Latest progress on suspected leakage of leachate from WENT Landfill
Regarding the suspected leakage of leachate from West New Territories (WENT) Landfill that occurred yesterday (July 8), a spokesperson for the Environmental Protection Department (EPD)provided the following details on the latest progress of the follow-up work:
The Environmental Protection Department, Photo source: reference image
The landfill contractor confirmed the source of the leakage last night and immediately commenced containment of the leakage at the source, remediation and overnight monitoring. Following urgent interception, the leakage of leachate through a stormwater outfall to Tai Shui Hang stopped last night, and no abnormalities were observed at the stormwater outfall and in nearby water bodies. Affected by the heavy rain early this morning, a small amount of leachate was spotted at the source location, which was a temporary condition during maintenance work. The contractor then immediately strengthened the pumping and interception measures. No leachate flowed into the downstream stormwater outfall or Tai Shui Hang, and the situation remains under control.
After on-site investigation, the incident is believed to have caused by a blockage in sub-soil leachate trench beneath the landfill's operational area, coupled with persistent heavy rain yesterday afternoon. This resulted in leachate flowing together with rainwater into the stormwater drains along the landfill haul roads, and subsequently to Tai Shui Hang. The contractor completed the source remediation work this morning, which included intercepting the leak and continuing to remove any remaining leachate. At the same time, further preventive and cleanup measures have been implemented, including removing stagnant water from the drainage channels and installing additional silt curtain in Tai Shui Hang to enhance containment. The contractor will continue to thoroughly clean the affected stormwater outfall to remove any traces of leachate remaining on the inner walls of the outfall.
The EPD further confirmed that no new leakage was found on-site during an investigation this morning, while tankers remain on standby at the scene as a precautionary measure. Based on on-site observations and the performance of the silt curtains, the EPD assessed that the amount of leachate leaked into Tai Shui Hang yesterday was limited. Given that the rainy season has begun, the EPD has demanded that the contractor strengthen the inspection and maintenance of the sub-soil leachate trenches and the drainage system to minimise the risk of similar incidents occurring during periods of intense rain.
In addition, the EPD continued today to collect water samples from Tai Shui Hang and the Deep Bay to monitor any changes in water quality. Preliminary analysis revealed that pH and the dissolved oxygen levels in the water samples are within the normal ranges,without signs of significant change in water quality. No fish deaths were found at the scene, and there were no signs of any significant ecological impact nearby. The EPD will continue to closely monitor the water quality in Tai Shui Hang and the Deep Bay.
West New Territories Landfill, Photo source: referece image
