9               COMMENTS AND CONCLUSIONS

 

9.1               As mentioned in executive summary, the baseline environmental monitoring results (air quality, noise, water quality and Chinese White Dolphin Monitoring) collected in 2011 was adopted for the contract

 

9.2               The baseline environmental monitoring was carried out in accordance with the EM&A Documents for HKLR, in respect of the methodology, equipment, location and monitoring parameters.

 

9.3               The baseline air quality (1-hour and 24-hour TSP levels) monitoring was conducted at two monitoring locations (AMS1 - Sha Lo Wan and AMS4 - San Tau) between 18th October 2011 and 31st October 2011. During the monitoring, some influencing factors (e.g. road traffic dust) may be affected the baseline dust monitoring results in the vicinity of the monitoring stations. The baseline air quality monitoring results are considered representative to the ambient air quality conditions of the respective sensitive receivers.  The Action and Limit Levels for the air quality were established based on the baseline monitoring results.

 

9.4               Baseline noise monitoring was conducted at two monitoring stations (NMS1 - Sha Lo Wan and NMS4 - San Tau) between 18th October 2011 and 1st November 2011.  The major noise sources identified at the monitoring stations are the noise from air traffic, road traffic, insect and bird calling. The baseline monitoring results are considered representative to the ambient noise level at all monitoring stations except at NMS3 as the construction activities (piling works) were operated from other construction site in vicinity of monitoring station.

 

9.5               Baseline water quality monitoring was conducted at 13 monitoring stations (IS1, IS2, IS3, IS4, CS1, CS2, SR1, SR2, SR3, SR6, ST1, ST2 & ST3) between 6th October 2011 and 31st October 2011. Baseline water quality monitoring was conducted at SRA between 8th November 2012 and 2nd December 2012. No observable pollution source was observed at the monitoring stations. Since no observable pollution activity was identified for all stations during sampling, the baseline monitoring results are considered representative of the ambient water quality levels.

 

9.6               Baseline Chinese White Dolphin monitoring (Line-transect Vessel Surveys) was conducted in the three survey areas (Northeast Lantau, Northwest Lantau, West Lantau) from September to November 2011 through another contract. Dolphin sightings, distribution, encounter rate, group size, habitat use, mother-calf pairs and behaviour were reported in the full baseline monitoring report. Photo-identification and range estimation of identified individuals were also made.

 

9.7               28-day Baseline Underwater Noise monitoring was conducted at 100m distance from one of the first three piling sites between November and December 2012. Major components affecting the background noise level are the noise generated from sea flow and the noise from marine traffic. Underwater noise sources other than sea flow and marine traffic may be from marine work conducted far away. Underwater noise recorded during the baseline monitoring was smaller than the action and limit levels proposed in the baseline underwater noise monitoring proposal.

 

9.8               Baseline dolphin north-south movement monitoring was carried out from 29 December 2012 to 30 January 2013 using theodolite tracking technique. Dolphin behaviour and movement change dependent upon natural (time of day, size of group) and anthropogenic (vessel presence) factors. It is proposed to take all baseline data into account, including times with no apparent anthropogenic activities near the dolphins, various vessel activities, and time of day and other variables for formulating the Action and Limit Levels of the Event Action Plan.

 

9.9               Baseline acoustic behaviour monitoring surveys were conducted between 15 January and 22 February 2013. The dolphin acoustic activities measured using both acoustic survey and passive acoustic monitoring methods. It is proposed that to take the response variables (clicking and whistling rates; and the hours in peak occurrence at the two EAR sites) into account for formulating the Action and Limit Levels of the Event and Action Plan.