Water Quality Monitoring at Tai Shui Hang

Environmental Protection Department (EPD) has set up four water quality monitoring points from the upstream to downstream along Tai Shui Hang (namely TSH1, TSH2, TSH3 and TSH4). Their locations are shown in the map below. EPD collects water samples twice a month during the wet season (i.e. March to October) and once a month during the dry season (i.e. November to February of the next year).
 
Locations of Water Quality Monitoring Points at Tai Shui Hang

Location of Water Quality Monitoring Point at Tai Shui Hang

 

Please click here for monitoring results of year 2018 to 2022 

 

Water Quality Monitoring Point (1) Weather Condition

Chemical Oxygen
Demand (mg/L)

5-day Biochemical Oxygen Demand (mg/L) Total Suspended Solids (mg/L) Ammonia-
Nitrogen (mg/L)
Date of sample taken : 19/1/2023
TSH1 Sunny N/A (3) <2 26 0.2
TSH2 Sunny N/A (3) <2 14 0.77
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 8/2/2023
TSH1 Cloudy N/A (3) <2 18 0.13
TSH2 Cloudy N/A (3) <2 16 0.53
TSH3 Cloudy 5 <2 <3 0.029
TSH4 Cloudy 10 <2 <3 0.046
Date of sample taken : 2/3/2023
TSH1 Sunny N/A (3) <2 10 0.16
TSH2 Sunny N/A (3) <2 20 0.2
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 17 <0.01
Date of sample taken : 16/3/2023
TSH1 Sunny N/A (3) <2 9.9 0.24
TSH2 Sunny N/A (3) <2 14 0.35
TSH3 Sunny <5 <2 <3 0.047
TSH4 Sunny <5 <2 <3 0.019
Date of sample taken : 14/4/2023
TSH1 Cloudy N/A (3) <2 8.4 0.14
TSH2 Cloudy N/A (3) <2 8.5 0.49
TSH3 Cloudy <5 3.2 3.4 0.95
TSH4 Cloudy <5 2.2 <3 0.35
Date of sample taken : 24/4/2023
TSH1 Cloudy N/A (3) <2 6.5 0.09
TSH2 Cloudy N/A (3) <2 9 0.13
TSH3 Cloudy 7 3.5 3.3 0.39
TSH4 Cloudy 12 9.3 5 0.47
Date of sample taken : 4/5/2023
TSH1 Sunny N/A (3) <2 41 (4) 0.16
TSH2 Sunny N/A (3) <2 58 (4) 0.076
TSH3 Sunny 5.5 <2 3.7 0.12
TSH4 Sunny 6.5 <2 3.3 0.86
Date of sample taken : 22/5/2023
TSH1 Sunny N/A (3) <2 6.5 0.09
TSH2 Sunny N/A (3) <2 9 0.13
TSH3 Sunny 7 3.5 3.3 0.39
TSH4 Sunny 12 9.3 5 0.47
Date of sample taken : 2/6/2023
TSH1 Sunny N/A (3) <2 6.1 0.087
TSH2 Sunny N/A (3) <2 24 0.11
TSH3 Sunny 16 <2 3.6 0.077
TSH4 Sunny 8.5 <2 8.2 0.066
Date of sample taken : 20/6/2023
TSH1 Sunny N/A (3) 13 8.1 0.074
TSH2 Sunny N/A (3) 21 (4) 24 0.37
TSH3 Sunny <5 <2 4.4 0.057
TSH4 Sunny <5 <2 4.8 0.057
Date of sample taken : 10/7/2023
TSH1 Sunny N/A (3) <2 50 (4) 0.011
TSH2 Sunny N/A (3) <2 42 (4) 0.082
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 21/7/2023
TSH1 Sunny N/A (3) <2 7 0.068
TSH2 Sunny N/A (3) <2 13 0.066
TSH3 Sunny <5 <2 <3 0.015
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 9/8/2023
TSH1 Cloudy N/A (3) <2 23 0.072
TSH2 Cloudy N/A (3) <2 16 0.046
TSH3 Cloudy 8.2 <2 <3 0.037
TSH4 Cloudy 8.9 <2 12 0.015
Date of sample taken : 23/8/2023
TSH1 Sunny N/A (3) <2 12 0.052
TSH2 Sunny N/A (3) 4.5 28 0.38
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 19/9/2023
TSH1 Sunny N/A (3) <2 9.1 0.16
TSH2 Sunny N/A (3) <2 <3 0.022
TSH3 Sunny 8.2 <2 <3 0.02
TSH4 Sunny 8.9 <2 <3 0.024
Date of sample taken : 26/9/2023
TSH1 Sunny N/A (3) <2 9.7 0.22
TSH2 Sunny N/A (3) 3.5 28 0.1
TSH3 Sunny <5 <2 <3 0.012
TSH4 Sunny <5 <2 <3 0.014
Date of sample taken : 4/10/2023
TSH1 Sunny N/A (3) <2 12 0.047
TSH2 Sunny N/A (3) <2 14 0.037
TSH3 Sunny <5 <2 <3 0.017
TSH4 Sunny 5.8 <2 3.6 <0.01
Date of sample taken : 25/10/2023
TSH1 Sunny N/A (3) 12 12 0.036
TSH2 Sunny N/A (3) <2 43 (4) 0.12
TSH3 Sunny <5 <2 <3 0.016
TSH4 Sunny <5 <2 <3 0.023
Date of sample taken : 9/11/2023
TSH1 Sunny N/A (3) <2 12 <0.01
TSH2 Sunny N/A (3) <2 14 <0.01
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 12/12/2023
TSH1 Sunny N/A (3) <2 16 0.016
TSH2 Sunny N/A (3) <2 14 0.062
TSH3 Sunny <5 <2 8.1 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 9/1/2024
TSH1 Sunny N/A (3) <2 8.9 0.31
TSH2 Sunny N/A (3) <2 11 0.38
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 20/2/2024
TSH1 Sunny N/A (3) <2 16 0.17
TSH2 Sunny N/A (3) <2 30 0.43
TSH3 Sunny <5 <2 <3 0.072
TSH4 Sunny <5 <2 <3 0.039
Date of sample taken : 15/3/2024
TSH1 Cloudy N/A (3) <2 35 (4) 0.14
TSH2 Cloudy N/A (3) <2 15 0.22
TSH3 Cloudy <5 <2 <3 0.017
TSH4 Cloudy <5 <2 <3 0.013
Date of sample taken : 25/3/2024
TSH1 Cloudy N/A (3) <2 10 0.056
TSH2 Cloudy N/A (3) <2 8 0.38
TSH3 Cloudy <5 <2 <3 <0.01
TSH4 Cloudy <5 <2 <3 0.02
Date of sample taken : 3/4/2024
TSH1 Cloudy N/A (3) <2 9.2 0.1
TSH2 Cloudy N/A (3) <2 21 0.79
TSH3 Cloudy <5 <2 <3 0.015
TSH4 Cloudy <5 <2 <3 0.027
Date of sample taken : 18/4/2024
TSH1 Cloudy N/A (3) <2 16 0.063
TSH2 Cloudy N/A (3) <2 9.7 0.059
TSH3 Cloudy <5 <2 18 0.012
TSH4 Cloudy <5 <2 16 <0.01
Reference level (2)

80 

20

30

5

 

Remarks :

  1. No water quality monitoring point at Tai Shui Hang is required under the WENT Landfill's Contract. If there is any abnormal change in the water quality, EPD will take follow-up actions.
  2. The water quality requirements at Tai Shui Hang are not specified under the WENT Landfill's Contract. The reference levels in the above table are referred to the Technical Memorandum under Water Pollution Control Ordinance (Cap. 358AK).
  3. At the time of sampling, this location was intruded by marine water. Since the chloride in marine water would have interference with the measured level of chemical oxygen demand, the level of chemical oxygen demand at this location was not measured.
  4. Stirred up bottom sediment at the interface of marine and river water at river mouth shores during sampling resulted into interference with the reporting parameters that was not measured or their slightly elevated content.

 

 

EPD staff obtains a water sample from Tai Shui Hang (TSH3)

EPD staff obtains water sample from Tai Shui Hang (TSH3)

Upstream of Tai Shui Hang (TSH4)

Upstream of Tai Shui Hang
 

 

 

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