Yuen Long Old Market & Town-Centre Older Buildings Drain Services

In October 2020 the Environmental Protection Department made surprise inspections of restaurants in Yuen Long and found two, on Kin Yip Street and Fung Kam Street in the town, discharging wastewater into public storm drains; the grease content exceeded the legal standard by 25 and 10 times respectively, and the operating companies were convicted in May 2021. By design, where a ground-floor kitchen's wastewater meets domestic sewage in a rear-lane manhole or a shared underground drain, the grease cools, sticks to the pipe wall and narrows the manhole outlet, so the shop and the low-floor flats usually back up first. The order of work is to clear the silt out of the manhole first, then feed the tools in from the manhole or a cleaning eye and jet the runs section by section, and finally check whether the shop's grease trap is being cleaned regularly.

According to a HK01 report in April 2025, the Drainage Services Department said that after years of development some commercial, industrial and residential buildings in Yuen Long had wrongly connected sewage pipes to the stormwater system, sending sewage into the Yuen Long Nullah and causing water-quality and odour problems. As a general inference, misconnections in older buildings tend to appear after kitchens or toilets are added, pipes are re-routed or rear-lane drains are altered. Suspect one if a storm-drain gully still runs with dirty water in dry weather, or you can see tissue or grease in it. CCTV drain inspection can trace where the pipes actually go; correcting a misconnection is work on the building's shared drains, so the owners or the owners' corporation must arrange a qualified contractor.

Before Super Typhoon Ragasa in September 2025, the Drainage Services Department and the Civil Engineering and Development Department listed "low-lying areas in central Yuen Long (including Tai Tseng Wai, Wang Chau, Shan Pui Village, Yuen Long Town Centre)" among the areas with a higher possibility of serious flooding. Given the terrain, when street drains and the nullah run high the building's drains cannot discharge, so ground-floor floor drains, rear-lane manholes and low-floor toilets overflow first. Before the rainy season, clear the rear-lane gullies and manholes and have sandbags or flood boards ready; once the water recedes, remove the silt and clean and disinfect anywhere sewage has reached.

The Buildings Department lists common defects as leaking or broken external drainage pipes, rusty internal pipes and unauthorised alterations to the drainage system, and it can serve drainage repair orders on owners under section 28 of the Buildings Ordinance. As an inference from building age, the external stacks on single-block buildings along the main road have been in use for decades, so loose brackets and leaking joints are common, and without an on-site management office a fault in a shared pipe often goes unattended. The Environmental Protection Department also notes that suspected asbestos-containing materials can be found in buildings put up before the mid-1980s, cement sewage pipes among the examples; asbestos cannot be told from a material's appearance or colour, so every suspect material should be treated as asbestos-containing until a registered asbestos consultant certifies that it is not. Do not hammer, cut or drill such a pipe before the material is confirmed, and if it does have to be taken out, the owner or occupier must engage a registered asbestos contractor and give the department written notice at least 28 days before the work starts.