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

 

 

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 : 11/11/2018
TSH1 Sunny

N/A (3)

<2

31 (4)

0.09
TSH2 Sunny

36

<2

30

0.08
TSH3 Sunny

5

<2

<3

0.02
TSH4 Sunny

10

<2

12

0.02
Date of sample taken : 4/12/2018
TSH1 Sunny N/A (3) 5.6 92 (4) 0.05
TSH2 Sunny River bed dry up, hence no water sample could be collected
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny 5 <2 3.3 0.06
Date of sample taken : 8/1/2019
TSH1 Cloudy N/A (3) <2 62 (4) 0.01
TSH2 Cloudy N/A (3) <2 20 0.01
TSH3 Cloudy <5 <2 <3 <0.01
TSH4 Cloudy 45 <2 <3 <0.01
Date of sample taken : 11/2/2019
TSH1 Cloudy N/A (3) <2 23 0.13
TSH2 Cloudy N/A (3) 4 17 0.34
TSH3 Cloudy <5 <2 3.4 0.02
TSH4 Cloudy 22 <2 10 <0.01
Date of sample taken : 4/3/2019
TSH1 Sunny N/A (3) <2 34 (4) 0.05
TSH2 Sunny N/A (3) <2 20 0.67
TSH3 Sunny 8 <2 8.7 <0.01
TSH4 Sunny 6 <2 11 0.02
Date of sample taken : 18/3/2019
TSH1 Sunny N/A (3) <2 12 0.28
TSH2 Sunny N/A (3) <2 15 0.15
TSH3 Sunny 6 <2 5.8 0.01
TSH4 Sunny 6 <2 6.1 0.02
Date of sample taken : 2/4/2019
TSH1 Sunny N/A (3) <2 57 (4) 0.07
TSH2 Sunny N/A (3) <2 38 (4) 0.16
TSH3 Sunny <5 <2 3.2 0.03
TSH4 Sunny 8 <2 14 <0.01
Date of sample taken : 18/4/2019
TSH1 Cloudy N/A (3) <2 6.2 0.2
TSH2 Cloudy N/A (3) <2 11 0.16
TSH3 Cloudy 27 <2 6.4 0.02
TSH4 Cloudy 10 <2 7.9 <0.01
Date of sample taken : 7/5/2019
TSH1 Cloudy N/A (3) <2 16 0.32
TSH2 Cloudy N/A (3) <2 24 0.46
TSH3 Cloudy <5 <2 4.7 0.01
TSH4 Cloudy 6 <2 6.5 0.02
Date of sample taken : 20 & 22/5/2019 (5)
TSH1 Cloudy N/A (3) <2 5.4 0.41
TSH2 Cloudy N/A (3) <2 9.4 0.43
TSH3 Sunny <5 <2 6.8 0.05
TSH4 Cloudy <5 <2 <3 0.02
Date of sample taken : 4/6/2019
TSH1 Cloudy N/A (3) <2 183 (4) 0.68
TSH2 Cloudy No water sample could be collected due to low water level
TSH3 Cloudy 22 <2 7.6 0.01
TSH4 Cloudy 11 <2 8.7 0.02
Date of sample taken : 17/6/2019
TSH1 Cloudy N/A (3) <2 47 (4) <0.01
TSH2 Cloudy No water sample could be collected due to low water level
TSH3 Sunny 6 <2 2.7 <0.01
TSH4 Cloudy 7 <2 4 <0.01
Date of sample taken : 2/7/2019
TSH1 Cloudy N/A (3) <2 53 (4) <0.01
TSH2 Cloudy N/A (3) <2 56 (4) 0.03
TSH3 Cloudy <5 <2 3.7 <0.01
TSH4 Cloudy <5 <2 5.7 <0.01
Date of sample taken : 17/7/2019
TSH1 Sunny N/A (3) <2 13 <0.01
TSH2 Sunny N/A (3) <2 3.2 0.03
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny 5 <2 <3 <0.01
Date of sample taken : 8/8/2019
TSH1 Sunny N/A (3) <2 20 0.03
TSH2 Sunny N/A (3) <2 7.4 0.03
TSH3 Sunny 6 <2 <3 0.02
TSH4 Sunny <5 <2 <3 0.02
Date of sample taken : 20/8/2019
TSH1 Cloudy N/A (3) <2 9.2 0.06
TSH2 Cloudy N/A (3) <2 14 0.06
TSH3 Cloudy 8 <2 <3 0.02
TSH4 Cloudy 8 <2 3.3 0.05
Date of sample taken : 5/9/2019
TSH1 Cloudy N/A (3) <2 31 (4) 0.15
TSH2 Cloudy N/A (3) <2 5 0.10
TSH3 Cloudy 7 <2 <3 0.08
TSH4 Cloudy <5 <2 <3 0.07
Date of sample taken : 19/9/2019
TSH1 Sunny N/A (3) <2 16 0.08
TSH2 Sunny N/A (3) <2 13 0.02
TSH3 Sunny 16 <2 <3 <0.01
TSH4 Sunny 9 <2 3.3 <0.01
Date of sample taken : 3/10/2019
TSH1 Sunny N/A (3) <2 68 (4) <0.01
TSH2 Sunny N/A (3) <2 52 (4) <0.01
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny 8 <2 <3 <0.01
Date of sample taken : 17/10/2019
TSH1 Sunny N/A (3) <2 29 0.08
TSH2 Sunny N/A (3) <2 16 0.09
TSH3 Sunny 11 <2 3.5 <0.01
TSH4 Sunny 5 <2 6.7 <0.01
Date of sample taken : 11/11/2019
TSH1 Sunny N/A (3) <2 38 (4) 0.04
TSH2 Sunny N/A (3) <2 19 0.07
TSH3 Sunny 10 <2 <3 <0.01
TSH4 Sunny 11 <2 3.2 <0.01
Date of sample taken : 9/12/2019
TSH1 Sunny N/A (3) <2 62 (4) 0.12
TSH2 Sunny N/A (3) <2 25 0.21
TSH3 Sunny 8 <2 <3 0.02
TSH4 Sunny <5 <2 5.4 0.01
Date of sample taken : 9/1/2020
TSH1 Cloudy N/A (3) <2 12 0.18
TSH2 Cloudy N/A (3) <2 18 0.15
TSH3 Cloudy 5 <2 <3 0.02
TSH4 Cloudy 8 <2 <3 <0.01
Date of sample taken : 10/2/2020
TSH1 Cloudy N/A (3) <2 22 0.04
TSH2 Cloudy N/A (3) <2 17 0.08
TSH3 Cloudy 15 <2 <3 0.03
TSH4 Cloudy 11 <2 <3 0.03
Date of sample taken : 2/3/2020
TSH1 Cloudy N/A (3) <2 15 0.15
TSH2 Cloudy N/A (3) <2 39 (4) 0.19
TSH3 Cloudy 14 <2 <3 <0.01
TSH4 Cloudy 11 <2 <3 <0.01
Date of sample taken : 16/3/2020
TSH1 Sunny N/A (3) <2 34 (4) 0.16
TSH2 Sunny N/A (3) <2 59 (4) 0.09
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny 10 <2 <3 <0.01
Date of sample taken : 6/4/2020
TSH1 Drizzle N/A (3) <2 14 0.18
TSH2 Drizzle N/A (3) <2 20 0.21
TSH3 Cloudy <5 <2 <3 <0.01
TSH4 Drizzle 11 <2 7.2 <0.01
Date of sample taken : 20/4/2020
TSH1 Sunny N/A (3) <2 5.2 0.07
TSH2 Sunny N/A (3) <2 12 0.05
TSH3 Sunny <5 <2 <3 0.05
TSH4 Sunny 6 <2 <3 <0.01
Date of sample taken : 4/5/2020
TSH1 Sunny N/A (3) <2 4.3 0.07
TSH2 Sunny N/A (3) <2 4.5 0.09
TSH3 Sunny 9 <2 <3 <0.01
TSH4 Sunny 13 <2 <3 <0.01
Date of sample taken : 25/5/2020
TSH1 Cloudy N/A (3) <2 5.8 0.14
TSH2 Cloudy N/A (3) <2 8.9 0.23
TSH3 Cloudy <5 <2 5.1 0.01
TSH4 Cloudy <5 <2 13 <0.01
Date of sample taken : 1/6/2020
TSH1 Sunny N/A (3) <2 23 0.07
TSH2 Sunny N/A (3) <2 15 0.08
TSH3 Sunny <5 <2 3.7 0.02
TSH4 Sunny <5 <2 7.4 <0.01
Date of sample taken : 18/6/2020
TSH1 Sunny N/A (3) <2 4.9 0.06
TSH2 Sunny N/A (3) <2 10 0.06
TSH3 Sunny 7 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 6/7/2020
TSH1 Sunny N/A (3) <2 15 0.05
TSH2 Sunny N/A (3) <2 35 (4) 0.06
TSH3 Sunny <5 <2 3.5 0.02
TSH4 Sunny <5 <2 4 <0.01
Date of sample taken : 20/7/2020
TSH1 Sunny N/A (3) <2 9.4 0.04
TSH2 Sunny N/A (3) <2 13 0.08
TSH3 Sunny 11 <2 3.3 <0.01
TSH4 Sunny 7 <2 5.3 <0.01
Date of sample taken : 10/8/2020
TSH1 Sunny N/A (3) <2 17 0.14
TSH2 Sunny N/A (3) <2 17 0.11
TSH3 Sunny <5 <2 <3 0.05
TSH4 Sunny <5 <2 <3 0.05
Date of sample taken : 24/8/2020
TSH1 Sunny N/A (3) <2 17 0.03
TSH2 Sunny N/A (3) <2 18 0.02
TSH3 Sunny <5 <2 <3 0.02
TSH4 Sunny <5 <2 <3 <0.01
Date of sample taken : 16/9/2020
TSH1 Cloudy N/A (3) <2 62 (4) 0.09
TSH2 Cloudy N/A (3) <2 44 (4) 0.06
TSH3 Cloudy 9 <2 34 (6) 0.01
TSH4 Cloudy 8 <2 35 (6) 0.02
Date of sample taken : 25/9/2020
TSH1 Sunny N/A (3) <2 27 0.02
TSH2 Sunny N/A (3) <2 26 0.06
TSH3 Sunny <5 <2 5.2 <0.01
TSH4 Sunny <5 <2 8.9 <0.01
Date of sample taken : 9/10/2020
TSH1 Sunny N/A (3) <2 35 (4) 0.05
TSH2 Sunny N/A (3) <2 21 0.02
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 3.3 <0.01
Date of sample taken : 22/10/2020
TSH1 Sunny N/A (3) <2 31 (4) 0.12
TSH2 Sunny N/A (3) <2 21 0.11
TSH3 Sunny <5 <2 <3 0.02
TSH4 Sunny <5 <2 <3 0.04
Date of sample taken : 9/11/2020
TSH1 Sunny N/A (3) <2 32 (4) 0.04
TSH2 Sunny N/A (3) <2 23 0.04
TSH3 Sunny <5 <2 <3 <0.01
TSH4 Sunny <5 <2 <3 0.4
Date of sample taken : 3/12/2020
TSH1 Sunny N/A (3) <2 34 (4) 0.17
TSH2 Sunny N/A (3) <2 21 0.17
TSH3 Sunny 12 <2 <3 0.05
TSH4 Sunny <5 <2 <3 0.02
Date of sample taken : 6/1/2021
TSH1 Sunny N/A (3) <2 45 (4) 0.11
TSH2 Sunny N/A (3) <2 28 0.09
TSH3 Sunny 6 <2 <3 <0.01
TSH4 Sunny 7 <2 5.4 <0.01
Date of sample taken : 4/2/2021
TSH1 Sunny N/A (3) <2 27 (4) <0.01
TSH2 Sunny N/A (3) 3.1 16 0.024
TSH3 Sunny 11 <2 <3 0.016
TSH4 Sunny 9 <2 <3 <0.01
Date of sample taken : 2/3/2021
TSH1 Sunny N/A (3) <2 46 (4) 0.26
TSH2 Sunny N/A (3) <2 22 0.36
TSH3 Sunny 10 <2 8.8 0.024
TSH4 Sunny 8 <2 14 0.028
Date of sample taken : 16/3/2021
TSH1 Sunny N/A (3) <2 11 0.24
TSH2 Sunny N/A (3) <2 13 0.26
TSH3 Sunny 8 <2 9.4 0.022
TSH4 Sunny <5 <2 21 0.033
Date of sample taken : 7/4/2021
TSH1 Sunny N/A (3) <2 6.7 0.097
TSH2 Sunny N/A (3) <2 5.2 0.094
TSH3 Sunny 5 <2 5.5 0.015
TSH4 Sunny 7 <2 26 0.08
Date of sample taken : 19/4/2021
TSH1 Cloudy N/A (3) <2 8.4 0.14
TSH2 Cloudy N/A (3) <2 20 0.13
TSH3 Cloudy 6 <2 7.4 0.029
TSH4 Cloudy 6 <2 18

0.053
Date of sample taken : 6/5/2021
TSH1 Sunny N/A (3) <2 7.7 0.089
TSH2 Sunny N/A (3) <2 21 0.13
TSH3 Sunny 5 <2 9 0.037
TSH4 Sunny 11 <2 13 0.061
Date of sample taken : 17/5/2021
TSH1 Sunny N/A (3) 2.1 13 0.067
TSH2 Sunny N/A (3) <2 12 0.19
TSH3 Sunny No water sample could be collected due to low water level
TSH4 Sunny No water sample could be collected due to low water level
Date of sample taken : 4/6/2021
TSH1 Cloudy N/A (3) <2 12 0.068
TSH2 Cloudy N/A (3) <2 14 0.13
TSH3 Cloudy <5 <2 12 0.033
TSH4 Cloudy <5 <2 15 0.13
Date of sample taken : 17/6/2021
TSH1 Sunny N/A (3) <2 9.5 0.037
TSH2 Sunny N/A (3) <2 20 <0.01
TSH3 Sunny 6 <2 11 0.024
TSH4 Sunny <5 <2 23 0.015
Date of sample taken : 13/7/2021
TSH1 Sunny N/A (3) <2 9.8 0.078
TSH2 Sunny N/A (3) <2 8.2 0.093
TSH3 Sunny 9 <2 5.6 0.021
TSH4 Sunny 8 <2 4 0.031
Date of sample taken : 23/7/2021
TSH1 Sunny N/A (3) <2 13 0.059
TSH2 Sunny N/A (3) <2 50 (4) 0.13
TSH3 Sunny <5 <2 3.4 0.03
TSH4 Sunny <5 <2 5.5 <0.01
Date of sample taken : 13/8/2021
TSH1 Cloudy N/A (3) <2 26 0.1
TSH2 Cloudy N/A (3) <2 18 0.25
TSH3 Cloudy <5 <2 3.2 0.028
TSH4 Cloudy 11 <2 3.8

0.022
Date of sample taken : 19/8/2021
TSH1 Cloudy N/A (3) <2 37 (4) 0.052
TSH2 Cloudy N/A (3) <2 7.8 0.19
TSH3 Cloudy <5 <2 <3 0.019
TSH4 Cloudy <5 <2 5.1 <0.01
Date of sample taken : 9/9/2021
TSH1 Sunny N/A (3) <2 18 0.1
TSH2 Sunny N/A (3) <2 20 0.1
TSH3 Sunny <5 <2 11 0.015
TSH4 Sunny <5 <2 7.9 0.016
Date of sample taken : 27/9/2021
TSH1 Sunny N/A (3) <2 50 (4) 0.079
TSH2 Sunny N/A (3) <2 67 (4) 0.12
TSH3 Sunny 9 <2 8.8 0.2
TSH4 Sunny 7 <2 12 0.015
Date of sample taken : 5/10/2021
TSH1 Sunny N/A (3) <2 25 0.043
TSH2 Sunny N/A (3) <2 49 (4) 0.18
TSH3 Sunny <5 <2 14 0.034
TSH4 Sunny <5 <2 11 0.026
Date of sample taken : 18/10/2021
TSH1 Sunny N/A (3) <2 22 0.028
TSH2 Sunny N/A (3) <2 24 0.062
TSH3 Sunny <5 <2 3.9 <0.01
TSH4 Sunny <5 <2 5 <0.01
Date of sample taken : 10/11/2021
TSH1 Sunny N/A (3) <2 39 (4) 0.17
TSH2 Sunny N/A (3) <2 24 0.17
TSH3 Sunny <5 <2 <3 0.32
TSH4 Sunny <5 <2 <3 0.02
Date of sample taken : 13/12/2021
TSH1 Cloudy N/A (3) 2 24 0.28
TSH2 Cloudy N/A (3) <2 13 0.55
TSH3 Cloudy 11 <2 <3 0.013
TSH4 Cloudy 12 <2 <3 0.017
Referencing water quality standards (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 standards at Tai Shui Hang are not specified under the WENT Landfill's Contract. The referencing water quality standards 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 demend, the level of chemical oxygen demend 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 in slightly elevated total suspended solids level.
  5. The sampling work was conducted on two days due to the inclement weather on 20/5/2019.
  6. Heavy sediment accumulation at TSH river due to frequent rainfall in mid September (amber rainstorm warning signal was recorded on 15/9), causing easy stir-up of sediments during sampling which results in elevated level of total suspended solid.

 

 

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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