for a northern and south-eastern extension to the quarry. Last year, they held a series of public exhibitions and information events to consult residents on their proposals. Since then, they have been reviewing the feedback and completing the environmental studies required to inform their final planning application.

Although the dates of these informtion events have now passed and the consultation period is now closed, should you have any questions then please contact Tarmac on 07483 920301 or email .  Alternatively, please contact Leicestershire County Council (being the minerals planning authority) on 0116 305 1085 or through

Last updated: Thu 2nd May, 2024 @ 13:43