Dye Test Inspection for Submarine Outfalls
Dye Test Inspection for Submarine Outfalls
Submarine outfalls are used for discharging treated sewage from DSD sewage treatment plants into the sea. These submarine outfalls are located in various water areas across Hong Kong.
Each year, every submarine outfall is scheduled to be tested once to ensure the integrity of the submarine outfalls for discharging effluent from the DSD sewage treatment plants. The dye test would generate a fluorescent green colour patch at the observed area, and it is the result of testing as the green dye emerges from the submarine outfall.
The dye used is a non-toxic dye and is harmless to the marine environment. The tidal current will disperse it rapidly.
Schedule of Dye Test Inspection of Submarine Outfalls
August 2026
|
Position |
Location |
Date of test |
Expected time of observation of dye at outfall point |
|
1 |
Tsing Yi PTW |
25-Aug-2026 |
14:25 - 14:40 |
|
2 |
Tseung Kwan O PTW |
25-Aug-2026 |
15:25 - 15:40 |
|
3 |
Shau Kei Wan PTW |
26-Aug-2026 |
14:25 - 14:40 |
|
4 |
Chai Wan PTW |
26-Aug-2026 |
15:25 - 15:40 |
|
5 |
Stonecutters Island STW |
27-Aug-2026 |
14:35 - 14:50 |
|
6 |
To Kwa Wan PTW |
27-Aug-2026 |
14:40 - 14:55 |
|
7 |
Kwun Tong PTW |
27-Aug-2026 |
14:45 - 15:00 |
|
8 |
North Point PTW |
27-Aug-2026 |
14:50 - 15:05 |
|
9 |
Stanley STW |
27-Aug-2026 |
14:55 - 15:10 |
|
10 |
Central PTW |
27-Aug-2026 |
15:00 - 15:15 |
|
11 |
Wan Chai East PTW |
27-Aug-2026 |
15:05 - 15:20 |
Outfalls Location on 25-27 August 2026 Schedule
September 2026
|
Position |
Location |
Date of test |
Expected time of observation of dye at outfall point |
|
1 |
Aberdeen PTW |
8-Sep-2026 |
13:25 - 13:40 |
|
2 |
Wah Fu PTW |
8-Sep-2026 |
14:10 - 14:25 |
|
3 |
Sandy Bay PTW |
8-Sep-2026 |
15:10 - 15:25 |
|
4 |
Aberdeen PTW |
9-Sep-2026 |
13:55 - 14:10 |
|
5 |
Cyberport STW |
9-Sep-2026 |
14:55 - 15:10 |
|
6 |
To Kwa Wan PTW |
10-Sep-2026 |
14:35 - 14:50 |
|
7 |
Kwun Tong PTW |
10-Sep-2026 |
14:40 - 14:55 |
|
8 |
North Point PTW |
10-Sep-2026 |
14:45 - 15:00 |
|
9 |
Central PTW |
10-Sep-2026 |
14:50 - 15:05 |
|
10 |
Wan Chai East PTW |
10-Sep-2026 |
14:55 - 15:10 |
Outfalls Location on 8-10 September 2026 Schedule
|
Position |
Location |
Date of test |
Dosing time |
|
1 |
Sha Tin STW, West Pipe |
11-Sep-2026 |
09:30 |
|
2 |
Sha Tin STW, East Pipe |
11-Sep-2026 |
13:45 |
Outfalls Location on 11 September 2026 Schedule
