Wambo Coal AEMR 2011-2012 - Peabody Energy

2011-2012 AEMR
3.11.2 Environmental Performance
Real Time Noise Monitoring
WCPL compile quarterly reports on monitoring data
from four fixed SentineX continuous noise
monitoring systems adjacent to WCPL. Below is a
summary of the quarterly reports for real time noise
monitoring during the reporting period.
Q1- July to September 2011
Assessment of noise impacts for the July to
September, 2011, monitoring period indicates that
WCM complied with the noise level criteria
prescribed in the Wambo Coal NMP. Review of the
L A1,1minute results indicates that animal noise, road
noise and meteorological influences dominate the
LA1 noise environment adjacent to the WCM.
Mining noise was encountered during audio review
at the N21 (WA) and N16 (Muller) site locations.
However, this was considered to represent only the
background contribution to measured noise levels
rather than the transient or peak events associated
with potential for sleep disturbance. It should be
noted that the N16 (Muller) monitoring location is
subject to cumulative mining noise impacts, and as
the source of mine noise contributions could not be
confirmed, exceedences could not be attributed to
the WCM.
Where mining noise impacts were observed,
uncertainty exists in the validity of the monitoring
data. While EPL 529 excludes data influenced by
strong temperature inversions (lapse rates of
3 C/100m and wind speeds up to 2 m/s), the
methods available to assess atmospheric stability
(sigma-theta method) provide conflicting evaluation
as to the validity of the noise monitoring data.
Pasquill Gifford (P-G) ‘F’ class stability was
commonly observed during the monitoring period,
denoting temperature lapse rates of between +1.5
and +4.0 deg/C per 100m. It stands to reason that
portions of the dataset monitored under ‘F’ class
stability conditions would be subject to lapse rates in
excess of 3.0 deg/C per 100m; however, in the
absence of available methods or data, the
frequency of this scenario could not be determined.
Consequently, all noise monitoring results observed
under ‘F’ class conditions were retained in the
analysis.
October to December, 2011
Assessment of continuous noise monitoring data
indicated that the WCM complied with the
L AeqLF,15minute noise level criteria for more than 88%
of time at the N21 (WA) monitoring location and
98% of the time at the N20 (Thelander) monitoring
location. Following a conservative detailed analysis
of the N16 (Muller) monitoring data, it was found
that L AeqLF,15minute noise levels attributable to WCM
operations exceeded the 40dB(A) criteria
approximately 22% of the monitoring period. The
measured exceedence rate attributable to all
environmental noise sources at this location was
approximately 48%.
Mine noise was audible at both the N21 (WA) and
N16 (Muller) sites; however, it was found to
comprise the background noise contribution for a
majority of these events. Meteorological influences
were also observed to contribute to measured noise
levels at these locations, and the passage of
vehicles on the Golden Highway was the dominant
noise impact at the N16 (Muller) monitoring location.
January to March, 2012
Measured noise levels were found to comply with
the L Aeq,15minute criteria more than 90% of the time at
the N21 (WA) monitoring location and 94% of the
time at the N20 (Thelander) monitoring location.
These results are consistent with those obtained in
the previous (October to December (2011)) period.
Analysis of monitoring results, including WCM
meteorological station data, demonstrates that lower
rates of night time temperature inversions were
observed as compared to the winter months. This
indicates that the WCM site may be less affected by
enhanced noise propagation associated with
temperature inversions in the summer months,
resulting in a higher rate of compliance with the
performance criteria.
Results of L Aeq,15minute audio review indicate that
mining noise impacts were present during the
January to March (2012) period; however,
environmental sources (including insects, livestock,
road noise and meteorological impacts) were found
to dominate the night time noise environment.
April to June, 2012
Assessment of continuous noise monitoring data
indicated that the WCM complied with the
L AeqLF,15minute noise level criteria for more than 83%
of time at the N21 (WA) monitoring location and
92% of the time at the N20 (Thelander) monitoring
location. Moderate (F class) and strong (G class)
temperature inversions (conditions under which
enhanced noise propagation may occur) were found
to be present for 36% of the night time monitoring
period from April to June. These inversion events
typically generate meteorological conditions under
which enhanced noise propagation may occur.
Comparison of the measured L AeqLF,15minute noise
level result distributions indicates that noise levels
above the relevant criteria may be observed with
higher frequency during the winter months.
Audio review suggested that mine noise was
present at both the N21 (WA) and N16 (Muller)
sites; however, environmental noise sources
(including road noise, insects and meteorological
impacts) were found to dominate the night time
noise environment. The passage of vehicles on the
Golden Highway was the dominant noise impact at
the N16 (Muller) monitoring location. Mining noise
was not observed to contribute to measured Sleep
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