Fact Sheet 7 Investigating Taste and Odour Complaints

WSAA Materials Facts Sheet No: 7 

Introduction 

WATER SERVICES ASSOCIATION 

of Australia 

An information sheet by the Water Services Association of Australia 

TACKLING TASTE AND ODOUR COMPLAINTS 

Taste and odours can be among the most common and difficult water quality complaints for water 

operators. Taste and odour problems may occur locally on an infrequent, occasional, seasonal or persistent 

basis. Similarly, they may arise from such diverse causes, and can be the result of such a wide variety of 

factors, that determining the cause of an episode may be extremely difficult. This information sheet the 

steps to follow for the call centre or help desk when dealing with the first point-of-contact of a customer 

complaint, usually over the phone. It provides advice in assessing the possible sources of the taste and 

odour problem and evaluating whether water sampling and further investigations are warranted. 

Terminology 

For convenience in this fact sheet, the person who receives the call is called the ‘Operator’. The person 

who makes the complaint is called the ‘Customer’. The water quality specialist, who would be called to 

investigate the complaint or take water samples from the customer’s property, is called a ‘Water Quality 

Technician’. The water authority, utility, company or council that is responsible for the water supply is 

called the ‘Water Agency’. The person responsible for the water supply and storage tanks servicing highrise 

residential complexes and office blocks is called the ‘Property Manager’. 

Tables 

The Table 1 lists common taste and odour complaints, questions to ask the Customer, possible causes and 

solutions, and whether it is necessary to transfer the complaint to a Water Quality Technician. Figure 1 

lists possible sources of tastes and odours in drinking water. Table 2 lists typical taste and odour 

descriptors. The Tables are by no means exhaustive, but will hopefully cover the most common examples 

of taste and odour complaints, and be adaptable to any complaint enquiry. 

Tastes and odours • storage tanks and reservoirs. 

Tastes and odours can be the result of natural or 

manmade conditions that exist anywhere within 

the total water supply system. The following 

have all been identified as sources of taste and 

odours: 

• raw water sources including seasonal or 

weather related effects, which affect 

stratification in dams and reservoirs, and 

run-off into dams, reservoirs and rivers, 

particularly after long periods of dry 

weather. 

• mixing of water from different sources e.g. 

groundwater and surface water. 

• water treatment processes, and in particular 

the amount of chlorine residual. 

Obsolete 

• the nature of distribution system, residence 

times and materials used in the distribution 

system. 

• consumer plumbing, including fixtures and 

appliances. 

• household rainwater tanks (poorly 

maintained). 

Regardless of the source of the taste and odour, 

it is often the Customer who will be the first to 

perceive the problem, usually in the kitchen 

and/or bathroom of their home, and complain to 

the Water Agency. A prompt response to these 

complaints is necessary to capture the episode 

and to reassure the customer that their water is 

safe to drink. 

Issue 1 Page 1 of 8 15 October 2003


Questioning the Customer • Customer needs reassuring – Customers 

Upon receipt of a Customer complaint it is 

important to record the Customer’s details and a 

full and accurate description of the complaint. It 

is necessary to ask pertinent questions to gain as 

much information about the complaint in the first 

instance. The questioning process should attempt 

to narrow down the extent and possible causes of 

the taste and odour complaint over the phone. 

The Operator should try to resolve the complaint 

without resorting to a site visit by a Water 

Quality Technician. 

Following questioning, if the Operator concludes 

that the cause of the complaint is attributable to 

the water being supplied to the property, it is the 

Water Agency’s responsibility to investigate the 

complaint further. Alternatively, if the complaint 

appears to be restricted to within the customer’s 

property, the operator may be able to suggest 

possible solutions or advise the Customer to 

employ a licensed plumber to rectify the 

problem. 

If the complaint cannot be resolved over the 

phone using the questions in the Table 1, or if 

the complaint is related to sickness, a Water 

Quality Technician should be notified to take 

samples and investigate the complaint further. 

Other factors to consider in reaching a decision 

to notify the Water Quality Technician include: 

• The number of complaints originating 

from the same area of the reticulation or 

distribution system – if several complaints 

are received from one area, the problem is 

likely to be the result of local conditions 

and investigations focussing on network 

conditions should be instigated by the 

Water Quality Technician. 

• Type of complaint – if the complaint is 

unusual, the Water Quality Technician 

should be advised to sample the Customer’s 

water. 

• The number of times a Customer has 

called previously – if a Customer calls 

because a complaint which was previously 

resolved over the phone has recurred, the 

Water Quality Technician should be 

requested to make a site visit. The potential 

for ongoing nuisance calls over complaints 

that have already been resolved necessitates 

early intervention. 

will occasionally still be worried about the 

safety and quality of their water even after 

the Operator has explained the most 

probable cause of their taste and odour 

complaint. Often a visit to the property will 

dispel any concerns they may still have, as 

well as act as a worthwhile public relations 

exercise within that Customer’s community. 

High-rise buildings 

Taste and odour problems in high-rise residential 

complexes and office blocks occur periodically. 

The problems can usually be sourced to the 

extensive length of water pipe within the 

building or the water storage tank on the roof of 

some of these complexes. Water plumbing 

infrastructure within these buildings is the 

responsibility of the Property Manager. Water 

storage tanks especially need regular inspection, 

testing and maintenance, Tanks should be 

operated to provide adequate cycling of water to 

prevent bacterial and ‘slime’ build-up, which can 

lead to unpleasant tastes and odours in the 

building water supply. If the tank is large it may 

need to be disinfected (chlorinated) or otherwise 

treated to stop bacterial growth. If repairs or 

relining of the tank is required, the Property 

Manager must ensure that the lining material is 

certified as ‘suitable for contact with drinking 

water’ at the appropriate surface area to volume 

ratio for that tank. These relining materials often 

require specific conditions (time, temperature 

and relative humidity) to cure thus ensuring they 

don’t impart any tastes or odours to the building 

water supply. Residents should be notified that 

the work is being undertaken and be advised to 

flush their taps thoroughly after the maintenance 

work has been completed. 

Obsolete 

Customers with taste and odour problems from 

industrial, commercial or high-rise residential 

complexes should initially direct their 

complaints to the Property Manager, who should 

inspect the integrity of any water storage 

facilities servicing the building. If there is any 

doubt to the cause of the problem, the Operator 

should request the Water Quality Technician to 

liaise with the Property Manager and investigate 

the complaint. 

Complaints handling 

Guidelines for the implementation of a 

complaints handling process, including 

processing oral complaints, can be found in 



Australian Standard 4269—1995 Complaints 

handling. 

The mechanism of taste and odour 

sensation 

Odours are detected by a small area of 

yellow/brown receptor cells located in the roof 

of the nose. 

Different individuals can demonstrate a wide 

variation in olfactory sensitivity. In some cases 

individuals suffer from “smell-blindness” 

(anosmia). Conversely, some individuals can 

exhibit hypernosmia, the opposite of anosmia, 

showing considerably greater sensitivity to 

odours than the general population. Some 

Consumers may recognise certain specific 

odours in drinking water that are not detected by 

Water Agency testing panellists. 

The sense of taste is detected by receptors (taste 

buds) mainly located on the upper surface of the 

tongue. There are four classic tastes—sourness 

(acidity), sweetness, saltiness and bitterness. 

Because of its composition in relation to saliva 

all ‘normal’ water tastes ‘negatively saline’. 

Hint 

An individual’s perception and ability to 

describe flavours and odours varies and is 

subject to fatigue and adaptation. Receptors 

screen out stimulants that are present for a long 

time. 

It often helps to offer some descriptive words 

such as ‘earthy’, ‘musty’, ‘metallic’ or 

‘medicinal’ to help Customers pinpoint the 

problem. Additional descriptors are listed in 

Table 2. 

Further Reading 

For a more scientific list of causes of tastes and 

odours in drinking water the following two 

papers may be useful. 

Exposure Assessment of Taste and odour 

Standards Used in the Method of Flavour Profile 

Analysis – Linda Schweitzer and I.H. (Mel) 

Suffet Wat.Sci.Tech. Vol.40, No.6, pp. 209-215, 

1999. 

The Drinking Water Taste and Odor Wheel for 

the Millennium: Beyond Geosmin and 2- 

Methylisoborneol – I.H. (Mel) Suffet, Djanette 

Khiari and Auguste Bruchet Wat.Sci.Tech. 

Vol.40 No.6, pp.1-13, 1999 

References 

Burlingame, G.A., (1999) Solving Customers’ 

Taste and Odor Complaints Part 1: The 

Importance of the First Response Opflow 

October vol.25, no.10 pp10-11 

Burlingame, G.A., (1999) Solving Customers’ 

Taste and Odor Complaints Part 2: Tracking 

Odors to their Source Opflow November vol.25, 

no.11 pp6-7 

Groshong, N.N., (1996) Dealing with Taste and 

Odor Complaints in the Distribution System. 

AWWA pp.593-597 

Khiari, D., Bruchet, A., et al (1999). 

Distribution-generated Taste-and-odor 

Phenomena Wat.Sci.Tech. Vol.40, No.6, pp129- 

133 

Mallevialle, J., Suffet, I.H.,(1996). Identification 

and Treatment of Tastes and Odors in Drinking 

Water. AWWARF (with Lyonnaise des 

Eaux).Denver, CO USA 

Rogers, H.R., (2001) Factors causing off-taste in 

waters, and methods and practices for removal of 

off-taste and its causes. Drinking Water 

Inspectorate, UK. Report No: DETR/DWI 

5008/1 

Disclaimer 

This Information Sheet is produced by the Water Services 

Association of Australia Inc (“WSAA”) for use by 

members of WSAA. This Information Sheet is intended to 

provide general information in relation to its subject matter 

and includes information obtained from a number of 

Obsolete 

sources. 

Over time, changes in industry standards and legislative 

requirements, as well as technical advances and other 

developments or factors relevant to the information 

contained in this Fact Sheet, may have affected the 

accuracy of that information. Accordingly caution should 

be exercised in relation to the use of the information in this 

Fact Sheet. 

Any views expressed do not represent the views or policy 

of WSAA, or any member of WSAA. No responsibility is 

accepted by WSAA, the editor, author, individual 

contributors or the suppliers of information, for the 

accuracy of any information contained in this Fact Sheet or 

the consequences of any person relying upon any 

information. 

Copyright 

Copyright 2003 Water Services Association of Australia 

Inc. Subject to the provisions of the Copyright Act (1968), 

no part of this Fact Sheet may be reproduced or copied in 

any form or by any means (electronic, graphic or 

mechanical including photocopying, recording, taping, 

microcopying or otherwise) or reproduced or used in 

connection with any information retrieval system or 

transmitted by any means, without the prior written 

permission of WSAA. 



TABLE 1 

COMMON TASTE AND ODOUR COMPLAINTS IN THE HOME AND APARTMENT, USEFUL QUESTIONS TO ASK, POSSIBLE 

CAUSES AND SOLUTIONS 1 

Note 1 The front garden tap should be used to sample the reticulated drinking water, i.e. the drinking water supplied by the Water Agency to 

the Customer and the front garden tap for the purposes of investigation of taste and odour complaints can be taken to be the changeover point 

in responsibility. If the point source of the taste and odour problem is within a Customer’s property, it is the Customer’s responsibility to 

employ a licensed plumber to fix the problem within their system. In the case of high-rise residential complexes and office buildings, the 

water should be sampled as close as practicable to the water main connection. 

Note 2 The general questions used in example 2 may be used for all complaints and enquiries 

Complaint 2 

1. 

Chlorine Smell 

/ Chlorine taste 

(may be 

perceived as 

‘medicinal’ or 

‘metallic taste’) 

Examples of 

questions to ask 

Which tap(s) does 

the smell come 

from? 

Does the smell come 

from the hot and/or 

cold water taps? 

What time of day 

does it occur? 

Possible Causes Actions/Solutions Comments 

The mixing of hot and cold 

water from running a bath or 

shower may cause a chlorine 

vapour with a strong smell. 

Increased chlorine or chloramine 

levels from primary or 

secondary treatment. 

May not be high chlorine, but 

rather comparatively low FCR 

and high TCR (i.e. chloramines) 

Ensure that chlorine disinfectant levels to 

the residence are within acceptable 

limits. 

Flush taps first thing in the morning to 

dissipate the smell. 

Leave drinking water in a jug to stand for 

a few minutes until chlorine dissipates. 

Vigorous shaking or stirring will 

accelerate dissipation. 

Obsolete 

Issue 1 Page 4 of 8 15 October 2003 

Often can be resolved over the phone 

without visiting the property. 

Investigate possible causes of elevated 

chlorine in area - check distance of 

property from chlorination plant, check if 

nearby main has been flushed and 

chlorinated recently, check if chlorine 

tablet dosing of supply reservoir has 

occurred recently. 

To get the FCR and TCR closer together 

(i.e. FCR close to 80-90% of TCR), 

remove organics from mains by flushing 

and/or scouring.


Complaint 2 

2. 

Undrinkable 

water 

3. 

Funny, 

metallic, plastic 

smell / taste in 

tea / coffee 

Examples of 


Which tap is the 

Customer drinking 

from? 

Is it the hot or cold 

water tap? 

What time of day 

does the problem 

occur? 

Is the problem 

persistent or 

intermittent? 

Has the Customer 

recently moved from 

one part of the city to 

another? 

Has a new kettle 

been purchased 

recently? 

If so is it of the 

plastic variety? 


Unauthorised plumbing products 

(plastic pipes, taps, mixers, 

flexible hoses, appliance hoses) 

that have not been passed as 

suitable for contact with 

drinking water. Sometimes used 

in kitchen and bathroom 

renovations and/or extensions. 

If the bad taste is isolated to one 

particular tap investigate 

possible causes, e.g. dishwasher 

or mixer tap flexible hoses are 

documented sources of bad 

tastes in drinking water at the 

kitchen tap. Similarly, clothes 

washing machine flexible hoses 

can be the culprits, especially if 

the machine is installed in the 

kitchen (becoming more 

common in studio apartments). 

Problem may be more 

pronounced in summer months 

when plumbing pipework in 

roof cavity is heated. 

The 'new' plastic reacting to the 

heat when water is boiled. 

Ask the Customer to turn the stop valve 

off on the dishwasher when not in use. If 

the Customer cannot taste / smell the 

'bad' water it is the dishwasher hose. 

Look for flexible hoses (generally 

stainless steel braided rubber hoses) that 

connect the kitchen and/or bathroom taps 

to the plumbing system. 

These hoses should be authorised and 

bear a WaterMark sticker. If hoses are 

unauthorised, suggest that the Customer 

contact the plumber who installed them 

for replacement. Otherwise suggest that 

the Customer contact a licensed plumber 

to install authorised flexible hoses. 

The customer should also check the 

water quality at the front tap. 

If no source can be found, sampling may 

be required. 

Obsolete 

Ask Customer to refill and boil water in 

the kettle several times, before making 

tea / coffee. 

Otherwise return kettle and purchase 

another brand. 


Water generally perceived as 

‘undrinkable’ could be caused by many 

factors and ‘descriptors’ should be used 

to narrow down the possible causes (see 

Figure 1). 

If sampling is warranted, request the 

Water Quality Technician to investigate. 

Customer should engage a licensed 

plumber if replacement of plumbing 

items required. 

Complaints on plumbers installing 

unauthorised products should be directed 

to the plumbing regulator. 

Usually resolved over the phone.


Complaint 2 Examples of 


4. 

Plastic taste 

5. 

Musty / earthy 

smell 

6. Dirty 

appearance – 

colour / 

turbidity 

(Especially the 

combination of 

smell and dirty 

appearance) 

Questions as per 2. 

If it is a new house or 

apartment ask 

Customer to find out 

if plastic pipes were 

used in the water 

plumbing. May need 

to contact builder / 

plumber. 

How wide spread is 

the problem? 

Do neighbours 

complain of similar 

taste/smell? 

Questions as per 5. 

Is the problem 

restricted to the cold 

or hot water system 

(HWS)? 

Does the property 

have a galvanised 

steel/iron water 

service? 


Unauthorised plumbing products 

(plastic pipes) that have not been 

passed as suitable for contact 

with drinking water. Sometimes 

used in kitchen and bathroom 

renovations and/or extensions. 

If plastic piping has been 

installed throughout the house, 

the taste should be similar from 

all taps in house. 

Problem may be more 

pronounced in summer months 

when plumbing pipework in 

roof cavity is heated. 

Geosmin or MIB, substances 

produced by bacteria or bluegreen 

algae 

Turbidity in reticulated water 

supply 

Turbidity from galvanised water 

service pipe between the water 

meter and building. 

Turbidity from corroded shell of 

glass lined steel HWS. 

Compare the taste from several internal 

taps with the front garden tap 1 . If taste is 

only apparent from taps within the house, 

the source of problem is presumably the 

internal plumbing pipework. 

Regular flushing for a period, especially 

for new installations, may 

reduce / eliminate the problem. 

The source is normally in the raw water 

or in the treatment process, and 

complaints should normally be 

widespread. 

Obsolete 

Generally an operational / supply issue. 

Wide range of possible causes. 

Ask Customer to engage a licensed 

plumber to inspect the water service and 

other water plumbing pipes and to 

replace with new pipes as appropriate. 

If dirty water coming from hot water 

service ask Customer to either get the 

HWS tank cleaned / flushed or replaced. 


Plastic pipe systems have replaced 

copper as the most common water 

plumbing system used in Australia. In 

some areas these systems represent over 

80% of new installations. 

Reported cases would be more common 

in new houses and renovations. 

Complaints on suspected unauthorised 

products should be directed to the 

plumbing regulator. 

Customer could consider engaging a 

plumber to replace pipes with copper 

(expensive process) or install an in-line 

water filter below the kitchen sink. 

A Water Quality Technician should 

investigate. 

It is important to explain to the Customer 

that these compounds are not associated 

with health problems. 

A Water Quality Technician should 

investigate turbidity from Water Agency 

supply. 

If dirty water is coming from HWS it is 

likely that the shell lining has failed and 

the HWS should be replaced. Even 

replacing the HWS anode will not protect 

the steel shell with a failed lining.


FIGURE 1. POSSIBLE SOURCES OF TASTES AND ODOURS IN DRINKING WATER 

1. Source Water 

Mixing sources e.g. groundwater and 

surface water 

Chemical spills 

Industrial discharges 

Odour causing precursors in run-off 

Mineral content variability 

Wastewater discharges 

Iron, manganese, sulphur, and biological 

problems 

Anaerobic sediments or stratification in 

water columns 

Biological growth in surface waters and 

soils 

2. Water Treatment Plants (WTP) 

Disinfection by-products 

4. Water Mains 

Corrosion of metallic components in 

water mains (e.g. pipes, fittings, 

valves, hydrants, tapping bands) 

Biological activity in a section of main 

Cross connections or backflow events 

Oversized mains with low usage - 

stagnant water 

New main construction – taste and 

odours from lubricants, pipe linings 

and materials 

Recently rehabilitated (relined) water 

mains – taste and odours from lining 

materials such as sprayed epoxies, 

cured-in-place liners and inserted 

plastic pipes 

Chemicals from permeation through 

pipe, fittings and joints 

Biological growth with in the WTP 

5. Homes and Buildings 

Algae disinfection New plumbing products, materials or 

Anaerobic conditions within WTP 

appliances (dishwashers) 

Oxidation by-product odours 

Variability or overdosing of chlorine or 

chloramines 

Changes in treatment or water source 

3. Distribution Systems 

Biological regrowth and odour production 

Old plumbing materials e.g. 

galvanised steel/iron pipes 

Recent renovations (e.g. kitchen) or 

alterations or additions 

Hot water systems - new and old 

Poorly maintained on-site treatment 

systems e.g. water filters 

Tank / Service reservoir linings (new) Cross connections and backflow 

events e.g. rainwater tanks 

Old reservoir materials e.g. bitumen type 

coatings Dead end mains (cul-de-sac) and long 

mains with low flows 

Disinfection by-products 

Chlorinous odours from di- and trichloramines, 

or high level of free chlorine 

Re-chlorination of reservoirs or mains 

Ingress of contaminated water and soil 

into water mains e.g. during break repairs 

and cut-ins 

Unusually high flow velocities such as 

may occur during fire fighting operations 

Obsolete 

Flexible rubber lined supply hoses e.g. 

kitchen mixer taps and dishwashers 

Localised biological growth within 

water service pipes 

Chemicals from permeation through 

pipe, fittings and joints – especially 

plastic water service pipes in property 

yards recently treated by spraying for 

termites, other insects, herbicides etc 



TABLE 2. TYPICAL TASTE AND ODOUR DESCRIPTORS 

Taste/Odour Descriptor Examples of possible sources 

‘Medicinal’ 

‘Chemical’ 

‘Kerosene’ 

‘Oil’ 

‘Chlorinous’ 

‘Bleach-like’ 

‘Swimming pool’ 

‘Earthy’ 

‘Musty’ 

‘Mouldy’ 

‘Fishy’ Metabolites of algae 

Chlorophenols, bromophenols or iodoforms 

formed during the water treatment process or 

the relining of reservoirs and water mains 

Chlorine species (see 'Chlorinous' below) 

Hydrocarbon contamination from incorrect 

reservoir relining procedure or materials 

Could be an issue with infiltration of road 

grime (eg oils, organic material) via a nonsprung 

fire hydrant mushroom (ball), as 

occurs when shutdowns take place 

Chloramines from the disinfection process 

Elevated free-chlorine residuals 

A longer lasting chlorine odour (rather than 

just an initial whiff) is from the reaction of 

chlorine with organic matter built up in the 

distribution system. This can be fixed by 

cleaning the water mains to remove the 

material 

‘Metallic’ Corrosion by-products 

Metabolites of actinomycetes (filamentous 

bacteria) or cyanobacteria – e.g. Geosmin, 2- 

MIB (methyl isoborneol) 

Can be a chlorine and chloramines issue, eg 

too much organic material in the mains or not 

enough chlorine 

Obsolete 

‘Plastic’ PVC piping or poly-type pipes 

‘Chalky’ Leaching from cement lined water pipe

Fact Sheet 7 Investigating Taste and Odour Complaints

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