Loading page…
Loading page…
Hang Hau · HOS / PSPS
Completed 1990 · 6 blocks, 2,300 flats · a PSPS court on reclaimed land
On Ning Garden stands at 10 Sheung Ning Road in Hang Hau, a Private Sector Participation Scheme court in Area 40 of Tseung Kwan O.
Last reviewed ·
Choose the problem you are seeing to read the likely cause and next step.
Legislative Council paper CB(1)1453/00-01 records that at the subcommittee meeting of 8 March 2001 the MTR Corporation's Engineering Director said various problems had appeared at ground level on the estate involving utility pipes such as sewers and fire mains, and that after consulting the estate's owners' committee the corporation agreed to carry out remedial works in the car park and undertook to refurbish the utility pipes. For residents today the practical meaning is that the pipe trouble on official record here was never inside the flats — it was at ground level and in the car park. So if a sewage smell, standing water or staining round a manhole keeps coming back on the podium, along a covered walkway or in the car park, the first move is to ask the management office to check the shared drains and manholes, rather than treating it as a blockage of your own and pouring in more drain cleaner.
The Sai Kung District Council's Housing, Planning and Environment Committee carried a continuing item headed, in the council's own English record, "Request the Buildings Department to offer technical support to residents of Fu Ning Garden and On Ning Garden, rectifying the alleged non-compliance with legal requirements for traps connecting with soil pipes, and to provide financial assistance to needy tenants, lest residents continue being exposed to health risks". The department's written reply of 20 August 2021 (paper SKDC(HPEC) No. 15/21) said that an owner wishing to erect, alter or remove the drainage system of a flat, including an anti-syphonage pipe or a trap, may appoint a suitable contractor registered under the Buildings Ordinance under the simplified requirements of the Minor Works Control System. The reply also recorded that staff had been sent to distribute a set of guidelines to the management company of Fu Ning Garden on 11 May and that it planned to do the same at On Ning Garden on 24 and 25 August, reminding owners to maintain and repair drainage pipes properly — so the Fu Ning Garden visit had happened, while this estate's two dates were still only planned at the date of the reply, and the public record does not say what came of them. The minutes of 21 September 2021 show that members noted the Buildings Department's written reply and agreed to the chairman's suggestion that the item be deleted at the next meeting. To be clear: the word "alleged" comes from the members' own item title, and the department's reply did not confirm that any flat breaches the regulations. What is worth doing in practice is confirming whether your flat's trap is still there, whether it has been swapped for a shallower type, and whether an anti-syphonage pipe still vents the water seal.
The footnote to that Buildings Department reply points to the March 2021 booklet Guidelines on Inspection and Maintenance of Drainage Pipes and Sanitary Fitments of Residential Units — the set of guidance the department said it would hand to the management company. Several of its points are directly useful here: when a bathtub is converted to a shower tray a suitable trap must be fitted; a washing-machine drainage outlet should have a suitable trap and connect to a waste pipe; exhaust fans of excessive capacity should not be installed in bathrooms; and a trap should be ventilated by an anti-syphonage pipe, or else constructed so that the water seal cannot be lost. Flats here have been occupied for more than thirty years and, inferring from that age, most have been refitted once or twice — and converting a bathtub to a shower tray, adding a washing-machine outlet and building a false ceiling are precisely the three jobs most likely to disturb a trap or an anti-syphonage pipe. If the smell only started after a refit, or arrives the moment you shut the door and switch the fan on, check these points first rather than masking it with fragrance or bleach.
By design, residential blocks of this generation each have a number of vertical soil and waste stacks, and the toilet, basin, bathtub and bathroom floor drain of the same flat position on every floor discharge into the same set of stacks. Inferring from age, after more than thirty years of service the lower part of a stack and its outlet are the easiest places for grease, tissue and debris to narrow. Once that happens, water from the floors above shows up first in low-floor flats as a rising water level, bubbling or backflow at the toilet and the floor drain, especially at the morning and evening peaks. Telling them apart is direct: one slow fixture on its own usually means your branch pipe or trap, while the toilet and floor drain moving together — or neighbours above and below reporting the same thing — should be treated as the shared stack and reported to the management office at once, without tipping strong drain cleaner into old pipework.
Photos or a short video on WhatsApp help us tell a single-fixture blockage from a shared-stack problem.
On Ning Garden stands at 10 Sheung Ning Road in Hang Hau, a Private Sector Participation Scheme court in Area 40 of Tseung Kwan O. It was completed in 1990 and occupied from 1991, with six blocks holding 2,300 flats and 200 parking spaces. The estate is built on reclaimed land; a Legislative Council record from 2001 records various problems involving utility pipes at ground level on the site and the remedial works the MTR Corporation agreed to carry out, and in 2021 the Buildings Department told the District Council it planned to hand the estate's management company a set of guidance on maintaining drainage pipes and sanitary fitments on 24 and 25 August. So when there is odour, a slow drain or a sewage smell around the grounds here, the first step is not to start rodding but to work out whether the fault sits in your flat's branch pipe and trap or in the estate's shared and ground-level drains.
Wikipedia records that On Ning Garden was developed by Hening Investment Ltd, a subsidiary formed by CFE Engineering & Contracting Limited and a Hong Kong construction group, to a design by a local firm of architects — both of those firms appear on Wikipedia under their Chinese names only. It was completed in 1990 with six blocks holding 2,300 flats and 200 parking spaces, plus a small shopping centre and covered walkways between the blocks. The same entry names Hong Yip Service Company Limited as the management company, but gives no as-of date, so go by the estate's own notices. The English Wikipedia entry, citing the 2016 by-census, gives the estate a population of 6,921 with an average household size of 3.2. As a general inference from building age, flats occupied from 1991 are now more than thirty years old: the stacks, branch pipes and original traps have been in service that long and accumulate grease, soap scale and matted hair on the inner wall, and after a round or two of renovation the trap types, drain positions and connection details inside one block often no longer match from flat to flat.
The background worth knowing is that the estate sits on reclaimed land. Legislative Council paper CB(1)1453/00-01 — the minutes of a Transport Panel subcommittee meeting on 8 March 2001 — records the Principal Assistant Secretary for Transport saying that the government first received reports of abnormal settlement in early 1999, that an independent investigation into its causes and its effect on existing buildings was completed in November 2000, that the main cause was a large loss of groundwater from the subsoil of the reclamation, and that the only credible cause was groundwater flowing into the Stage I tunnel of the Strategic Sewage Disposal Scheme built outside the Tseung Kwan O reclamation. The same record states that the investigation confirmed all the buildings to be structurally safe. To be clear: settlement and building structure are a separate subject from the drainage system, and this page does not treat them as drainage defects.
The part that really is about drains comes in the next section of the same record. The MTR Corporation's Engineering Director told members that residents had already complained to the government about building quality before construction began at Hang Hau, and that various problems had appeared at ground level on the estate involving utility pipes such as sewers and fire mains. Although the corporation did not consider the problems to be of its making, after consulting the estate's owners' committee it agreed to carry out remedial works in the car park and undertook to refurbish the utility pipes. In other words, the pipe trouble on official record here was at ground level and in the car park. Attention only moved indoors in 2021, when the Buildings Department said it planned to give the management company a set of drainage-maintenance guidance. What any individual block or flat is like today still depends on its own repair and renovation history, and cannot be read off the estate name.
Note: statements based on building age and type are general inferences, not findings for any particular flat.
A clear process from enquiry and assessment to an agreed scope of work
Tell us the drain problem and district and ask about available timing.
Confirm timing based on the district and schedule, then inspect the blockage or odour issue.
Explain the proposed approach, scope and price before agreed work begins.
Use suitable tools for the site conditions and agreed scope of work.
After the agreed work, test drainage and explain the observed result and any next steps.
PipeButler is an independent drain-service provider with no affiliation to the developer, owners' corporation, management company or Housing Department of the places above. Facts come from public sources checked on the dates shown; work on common drains or common parts follows the management office's and deed of mutual covenant's arrangements.
WhatsApp with the problem and district, and we will confirm available timing.