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Trade effluent refers to any liquid, including particles of matter and other substances suspended in the liquid, that is the outflow from any trade, business, or manufacture or of any works of engineering or building construction.
Used water is a precious resource to Singapore as PUB reclaims used water to produce NEWater. Used water discharged from industries and households is collected and conveyed via an extensive sewerage network system and treated at the water reclamation plants. The treated used water is further purified using advanced membrane technologies to produce high-grade reclaimed water, known as NEWater. You can help preserve this water resource by complying with our Sewerage and Drainage Act and Sewerage and Drainage (Trade Effluent) Regulations.
Discharging trade effluent containing prohibited substances or excessive concentration of regulated substances may pose the following risks:
For example, the presence of volatile solvents in certain quantities renders the atmosphere in the public sewer explosive and can result in fire or explosion endangering safety of workers maintaining the public sewerage system.
Premises which discharge trade effluent into the public sewerage system are required to obtain a permit (Written Approval) from PUB, Singapore’s National Water Agency.
Application can be done via an online system, GoBusiness. Documents required for submission include type of trade, name and quantum of chemicals used, procedure to manage spent chemicals and design details of wastewater treatment plant.
Written Approvals are valid for 5 years upon issuance. Written Approval holders are encouraged to renew their Written Approval three months before its expiry. To renew your WA, you should submit the completed renewal form by e-mail to PUB_WA@pub.gov.sg.
Businesses are required to inform PUB in the following scenarios:
Trade Effluent Fee (TEF) Scheme
Trade effluent to be discharged into the public sewer must at all times meet the standards specified in the Sewerage and Drainage (Trade Effluent) Regulations. If trade effluent discharged into the public sewer contains BOD or TSS greater than 400mg/L or COD greater than 600mg/L, you may consider taking up the Trade Effluent Fee (TEF) scheme and pay TEF in accordance with the scale set out in the Fourth Schedule of the regulations, subject to approval by PUB. The maximum limits for TEF specified under reg 11 of TER are BOD < 6,000mg/L, TSS < 6,000mg/L, and COD < 10,000mg/L O2 and/or COD/BOD ratio < 3. The TEF is computed based on the concentration of BOD, TSS and COD in the trade effluent and the volume of trade effluent discharged into the public sewer. The concentrations will be established based on trade effluent samples taken from your premises. Companies under the TEF scheme should make payment promptly or risk being removed from the scheme.
Discharging chemicals such as solvents into the drains or sewers can not only affect our water reclamation process but can also be harmful to the environment and personnel maintaining the sewerage and drain networks.
Adopting proper source-control practices can ensure spent chemicals are properly disposed to prevent accidental discharge into public sewers:
Premises which discharge trade effluent into the public sewerage system are required to obtain a permit (Written Approval) from PUB, Singapore’s National Water Agency.
Application can be done via an online system, GoBusiness. Documents required for submission include type of trade, name and quantum of chemicals used, procedure to manage spent chemicals and design details of wastewater treatment plant.
Written Approvals are valid for 5 years upon issuance. Written Approval holders are encouraged to renew their Written Approval three months before its expiry. To renew your WA, you should submit the completed renewal form by e-mail to PUB_WA@pub.gov.sg.
Businesses are required to inform PUB in the following scenarios:
Trade Effluent Fee (TEF) Scheme
Trade effluent to be discharged into the public sewer must at all times meet the standards specified in the Sewerage and Drainage (Trade Effluent) Regulations. If trade effluent discharged into the public sewer contains BOD or TSS greater than 400mg/L or COD greater than 600mg/L, you may consider taking up the Trade Effluent Fee (TEF) scheme and pay TEF in accordance with the scale set out in the Fourth Schedule of the regulations, subject to approval by PUB. The maximum limits for TEF specified under reg 11 of TER are BOD < 6,000mg/L, TSS < 6,000mg/L, and COD < 10,000mg/L O2 and/or COD/BOD ratio < 3. The TEF is computed based on the concentration of BOD, TSS and COD in the trade effluent and the volume of trade effluent discharged into the public sewer. The concentrations will be established based on trade effluent samples taken from your premises. Companies under the TEF scheme should make payment promptly or risk being removed from the scheme.
Discharging chemicals such as solvents into the drains or sewers can not only affect our water reclamation process but can also be harmful to the environment and personnel maintaining the sewerage and drain networks.
Adopting proper source-control practices can ensure spent chemicals are properly disposed to prevent accidental discharge into public sewers:
Premises which discharge trade effluent into the public sewerage system are required to obtain a Written Approval (WA) from PUB. The WA specifies the conditions that you must comply with if you want to discharge trade effluent into the sewers. You can apply for a WA online at https://www.gobusiness.gov.sg
You are responsible for ensuring your trade effluent is collected and disposed of responsibly. Do remember that discharging trade effluent into a sewer without approval from PUB or discharging non-compliant trade effluent into public sewers is a violation of the Sewerage and Drainage Act (SDA) and is illegal. As a business operator, you have a duty to ensure that any waste you generate is handled safely and in accordance with all environmental legislations.
Businesses are required to inform PUB in the following scenarios:
a) Change in company’s name, address, process or operation
b) Change in plant layout or machinery, which affects the amount or nature of trade effluent discharged
c) Change in company’s status e.g. from sole proprietor to private limited
d) Company has ceased operations
Written Approvals have a validity period of 5 years upon issuance. Please ensure your Written Approval is valid and re-apply for a new Written Approval at least 3 months before the existing one lapses.
If you are not able to meet the water quality discharge requirements, you can either:
a) Install a wastewater treatment facility in your premises to pre-treat the non-compliant trade effluent so that the water quality parameters are within the acceptable limits, or
b) Engage a licensed waste collector to collect and dispose your trade effluent off-site.
You may apply for permission to discharge the trade effluent under the “Trade Effluent Fee Scheme”. Under this scheme, upon approval from PUB, you will pay fees for the discharge of such trade effluent into public sewers. The fees payable shall be in accordance with the scale set out in Annex B. However, approval will not be granted for the discharge of trade effluent which contains:
a) BOD greater than 6,000 mg/l of the trade effluent, or
b) TSS greater than 6,000 mg/l of the trade effluent, or
c) COD greater than 10,000 mg/l of the trade effluent or three times the concentration of BOD in the trade effluent, whichever is the lower.
Here are some practical and simple tips you can follow to avoid accidentally discharging any illegal trade effluent:
a) Ensure that your sanitary drainage plan is updated and clearly identifies the locations and flow of all existing drains and sewers around your premises.
b) Maintain your pre-treatment plant to ensure proper treatment of trade effluent. Examples of common pre-treatment plants include oil interceptors and pH neutralizing systems.
c) Clearly demarcate and familiarise yourself where the discharge points for collection of spent solvents for disposal by licensed waste collectors. When discharging trade effluent, check that you are connected to the correct system.
d) Store and handle raw materials, wastes, chemicals, and fuels responsibly so that they do not enter the sanitary drain-lines, floor traps and sewers on your premises.
e) Spill kits or absorbent granules/sawdust should be readily available at locations where there is a risk of spillage or leakage of pollutants into sewers. Ensure employees know where they are and how to use them.
f) Do not wash spilled chemicals down the sewer or drain.
g) Ensure that all relevant employees and contractors are familiar and comply with your procedures for handling, disposing and discharging liquid wastes.
h) Explore possibilities for using alternative materials and practices.
If you have a pre-treatment plant in your facility, a maintenance schedule is essential to ensure that the plant is operating properly and treating your trade effluent adequately. You may refer to your operation manuals or contact your consultant, vendor, contractor to plan a comprehensive inspection and maintenance schedule.
Here are some useful tips:
a) Keep records of all the servicing and calibration intervals of all the process instruments used in the wastewater treatment plant.
b) Implement a servicing schedule for tasks including thorough inspection of the equipment and replacement of any consumable parts on a regular basis.
c) Keep proper records of the mechanical components such as the pumps and stirrers in the wastewater treatment plant.
Together with a maintenance schedule, a process monitoring schedule effectively monitors the performance of your treatment process.
Here are some useful pointers: -
a) Implement a schedule to regularly collect trade effluent samples from the pre-treatment plant and check that the treatment complies with the discharge limits as stipulated in the SD(TE)R. You may use commercially available analytical kits such as colorimetric tests.
b) From time to time, collect and send trade effluent samples to an external accredited laboratory for accurate analysis.
c) Keep records of all test results, monitor for any process trends, and revise the maintenance and monitoring schedules accordingly.
Here are some useful pointers:
a) An oil interceptor has to be maintained regularly so that it can continue to treat trade effluent properly. You should implement a maintenance schedule which requires regular checks for:
(i) Excessive build-up of scum and debris which may get carried into the public sewers
(ii) Build-up of oil stains on the walls of the interceptor, and
(iii) Sufficient water level in the interceptor
b) You are encouraged to implement a monitoring schedule to regularly check the quality of the trade effluent discharged from oil interceptors. Trade effluent samples may be collected from the outlet of an interceptor and sent to accredited laboratories for two tests: “Oil-and-Grease (Total)” and “Oil-and-Grease (Hydrocarbon)”. If you operate a motor-shop or trade that involves the use of industrial solvents such as metal degreasers, you are encouraged to send your trade effluent samples for “Gas Chromatographic Mass Spectrometry (GCMS)” analysis to detect for inflammable substances. Such laboratorial tests are useful for you to review your maintenance schedule of the oil interceptor.
c) The collection, transportation and disposal of toxic wastes such as waste oil and spent solvents are regulated by the Environmental Public Health (Toxic Industrial Waste) Regulations, administrated by the National Environmental Agency (NEA).
d) An oil interceptor needs to be cleaned periodically. The recommended steps for cleaning oil interceptors are as follows:
The sample that you collect for analysis should be representative of the trade effluent from your trade premise.
a) If the trade premise has a pre-treatment plant, samples should be collected at the sampling tank or sump of the pre-treatment plant.
b) If the trade premise does not have a pre-treatment plant, samples should be collected at the last inspection chamber of the trade premise.
You may refer to the Sewerage and Drainage Act and Sewerage and Drainage (Trade Effluent) Regulations here.
Alternatively, to speak to a PUB officer regarding the discharge of trade effluent into the public sewers, please contact: PUB-ONE (24-hour toll free hotline) at 1800-2255-782.1800-2255-782
Premises which discharge trade effluent into the public sewerage system are required to obtain a Written Approval (WA) from PUB. The WA specifies the conditions that you must comply with if you want to discharge trade effluent into the sewers. You can apply for a WA online at https://www.gobusiness.gov.sg
You are responsible for ensuring your trade effluent is collected and disposed of responsibly. Do remember that discharging trade effluent into a sewer without approval from PUB or discharging non-compliant trade effluent into public sewers is a violation of the Sewerage and Drainage Act (SDA) and is illegal. As a business operator, you have a duty to ensure that any waste you generate is handled safely and in accordance with all environmental legislations.
Businesses are required to inform PUB in the following scenarios:
a) Change in company’s name, address, process or operation
b) Change in plant layout or machinery, which affects the amount or nature of trade effluent discharged
c) Change in company’s status e.g. from sole proprietor to private limited
d) Company has ceased operations
Written Approvals have a validity period of 5 years upon issuance. Please ensure your Written Approval is valid and re-apply for a new Written Approval at least 3 months before the existing one lapses.
If you are not able to meet the water quality discharge requirements, you can either:
a) Install a wastewater treatment facility in your premises to pre-treat the non-compliant trade effluent so that the water quality parameters are within the acceptable limits, or
b) Engage a licensed waste collector to collect and dispose your trade effluent off-site.
You may apply for permission to discharge the trade effluent under the “Trade Effluent Fee Scheme”. Under this scheme, upon approval from PUB, you will pay fees for the discharge of such trade effluent into public sewers. The fees payable shall be in accordance with the scale set out in Annex B. However, approval will not be granted for the discharge of trade effluent which contains:
a) BOD greater than 6,000 mg/l of the trade effluent, or
b) TSS greater than 6,000 mg/l of the trade effluent, or
c) COD greater than 10,000 mg/l of the trade effluent or three times the concentration of BOD in the trade effluent, whichever is the lower.
Here are some practical and simple tips you can follow to avoid accidentally discharging any illegal trade effluent:
a) Ensure that your sanitary drainage plan is updated and clearly identifies the locations and flow of all existing drains and sewers around your premises.
b) Maintain your pre-treatment plant to ensure proper treatment of trade effluent. Examples of common pre-treatment plants include oil interceptors and pH neutralizing systems.
c) Clearly demarcate and familiarise yourself where the discharge points for collection of spent solvents for disposal by licensed waste collectors. When discharging trade effluent, check that you are connected to the correct system.
d) Store and handle raw materials, wastes, chemicals, and fuels responsibly so that they do not enter the sanitary drain-lines, floor traps and sewers on your premises.
e) Spill kits or absorbent granules/sawdust should be readily available at locations where there is a risk of spillage or leakage of pollutants into sewers. Ensure employees know where they are and how to use them.
f) Do not wash spilled chemicals down the sewer or drain.
g) Ensure that all relevant employees and contractors are familiar and comply with your procedures for handling, disposing and discharging liquid wastes.
h) Explore possibilities for using alternative materials and practices.
If you have a pre-treatment plant in your facility, a maintenance schedule is essential to ensure that the plant is operating properly and treating your trade effluent adequately. You may refer to your operation manuals or contact your consultant, vendor, contractor to plan a comprehensive inspection and maintenance schedule.
Here are some useful tips:
a) Keep records of all the servicing and calibration intervals of all the process instruments used in the wastewater treatment plant.
b) Implement a servicing schedule for tasks including thorough inspection of the equipment and replacement of any consumable parts on a regular basis.
c) Keep proper records of the mechanical components such as the pumps and stirrers in the wastewater treatment plant.
Together with a maintenance schedule, a process monitoring schedule effectively monitors the performance of your treatment process.
Here are some useful pointers: -
a) Implement a schedule to regularly collect trade effluent samples from the pre-treatment plant and check that the treatment complies with the discharge limits as stipulated in the SD(TE)R. You may use commercially available analytical kits such as colorimetric tests.
b) From time to time, collect and send trade effluent samples to an external accredited laboratory for accurate analysis.
c) Keep records of all test results, monitor for any process trends, and revise the maintenance and monitoring schedules accordingly.
Here are some useful pointers:
a) An oil interceptor has to be maintained regularly so that it can continue to treat trade effluent properly. You should implement a maintenance schedule which requires regular checks for:
(i) Excessive build-up of scum and debris which may get carried into the public sewers
(ii) Build-up of oil stains on the walls of the interceptor, and
(iii) Sufficient water level in the interceptor
b) You are encouraged to implement a monitoring schedule to regularly check the quality of the trade effluent discharged from oil interceptors. Trade effluent samples may be collected from the outlet of an interceptor and sent to accredited laboratories for two tests: “Oil-and-Grease (Total)” and “Oil-and-Grease (Hydrocarbon)”. If you operate a motor-shop or trade that involves the use of industrial solvents such as metal degreasers, you are encouraged to send your trade effluent samples for “Gas Chromatographic Mass Spectrometry (GCMS)” analysis to detect for inflammable substances. Such laboratorial tests are useful for you to review your maintenance schedule of the oil interceptor.
c) The collection, transportation and disposal of toxic wastes such as waste oil and spent solvents are regulated by the Environmental Public Health (Toxic Industrial Waste) Regulations, administrated by the National Environmental Agency (NEA).
d) An oil interceptor needs to be cleaned periodically. The recommended steps for cleaning oil interceptors are as follows:
The sample that you collect for analysis should be representative of the trade effluent from your trade premise.
a) If the trade premise has a pre-treatment plant, samples should be collected at the sampling tank or sump of the pre-treatment plant.
b) If the trade premise does not have a pre-treatment plant, samples should be collected at the last inspection chamber of the trade premise.
You may refer to the Sewerage and Drainage Act and Sewerage and Drainage (Trade Effluent) Regulations here.
Alternatively, to speak to a PUB officer regarding the discharge of trade effluent into the public sewers, please contact: PUB-ONE (24-hour toll free hotline) at 1800-2255-782.1800-2255-782
