Reference number  
DRS 181: 2018  
© RSB 2018  
 
 
 RWANDA 
STANDARD  DRS 
181 
 
Second edition  
2018 -mm-dd 
 
Solid waste — Handling , collection, 
transportation and disposal  — Code of 
practice  
 
 
  DRS  181: 2018  
©RSB 2018 - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2018  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reproduce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
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Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw   
ePortal: www.portal.rsb.gov.rw     DRS  181: 2018  
iii                ©RSB 2018  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Term s and definitions  ................................ ................................ ................................ ..................  1 
4 Domestic solid waste  ................................ ................................ ................................ ...................  2 
4.1 Handling  ................................ ................................ ................................ ................................ ........  2 
4.2 Waste collection  ................................ ................................ ................................ ...........................  2 
 Waste collection system  ................................ ................................ ................................ ..............  2 
4.3 Waste storage modalities  ................................ ................................ ................................ ............  3 
4.4 Waste collection modalities  ................................ ................................ ................................ ........  3 
4.5 Transportation  ................................ ................................ ................................ ..............................  4 
5 Commercial solid waste ................................ ................................ ................................ ...............  4 
5.1 Handling  ................................ ................................ ................................ ................................ ........  4 
5.2 Transportati on ................................ ................................ ................................ ..............................  5 
5.3 Disposal  ................................ ................................ ................................ ................................ .........  5 
6 Industrial solid waste  ................................ ................................ ................................ ...................  5 
6.1 Handling  ................................ ................................ ................................ ................................ ........  5 
6.2 transportati on ................................ ................................ ................................ ...............................  5 
6.3 Disposal  ................................ ................................ ................................ ................................ .........  6 
7 Environment management  ................................ ................................ ................................ ..........  6 
Annex  A (normative)  Methods of households refuse treatment  ................................ .........................  7 
A.1 Disposal  ................................ ................................ ................................ ................................ .........  7 
A.2 A.2 Recovery materials from household refuse  ................................ ................................ ........  8 
Annex  B (normative)  Methods of households refuse treatment  ................................ .........................  9 
Annex  C ................................ ................................ ................................ ................................ ....................  10 
Annex  D (informative)  Pollutants and their sources  ................................ ................................ ..........  12 
 DRS  181: 2018  
©RSB 2018 - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national st andards.  Final Draft Rwanda S tandards adopted 
by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 181 was prepared by Technical Committee RBS/TC  041, Environment Protection . 
In the preparation of this standard, reference was made to the following standard:  
MS 59, Solid  waste  ― Handling , transportation  and disposal ― Code of practice  
The assistance delivered from the above source is hereby acknowledged with thanks . 
This second edition cancels and replaces the first  edition (RS  181: 2013 ), which has been  technically revised.  
    DRS  181: 2018  
v                ©RSB 2018  - All rights reserved  
 Committee membership  
The following organizations were represented on the Technical Committee on Environment Protection  (RSB/TC 
041) in the preparation of this standard.  
Bugesera District  
Gakenke District  
Huye District  
Kamonyi District  
Kicukiro District  
Ministry of Disaster Management and Refugee Affairs (MIDIMAR)  
Ministry of Environment  
Ngoma District  
Nyagatare District  
Nyamagabe District  
Nyamasheke Distric t 
Ruliba Clays Ltd 
Rulindo District  
Rusizi District  
Rutsiro District  
Rwanda Fisheries Sector (RFS)  
Rwanda Polytechnic/Integrated Polytechnic Regional College - Kigali (RP/IPRC Kigali)  
Rwanda Utilit ies Regulatory Authority (RURA)  
SULFO Rwanda  Industries  
Water and  Sanitation Corporation (WASAC)  
Rwanda  Standards Board  (RSB) – Secretariat  
 DRS 181: 2018  
1                ©RSB 2018  - All rights reserved  
 Solid waste — Handling, collection, transportation and disposal — Code 
of Practice  
1 Scope   
This Draft Rwanda standard prescribes the recommended procedure for the handling, collection, transportation 
and disposal of solid waste to ensure safety of operatives, passers -by, animals a nd the environment.  
Domestic, commercial and industrial solid waste is part of this standard.  
Waste from health -care units is covered in RS 208.  
Construction and demolition waste is covered in RS 367.  
Electrical and Electronic wastes ( E-waste) are covered  in RS 276 (Part 1 and 2) . 
2 Normative references  
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated references, the latest edition of the referenced do cument 
(including any amendments) applies . 
RS ISO 14001, Environmental management system — Requirements  with guidance for use  
3 Terms and definitions  
For the purposes of this standard , the following terms and definitions apply .  
3.1 
industrial waste  
all solid waste emitted at the level of the industries, except the construction sector that  mostly emits mineral 
waste that is considered to be internally managed as embankment by the companies. In  Rwanda, the largest 
part of this waste is non -hazardous but a  significant part could be hazardous  
3.2 
commercial waste  
any premises used wholly or mainly for trade, business, sport or entertainment (excluding household and  
industrial waste). They are mostly composed of organics and p ackaging without hazardous part  
3.3 
domestic waste (also called household waste)  
all solid waste emitted at the level of households. It is largely non -hazardous like cooking residue and packaging, 
but some of it is hazardous like th e batteries or electronic waste  
3.4 
E-waste  
popular, informal name for electronic products nearing the end of their “useful life”. Computers, televisions, 
VCRs, stereos, copiers, and fax machines  are common electronic products   
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 4 Domestic solid waste  
4.1 Handling  
4.1.1  Domestic solid waste (refuse from residential areas) shall be segregated at source . Plastics, glass, 
ceramic waste and other non -biodegradable waste shall be put together in one bucket. Non -biodegradable 
plastic bags in particular should be handled separat ely. 
4.1.2  Waste such as papers or plastics intended for incineration shall be put at one place preferably in a 
dugout rubbish pit and transported to the appropriate place where incineration has to be done. Biodegradable 
waste such as food remains ha s seve ral useful -disposal methods and need s be put apart, e.g., in a home 
vegetable garden.  
4.1.3  Metallic or plastic was te containers shall be used. These shall comply with the requirements of the 
waste collection local  authority . 
4.1.4  The composition of house hold waste is such that rapid decomposition takes place under most climatic 
conditions. Housekeeping should ensure that all containers used for handling waste and in areas where waste 
is stored and processed by composting are  adequately clean . 
4.1.4.1  Hous eholders should be strongly encouraged to wrap food and vegetable waste before disposal, if 
these are to be disposed into bins for collection by a waste collector.  
4.1.4.2  Waste containers for householders shall not be overfilled and shall be properly cove red at all times. 
The containers shall be immediately replaced once they are worn out to an extent of developing holes.  
4.1.5 The manual handling of containers should be minimized to achieve an economical and safe collection 
service. The collector should not normally be required to carry full individual waste containers for a distance of 
more than 25 m. Where this is non -applicable, the collector and local authority will dete rmine the appropriate 
distance.  
4.1.6  Communal waste containers shall be replaced at such a position so  as to allow access by collection 
vehicles. No waste shall be disposed outside the communal waste container even when the container is full.  
4.1.7  The local authority that is responsible for waste collection shall be consulted when the  communal waste 
container is about three -quarter full where it is provided . 
4.2 Waste collection  
 Waste collection  system  
Waste collection shall be understood in two ways:  
a) waste from households to transit sites /transfer stations/recycling centres  and from trans it sites /transfer 
stations/recycling centres  to landfill ; and 
b) from households and transp orted directly to the landfill.  
NOTE  The improved collection system  is composed of two main steps:  
a) primary collection; and  
b) secondary collection.  DRS 181: 2018  
3                ©RSB 2018  - All rights reserved  
 4.3 Waste storage modalities  
Before collection waste shall be well kept to avoid any hazard to people and to the environment  For that, different 
methods as per Annex A  shall be used to store waste and this depends strongly on the type of waste  and that 
of waste generator. I n any case, appropriates waste storage methods are to be used:  
a) plastic waste bags with single use that shall be put inside bin at the waste generation level;  
b) small bin that shall be used at the waste generation level; and  
c) big containers that shall be put at the waste storage level.  
4.4 Waste collection modalities  
4.4.1.1  The primary collection  
The primary collection  concerns the operation of waste collection from household level up to the collection 
point which shall be on the pre-collect ion centre  or on the transit site/transfer s tation/ recycling c entre . 
4.4.1.1.1  Door to door collection services  
Door to door collection service can in other terms be referred to as “road side collection” method. This  is a 
system where stored waste bags or waste bins  are put in front of the gates for the waste collectors to pick them 
on specified days and time. The two concerned parties agree  on the collection schedule so as to avoid points 
of conflict, and if any change, upon agreement, the concerned part y shall offi cially notify or communicate the 
change on schedules in place before 24 h.  
4.4.1.1.2  Corn er to corner c ollection s ervice  
This service concern s clients that generate a lot of waste such as hotels, restaurants, hostels, off ice buildings, 
shopping malls,  schools, business centres, and any other building holding different activities. Such premises 
shall have well located waste corners with an organized system of sorting and storage of waste, and located in 
places wh ich can easily be accessed by the collect ion truck.  
4.4.1.1.3  Container to container collection  
This method can be used in big places/institutions where there can be more than one container to be removed 
to transit sites/transfer stations. These containers sh ould be provided by the collector or by the inst itution. 
Appropriate trucks sh all be provided by the collector to remove containers in specified place (s) for unloading 
the container on transit site/transfer station/recycling centre before dumping.  
4.4.1.2  Secondary collection  
Secondary collection concerns trans portation of waste from the collection point/ transit ste/transfer 
station/ recycling centre to the dumpsite  or landfill or advanced recycling centres . 
4.4.1.2.1  Site to site collection s ervice  
Site to site collection s ervice is the type of collection where different waste collection transit sites shall be 
established and managed by individuals or in collaboration with the collector to make waste accessib le easily 
for the places that are not well organized. The main focus of such transit sites shall be on the waste mea nt for 
recycling either biodegradable or non biodegradable .  
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 4.4.1.2.2  Transfer station  to transfer station  
Waste can be picked from different transfer stations to landfill for time management and trucks volume  
optimization.  Therefore , transfer station is for advanced waste separation into recyclables and disposables so 
that from the transfer station, some waste can go to recycling centres and others to dumping site.  
4.4.1.3  Collection frequency  
4.2.3.3.1  According to the requirements of the competent authority , the collection company shall follow the 
set minimum standards regar ding waste collection frequency  including : 
a) waste from food makers like restaurants, bars and hotels should be collected daily;  
b) waste collection from the market should b e done daily; and  
c) waste collection from residential areas should be done at least once a week.  
4.2.3.3.2  Waste collection from institutions and office premises should  be done once or more than once a 
week according to the agreement between two parties . 
4.5 Transportation  
4.3.1  Transportation of domestic waste from waste generators to the disposal site shall be done in such a 
manner that prevents scattering of waste on the way.  
4.3.2 The transporter of such waste is responsible for clearing any waste off the road if, by accident such 
waste has been deposited along the road.  
4.3.3 For the safety and health of the waste -handler, waterproof hard -plastic gloves, gumboots and, where 
appropriate, respirators shall be provided . 
4.3.3  In planning  transportation of dom estic waste, current regulations as published in the Official Gazette  or 
by local authorities shall be referred to . 
5 Commercial solid waste  
5.1 Handling  
5.1.1  Commercial solid waste may be different or similar to household waste depending on type of trade. A 
catering service business produces waste that can largely be regarded as household waste and can be treated 
as such.  
5.1.2  This section deals with waste from offices and general trade activities, such waste as wrappers (plastics 
or paper), rubber, cans and m etals that are found on streets  thrown out by grocery, store owners and office 
workers.  
5.1.3  Each business entity or office shall have waste bins for solid waste. A disposal system shall also be 
instituted for such waste . 
5.1.4  Each entity is responsible for the waste it generates . 
5.1.5  In case of failure of an original disposal system, a back -up system shall be available . DRS 181: 2018  
5                ©RSB 2018  - All rights reserved  
 5.2 Transportation  
5.2.1  Commercial solid waste shall be transported in such a manner that no waste is disposed of along the 
haul distance . 
5.2.2 A collection schedule shall be designed in such a manner as to avoid over -accumulation of waster at 
any premises.  
5.3 Disposal  
The following disposal methods shall be employed where appropriate : 
a) sanitary land filling, this could  be: 
1) area sanitary land filling ; 
2) quarry sanitary land filling ; 
3) ramp sanitary land filling ; 
4) trench sanitary land filling ; and  
5) wet area sanitary land filling . 
b) Incineration ; 
c) hydrolysis ; and  
d) controlled tipping : pulverization or refuse baling could be done before controlled tipping to  maximize space.  
NOTE  Annex A shoul d also be referred to in deciding which disposal method to employ . 
6 Industrial solid waste  
6.1 Handling  
6.1.1  Solid waste generated in manufacturing and industrial processes may contain chemicals requiring 
analysis. It is recommended that such an analysis be done before disposal to determine the quality, nature and 
quantity of chemicals contained. A list of common chemicals found in solid waste from industries is given in 
Annex D.  
6.1.2  The handler of such waste shall wear complete protective garments that shall include heavy -duty 
industrial boots, water resistant overalls, respirator and waste -resistant hand gloves.  
6.1.3  The containers of such waste shall not be over -filled to avoid inappropriate dispersal of waste. Such 
containers shall be clearly labelled to indicate the nature of waste.  
6.1.4  Written procedures shall be readily available for all workers for waste handling.  
6.1.5  Every sub-section that is a waste generator shall h ave its own waste r eceptacles . 
6.2 transportat ion 
6.2.1  Industrial solid waste may contain toxic chemicals and other substrates hazardous to human health, 
the environment and wildlife. This entails a more stringent transportation procedure that shall be adhered to at 
all times.   
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 6.2.2  It is the duty of  the waste generator to make sure that no loss of waste occurs within the haul distance. 
In the event of the dispersal of waste within the haul distance, the transporter shall immediately clean -up the 
waste.  
6.2.3  Containers for such waste shall be properl y marked and/or colour coded. It is required that different 
chemical waste be contained in separate containers. These can however, be transported by the sane vehicle.  
6.2.4  A licence for transportation and disposal of such waste shall be obtained  as per the prevailing 
regulations.  
6.3 Disposal  
The disposal method outlined in 5.3 apply. Details described in Table B 2 may also assist in choice of  disposal 
method.  
7 Environment m anagement  
7.1 Businesses are encouraged to put in place Environmental Management Systems at all industries 
according to RS ISO 14001 . 
7.1 Audits should be conducted by  relevant authorities to assess environmental performance for industries.  DRS 181: 2018  
7                ©RSB 2018  - All rights reserved  
 Annex  A 
(normative)  
 
Methods of hous eholds refuse treatment  
A.1 Disposal  
A.1.1  Methods of household refuse disposal and with respective advantages and disadvantages are 
summarized in Table A.1: 
Table A 1  — Methods, advantages and disavantages of refuse treatment  
Method  Advantages  Disadvantages  
Controlled tipping  Provides means of  
land reclamation   May i nvolve increased transportation  
 Amenity damage  
Pulverization  
before  
controlled tipping   Higher density in tip  
 Less subsequent settlement  
 Less top covering requirement  
 More acceptable near housing  
 Recovery of metals possible   Higher cost  
 Additional processing plant required  
 Odour nuisance  
Refuse baling  
before  
controlled tipping   As for pulverization -maximum  
 use of tipping space  As for pulverization  
Separation  
  Recovers many valuables such 
as metals, glass and refuse -
derived fuels (RDF).  
 Products relatively clean.  
 Maximized resource conservation  High cost suitable outlets required.  
Direct incineration  
   Large reduction in volume.  
 Limited energy (fuel) required  
 Ferrous metal extraction possible 
from clinker.  
 Further extraction of alumini um 
and copper possible.  
 Allows use of waste heat.  
 Mixed refuse and sewage sludge 
can be treated.   High installation and maintenance costs.  
 Pockets of unmixed waste in the firebed disrupt burning 
control.  
 Expensive flue gas cleaning necessary.  
 Recovery limited to non -combustibles.  
 Corrosion problems with waste -heat utilization.  
Composting  
 Refuse can be composted with 
sewage sludge, attractive  in areas 
where soil humus is depleted.   Expensive, and leaves a proportion to be tipped  
 Metal content of compost may limit its use  
Pyrolysis  
  No air pollution.  
 Greater recycling of waste  
 metal extraction processes  
 applicable  
 Gaseous, liquid and solid  
by-product fuels produced in excess of  
process requirement.  
 Other chemical by products 
available from condensate.   High installation cost.  
 Special site requirement  
 Viable by -product outlets needed.  
Hydrolysis   Suitable for refuse with high 
paper content  
 Producing sugars, protein, yeast, 
etc for recovery  Only theoretical exercises and small pilot projects on special 
trade wastes at present.   
©RSB 2018 - All rights reserved                  8 
 A.1.2  The choice of a disposal method should always take into account the following e xisting legislation and 
by-laws:  
a) safety of people and animals;  
b) environmental conservation; and  
c) cost and applicability.  
A.1.3  Where  the waste generator or handler is in doubt, the local authority or appropriate organization shall 
be consulted.  
A.2 A.2 Recovery materials from household refuse  
A.2.1  In the investigation of ways of recover y of valuable materials from household refuse it is important to 
identify what is available for recovery.  Two broad categories are employed which are material and energy.  
A.2.2  A detailed qualitative composition of household refuse is here given for guidance:  
A.2.2.1  Dust and cinder  
Ash, soil, stones, sweepings, crockery, glass, dust.  
A.2.2.2  Vegetables and putrescible  
Fruit and vegetable waste, meat waste, bones garden waste, wood  
A.2.2.3  Paper  
Newsprint, magazines, books, ca rdboard, waxed board, pac kaging  
A.2.2.4  Metal  
Food and beverage cans, bottle tops, foil, foil containers, toy, discarded household items, electrical discards, 
discarded consumer durables, batteries, car spares, wire, nails, screws, nuts and bolts.  
A.2.2.5  Rag and textile  
Clothing of natural or synthetic fibre, carpet, rags, and leather.  
A.2.2.6  Glass  
Whole bottles, broken glass, white/brown or green glass, discarded household  items (usually broken).  
A.2.2.7  Plastic  
Film packaging, containers, sponges, buttons, toys, consumer durabl es, house durables, household items, 
clothing, footwear, rubber.  
Alternatives available for resource recovery from household refuse are summarized in Annex B below.  
 DRS 181: 2018  
9                ©RSB 2018  - All rights reserved  
 Annex  B 
(normative)  
 
Methods of households refuse treatment  
Table  B 2 — Alternative resource recovery from refuse  
Alternative  Methods  
Unprocessed waste  Energy recovery (followed by D)  
Direct by incineration  
Indirect by pyrolysis to a gas, liquid and solid fuel  
Indirect by landfill to give methane by anaerobic decomposition  
Primary physical separation into organic and 
inorganic fractions  Dry separation  
Wet separation  
Secondary physical separation of organic fraction.  Paper fibre recovery  
compos ting to give humus  
Plastic recovery  
Secondary physical separation of inorganic fraction  Ferrous metal recovery  
Non-ferrous metal recovery  
Total and individ ual, copper, aluminium and zinc  
Glass recovery, total and by colour -clear, green, brown  
Thermal processing of organic fraction  Incineration for heat recovery  
Use of coal substitute -REF (refuse derived fuel)  
Pyrolysis to gas, liquid and solid fuel/chemicals  
Chemical processing of organic fraction  Hydrogenation: pyrolysis in a hydrogen atmosphere  
Gasification by partial oxidation or stream reforming; adaption of 
pyrolysis and natural  gas manufacture  
Oxidation in aqueous medium to organic acids  
Hydrolysis to sugar  
Biological processing of organic fraction  Hydroly sis and fermentation to ethanol  
Hydrolysis a nd fermentation to yeast -single cell protein  
Anaerobic digestion to methane  
Energy recovery from household refuse has several procedures each with its respective advantages and 
disadvantages. Information in Annex C can  offer a guide in deciding which pr ocess to utilize in recovering energy 
from household refuse.  
  
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 Annex  C 
(informative)  
Energy recovery refuse  
Table C 3 — Methods, advantages and disavantages of energy recovery refuse  
Method  Advantages  Disadvantages  
Incineration with heat 
recovery   Good method for district heating.  
 Higher burn -out efficiencies can be 
expected with prepared fuel (RDF) than 
with unprepared refuse.  
 Commercially available plant.  
 Can be developed to air conditioning 
system  
 High volume -reduction of refuse  
 Sterile char   Corrosion of boiler tubes at high steam 
temperatures  
 Steam flow not sufficiently dependable to run 
power plant auxiliary systems  
 High initial costs  
 Slagging of heat exchange surface can give 
high cleaning costs and downtime  
 Pollution problems.  
Incineration with 
electricity generation   Total electric power production 
package available  
 Good overall system efficiency  
 Possible revenue from material 
recovery  
 High volume -reduction  of refuse  
 Sterile char   Serious technical problems with gas clean -up 
before turbine  
 New electrical  ge neration equipment required  
 Very high initial and running costs  
 Other problems as (a)  
Pyrolysis to give oil, 
gas and char   Oil can be used in conventional boiler 
with minor modifications  
 Existing power plant can be used  
 Higher – value products than 
incineration  
 Front – or back – end resource recovery 
options may be included  
 High volume – reduction of refuse and 
sterile char  
 Overall disposal cost claimed to be less 
than landfill   Technology unproven  
 Problems with corrosiveness and storability of 
hydrol ytic oil  
 High initial and operating cost  
 Costly feed preparation  
 Waste – Water disposal problem  
Pyrolysis to give gas 
and char/slag 
(gasification)   Produces low to medium heating – 
Value gas  
 Feed preparation not essential, 
although preferred  
 Existing power  plan can be used  
 Fairly high overall system efficiency  
 Higher -value products than with 
incineration  
 Fuel gas usable in most boiler types  
 Technology more advanced than (c)  
 Front – back -end resource recovery 
options may be included  
 Gas may be employed as chemical 
feedstock  
 High volume – reduction and sterile 
char  Potential plugging of slug  
 Fuel gas not compatible with natural gas 
without additional processing/expenditure  
 Storage of fuel not viable  
 High initial and operating cost  
 Unproven viability  
 Waste -water disposal problem  
 Low heating value of gas necessitates local 
use 
Soiled fuel preparation 
as RDF   Gaining acceptance by manufacturers 
and users  
 Existing facilities can be used with 
minor modification to generate steam or 
electricity  
 Revenue from other recovered 
materials  
 High overall system efficiency   Low bulk density of unprepared refuse makes 
storage difficult  
 Potential increase in particulate  loading and 
pollution  
 Densifying  and pelletizing  equipment still 
presents problems  
 High costs and unproven viability  DRS 181: 2018  
11                ©RSB 2018  - All rights reserved  
  Relatively low costs RDF improves 
storage and handling  
 Largely proven technology  
 Plant available commercially  
Anaerobic digestion to 
give methane   Existing steam or electricity generation 
plant can be used  
 Revenue from other recovered 
materials possible  
 Product compatible with SNG after 
carbon dioxide removal.   Sensitive to moisture and oxygen environment  
 Very low overall system efficiency  
 Product contaminated with carbon dioxide 
which requires separation  
 Reaction rates very low, requiring large 
reactors and long residence times  
 Residue disposal problem unless landfill is 
employed  
Fermentation to 
chemicals   Revenue from other recovered 
materials possible  
 Technology well developed  
 High-value products recovered   Sensitive to contamination  
 High energy  costs in purification from an 
aqueous base  
 High costs  
 Residue disposal problem  
 Viability doubtful   
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 Annex  D 
(informative)  
 
Pollutants and their sources  
Table D.3 provides details on pollutants and their sources as follows:  DRS 181: 2018  
13                ©RSB 2018  - All rights reserved  
  
 
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DRS 181: 2018  
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Key:  
G   Pollutant occurs as a gas; 
L   Pollutant occurs as a liguid;  
S   Pollutant occurs as a solid;  
P   Pollutant occurs in particulate form;  
A   Pollutant occurs in aqueous solution or suspension.  
 
DRS  182: 2018  
ICS 13.030.10  
 
 
©RSB 2018 - All rights reserved