Sewerage and Drainage Act
(Chapter 293A, Sections 73 and 75)
Sewerage and Drainage (Trade Effluent) Regulations
Rg 5
G.N. No. S 170/1999

REVISED EDITION 2001
(31st January 2001)
[1st April 1999]
Citation
1.  These Regulations may be cited as the Sewerage and Drainage (Trade Effluent) Regulations.
Definitions
2.  In these Regulations, unless the context otherwise requires —
“grease trap” means any interceptor, arrestor, tank or pit situated above or under the ground which allows culinary wastewater to cool and the grease therein to be separated from the wastewater;
“organic sludge” means organic matter in trade effluent which has a minimum solid content of 3% by weight or a maximum moisture content of 97% by weight.
Lawful discharge into public sewer, etc.
3.—(1)  The Director may, by notice in writing, require the owner of any premises to cause all trade effluent from those premises to be discharged into a public sewer in accordance with these Regulations.
(2)  A discharge of trade effluent shall be lawful for the purposes of section 17(4) of the Act if the discharge is —
(a)made in accordance with a notice referred to in paragraph (1); or
(b)made into a trade effluent treatment plant in accordance with these Regulations.
Approval for discharge into public sewer, etc.
4.—(1)  An application for approval to discharge trade effluent into a public sewer or any drain-line or sewer communicating with a public sewer referred to in section 17(1) of the Act shall be in such form as the Director may require.
(2)  The applicant shall, in his application, furnish to the Director —
(a)particulars of the trade, manufacture, business or building construction carried on or to be carried on by him and in the course of which the trade effluent is wholly or partly produced or of which the trade effluent is the waste or refuse;
(b)details of all the processes or operations employed or to be employed by him to produce the final products of the trade, manufacture, business or building construction;
(c)particulars of all the raw materials and chemicals used or to be used in the processes or operations;
(d)details of the layout of all the machinery, plant and equipment used or to be used in the premises in which the trade, manufacture, business or building construction is being or is to be carried on, as the case may be;
(e)an estimate of the amount of water consumed or used or to be consumed or used in the trade, manufacture, business or building construction;
(f)particulars of the physical, organic and chemical nature of the trade effluent; and
(g)such other information relating to the trade effluent and the discharge thereof as the Director may require.
(3)  The Director may, in granting any approval referred to in paragraph (1), impose such conditions as he thinks fit.
(4)  Where a person has been granted any approval referred to in paragraph (1), he shall notify the Director in writing, within 14 days of any change in —
(a)any process or operation employed by the person in paragraph (2)(b); or
(b)the layout of the machinery, plant and equipment used by the person in paragraph (2)(d),
which affects the amount or the physical, organic or chemical nature of the trade effluent discharged.
(5)  Any approval referred to in paragraph (1) —
(a)may be revoked or suspended for any period by the Director without assigning any reason; and
(b)shall cease to be valid when the person granted the approval fails to comply with these Regulations or any condition imposed under paragraph (3).
Installation of grease trap
6.—(1)  Any person who discharges trade effluent into any sewerage system shall, in connection with the discharge, install a grease trap, as the Director may require.
(2)  The person referred to in paragraph (1) shall ensure that the grease trap is maintained from time to time as the Director may, by notice in writing, require.
Particulars to be furnished
7.  Any person who discharges trade effluent into a sewerage system shall, at such times as the Director may require, submit particulars of —
(a)the amount of water consumed or used for the purposes of any trade, manufacture, business or building construction carried on by him and in the course of which the trade effluent is wholly or partly produced or of which the trade effluent is the waste or refuse;
(b)the physical, organic and chemical nature of the trade effluent;
(c)the raw materials and chemicals used in the trade, business, manufacture or building construction and the direction of the flow of any liquid or the trade effluent from or produced by any machinery, plant or equipment used in the trade, business, manufacture or building construction; and
(d)such other matters relating to the trade effluent and the discharge thereof as may be required by the Director.
Nature and type of trade effluent to be discharged
8.—(1)  No trade effluent other than that of a nature or type approved by the Director shall be discharged into any public sewer.
(2)  The temperature of the trade effluent shall not exceed 45° Celsius at the point of its entry into any public sewer.
(3)  The pH value of the trade effluent shall not be less than 6 nor more than 9 at the point of its entry into any public sewer.
(4)  The caustic alkalinity of the trade effluent shall not be more than 2,000 milligrams of calcium carbonate per litre at the point of its entry into any public sewer.
(5)  Any trade effluent shall be treated before it is discharged into a public sewer if the Director so requires.
Trade effluent to be free of certain substances
9.  The trade effluent discharged into a public sewer shall not contain any of the following substances:
(a)rain water, storm water, ground water or other water from street drainage, sub-surface drainage, roof drainage or yard drainage;
(b)calcium carbide;
(c)petroleum spirit or other inflammable solvent;
(d)any liquid, solid or gas which by reason of its quantity is likely or is sufficient to cause fire or explosion or to cause damage to the public sewer or a sewerage system to which the public sewer is connected;
(e)any substance that either by itself or in combination or by reaction with other waste or refuse may give rise to any gas, fume, odour or substance which is or is likely to be a hazard to human life, a public nuisance, injurious or otherwise objectionable, or which prevents or is likely to prevent entry into the public sewer by workmen maintaining or repairing it;
(f)yeast, spent or unspent molasses, crude tar, tar oil, crude oil, carbon disulphide, hydro-sulphide and poly-sulphide;
(g)any radioactive material;
(h)any waste or refuse liable to form a viscous or solid coating or deposit on any part of the public sewer or sewerage system;
(i)any excessively discolouring substance;
(j)any substance of a nature and quantity likely to damage the public sewer or to interfere with the proper working of any sewerage treatment works, machinery or equipment or to interfere with a process of treating the trade effluent, or other waste or refuse from the public sewer; or
(k)any pesticide, fungicide, herbicide, insecticide, rodenticide or fumigant .
Maximum concentrations of certain substances
10.—(1)  Any trade effluent discharged into a public sewer shall not —
(a)contain any of the substances listed in the First or Second Schedule in concentrations greater than those specified therein;
(b)have a 5-day Biochemical Oxygen Demand at 20° Celsius (referred to in this regulation as BOD) greater than 400 milligrams per litre of the trade effluent; or
(c)have a Chemical Oxygen Demand (referred to in this regulation as COD) greater than 600 milligrams per litre of the trade effluent.
(2)  The Director may stipulate —
(a)the maximum volume and quantity of a substance which may be discharged into a public sewer under this regulation; and
(b)the maximum rate at which the substance may be so discharged.
(3)  Where the Director stipulates the maximum volume and quantity of a substance which may be discharged into a public sewer under this regulation and the maximum rate at which the substance may be so discharged, no person who has been informed by the Director by notice in writing of the volume, quantity or rate may discharge the substance into a public sewer in a volume or quantity or at a rate in excess of that so stipulated.
Permission required to discharge certain trade effluent
11.—(1)  Subject to paragraph (2), any person may, notwithstanding regulation 10, with the prior permission of the Director discharge into any public sewer trade effluent containing BOD or Total Suspended Solids (referred to in this regulations as TSS) greater than 400 milligrams per litre of the trade effluent .
(2)  No person shall discharge into any public sewer trade effluent containing BOD or TSS greater than 4,000 milligrams per litre of the trade effluent.
(3)  Any person may, with the prior permission of the Director , dispose of organic sludge at any sewage treatment works specified by the Director .
(4)  The Director may, in granting any permission under paragraph (1), (2) or (3), impose such conditions as he thinks fit.
(5)  An application for the permission of the Director —
(a)under paragraph (1) shall be accompanied by the appropriate fee computed in accordance with the scale set out in the Third Schedule;
(b)under paragraph (3) shall be accompanied by a fee of $6 per cubic metre or part thereof of organic sludge.
(6)  In computing the fee payable by any person under paragraph (5), any fraction of a dollar shall be ignored.
Method of analysis
12.  For the purposes of these Regulations, trade effluent discharged into a public sewer shall be analysed in accordance with the latest edition of “Standard Methods for the Examination of Water and Wastewater” published jointly by the American Public Health Association, the American Water Works Association and the Water Pollution Control Federation of the United States, as amended from time to time, or in accordance with such other method of analysis as the Director thinks fit.
Payment of fees
13.  The fees payable under these Regulations shall be paid to the Director by interbank GIRO or such other means as the Director may allow.
Penalty
14.  Any person who contravenes or fails to comply with any provision of these Regulations shall be guilty of an offence and shall be liable on conviction to a fine not exceeding $5,000 and, in the case of a continuing offence, to a further fine of $500 for every day or part thereof during which the offence continues after conviction.
Transitional provision
15.  For the purposes of section 76(2) of the Act —
(a)any written permission granted under regulation 4(2) of the revoked Trade Effluent Regulations (Cap. 348, Rg 4) in relation to the discharge of trade effluent into a public sewer shall be deemed to be an approval granted under section 17(1) of the Act;
(b)any written permission or approval granted under regulation 7 of the revoked Trade Effluent Regulations (Cap. 348, Rg 4) shall be deemed to be a clearance certificate or an approval, as the case may be, granted under section 34 of the Act; and
(c)any special approval granted pursuant to the footnote to the Second Schedule of the revoked Trade Effluent Regulations shall be deemed to be an approval granted under regulation 11(1) of these Regulations.