Contract No. HY/2013/12Tuen Mun - Chek Lap Kok Link - North ern Connection Toll Plaza and Associated Works
Investigation Report on Action or Limit Level Non - compliance
| Reference number | TCS00670/13/300/F0331 |
| Date | 22 August 2017 |
| Environmental Aspect | Air Quality |
| Parameter | 1-hour TSP |
| Monitoring Location | ASR1 (Tuen Mun Fireboat Station) |
| Measurement Period | 15:05-16:05 |
| Action Level (ug/m3) | 331 |
| Limit Level (ug/m3) | 500 |
| Measured Level (ug/m3) | 360 |
| Exceedance | Action Level |
| Possible reason for Action or Limit Level Non-compliance | 1. According to site information provided by CRBC-Kaden JV, only typhoon precaution works was conducted on 22 August 2017. 2. To reduce to dust impact arises from the contract. mitigation measures for construction dust control were implemented and they are included the following:• water trucks were arranged on haul road to keep road surface wet (refer to photo 1 and water spraying record) • for un-accessible area, water spraying by workers was provided (refer to photo 2 and water spraying record) • covered part of the exposed slopes and stockpile by tarpaulin sheet (refer to Photo 3 to 5) • to set speed control at 8 km/hr for all vehicles using the haul road (refer to photo 6) 3. During site inspection on 22 August 2017, it was observed that the dust mitigation measures were implemented and the site condition is acceptable. Photo showing the implemented dust mitigation measures on 22 August 2017 is shown in photo record. 4. During the course of monitoring, only typhoon precaution works such as clean up the existing channel, cover the exposed slope, housekeeping and fixing the construction materials was undertake on 22 August 2017. It is unlikely to create heavy construction dust impact. (Ref. to Location Plan) 5. The monitoring station ASR1 is located most apart from the construction site. According to other surrounding monitoring stations (AQMS 1, ASR 5, 6 & 10) which are located closely to the construction site, no exceedances were recorded at similar time. The TSP concentration in other stations (72-290 ug/m3) is much lower to the exceeded station ASR1. Also the contractor was properly implemented the dust mitigation measure under EMIS requirement. Therefore we considered that the cause of exceedance is due to other pollutant source rather than the construction site. |
| 6. Based on above investigation, the exceedance is unlikely related to the Contract work and no corrective action was required accordingly. | |
| Action to be taken | ET will continue regular audit and inspection for the implemented dust mitigation measures during the construction period. |
Designation : Environmental Team Leader
Date : 14 September 2017
Photo Record
| Photo 7 Watering of haul road by water truck to keep road surface wet was observed during the site inspection on 22 August 2017 | Photo 8 Watering of haul road by water truck to keep road surface wet was observed during the site inspection on 22 August 2017 |
| Photo 9 Typhoon precaution works on 22 August 2017. |
Figure 1. Location Plan
