Hong Kong officials on Thursday addressed concerns over black particles found in tap water at two housing estates in Fanling, assuring residents that the water remains safe for consumption despite the presence of residue likely stemming from infrastructure materials used years ago.
Roger Wong, director of the Water Supplies Department, said tests indicate the particles, reported by residents last week at Queen’s Hill Estate and Shan Lai Court, are primarily bitumen and resin residues. These materials, officials believe, entered the water supply system as early as three years ago. Bitumen was used as a coating for water pipes until 2005, when the department switched to resin, Wong explained during a media briefing.
The particles are thought to be protective coatings that peeled off from valves within the water system, Wong said, citing the color and chemical composition of tested samples. Similar issues were reported at Queen’s Hill Estate in 2021, prompting the installation of a fine-grained filter in December 2022 to screen out sediments. “We flushed the pipes at that time and installed a very fine-grained filter to screen out all the black particles or other sediments that may move into the internal plumbing system,” Wong told reporters.
He suggested that the recent resurgence of particles could be due to increased water flow, which may have dislodged finer residues that had accumulated over time. Wong noted that regular cleaning of the filter had shown no signs of black particles until recently, indicating the residues likely entered the internal plumbing before the filter was installed.
Despite the impurities, Wong emphasized that the water at both estates meets safety standards. Bitumen, he noted, is insoluble and poses no health risks to humans. Previous tests by a government-appointed consultant also confirmed that boiling water containing bitumen does not release carcinogenic substances.
To address public concerns, the Water Supplies Department pledged to intensify pipe cleaning efforts and conduct daily water sample tests until the water supply is free of black specks. Test results will be released each morning to maintain transparency, Wong said.
The government’s swift response aims to reassure residents, many of whom expressed alarm after noticing the particles. Wong’s assurances and the department’s proactive measures underscore efforts to maintain trust in Hong Kong’s water supply system amid recurring concerns about aging infrastructure.
