UGANDA STANDARD  
  US 201
Second Edition
2008 -09-08
 
 
Reference numbe r
US 201: 2008
 © UNBS 2008 
  
Drinking (potable) water — Specification  
 US 201: 2008 
ii © UNBS 2008 – All rights reserved
 Compliance with this standard does not, of itself confer immunity from legal obligations 
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2008 
All rights reserved. Unless otherwise sp ecified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, in cluding photocopying and microf ilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala  
Uganda 
Tel: 256 414 505995 
Fax: 256 414 286123 
E-mail: unbs@infocom.co.ug
Web: www.unbs.go.ugUS 201: 2008 
© UNBS 2008 – All rights reserved  iii
 Contents Page 
Foreword ............................................................................................................................................................iv  
1 Scope.......................................................................................................................... ............................1  
2 Normative re ferences........................................................................................................... .................1  
3 Terms and de finiti ons .......................................................................................................... .................3  
4 Requirements................................................................................................................... ......................4  
4.1 Factors affecting orga noleptic and physical  characteristics ...........................................................4  
4.2 Chemical requirements .......................................................................................................... ...............4  
4.3 Microbiological requirements ................................................................................................... ...........9  
5 Water safety  plans............................................................................................................. ....................9  
6 Surveilla nce ................................................................................................................... ......................10  
6.1 General surveillan ce requir ements .............................................................................................. .....10  
6.2 Sampling requi rements.......................................................................................................... .............11  
6.3 Parameters required for minimum moni toring.................................................................................11  
Annex A (informative)  R ecommended test  methods................................................................................ ...13 
Bibliography................................................................................................................... ...................................14  
 US 201: 2008 
iv © UNBS 2008 – All rights reserved
                                                      Foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry  of Tourism, Trade and 
Industry established under Cap 327, of the Laws of Uganda.  UNBS is mandated to co-ordinate the 
elaboration of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex A limentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agre ements of the World Tr ade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a given field or area and  consists of representatives of 
consumers, traders, academicians, manufactur ers, government and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committ ee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda St andards by the National Standards Council. 
This Uganda Standard (US 201) was first declared a national standard in 1994 and it has now been 
technically revised to update it in accordance with developments in the sector. This is in line with new 
guidelines of the World Health Organisation (WHO) and other market requirements. The standards also takes 
into consideration the various types of potable wate r available in Uganda including the water which is 
conventionally treated and water made available for rural water consumers through boreholes, protected 
springs, shallow wells, gravity flow schemes and harv ested rain water which may be used for consumption in 
accordance with the guidelines provided by the Directorate of Water Development (DWD).  
The standard has also undergone a stru ctural change in editorial style. 
Annex A is for information only. 
Committee membership1) 
The following organisations were represented on the Technical Committee on Food and agriculture standards, 
UNBS/TC 2, in the development of this standard: 
• Blue wave Beverages Limited 
• Consumer Education Trust (CONSENT) 
• Directorate of Water Development 
• Government Analytical Laboratories 
• House of Eden Limited 
• Ministry of Agriculture Animal Industr y and Fisheries (Fisheries Department) 
• Ministry of Health 
• Mukwano Industries Limited 
• NC Beverages Limited 
• Rwenzori Beverages Limited 
• Uganda National Bureau of Standards 
 
 
1) Does not include of members who were responsible for the development of First edition of 1994 UGANDA STANDARD US 201: 2008
 
©  U N B S  2 0 0 8 –  A l l  r i g h t s  r e s e r v e d                 1  
 Drinking (potable) water — Specification 
1 Scope 
1.1 This Uganda Standard prescribes the quality and safety  requirements for drinking (potable) water. It 
also lays down the factors required during surveillance of water sources to ensure that the quality and safety 
of water is maintained. 
1.2 It describes two classes of drinking water: 
a) Class I potable water available from conventional treatment processes such as chlorination, filtration, 
and ozonation; and used in food establishments or dist ributed through the water distribution systems. 
This water is comparable to current international st andards for water quality. This water is considered 
to be acceptable for lifetime consumption, and is the recommended compliance limit.  
b) Class II (untreated water) potable water availabl e for water consumers through boreholes, protected 
springs, shallow wells, gravit y flow schemes and harvested rain water which may be used for 
consumption in accordance with the guidelines provided by the Directorat e of Water Development 
(DWD).  This class specifies a water quality range that poses an increasing risk to consumers 
depending on the concentration of the determinant within the specified r ange and the possibility of 
monitoring its quality. It is considered to represent  drinking water for consumption for a limited period. 
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 document (including any amendments) applies. 
US ISO 5664, Water quality — Determination of ammonium — Distillation and titration method 
US ISO 5666,  Water quality — Determination of mercury 
US ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes  
US ISO 5667-2, Water quality — Sampling — Part 2: Guidance on sampling techniques 
US ISO 5667-3, Water quality — Sampling — Part 3: Guidance on preservation and handling of water 
samples 
US ISO 5667-4, Water quality – Sampling – Part 4: Guidance on sampling from lakes, natural and man-made.  
US ISO 5667-5, Water quality — Sampling — Part 5: Guidance on sampling of drinking water from treatment 
works and piped distribution systems 
US ISO 5667-6, Water quality — Sampling — Part 6: Guidance on sampling of rivers and streams 
US ISO 5667-11, Water quality — Sampling — Part 11: Guidance on sampling of groundwaters 
US ISO 5961 , Water quality — Determination of cadmium by atomic absorption spectrometry US 201: 2008 
2 © UNBS 2008 – All rights reserved
 US ISO 6058, Water quality — Determination of calc ium content — EDTA titrimetric method 
US ISO 6059,  Water quality — Determination of the sum of calcium and magnesium — EDTA titrimetric 
method 
US ISO 6222 , Water quality — Enumeration of culturable micro- organisms — Colony count by inoculation in a 
nutrient agar culture medium 
US ISO 6332,  Water quality — Determination of iron — S pectrometric method using 1,10-phenanthroline 
US ISO 6333,  Water quality — Determination of mangane se — Formaldoxime spectrometric method   
US ISO 6703-1,  Water quality — Determination of cyanide — Part 1: Determination of total cyanide  
US ISO 6703-3 , Water quality — Determination of cyanide — Pa rt 3: Determination of cyanogen chloride 
US ISO 6777, Water quality — Determination of nitrite — Molecular absorption spectrometric method 
US ISO 7027, Water quality — Determination of turbidity  
US ISO 7393-1 , Water quality — Determination of free chlorine and total chlorine — Part 1: Titrimetric method 
using N,N-diethyl-1,4-phenylenediamine 
US ISO 7887, Water quality — Examination and determination of colour  
US ISO 7888 , Water quality — Determination of electrical conductivity 
US ISO 7890-3 , Water quality — Determination of nitrate — Part  3: Spectrometric met hod using sulfosalicylic 
acid 
US ISO 7980, Water quality — Determination of calcium and magnesium — Atomic absorption spectrometric 
method 
US ISO 8199,  Water quality — General guidance on the enumeration of micro-organisms by culture 
US ISO 8288, Water quality — Determination of cobalt, nickel, copper, zinc, cadmium and lead — Flame 
atomic absorption spectrometric methods  
US ISO 9174, Water quality — Determination of chromium — Atomic absorption spectrometric methods  
US ISO 9308-2, Water quality — Detection and enumeration of coliform organisms, thermotolerant coliform 
organisms and presumptive Escherichia coli — Part 2: Multiple tube (most probable number) method  
US ISO 9390, Water quality — Determination of borate — Spectrometric method using azomethine-H  
US ISO 9964-1, Water quality — Determination of sodium and pota ssium — Part 1: Determination of sodium 
by atomic absorption spectrometry 
US ISO 9965,  Water quality — Determination of selenium — At omic absorption spectrometric method (hydride 
technique)  
US ISO 10304-1 , Water quality — Determination of dissolved fl uoride, chloride, nitrite, orthophosphate, 
bromide, nitrate and sulfate ions, using liquid chromatography of ions — Part 1: Method for water with low 
contamination 
US ISO 10359-2, Water quality — Determination of fluoride — Part 2: Determination of inorganically bound 
total fluoride after digestion and distillation 
US ISO 10523 , Water quality — Determination of pH US 201: 2008 
© UNBS 2008 – All rights reserved  3
 US ISO 10566,  Water quality — Determination of aluminiu m — Spectrometric method using pyrocatechol 
violet 
US ISO 10705-2 , Water quality — Detection and enumeration of  bacteriophages — Part 2: Enumeration of 
somatic coliphages 
US ISO 11423-1,  Water quality — Determination of benzene and so me derivatives — Part 1: Head-space gas 
chromatographic method 
US ISO 11423-2 , Water quality — Determination of benzene and some derivatives — Part 2: Method using 
extraction and gas chromatography 
US ISO 11885,  Water quality — Determination of 33 elements by inductively coupled plasma atomic emission 
spectroscopy 
US ISO 11969 , Water quality — Determination of arsenic — Atom ic absorption spectrom etric method (hydride 
technique) 
US ISO 12020, Water quality — Determination of aluminium — Atomic absorption spectrometric methods 
US ISO 14403, Water quality — Determination of total cyanide and free cyanide by continuous flow analysis 
US ISO 15061, Water quality — Determination of dissolved br omate — Method by liquid chromatography of 
ions 
US ISO 15553,  Water quality — Isolation and identification of Cryptosporidium oocysts and Giardia cysts from 
water 
US ISO 16590, Water quality — Determination of mercury — Methods involving enrichment by amalgamation 
3 Terms and definitions  
For the purposes of this standard, the following terms and definitions shall apply. 
3.1 
approved water supply 
source of water that has been inspected and approved  by the competent authori ty for the intended purpose 
3.2 
water distribution system  
public or private water systems providing consumers with tap water suitable for direct consumption 
3.3 
treated water 
water that is conventionally treated usually by coagulation, sedimentatio n, filtration, and disinfection and 
distributed through a wate r distribution system 
3.4 
untreated/rural water 
water that is either mined or harvested from natural sources without any conventional treatment applied to it 
such as borehole water, spring water, shallow wells, or harvested rainwater 
3.5 
conventional treatment 
collection, storage and distribution of drinking water invo lving deliberate coagulation, sedimentation, filtration, 
and disinfection to improve the safety and quality of the finished drinking water for consumers US 201: 2008 
4 © UNBS 2008 – All rights reserved
 3.6 
potable 
water which is suitable for human consumption 
4 Requirements  
4.1 Factors affecting organoleptic and physical characteristics 
Drinking water shall conform to the requirements for factors affecting organoleptic and physical  characteristics 
corresponding to a given class indicated in Table 1. 
Table 1 — Requirements for factors affecting organoleptic and physical characteristics 
Requirement levels Characteristic  
Class I Class II Method of test  
Colour  15 true colour units (TCU) 15 true colour units (TCU) US ISO 7887 
Taste  Acceptable to consumers and no 
abnormal changes Acceptable to consumers and 
no abnormal changes - 
Odour Acceptable to consumers and no 
abnormal changes Acceptable to consumers and no abnormal changes Annex A 
Electrical conductivity, at 25 
oC 1500 μS/cm 2500 μS/cm US ISO 7888 
pH 5.5 – 8.5 6.5 – 8.5 US ISO 10523 
Turbidity 5 Nephelometric Turbidity Units 10 Nephelometric Turbidity 
Units US ISO 7027
Total dissolved solids (TDS) 500 mg/L 1 500 mg/L Annex A 
Iron  0.2 mg/L  1 mg/L US ISO 6332,
Ammonia 0.5 mg/L 1.0 mg/L US ISO 5664 
Aluminium 0.2 mg/L 0.2 mg/L US ISO 10566  US 
ISO 12020 
Potassium as K, mg/l, max. 50 100 US ISO 9964-1 
Sodium as Na, mg/l, max. 200 mg/L 400 mg/L US ISO 9964-1 
Chloride 250 mg/L 500 mg/L US ISO 10304-1 
Magnesium 100 mg/L 150 mg/L US ISO 6058, US 
ISO 6059 
US ISO 7980 
 
4.2 Chemical requirements 
Drinking water shall conform to the maximum limits for chemicals of health significance in drinking water as 
indicated in Table 2, Table 3, Table 4 and Table 5. 
NOTE  Safety factors indicated in Table 3, Table 4 and Table 5 apply to both Class I and Class II. US 201: 2008 
© UNBS 2008 – All rights reserved  5
 Table 2 — Requirements for naturally occurring chemicals 
Maximum limit, 
mg/L Chemical 
Class I Class II Method of test 
Arsenic 0.01  calculated as total As 0.05 FDUS ISO 11969
Barium 0.7 1.0 Annex A 
Boron 1.0  US ISO 9390,
Chromium 0.05  calculated as total Cr. 0.05 US ISO 9174 
Fluoride 1.0 1.5 US ISO 10359-2 
Manganese 1.0 0.1 US ISO 6333 
Molybdenum 0.07  Annex A 
Selenium 0.01 0.01 US ISO 9965 
Uranium 0.015 0.015 Annex A 
Mercury 0.001 0.001 US ISO 16590 
 US 201: 2008 
6 © UNBS 2008 – All rights reserved
 Table 3 — Requirements for chemicals used in water treatment2) 
Chemical Required limit, max, 
mg/L Method of test 
Acrylamide  0.0001 * 
Antimony 0.005 Annex A 
Benzo[a]pyrene 0.0001 *
 
Bromate 0.01 US ISO 15061
Bromodichloromethane 0.06 * 
Bromoform 0.1 *
 
Chlorate 0.7 *
 
Chlorine  5 US ISO 7393-1
Chlorite 0.7 *
 
Chloroform 0.3 *
 
Copper 2 US ISO 8288 
Cyanogen chloride 0.07 US ISO 6703-3
Dibromoacetonitrile 0.07 *
 
Dibromochloromethane 0.1 *
 
Dichloroacetate 0.05 *
 
Epichlorohydrin 0.0001 *
 
Lead 0.01 US ISO 8288 
Monochloroacetate 0.02 *
 
Monochloroamine 3 *
 
Nickel 0.02 US ISO 8288 
Trichloroacetate 0.2 *
 
Trichlorophenol, 2,4,6- 0.2 *
 
Trihalomethanes3, total 0.1 *
 
Vinyl chloride 0.0003 *
 
* Methods of test of the ASTM or APHA may be used (see Annex A) 
 
                                                      
2) Includes disinfectants, disinfections by products, contaminants from treatment  chemicals and contaminants from pipes 
and fittings 
3) Trihalomethanes (bromoform, bromodichlorome thane, dibromochloromethane, chloroform) are formed in drinking-water primarily as a  
result of chlorination of organic matter present naturally in raw water supplies. US 201: 2008 
© UNBS 2008 – All rights reserved  7
 Table 4 — Requirements for residues of agricultural chemicals  
Chemical Maximum limit, mg/L, 
Max. Remarks 
Alachlor  0.02 a)
 
Aldicarb 0.01 Applies to aldicarb sulfoxide 
and aldicarb sulfone 
Aldrin and dieldrin 0.00003 For combined aldrin plus 
dieldrin 
Atrazine 0.002 a)
 
Chlordane 0.0002 Currently 0.0003 
Chlorpyrifosb)
 0.03 a)
 
Chlorotoluron 0.03 a)
 
2,4-D (2,4-
dichlorophenoxyacetic 0.03 Applies to free acid acid) 
2,4-DB 0.09 a)
 
DDT and metabolites b)
 0.001 a)
 
Dichlorprop 0.1 a)
 
Dimethoate 0.006 a)
 
Endrin 0.0006 a)
 
Fenoprop 0.009 a)
 
Isoproturon 0.009 a)
 
Lindane 0.002 a)
 
MCPA 0.002 a)
 
Mecoprop 0.01 a)
 
Methoxychlor 0.02 a)
 
Metolachlor 0.01 a)
 
Molinate 0.006 a)
 
Nitrate (as NO 3) 50 Short-term exposure 
3 Short-term exposure 
Nitrite (as NO 2) 
0.2 Long-term exposure 
Permethrin b)
 0.3 Only when used as a larvicide 
for public health purposes 
Pyriproxyfen b)
 0.3 a)
 
Simazine 0.002 a)
 
2,4,5-T 0.009 a)
 
Terbuthylazine 0.007 a)
 
Trifluralin 0.02 a)
 
a) Methods of test of the ASTM or APHA may be used (see Annex A)  
b) Chemicals used in water for public health purposes  such as treatment  of mosquito nets and 
 larvicidal effects on water surfaces  US 201: 2008 
8 © UNBS 2008 – All rights reserved
 Table 5 — Requirements for chemicals from industrial sources  
Chemical Maximum limit, mg/L, 
Max. Remarks 
Benzene 0.001 US ISO 11423-1  US ISO 
11423-2
Cadmium 0.003 US ISO 5961   
US ISO 8288 
Carbon tetrachloride 0.004 *
 
Cyanide  0.07 US ISO 14403
Di(2-ethylhexyl)phthalate 0.008 *
 
Dichlorobenzene, 1,2- 1 *
 
Dichlorobenzene, 1,4- 0.3 *
 
Dichloroethane, 1,2- 0.03 *
 
Dichloroethene, 1,2- 0.05 *
 
Dichloromethane 0.02 *
 
Dioxane, 1,4- 0.05 *
 
Edetic acid (EDTA) 0.6 Applies to the free acid 
Ethylbenzene 0.3 *
 
Hexachlorobutadiene 0.0006 *
 
Nitrilotriacetic acid (NTA) 0.2 *
 
Pentachlorophenol 0.009 *
 
Styrene 0.02 *
 
Tetrachloroethene 0.04 *
 
Toluene 0.7 *
 
Trichloroethene 0.02 *
 
Xylenes 0.5 *
 
* Methods of test of the ASTM or APHA may be used (see Annex A) 
 
Table 6 — Requirements of radioactive matter in drinking water 
Total radioactivity present in the form of Maximum limit 
Total beta activity (except K40 and H3) *
 1 Bq/L 
Total alpha activity 0.5 Bq/L 
*
 The contribution of potassium-40 to beta acti vity shall be calculated using beta activity 
 of 27.6 Bq/g of stable potassium and subtract ed from total beta activity. If beta activity 
 levels are higher than 1 Bq/Ll after adjus ting for potassium-40 beta activity due to 
 tritium shall be determined and shall not exceed 100 Bq/L.. 
 US 201: 2008 
© UNBS 2008 – All rights reserved  9
 4.3 Microbiological requirements 
Drinking water shall conform to the maximum microbiological limits given in Table 7. 
Table 7 — Maximum microbiological limits of drinking water 
Allowable compliance limits and 
contribution of samples, 
% a)
 Microorganism 
Minimum 
95%. Maximum of 
4% of 
samples,  Maximum of 
1% of 
samples  Method of test 
Heterotrophic plate count, 
count/mL 100 1 000 10 000 US ISO 6222 
Total coliform bacteria count b)
, 
count/100 mL Not detected 10 100 
E. coli, count b)
,/100 mL Not detected Not detected 1 US ISO 9308-2 
Clostridium perfringens (including viable  spores), count/100 mL Not detected Not detect ed Not detected Annex A 
Somatic coliphages count, count/10 mL  Not detected 1 10 US ISO 10705-2
Enteric viruses count, count/100 L Not detected 1 10 Annex A 
Protozoan parasites (Giardia/Cryptosporidium) count, 
count/ 10 L Not detected Not detected 1 US ISO 15553 
a)
, The allowable compliance contribution shall be at least 95 % of the samples to conf orm to the limits of 100 
CFU/mL, and  a maximum of 4 % and 1 % of samples, re spectively, to conform to the limits of 1000 CFU/mL 
and 10 000 CFU/mL. The objective of disinfection should, nevertheless, be to attain 100 % compliance to the 
limit of 100 CFU/100mL. 
b), In most instances it will not be necessary to conduct both these tests; one or the ot her will normally suffice as 
the required indicator. 
5 Water safety plans 
5.1 Drinking water systems operators s hall develop, implement and maintain a water safety plan taking into 
consideration the potential risks to the safety of t he water from the supply catchments to the consumer. 
5.2 A water safety plan shall consist of three key components:  
a) system assessment to determi ne whether the drinking-water su pply chain (up to the point of 
consumption) as a whole can deliver water of  a quality that meets health-based targets; 
b) identifying control measures in a drinking water sy stem that will collectively control identified risks and 
ensure that the health-based targets are met; and 
c) management plans describing actions to be taken during normal operation or incident conditions and 
documenting the system asse ssment (including upgrade and im provement), monitoring and 
communication plans and supporting programmes.  
5.3 A water safety plan shall include:  
a) measures to protect the source of drinking water from risks of pollution; US 201: 2008 
10 © UNBS 2008 – All rights reserved
 b) measures to ensure all installations intended for the production of drinking water exclude any 
possibility of contamination. For this purpose and in particular: 
• the installation for collection, the pipes and the reservoirs shall be made from materials suited 
to the water and in such a way as to prevent t he introduction of forei gn substances in water; 
• the equipment and its use for production, especially installation for washing and packaging, 
shall meet hygienic requirements; 
c) measures to ensure an appropriate treatment su ch as pretreatment coa gulation, flocculation, 
sedimentation, filtration and disinfection are unde rtaken to assure the safety of water for the 
consumers; 
d) appropriate operational monitoring system includ ing monitoring parameters that can be measured and 
for which limits have been set to define the operati onal effectiveness of the activity; frequency of 
monitoring and  procedures for corrective action t hat can be implemented in response to deviation 
from limits. If, during production it  is found that the water is pollu ted, the producer shall stop all 
operations until the cause of pollution is eliminated; and 
e) a verification plan to ensure that individual co mponents of a drinking-water system, and system as a 
whole is operating safely. 
6 Surveillance 
6.1 General surveillance requirements 
Drinking-water suppliers shall ensure, at all times, the qua lity and safety of the water t hat they produce. Public 
health surveillance (that is, surveillanc e of health status and trends) contri butes to verifying drinking-water 
safety. 
Adequate infrastructure, proper monitoring and effective planning and management; and a system of 
independent surveillance are basic and essential requir ements to ensure the safety of drinking-water. 
Surveillance shall cover the total supply network from t he source of untreated water to the consumer delivery 
points.  
A sampling programme that takes into consideration appropriate international recommendations shall be established and implemented. The sampling shall be regular and its frequency shall mainly depend on the 
following factors 
a) quality of water harnessed including effects on the water from climatic, human and industrial activities; 
b) type of treatment for drinking worthiness; 
c) volume of water processed; 
d) risks of contamination; 
e) background of public water supply network; 
f) population served; and  
g) capabilities of the analytical facility (both in term s of capacity and in terms of analytical performance). US 201: 2008 
© UNBS 2008 – All rights reserved  11
 6.2 Sampling requirements 
The recommendations given in US ISO 5667-1 shall be us ed as the basis for the establishment of a sampling 
programme, and the recommendations given in US IS O 5667-2, US ISO 5667-3, US ISO 5667-4, US ISO 
5667-5, US ISO 5667-6 and US ISO 5667-11 shall be used as the basis for implementing the sampling 
programme. 
In the absence of a formally established sampling programme, the minimum sampling frequency given in 
Table 8 shall be used as an interim measure. 
Table 8 — Minimum frequency of sampling of water for surveillance 
Population served Frequency *
 (minimum) of sampling 
More than 100 000 10 samples every month per 100 000 of population 
served 
25 001 – 100 000 10 samples every month 
10 001 – 25 000 3 samples every month 
2 500 – 10 000 2 samples every month 
Less than 2 500 1 sample  every month 
* During the rainy season, sampling should be carried out more frequently  
 
6.3 Parameters required for minimum monitoring 
It is recognized that, in many instances, the cost of performing a full analysis against Table 1, Table 2, Table 
3, Table 4, Table 5, Table 6 and Table 7 can be prohibitive.  
Analysis of the parameters in Table 9 may be deemed acceptable for the purpose of indicating ongoing levels 
of operational efficiency in a water treatment plant. US 201: 2008 
12 © UNBS 2008 – All rights reserved
 Table 9 — Parameters for surveillance of drinking water safety 
Property Methods of test 
Physicochemical: 
 Conductivity, or dissolved solids 
 Colour 
 Turbidity; 
 Taste 
 Odour  
 
 
See Table 1  
Microbiological 
 Faecal coliform bacteria or E. coli ; 
 Clostridium perfringens 
 Heterotrophic plate count  
 
See Table 7 
Chemical  
 Fluoride as F- 
 (Nitrate and nitrite) as N 
 pH value 
 Aluminum 
 
 Iron 
 Ammonia 
 Appropriate residual treatment chemicals  and 
disinfectants See Table 2  
DUS/ ISO 10304-1
See Table 1  
DUS/ ISO 10566
DUS/ ISO 12020 
DUS/ ISO 6332,
DUS/ ISO 5664 
If abnormal results are encountered in any of these analyses, sampling frequency shall be increased and/or 
additional analyses carried out. 
NOTE A consumer complaints register for the aesth etic qualities of the water should be maintained. US 201: 2008 
© UNBS 2008 – All rights reserved  13
 Annex A 
(informative) 
 
Recommended test methods 
A.1 General 
The test methods listed in Tables 1 - 7 are recommended 
A.2 ASTM standard test methods 
All the determinants for which the requirements are list ed in Tables 1-7 may be evaluated with the required 
accuracy, using ASTM  test methods (see bibliography). 
A.3 APHA-AWWA-WPCF test methods 
All the determinants for which the requirements are list ed in Tables 1 - 7 may be evaluated with the required 
accuracy, using the test methods given in the latest edition of Standard methods for the examination of water 
and wastewater  (see bibliography). US 201: 2008 
14 © UNBS 2008 – All rights reserved
 Bibliography 
[1] Annual book of ASTM standards 2003 – Section 11:  Water and Environmental Technology – Volume 
11.01: Water  (I). 
[2] Annual book of ASTM standards 2003 – Section 11: Water and Environmental Technology – Volume 
11.02: Water (II). 
[3] Standards methods for the examination of water and wastewater.  17th Ed., 1989, Washington, DC: 
American Public Health Association (APHA), Am erican Water Works Association (AWWA), Water 
Pollution Control Federation (WPCF). 
[4] Guidelines for Drinking-water Quality [electronic resource]: incorporating first addendum. Vol. 1, 
Recommendations. – 3rd ed., 2006, World Health Organization  
 
[5] SANS 241:2001, Drinking Water ─ Specification . South African Bureau of Standard 
 US 201: 2008 
©  U N B S  2 0 0 8 –  A l l  r i g h t s  r e s e r v e d                 1  
 Certification marking 
Products that conform to Uganda standards may be marked with Uganda National Bureau of Standards 
(UNBS) Certification Mark shown in the figure below.  
The use of the UNBS Certification Mark is gover ned by the Standards Act, and the Regulations made 
thereunder. This mark can be used only by those licens ed under the certification ma rk scheme operated by 
the Uganda National Bureau of Standards and in c onjunction with the relevant Uganda Standard. The 
presence of this mark on a product or in relation to a product is an assurance that the goods comply with the 
requirements of that standard under a system of supervision,  control and testing in accordance with the 
certification mark scheme of the Uganda Nationa l Bureau of Standards. UNBS marked products are 
continually checked by UNBS for conformity to that standard.  
Further particulars of the terms and conditions of  licensing may be obtained from the Director, Uganda 
National Bureau of Standards.  
 
 US 201: 2008 
 
 
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