Noise > Environmental > Clay Pigeon Shooting
The Department of the Environmental (as was) funded a study by the UK's Building Research Establishment [BRE] to study how best to measure clay target shooting noise and to establish the correlation between such measurements and community response. The Chartered Institute of Environmental Health [CIEH] has incorporated the results of this research into a consultation draft for Clay Target Shooting Noise, dated Nov 1997 [REFERENCE 1]; it is intended that this document would be adopted under Section 71 of The Control of Pollution Act 1974. The BRE research is the only study of its kind ever to have been conducted in the UK or elsewhere. Some of the research findings are surprising and all have important implications for the assessment of clay target shooting.
Initially it had been hoped that agreement could be reached between the CIEH and the sport's governing body the CPSA to produce a joint document; however, the CIEH have decided to "go it alone" and their document can be seen on their website here.
This paper examines the main findings of the BRE research, compares it with the two most commonly used standards for assessing clay target shooting noise, by reference to measurements made at a typical shooting ground, and finally draws conclusions.
The BRE research report has still not been published, but some details have emerged
The conclusions as how best to measure this noise are based on measurements around 20 shooting grounds. The analysis of community response to shooting noise impact was based on a subset of 8 shooting grounds. All noise measurements were made with a positive wind component, e.g. at locations to the southwest of a shooting ground measurements were always made with a light northeasterly wind.
COMPARISON WITH OTHER ASSESSMENT METHODS
The two main standards for assessing noise to date, have been produced by the Clay Pigeon Shooting Association [CPSA] - reference 2 and CIEH - reference 3 [but based on Ref.4]. Both documents are very detailed. Only a brief summary is given below.
This document requires the noise of individual gunshots to be measured, and then compares the logarithmic average level of all measurable gunshots against a limit value that depends upon the preexisting background level of noise in the area:
This code says that "It is recommended that unless by virtue of planning consent, accepted existing use, or mutual agreement between the shoot organiser(s) and the local community, shooting should not normally take place on any Sunday, Bank or Public Holiday, or evening period." Also "The hours of shooting on weekdays (inclusive of Saturday) should be confined to be between 9.30 am and 6.00 pm subject to a single organised event taking place over a maximum duration of one four-hour consecutive period."
This Code of Practice attempts to weigh the factors of noise level, character of noise, duration of exposure, time of day and so on by recommending inter alia that:-
Both the existing assessment methods consider that Sundays are more sensitive than other days of the week, and permit the measurements to be made by writing down the results from the display of a standard sound level meter; also, both derive the logarithmic average of all measurable gunshots. The CIEH draft Professional Practice Note [ref.3] also considers that the excess of shooting noise over background level is important.
ASSESSMENT OF A SHOOTING GROUND
Figure 1 shows a real shooting ground "somewhere in the south of England". The shoot lies to the northeast of the measurement position, and a busy bypass lies to the southwest of measurement position, when the wind is from the northeast the shoot noise is relatively high and the background relatively low, and the situation is reversed when the wind is from the southwest.
On a particular day the weather conditions were constant with a light northeast wind. It can be seen that there is no screening by barriers and little variation in separation distance or firing direction from stand to stand; however, even at this ground, there was a 30 dB(A) variation between the loudest and quietest shots. Over the course of 2½ hours, some 850 individual shots were measured; therefore, 170 shots represent approximately 30 minutes worth of data. It is possible to compare the "rolling" logarithmic average of 170 shots (30 minutes), against the "rolling" average of the loudest 25 of the same 170 shots, i.e. to compare the "BRE" assessment method against that of the CPSA (and CIEH). The background noise level at the measurement location was 42 LA90.
The second figure shows the results of the comparison. It can be seen that on this day, the assessment methods were relatively stable; both varied within a 3.5 dBA band. The BRE method was around 76.5 dBA and the CPSA/CIEH around 71 dBA; the mean difference between the two methods was 5.5 dBA, again for this shoot on this day.
By contrast, on days when the wind was from the southwest, the CPSA/CIEH method would produce a rating of 55 dBA compared with a BRE rating of 56 dBA. The background noise levels were 50 LA90. The different wind direction produced lower shooting noise levels, and higher background noise levels; hence, the range of measurable gunshots was compressed. Such a variation in noise impact for different weather conditions is not unusual.
Comparison with CPSA and CIEH Recommendations
Looking at the results from the real shoot, it seems likely that for most shoots, the BRE method will be between 1 and 6 dBA above the CPSA/CIEH method.
The CPSA code of practice seeks to avoid ratings in excess of 61 to 65 dBA (using BRE method), which ties in reasonably well with the BRE’s conclusions that widespread annoyance is likely above around 65 dB(A) (using BRE method).
If we now compare the BRE assessment method with that of CIEH, for many shooting locations the daytime background noise levels are between 35 and 45 LA90. Accordingly the CIEH Code of Practice seeks to avoid ratings in excess of 56 to 66 (using BRE method), depending on the background level of noise and the variability of shooting noise.
If we now assess the real shoot results using all three methods; noise levels on the first occasion exceeded the recommended limits of both the CPSA and CIEH, and the BRE research would indicate that widespread annoyance is likely. On the second occasion noise levels were within the recommended limits of the CPSA and CIEH, and the BRE research would indicate that widespread annoyance is unlikely. None of the assessment methods give guidance on the implications of variation in noise impact from day to day.
Finally the 30 dB(A) spread between the loudest and quietest shots has another important consequence (see Figure 3 below); the BRE method is based on the loudest 25 shots in a 30 minute period; therefore, the higher the firing rate the more likely it is that the loudest 25 shots will be lie towards the upper end of the spread of results, i.e. the higher the firing rate the higher the rating level; an increase from 3 shots/minute to 33 shots per minute would increase the SNL by 4.5 dB(A). By contrast the research did not find that firing rate affected annoyance.
 "Clay target shooting, guidance on the management and control of noise, public consultation draft, November 1997", Chartered Institute of Environmental Health, British Shooting Sports Council, Clay Pigeon Shooting Association.
 "Draft Code of Practice on Noise from Clay Pigeon Shooting 1989" Clay Pigeon Shooting Association.
 "Noise from Clay Target Shooting - Professional Practice Note, draft for consultation June 1993" Chartered Institute of Environmental Health
 "Code of Practice on Noise from Clay Target Shooting" Midland Joint Advisory Council for Environmental Protection - Fourth Revision August 1994.
This footnote is to remind you that the correct spelling is "clay pigeon shooting" not "clay pidgeon shooting". "Pidgeon" was the way Walter Pidgeon spelt his name; it is not the correct spelling for the bird.