Transcript water-environment.vin.bg.ac.rs

WATER QUALITY AND HEALTH
ALBANIAN CASE
Tania Floqi
Polytechnic University of Tirana
Vrnjacka Banja, 10.10.2007




Importance of water quality
Drinking water supply in Albania
Water supply in Tirana
Tirana’s water quality
- Physical characteristics
- Chemical characteristics
- Microbiological characteristic
- Disinfection process
- Health risks

Conclusions and Recommendations
Importance of water quality







Water is one of the most important chemicals known to
men
Rain, snow, sleet, hail, fog and dew - water present in
the air
Water is present on the earth surface as lakes, streams,
wetlands, waterfalls and glaciers
The human body is composed of 50 % water
Water is important as a solvent. Many substances
dissolve in water – sugar, salt, alcohol, etc.
Access to safe drinking-water is important as a health
and development issue at a national, regional and local
level
Water supply must be available to all
Drinking water supply in Albania


Albania is a small mountainous
country (28748 km2). It has a
rich hydrographic net
(groundwater, streams, rivers,
springs, lakes, wetlands). This
net includes over 200 big natural
resources of flowing
groundwater.
Natural water qualities of our
country are generally good
Drinking water supply in Albania


Drinking water origin
- 80 % of – groundwater
- 20 % - surface waters
Population supply
- 85% – By public system (Urban areas – at home;
Rural areas – public taps and standpipes)
- 10% – private wells
- 4.9% – treated surface water
- 0.1% – untreated surface water
Drinking water supply in Albania
Quantity
 20 – 50 lit/person/day at the taps
 120 lit/person/day at the source
 50-70% of the quantity is lost in the
distribution system
- Obsolete & old infrastructure
- Poor maintenance & mismanagement
Water supply in Tirana



Tirana region has a wide
variety of natural geological
conditions that influence water
quality
Tirana city takes water from
- surface water (Bovilla damreservoir)
- flowing underground sources
- artesian pumped wells
All the above sources are
different regarding physical,
chemical and microbiological
characteristics
Tirana’s water quality
Physical characteristics
 Turbidity
- usually in normal parameters
- In rainy periods & damaged supply network ranges from 8 – 92
ntu
 Odor & Taste
- usually in normal parameters
- faecal odors & oil odors in rainy periods and damaged supply
network
- odors from algae (Cyklotela diatomea) occurs since 2 years ago
in Bovilla reservoir - from these period began the monitoring of
human activites impact such as biological, physical and chemical
indicators
 Temperature – of Tirana’s water sources ranges from 7 -17º C
depending from the type of source
Tirana’s water quality
Chemical characteristics
 Fluoride – low levels
 Arsenic, mercury and lead – not present
 Nitrates – varies from 3-30.4 mg/l in Bovilla reservoir
and pumped wells in the lowlands
 Nitrates in natural groundwater in mountainous
areas are not present
 Pesticides and herbicides – not present in Bovilla
reservoir; analyzed since one year ago
 Organic Matter – present in all water sources but not
monitored because the lack of facilities
Chemical characteristics


Ammonia nitrogen - present in Bovilla reservoir, pumped
wells and the distribution supply network
Ammonia nitrogen is monitored as chemical indicator of
sanitary pollution
In pollution cases the ammonia level can reach 16 mg/l
NH4+ during monitoring in May 2007
0.09
0.08
0.07
0.06
mg/l

0.05
NH4+
0.04
0.03
0.02
0.01
0
Sampling points
Chemical characteristics




Total Dissolved Solids (TDS) –
varies from 188.9 mg/l to 802.2
mg/l
- Water from pumped wells has
higher TDS than natural
surface or groundwater
Conductivity - from 208
µmhos/cm to 944 µmhos/cm –
related with TDS concentration
Hardness ranges:
- natural groundwater, 71 – 79
mg/l CaCO3
- pumped wells, 210 – 275
mg/l CaCO3
Hardness is dependent from
natural geological conditions
pH – varies from 6.96 to 7.85,
don’t present carbonate
alkalinity
Tirana’s water quality
Microbial cases with pollution (2004-2006)
December
November
October
September
August
July
June
May
April
March
February
January
18
16
16
14
14
12
12
10
10
8
8
6
6
4
4
2
2
0
0
5
NH4+
N/100
18
ça
N.P
av
llo
I D
olla
ku
Bu
Ko
lZ
nvi
og
kti
u1
Lic
eu
Art
ist ik
VL
ua
ras
i
Rr
Sa
raç
ve
Ç.T
op
ulli
F. X
ha
jko
KM
an
ast
irit
G.
He
ba
S.
Pa
sh
a
M.
Lle
sh
i
Rr
Ka
vaj
es
Sh
.Be
rxo
Q.
lli
Gu
ran
jak
u
M.
Sh
yri
M.
Pe
za
H.T
as
in
mg/l
0
1
2
3
4
Lidhja midis përqendrimit të NH4+ dhe ndotjes mikrobiale në disa pjesë të rrjetit shpërndarës
gjatë 2006
M.
Mu
Microbiological characteristics
 Tirana’s water supply system is
monitored by specialists from
the Directorate of Public Health
and from the City Water Supply
and Sewerage Enterprise itself
 The monitored indicators are
E.Coli, Streptococcus Faecalis
and Total Coliforms
Coliforme
E-coli
Tirana’s water quality
Disinfection process
 Primary disinfectant used in
Bovilla treatment plant –
sodium hypochlorite (NaOCl)
 Secondary disinfectant used in
distribution depots – sodium
hypochlorite (NaOCl)
 The chlorination process is
made manually by operators
often not very qualified and
responsible, affecting the level
of chlorine which varies from
very high to very low values
Chlorine level cases in percentage
9%
25%
0 - 0.3 mg/l
29%
0.3 - 0.5 mg/l
0.5 - 1 mg/l
> 1 mg/l
37%
Health risks
If feacal contamination is recent it is responsible for
the presence of pathogenic agents including
bacteria, viruses, protozoa, which may cause
diseases from gastroenteritis to sometimes fatal
diarrhea, dysentery, hepatitis, typhoid fever or
cholera
 There was a cholera outbreak in 1994, in Albania,
with 626 infected cases and 25 dead people
 Data from the Institute of Public Health indicate that
there is a high incidence of gastroenteritis in Albania
- the conclusions of health experts indicate that in
most of cases the gastroenteritis is coming from
drinking water pollution
Health risks
 In 2006 in Tirana, there was a critic situation of the hepatitis B
disease, because of the contamination of distribution supply
system
 The Ministry of Health (National Sanitary Inspectorate)
decided to increase the quantity of disinfectant in the
distribution system so the residual chlorine should be from 0.3
– 0.5 mg/l (national standard) to 1 mg/l
Hepatitis cases for Jan 2006 - Aug 2007
300
250
200
150
100
50
Ja
n
Fe
b
M
ar
A
pr
M
ay
Ju
n
Ju
l
A
ug
S
ep
O
ct
N
ov
D
ec
Ja
n
Fe
b
M
ar
A
pr
M
ay
Ju
n
Ju
l
A
ug
0
Hepatitis
Tirana’s water quality
Disinfection by-products – THM
 NOM can cause various interferences in water
treatment such as:
- React with chemical disinfectant (chlorine) to form
disinfection by-products such as trihalomethanes.
Trihalomethanes are suspected to be mutagenic,
carcinogenic and/or teratogenic
 THM (18 compounds) are monitored since one year
ago and are all in low levels
Conclusions







The quality of drinking water in Tirana is strongly linked to the type of sources used to
supply the population. Tirana is supplied with drinking water from surface, underground
sources and artesian pumped wells. Each of these sources has different microbiological,
physical, chemical and acceptability characteristics.
Hardness can be classified as very hard (above 20 German degrees) for the waters in
lowland regions and as soft for the natural groundwater in mountainous areas
The quality of drinking water in Tirana has been deteriorating in the last years. There are
more and more cases with microbial contamination, mainly with feacal origin. Main reason
of this is the continuing amortization of both; drinking supply system and sewerage system.
Summer months are the most common in regard to microbial contamination. Also, heavy
rainfalls have shown to affect considerably the microbial quality of drinking water. The
critical situation of the sewerage system creates a constant risk for the population health,
depending mainly on infiltrations and out-spills in these specific days.
Analyses have shown that the chemical indicator of water sanitary pollution (NH4+) is in
accordance with bacteriological indicators. In many cases the presence of NH4+ is much
higher than the allowed levels, going up to 1.4-1.6 mg/l.
The disinfection process is not consequent and analyses show that the level of chlorine is
very variable in time and in different places of the supply network. Despite the bad
technical conditions, the lack of experience and knowledge of the workers dealing with the
chlorination process are main causes that affect negatively the distribution of chlorine in the
distribution network.
Analyses have shown that the chlorine concentration in the network is in an oblique
correlation with the bacteriological (E. coli, Str. faecalis, Coliform Total) and chemical
(NH4+) indicators. Nevertheless there are cases when the concentration of chemical and
bacteriological indicators is in such high levels that the chlorination process is not enough
to bring them within the allowed standards
Recommendations








The drinking water quality should not be considered as an isolated parameter of water
supply, but as an important element that affect directly the health of the people.
Because the water supply organs are responsible for the quality and safety of drinking
water, there is a need to combine good operation techniques and preventive measures
supported by continuous monitoring and control of the quality.
A special attention should be made to microbiological characteristics of quality. The
potential consequences linked to microbial contamination are so unpredictable that
microbial control should always be of a primary importance and during it no changes or
compromises should be made.
The improvement of drinking water quality is closely related with its systematic monitoring.
The establishment of a well-planned survey system in time and space will positively affect
the safety of drinking water.
Defense measures of water sources should be made according to their type. In the case of
underground water sources, protection around them should be enforced, not allowing
human activities within a certain radius. For surface waters, the selection of treatment
processes should be oriented towards a greater water quality and safety.
The sanitary inspection organs should expand and intensify their controls in the entire
supply network. This will prevent future contaminations and diseases.
During disinfections compromises should not be made in attempt to control disinfection byproducts. Lowering the level of chlorine in the network is not commendable for the moment
as the network is in a poor technical situation, but its level should be kept constant and
within allowed values.
Measures should be made to improve the disinfection process and in particular for the level
of chlorine in the network. The fluctuations of chlorine level from very high to very low
values can bring negative impacts on health. The promotion of automatic chlorinating
systems should be promoted to replace manual chlorination.
MERCI!
THANK YOU!
HVALA!