1. Emergency generator is not often in use. Is it worthwhile to conduct regular testing and ensure no dark smoke emission when being tested?
    From our experience, regular maintenance and proper operation can significantly reduce dark smoke emission from generators.
    The statutory control on dark smoke: it is an offence for any equipment to emit dark smoke (i) for more than 6 minutes in any period of 4 hours; or (ii) for more than 3 minutes continuously at any one time.
    Indeed, dark smoke emitted from generator will not only causes nuisance to residents nearby, but also indicates malfunction of the generator. Testing should be suspended if dark smoke is found. Maintenance should be carried out as soon as possible so as to ensuring the generator can perform well during emergency.
  2. Are there any devices for measuring dark smoke emission from chimneys besides visual inspection?
    Yes, a device can be installed inside a chimney to measure the concentration of dark smoke. However, this kind of device is quite expensive. A more common way is to use "Ringelmann Chart" to assess the concentration of dark smoke.
    "A Guide to the Air Pollution Control (Smoke) Regulations" contains different shades of darkness on the "Ringelmann Chart" for easy reference. This guide is available at all regional offices of the EPD.
  3. Why does the EPD require restaurants to install chimneys, even when air pollution control equipment is already in place?
    Besides air pollution control equipment, proper positioning of chimneys would effectively avoid the emission of cooking odour / oily fume to become nuisances to the nearby residents.
  4. Is open-air BBQ activity at night organized by club house at the podium or inside an estate governed by laws?
    When large-scale BBQ activity is to be held at the podium or inside an estate, the impacts of oily fume and noise suffered by the nearby residents should be considered. The management office should consult residents before holding this kind of activity.
    If such activity causes nuisance to any residents, the EPD may request the management companies to remedy the situation.
  5. Will residents commit an offence if they burn incense papers and create smoke during the Yu Lan Festival?
    Generally, it is not an offence for residents to burn joss paper for ritual purpose. Management office should designate suitable locations and provide incense burners inside the estate for such purpose.
    Incense burners should be far away from residents. In choosing appropriate locations, the management office should take into account the wind direction as well as the surroundings, so that emission of smoke and flying ash would not cause air nuisance to the nearby residents.
  6. Is the hot air emitted from air-conditioners being controlled by the EPD?
    Nuisance caused by hot air from air-conditioners is governed by legislations of the Food and Environmental Hygiene Department.
Back to top


  1. What is "environmental noise"?
    Noise is unwanted sound. Various types of noise in our daily environment are environmental noise.
  2. How to control environmental noise in Hong Kong?
    The Noise Control Ordinance (NCO) (Cap. 400) provides control on most type of environmental noise except aircraft noise, road traffic noise and marine traffic noise.
  3. How to control aircraft noise in Hong Kong?
    The Civil Aviation (Aircraft Noise) Ordinance (Cap. 312) provides control on aircraft noise, with the Director of Civil Aviation as Authority. You can lodge a complaint to the Department of Civil Aviation against excessive noise generated by aircrafts (and helicopters), regardless they flies over residential buildings or other noise sensitive receivers.
  4. Which departments are responsible for controlling road traffic noise in Hong Kong?
    The control of road traffic noise depends on different circumstances. For new projects, the EPD will provide professional advice to project proponents in the planning stage for exploring and formulating practicable noise mitigation measures to abate road traffic noise impact. At the start, the alignment of the new road would be carefully considered to minimize the population exposed to traffic noise. A buffer distance may be inserted between the road and the buildings, or roadside barriers may be provided where practicable. As for existing roads, various noise abatement measures would been considered, such as re-surfacing roads with noise absorbing materials and installing noise insulation works for schools. The Government has also set out a new policy to address the serious noise impact of existing roads by a number of works including installation of noise barriers and re-surfacing existing roads with sound-absorbing materials where possible. The Noise Control (Motor Vehicles) Regulation also requires that only motor vehicle complying with stipulated noise emission standards can apply for first registration in Hong Kong.
  5. How to control marine traffic noise in Hong Kong?
    The NCO is not applicable to the control of marine traffic noise. However, noise caused by amplifiers on board in public waters is equivalent to noise emanating in public places which is subject to control under sections 4 and 5 of the NCO. The Police is empowered to enforce such provision.
  6. How to control occupational noise in Hong Kong?
    Occupational noise (that is noise generated inside a factory or other industrial undertaking affecting employees working there) is subject to control under the Factories and Industrial Undertakings (Noise at Work) Regulation (Cap. 59), which is enforced by the Labour Department.
  7. How is environmental noise classified under the NCO?
    Under the NCO, environmental noise is classified into the following categories according to its locations and sources:
    1. Noise from domestic premises or public places (often referred to as general neighbourhood noise);
    2. Noise from construction work (including piling);
    3. Noise from industrial or commercial premises;
    4. Noise from intruder alarm systems installed in any premises or vehicles;
    5. Noise from individual items of plant or equipment;
    6. Noise emission from motor vehicles.
  8. What is noise from domestic premises and public places?
    Noise from domestic premises and public places includes noise which is produced in domestic premises by sources such as television sets, air-conditioners or dogs, and noise produced in public places by sources such as radios, hawkers or loudspeakers
  9. How to control noise from domestic premises and public places in Hong Kong?
    Noise from domestic premises and public places is controlled under the provisions in sections 4 and 5 of the NCO. Section 4 of the Ordinance is a general provision to control noise from such places which is causing annoyance to any person at night (11 p.m. to 7 a.m.) or on a general holiday. Section 5 of the Ordinance provides control over particular noise sources, such as animals and birds, musical instruments, loudspeakers, games, trades or businesses or air conditioners in domestic premises or public places at any time of the day or night. These provisions are enforced by the police on a subjective nuisance basis
  10. What is "domestic premises"?
    Under the Ordinance, "domestic premises" means any premises used wholly or mainly for residential purposes and constituting a separate household unit; and any part of a hotel or boarding-house that is let by the keeper of the hotel or boarding-house to a guest. It should be noted that the term "domestic premises" applies to individual dwellings or household units but not to an entire building. Noise from the non-residential parts of buildings is industrial and commercial noise, which is controlled under section 13 of the NCO
  11. What is noise from construction sites?
    Under the Ordinance, noise from construction sites generally refers to noise generated from construction work which includes any work in connection with or for the construction, demolition, re-construction, maintenance or repair of buildings, roads and public facilities, or any work related to these kinds of work. Construction activities are mainly divided into the following two categories:
    (a) general construction work (such as construction, reclamation, site formation, non-percussive piling work, excavation, formwork, concrete grouting and so on); and
    (b) percussive piling (such as piling by means of hammering or other percussive methods).
    These two categories of construction activities are controlled by the respective system of Construction Noise Permit (CNP)
  12. What is noise from piling works?
    Noise from piling works is one of the many types of construction noise. Piling works are mainly divided into percussive piling and non-percussive piling. Percussive piling means driving a pile into the ground by means of hammering or other percussive means with great force, so the noise generated is extremely loud. Non-percussive piling (such as bored piling) does not involve hammering and produces less noise. It is therefore not as disturbing as percussive piling. Non-percussive piling is classified as general construction work under the NCO
  13. How to control noise from general construction work in Hong Kong?
    The carrying out of general construction work using powered mechanical equipment during the restricted hours, that is between 7 p.m. and 7 a.m. or at any time on a general holiday (including Sunday), is prohibited under the NCO unless a valid CNP is in force. In general, a CNP would not be issued unless the overall noise level of a construction work complies with the statutory limits set out in the relevant technical memoranda under the NCO for issuance a permit. Besides, the use of specified powered mechanical equipment (such as hand-held breakers and dump truck) and / or the carrying out of the prescribed construction work (such as hammering) in the densely populated built up areas (designated areas) is strictly controlled under the same CNP system. The specific locations of designated areas are defined under the Noise Control (Construction Work Designated Areas) Notice
  14. How is noise from percussive piling being controlled in Hong Kong?
    Percussive piling is prohibited between 7 p.m. and 7 a.m. and on holidays. A CNP is required for the carrying out of percussive piling during day time of weekdays. The operation of piling machine is restricted to 3, 5 or 12 hours every day, depending on the noise impact caused
  15. How to apply for a CNP?
    An application for a CNP shall be made to the Noise Control Authority (that is the EPD) in the prescribed form and be accompanied by the required fee. In considering applications for general construction work or percussive piling work, the Authority shall assess the noise impact generated by the equipment to be used on the nearby noise sensitive receivers, such as domestic premises, in accordance with the assessment procedures set out in the relevant technical memoranda. If the Authority satisfies that the noise generated by the relevant equipment complies with the requirements set out in the relevant technical memoranda, a CNP would be issued with appropriate conditions imposed
  16. How to control noise from domestic renovation work in Hong Kong?
    Except for public holidays, noise generated from domestic renovation work during daytime (that is 7 a.m. to 7 p.m.) is not under the jurisdiction of the NCO. A contractor shall not use powered mechanical equipment to carry out renovation work after 7 p.m. or any time on a general holiday (that is the restricted hours), unless he has a valid CNP. The carrying out of prescribed construction activity in designated area (referred to as densely populated built up areas under the Notice) is also subject to control. However, owner or tenant of domestic premises carries out small works on his own with a portable mechanical device is exempted. Nevertheless, the general provision under section 4 stipulates that any person who between the hours of 11 p.m. and 7 a.m., or at any time on a general holiday in any domestic premises should not make any noise which is a source of annoyance to any person. Therefore, neither owner nor tenant should carry out renovation during that time.
    Except for the control under the NCO, management office of domestic premises has the right to control noise from domestic premises in other forms
  17. What is noise from commercial and industrial premises?
    Under the Noise Control Ordinance, this kind of noise is called "Noise from Places other than Domestic Premises, Public Places or Construction Sites". Typical examples are noise from ventilating systems of restaurants and shopping malls, noise from lifts, lift machine rooms and pumping systems of multi-storey residential buildings, noise from karaoke lounges and so on
  18. How to control noise from commercial and industrial premises in Hong Kong?
    The Authority controls this type of noise by issuing Noise Abatement Notices (NAN) which may be served to owners or occupiers of the concerned premises, specifying a date by which the owner or occupier should reduce the noise within the stipulated level. Non-compliance with the NAN is an offence
  19. How to control noise from intruder alarm systems under the NCO?
    Under the NCO, intruder alarm systems installed in any premises and vehicles shall not sound for more than 15 minutes and 5 minutes respectively after being triggered. In addition, the vehicle alarms shall not sound unless the vehicles are being tampered with. The controllers or registered owners have to ensure their intruder alarm systems comply with the requirements
  20. What are the penalties of the NCO?
    Any person who commits an offence under the Ordinance shall be liable to the following maximum penalties:
Section(s) Offence(s) Maximum Penalty
4, 5 Noise from Domestic Premises and Public Places (Neighbourhood Noise) A fine of $10,000
6,7 Noise from Construction Sites On first conviction to a fine of $100,000
13 Noise from Places other than Domestic Premises, Public Places or Construction Sites (Industrial and Commercial Noise) On second or subsequent conviction to a fine of $200,000, and a fine of $20,000 for each day
13A Noise from Intruder Alarm System Installed in Any Premises A fine of $10,000 and to imprisonment for 3 months
13B Noise from Intruder Alarm System Installed in Any Vehicles A fine of $10,000
Back to top


  1. What are the roles of government departments in handling wastewater discharge from residential buildings?
    The EPD, the Buildings Department (BD), the Food and Environmental Hygiene Department (FEHD) and the Drainage Services Department (DSD) are all responsible for wastewater discharge under their purview. If there is a misconnection of sewers to storm-water drains in an individual unit, the EPD would conduct investigation and request the concerned premises owner to stop such discharge. The BD would follow up the non-compliance with building plans approved by the Government. In case of overflow caused by drains leakage or blocked manholes, the FEHD would ask the concerned owners to rectify the situation in order to safeguard public health. If the blocked manhole is government property, the DSD would be responsible to clear the blocked manholes.
  2. How can owners' corporation or management office ensure the compliance of wastewater discharge from residential buildings?
    Owners' corporation or management office should conduct regular drainage maintenance and avoid any mis-connection. They should also obtain necessary licences for sewage treatment, make sure that their treatment facilities function properly, and, the discharge complies with licence conditions. Please contact the EPD for any queries.
  3. Will management office companies be prosecuted for sewer misconnection or improper operation of sewage treatment facilities?
    The pollution control performed by the EPD is in line with the rest of the world. For effective performance of this function, we have to, on the one hand, educate polluters the importance of compliance with the relevant regulations, and on the other hand, strictly enforce the environmental legislations to punish the offenders. In the cause of prevent pollution and protect the environment, the EPD attaches great importance to establishing a good partnership with property management organizations. All the owners' corporations, property management companies and dischargers have to comply with the relevant legislations. Owing to the limited resources of the EPD, we need to set our enforcement priority according to the potential impacts of different pollution acts. Any incidents that may lead to massive pollutants, grave harm to public health and serious impacts on the environment are given the highest priority by the EPD.
  4. It is common for owners' corporation or management office to outsource the operation of sewage treatment facilities. If non-compliance of related legislation is due to improper operation of such treatment facilities, will the EPD prosecute the concerned contractor only?
    The contractor, owners' corporation and management office are responsible for ensuring the operation of sewage treatment facilities complying with the requirements of wastewater discharge. The owners' corporation and the management office should monitor the operation of the contractor and make sure the requirement is met. Therefore, the contractor, owners' corporation and management office may be prosecuted subject to the evidence of each case.
  5. Is it necessary for a restaurant operating inside a shopping mall to apply for a discharge licence?
    If the wastewater is discharged directly into public sewers, the restaurant should apply to the EPD for a discharge licence. If the wastewater is discharged into communal sewage treatment facilities operated by the owner of the shopping mall or the management office, the owner or the management office should apply for the licence. Therefore, owner or management office of the shopping mall should set out provisions in the lease of tenancy stating clearly the respective responsibility of each party.
  6. Who will be prosecuted, if a restaurant inside a shopping mall has infringed the standards listed in the discharge licence?
    Under the Water Pollution Control Ordinance, dischargers or occupiers of premises that discharge wastewater will be prosecuted. Holder of the discharge licence should be responsible for the breach of discharge standards. The EPD will prosecute the restaurant owner, if he is the licencee holder. However, if the holder is the owner or the management office of the shopping mall, even though the failure to meet the stipulated discharge requirement is due to poor management of the restaurant, the EPD may consider taking legal action against the owner or the management office of the shopping mall.
  7. What can an owners' corporation or a management office do to help prevent pollution caused by renovation workers, like disposing of solvent and chemical waste into communal drains?
    When carrying out building renovation, the owners' corporation or the management office should persuade the contractor to try reusing and recycling chemicals such as solvent and paint, and remind them not to pour chemical waste into communal drains to avoid polluting the environment. Small quantity of waste solvent and paint can be disposed with other domestic waste. For the disposal of large quantity of solvent and chemical waste, the owners' corporation or the management office can ask the contractor to register as chemical waste producer who should make proper arrangement for the storage of such materials and employ a qualified chemical waste collector to handle and dispose of the chemical waste. Property management companies can also consider to register as a chemical waste producer and offer a value-added service to centrally collect waste solvent or solvent-based paint for subsequent collection by licenced chemical waste collector. Information on chemical waste collectors can be obtained from the EPD.
  8. What owners' corporation or management office has to note in drainage repair and maintenance works, in order to comply with legislative environmental requirement?
    Management office should make sure all wastewater is discharged to nearby sewers, and not discharged into nearby stormwater drains that pollute the environment. Management office may also minimize sewage disposal by setting out proper arrangements, such as termination of water supply during maintenance that lasts for a short period.
  9. Will the EPD deal with pollution caused by water dripping from air-conditioners or water cooling towers?
    The FEHD will deal with water dripping from air-conditioners or water cooling towers.
  10. Can wastewater discharged from washing machines be connected to storm-water drains?
    No, wastewater from washing machines should be discharged into sewers.
Back to top

Waste Separation and Recovery

For problems and solutions on waste separation and recovery, please browse the webpage of EPD Waste Reduction Programmes.
Back to top