Deep Bay Link

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Note: All Action and Limit Levels listed below are subject to EPD's approval

   

During Construction Stage

Northern Section

Action and Limit Levels for 1-hour TSP and 24-hour TSP

Parameter

Location

Action Level, mg/m3

Limit Level, mg/m3

1-hour TSP

AN3

(Tsing Chuen Wai)

297.7

500

24-hour TSP

158.4

260

   

Action and Limit Levels for Construction Noise

Time Period

Action Level

Limit Level, dB(A)

AN3

(Tsing Chuen Wai)

N4

(Tsoi Yuen Tsuen (West))

0700 – 1900 hours on normal weekdays (Leq, 30mins)

When one documented complaint is received from any one of the sensitive receivers

75

75

1900 – 2300 hours on all days (Leq, 15mins)

65

65

0700 – 1900 hours on general holiday (Leq, 15mins)

65

65

2300 – 0700 hours on all days (Leq, 15mins)

50

50

   

Action and Limit Levels for Local Stream Water Quality Monitoring

  Station

Parameter

Action

Limit

S2

DO, mg/L

4.61

4 mg/L or 40% saturation at 15OC

Turbidity, NTU

43.0 and 120% of upstream control station’s turbidity at the same tide of the same day

60.2 and 130% of upstream control station’s turbidity at the same tide of the same day

SS, mg/L

28.8 and 120% of upstream control station’s SS at the same tide of the same day

30.6 and 130% of upstream control station’s SS at the same tide of the same day

S4

DO, mg/L

4 mg/L or 40% saturation at 15OC*

4 mg/L or 40% saturation at 15OC

Turbidity, NTU

16.7 and 120% of upstream control station’s turbidity at the same tide of the same day

19.4 and 130% of upstream control station’s turbidity at the same tide of the same day

SS, mg/L

25.3 and 120% of upstream control station’s SS at the same tide of the same day

31.5 and 130% of upstream control station’s SS at the same tide of the same day

S6#

DO, mg/L

4.53

4 mg/L or 40% saturation at 15OC

Turbidity, NTU

15.9

21.2

SS, mg/L

20.5

22.5

S8

DO, mg/L

4 mg/L or 40% saturation at 15OC*

4 mg/L or 40% saturation at 15OC

Turbidity, NTU

251.0 and 120% of upstream control station’s turbidity at the same tide of the same day

271.0 and 130% of upstream control station’s turbidity at the same tide of the same day

SS, mg/L

247.5 and 120% of upstream control station’s SS at the same tide of the same day

362.3 and 130% of upstream control station’s SS at the same tide of the same day

S10

DO, mg/L

4 mg/L or 40% saturation at 15OC*

4 mg/L or 40% saturation at 15OC

Turbidity, NTU

48.5 and 120% of upstream control station’s turbidity at the same tide of the same day

70.5 and 130% of upstream control station’s turbidity at the same tide of the same day

SS, mg/L

45.1 and 120% of upstream control station’s SS at the same tide of the same day

49.0 and 130% of upstream control station’s SS at the same tide of the same day

 * Since 5%-ile of the baseline data is less than 4 mg/L (the Limit level), the dissolved oxygen Limit level was adopted as its Action level.

# No appropriate upstream monitoring station could be identified for S6. For future turbidity and suspended solids assessment, water quality at S6 would be compare with its baseline data only.

 

Southern Section

Action and Limit Levels for 1-hour TSP and 24-hour TSP

Parameter

Location

Action Level, mg/m3

Limit Level, mg/m3

1-hour TSP

AN6

319.9

500

AN7

304.7

E1

304.0

E2

297.4

24-hour TSP

AN6

164.8

260

AN7

189.8

E1

210.0

E2

182.3

Action and Limit Levels (Leq) for Construction Noise

Time Period

Action Level

Limit Level, dB(A)

N5

AN6

AN7#

E1

E2

0700 – 1900 hours on normal weekdays

When one documented complaint is received from any one of the sensitive receivers

75

75

70/65*

75

75

0700 – 2300 hours on general holiday 1900 – 2300 hours on all other days

65

65

-

65

65

2300 – 0700 hours of next day

50

50

-

50

50

* Reduced to 65 dB(A) during examination periods

#  Not consider as a sensitive receiver during restricted hours. 


 During Operational Stage

AProposed Criteria to be Used for Determination of Cleaning Frequency, Action Level and Action

Parameter
Reference Criteria for Determination of Cleaning Frequency
Action Level
Action
Total suspended solids (mg/L)
81
3 consecutive monitoring with the same parameter (1 or more than 1 parameter) exceeded the criteria
Increase 1 cleaning event per week
Total organic carbon (mg/L)
25
Chemical oxygen demand (mg/L)
90
Nitrite and nitrate (mg/L)
0.72
Total Kjeldahl Nitrogen (mg/L)
6.4
Total phoshorus (mg/L)
0.95
Copper (mg/L)
0.174
Lead (mg/L)
0.31