Impacts of climate change on surface water quality in relation
to drinking water production
I. Delpla, A.-V. Jung, E. Baures, M. Clement, O. Thomas
School of Public Health (école des Hautes études en Santé Publique), Laboratoire d'étude et de Recherche en Environnement et Santé (LERES), Avenue Professeur Léon Bernard,
35043 Rennes Cedex, France
Received 13 March 2009
Accepted 3 July 2009
Available online 29 July 2009
Besides climate change impacts on water availability and hydrological risks, the consequences on water
quality is just beginning to be studied. This review aims at proposing a synthesis of the most recent existing
interdisciplinary literature on the topic. After a short presentation about the role of the main factors
(warming and consequences of extreme events) explaining climate change effects on water quality, the focus
will be on two main points. First, the impacts on water quality of resources (rivers and lakes) modifying
parameters values (physico-chemical parameters, micropollutants and biological parameters) are consid-
ered. Then, the expected impacts on drinking water production and quality of supplied water are discussed.
The main conclusion which can be drawn is that a degradation trend of drinking water quality in the context
of climate change leads to an increase of at risk situations related to potential health impact.
? 2009 Elsevier Ltd. All rights reserved.
1. Introduction .............................................................. 1225
2. Impacts on water quality parametes .................................................. 1226
2.1. Basic parameters ........................................................ 1226
2.2. Dissolved Organic Matter .................................................... 1226
2.3. Nutrients............................................................ 1228
2.4. Inorganics micropollutants ................................................... 1228
2.5. Organics micropollutants .................................................... 1229
2.6. Pathogens ........................................................... 1229
2.7. Cyanobacteria and cyanotoxins ................................................. 1229
2.8. Water quality indicators ..................................................... 1229
2.9. Synthesis ............................................................ 1229
3. Expected impacts on drinking water production ............................................. 1230
3.1. DBPs determinants ....................................................... 1230
3.2. Potential impacts ........................................................ 1230
3.3. Monitoring and modeling of impacts ............................................... 1231
3.4. Synthesis ............................................................ 1231
4. Conclusion .............................................................. 1232
References ................................................................. 1232
Environment International 35 (2009) 1225–1233
? Corresponding author. Tel.: +33 2 99 02 29 20; fax: +33 2 99 02 29 29.
E-mail address: Olivier.Thomas@ehes p.fr (O. Thomas).
0160-4120/$ – see front matter ? 2009 Elsevier Ltd. All rights reserved.
Contents lists available at ScienceDirect
journal 顺心彩票page: www.elsevier.com/locate/envint
Floods and droughts are the main impacts of climate change on
water availability. Besides these quantitative impacts, surface water
quality is also affected by climate change. For example, it seems
obvious that a drought may imply at least a modi?cation of surface or
ground water quality (concentration) sometimes leading to water
supply limitation. If surface water withdrawal can be directly affected
by water quality degradation, wells pumping can be cut off for sanitary
reasons (groundwater quality) as well as for security reasons (?oods
threats). However, even if these facts are well known, few scienti?c
works have been published until recently on the impacts of climate
change on water quality modi?cation.
Actually, climate change is not the only factor affecting water quality.
Integrated i nto th e global change concept, land use evolution,
deforestation, urban spreading and area waterproo?ng may also
contribute to water quality degradation. But more often, water pollution
is directly linked to human activities of urban, industrial or agricultural
origin, and climate change could lead to degradation in surface water
quality as an indirect consequence of these activities. When point source
pollution is reduced in many countries (even if wastewater treatment
plants begin to reach their capacity limits), climate (global) change
impacts could tend to increase the diffuse pollution with for example
urban or agricultural runoff. The climate change determinants affecting
water quality are mainly the ambient (air) temperature and the increase
of extreme hydrological events. Soil drying-rewetting cycles and solar
radiation increase may also be considered.
First of all, temperature (in general) must be viewed as the main
factor affecting almost all physico-chemical equilibriums and biologi-
cal reactions. It is well known that all physico-chemical “constants”
vary with temperature, and frequently increasin g en dotherm ic
reactions. According to Arrhenius relation, kinetic of a given chemical
reaction can be doubled for a temperature incre ase of 10 °C.
Consequently, several transformations or effects related to water will
be favoured by water temperature increase such as dissolution,
solubilisation, complexation, degradation, evaporation, etc. This
phenomenon globally leads to the concentration increase of dissolved
substances in water but also to the concentration decrease of dissolved
gazes. This last point is very important with respect to dissolved
oxygen in water. In fact, its saturation concentration decreases of
almost 10% with a 3 °C increase (10 mg/L at 15 °C). Remind that,
whatever the IPCC scenario, the average global air temperature should
increase between 1.8 and 4.0 °C (Bates et al., 2008) during the 21st
century. M oreover, a drying tendency in summer is expected,
particularly in subtropics, low and mid-latitudes, in addition with an
extreme events increase in general (Bates et al., 2008).
Floods and droughts will also modify water quality by direct effects
of dilution or concentration of dissolved substances. For low river ?ow
rates, the main effect on water quality is as for a temperature increase,
a concentration increase of dissolved substances in water but a
concentration decrease of dissolved oxygen (Prathumratana et al.,
2008; Van Vliet and Zwolsman, 2008). A correlative positive effect is
the concentration decrease of some pollutants due to a low water
velocity (aquatic plants assimilation of nutrients and adsorption/
complexation of heavy metals on suspended matter and settling).
These phenomenons will be detailed hereafter. For heavy rain falls and
strong hydrologic conditions, runoff and solid material transportation
are the main consequences. For countries in the temperate zone,
climate change will decrease the number of rainy days but increase
the average volume of each rainfall event (Brunetti et al., 2001; Bates
et al., 2008)). As a consequence, drought–rewetting cycles may impact
water quality as it enhances decomposition and ?ushing of organic
matter into streams (Evans et al., 2005).
Solar irradiation increase could also alter water quality and
especially characteristics of natural organic matter in freshwaters
systems both by warming and UVB radiation (increasing photolysis)
(Soh et al., 2008). Phototransformation should be seriously taken into
account when evaluating the possibility of formation of UV transfor-
mation products from organic micropollutants such as pharmaceu-
ticals (Canonica et al., 2008). Many papers consider pharmaceuticals
to be photo reactive substances (
Boreen et al., 2003; Buerge et al.,
2006; Petrovic and Barceló, 2007).
This paper aims at reviewing the main impacts on water quality
parameters, generally described for surface water (rivers and lakes),
and the expected impacts on drinking water production.
2. Impacts on water quality parametes
Water quality parameters can be classi?ed according to i) physico-
chem ical basic parameters (temperature, pH, dissolved oxygen,
dissolved organic matter …) and nutrients, ii) micropollutants
(inorganic and organic) including metals, pesticides and pharmaceu-
ticals, and iii) biological parameters with pathogens microorganisms,
cyanobacteria and water quality proxies (Table 1).
2.1. Basic parameters
A rise in surface water temperatures was observed since the 1960s in
Europe, North America and Asia (0.2–2 °C), mainly due to atmospheric
warming in relation to solar radiation increase (Bates et al., 2008). In
European rivers,Zwolsman and van Bokhoven (2007),andVan Vliet and
Zwolsman (2008) observed an average increase in water temperature of
around 2 °C respectively in Rhine and Meuse rivers after the severe
drought of 2003, with a pH increase (re?ecting a decrease in CO
concentration), and a decrease in dissolved oxygen (DO) solubility
re?ecting a lower DO solubility under higher water temperatures. A DO
decrease can also be associated to an increase in DO assimilation of
biodegradable organic matter by microorganisms (linked to an increase
in Dissolved Organic Carbon (DOC)) (Prathumratana et al., 2008). In the
same study dealing with the surface water quality in the lower Mekong
River, negative signi?cant correlations were generally found between
precipitation (or discharge ?ow) and DO, pH and conductivity (from 0.2
to 0.9). In several lakes in Europe and Northern America, the strati?ed
period has lengthened by 2–3 weeks and water temperatures have risen
of 0.2 to 1.5 °C, which have an in?uence on thermal strati?cation
(Komatsu et al., 2007)andlakeshydrodynamics(Bates et al., 2008).
Computer models predict an increase of around 2 °C by 2070 in
European lakes, although this rise will also depend on lake character-
istics and season (George et al., 2007; Malmaeus et al., 2006). It has been
demonstrated that shallow lakes are likely to be the most vulnerable to
climate change. Water temperatures have an impact on internal lake
processes like diffusion, mineralization and vertical mixing (Malmaeus
et al., 2006). Residence timeof lakes would probably increase in summer
by 92% in 2050 for lakes with short residence times George et al. (2007).
Also, it is predicted that especially shallow lakes will experience an
increase of temperature in epilimnion and hypolimnion during summer
(J?hnk et al., 2008), although man-made lakes (in The Netherlands)
respond even more directly to weather variations (Mooij et al., 2005).
Nevertheless, deepest lakes are most sensitive to climate warming on a
long period of time due to their greater heat storage capacity and will
consequently show the highest winter temperatures (George et al.,
2007). An increase in water temperature has also an impact on lakes
chemical processes with increases in pH and greater in-lake alkalinity
generation (Psenner and Schmidt, 1992). Concerning the impacts of the
predicted increase in winter precipitations on lake waters, it depends on
the lake size. Small lakes with short residence times will be particularly
sensitive to a change in rainfalls (George et al., 2007).
2.2. Dissolved Organic Matter
Dissolved Organic Matter (DOM) affects the functioning of aquatic
ecosystems through its in?uence on acidity, trace metal transport,
1226 I. Delpla et al. / Environment International 35 (2009) 1225–1233
Impacts of climate change on water quality parameters.
Water quality parameter
Water body Reference Comments
pH Droughts River Van Vliet and Zwolsman, 2008 Higher maximum values in Meuse river.
Lakes Bates et al., 2008 Increase in pH.
River Prathumratana et al., 2008 Negatively correlated (Mekong).
Rivers and lakes Zwolsman and van Bokhoven, 2007;
Komatsu et al., 2007;
Van Vliet and Zwolsman, 2008
Lower dissolved oxygen solubility and concentration.
River Prathumratana et al., 2008 Negatively correlated (Mekong).
Rivers Zwolsman and van Bokhoven, 2007;
Van Vliet and Zwolsman, 2008;
Ducharne et al., 2007; Bates et al., 2008
Warming of the water column.
J?hnk et al., 2008; Komatsu et al., 2007;
Malmaeus et al., 2006; Mooij et al., 2005;
George et al., 2007
Increase in the epilimnion and hypolimnion, especially in shallow lakes.
Increase of temperature, stability of the water column and summer water residence times.
Streams and lakes
Monteith et al., 2007; Evans et al., 2005;
Worral et al., 2004; Hejzlar et al., 2003
DOC increase (UK, Scandinavia, Czech Republic, Northeastern USA and Canada).
Clark et al., 2008; Prathumratana et al., 2008
DOC ?ux increase during storm events (UK and Mekong basin).
Droughts River Van Vliet and Zwolsman, 2008;
Zwolsman and van Bokhoven 2007
Sediment release during droughts. Ammonium increase.
Wilhelm and Adrian, 2008 Increase mineralization and release of N, C and P from soil OM.
Wilhelm and Adrian, 2008; Jackson et al., 2007;
Malmaeus et al., 2006; Komatsu et al., 2007;
Petterson et al., 2003
Sediment nutrients release and pulses into the euphotic zone.
Strong changes in nutrient loading in shallow lakes.
Elevated phosphate and ammonium concentrations in the hypolimnion during the warm period.
River basins, lake,
Kaste et al., 2006; Arheimer et al., 2005;
Ducharne et al., 2007; Zhu et al., 2005;
Wilby et al., 2006; Weyhenmeyer, 2008
Increase N river loading (Norway) and nitrate load (UK river and Seine groundwater).
Increase N and P (Sweden) and nutrients (Canada) loading.
Climate change effects could be comparable between small and large lakes.
Stream and lakes Drewry et al., 2009; Mooij et al., 2005;
Prathumratana et al., 2008
Australia, Mekong basin. Increased P loading of Dutch lakes.
Bhat et al., 2007 Total Kjeldahl nitrogen (TKN) loading increase (USA).
Inorganics Metals Droughts River Van Vliet and Zwolsman, 2008;
Zwolsman and van Bokhoven, 2007
Selenium, Baryum, mercury, zinc, cadmium, lead and nickel increase.
High alpine lakes Thies et al., 2007 Increasing amount of snowmelt lead to a micropollutants increase (European Alps).
Streams Rothwell et al., 2007 Correlations between DOC and metals mobilisation (UK).
Stream Pédrot et al., 2008 Humic and fulvic acids mobilized various trace elements (Brittany).
Olivie-Lauquet et al., 2001
Trace element release coincide with a decline in redox potential and increase
of organic carbon content (Brittany)
Pesticides Temperature and
Bloom?eld et al., 2006 Changes in rainfalls intensity and seasonality and increased temperatures are main
climate drivers for changing pesticides fate and behaviour.
Lennartz and Louchart, 2007 Soil drying increased the biding of herbicidal compounds.
Streams Probst et al., 2005 Increased precipitations lead to an increase of pesticides ?ux.
Groundwater Massman et al., 2006 Arti?cial recharge pond. Change in redox conditions (anaerobic conditions)
with an increase in temperature (Deutchland).
Streams Lissemore et al., 2006 Correlations between DOC and pharmaceuticals concentrations in water.
Oppel et al., 2004
Clo?bric acid and iopromide are very mobile and could contaminate groundwaters through rivers.
Pathogens Temperature and
Surface waters Charron et al., 2004; Curriero et al., 2001 Half the waterborne disease outbreaks in USA during the last half century followed a period of
Hunter, 2003; Pednekar et al., 2005
Nearly 70% of the variability in the coliform record is due to seasonal and
interannual variability in local rainfall.
Lakes Arheimer et al., 2005; J?hnk et al., 2008;
Summer heatwaves boost the development of Cyanobacteria blooms (Nederlands and Sweden).
Lakes Brient et al., 2008; Wiedner et al., 2007 Cylindrospermopsis Raciborskii northern spread. Microcystin blooms during hot summers.
Fishes, green algae, diatoms
Freshwaters Daufresne et al., 2003; Daufresne and Bo?t, 2007 Pollutants uptake rate increase due to an increased metabolic rate and decrease in oxygen
solubility. Species predominance and abundance changes.
Soils Sardans et al., 2008 Increase enzymatic activity.
1227I. Delpla et al. / Environment International 35 (2009) 1225–1233
light absorbance and photochemistry and, energy and nutrient supply
(Evans et al., 2005). The principal source of DOM in surface waters is
soil leaching (Hejzlar et al., 2003). Furthermore, positive spatial
relationships between Dissolved Organic Carbon (DOC) export and
wetland areas like peatlands have been demonstrated (Evans et al.,
2005). Since the 1980s, various studies have shown signi?cant DOC
increases in Northern Europe (Evans et al., 2005; Monteith et al.,
2007; Worrall et al., 2004), Central Europe (Hejzlar et al., 2003) and
Northern America (Monteith et al., 2007). Many potential factors (air
temperature, increase in rainfalls intensity, atmospheric CO
and decline in acid deposition) have been proposed to explain these
trends in DOC, although there is no scienti?c consensus. Evans et al.
(2005) h ave shown that recovery from acidi?cation and water
temperature are potential drivers, since many compounds forming
part of DOC are acidic. In fact, a decrease in acid deposition is observed
resulting partly from a decrease in anthropogenic sulphur emissions
(industries, passengers/goods transportation…)(Monteith et al.,
2007; Evans et al., 2008). This could lead to an increase in soil pH
and consequently to an organic acids increase permitted by new redox
conditions. Nevertheless, trends in DOC are probably resulting from a
combination of various factors, including acid deposition, since
increasing trends have begun in a few places before reduction in
acid deposition (Worrall and Burt, 2007).
According to Clark et al. (2008), a variation in stream ?ow can be a
good indicator of changes in DOC concentration in streams draining
organo-minerals soils, although the same is false for peat soils (in this
case, temperature is better). Finally, Prathumratana et al. (2008)
shows that COD (Chemical Oxygen Demand), used as an indicator of
Natural Organic Matter (NOM), have weak to fair signi?cant
correlations with precipitations and discharge ?ows for the Mekong
River (from 0.3 to 0.4).
Finally, Prathumratana et al. (2008) shows that COD (Chemical
Oxygen Demand), used as an indicator of Natural Organic Matter
(NOM), have weak to fair correlations with precipitations (0.295–
0.426) and discharge ?ows (0.312–0.324).
An increase of N mineralization in soil due to an increase in mean
soil temperature is expected (Ducharne et al., 2007). Moreover,
droughts increase the soil extractible Total Organic Carbon (TOC)
concentration in winter and warming increases extractible nitrate in
summer and autumn and extractib le ammonium in winter. A
moderate increase in soil temperature (spring, summer and winter)
could lead to a large increase in enzymatic activity. Temperature is
positively correlated with nitri?cation process (increasing phospha-
tases activity and P mobilisation in soils). Changes observed in
enzymatic activity are linked with direct effect of soils warming which
stimulates biological activity and increases N availability (Sardans et
al., 2008). Soil warming increases soil extractable nitrates concentra-
tion in summer and autumn (N losses facilitated) and concentration of
extractable ammonium in winter.
Water bodies quality is subjected to weather seasonality which has
an important impact on their nutrient patterns (Zhu et al., 2005). A
warmer climate will create indirect impacts on water bodies like an
increase nutrients load in surface and groundwater (Van Vliet and
Zwolsman, 2008) and counteract policies effects of external nutrient
loading reduction (Wil helm and Adrian, 2008). Indeed, higher
temperatures will increase mineralization and releases of nitrogen,
phosphorus and carbon from soil organic matter. Moreover, an
increase in runoff and erosion due to greater precipitations intensity
should result in an increase in pollutants transport, especially after a
drought period. Higher ammonium concentrations could be observed
in rivers with a reducing dilution capacity caused by droughts
(Zwolsman and van Bokhoven, 2007; Van Vliet and Zwolsman,
2008). Furthermore, release of phosphorus from bottom sediments
in strati?ed lakes is expected to increase, due to declining oxygen
concentrations in the bottom waters (
Wilhelm and Adrian, 20 08).
Regional and global climate scenarios and models are useful tools
to produce data inputs for hydrological models in order to understand
and predict the potential effects of climate change on water bodies. An
increase in dry summertime frequency may lead to gradually mobilize
nitrogen in soils that would be ?ushed into streams at the beginning
of the wet season and cause higher rivers nitrate concentrations
(Wilby et al., 2006). Ducharne et al. (2007) predict an increase in
nitrate concentration in the Seine basin aquifer layers for the years
2050 and 2100 due to an increase in precipitations and consequently
in soil leaching. Kaste et al. (2006) and Arheimer et al. (2005)
respectively predict a 40–50% increase in nitrate ?ux by 2070–2100 in
a Norwegian river basin, and an increase in phosphorus (50%) and
nitrogen (20%) in a lake. Correlations between precipitations, air
temperature, discharge ?ow and phosphates, nitrates and Total
Phosphorus (TP) in the Mekong River have also been observed
(Prathumratana et al., 2008). These results are in accordance with
Bhat et al. (2007) who found that 73% of the total Kjeldhal nitrogen
load at a forested watershed outlet was exported by surface runoff
during storm events. Drewry et al. (2009) also found positive
correlations between TP, total nitrogen, suspended solids and ?ow. It
was also suggested that a major part of the phosphorus is adsorbed
onto suspended solids.
For lakes, higher phosphate and ammonium concentrations in the
hypolimnion are frequently observed during the warm period in
temperate countries (Petterson et al., 20 03 ). Climate change impact
these ecosystems with various manners: changes in temperature, ice-
cover, wind and precipitation (Mooij et al., 2005 ). P loading
exportation, which is governed by discharges following heavy rain
falls, will tend to increase with climate change and consequently have
an impact on lakes ( Mooij et al., 20 05 ). Conversely, streams nitrogen
concentrations are less dependent on stream discharge (Mooij et al.,
2005). Increasing temperatures is supposed to decrease nitrate
concentrations in lakes with an increase in denitri?cation rate and
higher N losses in upstream-situated soil and surface waters (Mooij et
al., 2005). On the contrary, the internal P loading increases thanks to
microbial decomposition of lake sediments (Jackson et al., 2007).
Accumula tion of so luble hypolimne tic phosp hor u s depends on
thermocline depth and hypolimnetic temperatures (Wilhelm and
Adrian, 2008). Indeed, higher hypolimnetic temperatures increase
both mineralization of organic hypolimnetic matter and phosphorus
release from sediments. Dramatic nutrient pulses into the euphotic
zone could be observed after heatwaves (Wilhelm and Adrian, 2008).
Hence, alternating mixing and long strati?cation events threat more
especially polymictic lakes than dimictic lakes ( Wilhelm and Adrian,
2008). P increases in the surface layer, fueling phytoplankton growth
(Jackson et al., 2007), leading to algal blooms and a deterioration of
water quality (Komatsu et al., 2007). Lastly, concerning Total Phos-
porous (TP) concentrations, higher temperatures may impact mainly
lakes with long residence times (Malmaeus et al., 2006), even though
rates of change of phosphate and nitrates concentrations seem to be
independent of lake morp顺心彩票try (Weyhenmeyer, 2008).
2.4. Inorganics micropollutants
In Western Europe, metal concentrations in rivers have greatly
decreased in the past decades with industrial and urban wastewater
treatment efforts. Nevertheless, droughts may have impacts on river
water quality (Zwolsman and van Bokhoven, 2007; Van Vliet and
Zwolsman, 2008), depending on the compound properties that could
be as well either negative or positive. First of all, signi?cantly higher
concentrations for barium, selenium and nickel were observed in river
Meuse during the drought of 2003 (Van Vliet and Zwolsman, 2008).
Conversely, signi?cantly lower concentrations of total lead, chromium,
mercury and cadmium were measured within the same period. These
1228 I. Delpla et al. / Environment International 35 (2009) 1225–1233
differences are mainly due to dissimilarities between adsorption
capacities by suspended solids but discrepancies exist between
studies. Indeed, in the Rhine river, it was observed that droughts
have a negative impact on metal concentrations of cadmium,
chromium, mercury, lead, copper, nickel and zinc which were higher
during the 2003 drought than during reference periods (Zwolsman
and van Bokhoven, 2007).
Thies et al. (2007) have studied high alpine lake waters (Alps)
response to climate warming and observed a solute release from an
active rock glacier ice. Surface waters over metamorphic rocks were
affected by the rising export of ions and heavy metals from meltwater.
They predicted that high mountain freshwater will thus become
increasingly affected by climate warming.
Furthermore, a strong complexation of some metals by DOC could
lead to a transport of dissolved lead, titane and vanadium in peatland
systems after a storm?ow (Rothwell et al., 2007). A seasonal change in
dissolved metal concentrations was also observed for various trace
elements (Fe, Mn, Al, La, U, Th, Cd and As). An increase of organic
carbon content and a decline in redox conditions seem to be related
with a trace elements release. A positive correlation is also found
between storm events and trace element concentrations in streams
(Olivie-Lauquet et al., 2001). In fact, organic and inorganic colloids
could play an important role in trace elements mobilisation in soils
and water (Pédrot et al., 2008).
2.5. Organics micropollutants
Surface waters are the main receptors for pesticides contamination
from the agricultural use. Bloom?eld et al. (2006) observed that
changes in rainfall seasonality and intensity and increased air
temperatures are the main climate drivers for changing pesticides
fate and behaviour, although effects of climate change are likely to be
variable and dif?cult to predict.
Lennartz and Louchart (2007) has studied the physico-chemical
interactions between soil organic matter and herbicidal compounds
(diuron and terbuthylazine) after drying and rewetting cycles to
examine impacts of climate induced soil water status variations.
Results show that variations in soil water contents modify the soil
organic matter structure, which hinder diffusion and trap pesticides.
An increase in extreme events with climate change will probably
counteract pesticides reduction measures. Probst et al. (2005)
simulate pesticides entries into streams and found, with a heavy
rainfalls scenario (precipitation increase from 10 to 20 mm/day), that
isoproturon and bifenox could potentially present a greater risk due to
For pharmaceuticals, in a Southern Ontario watershed, Lissemore
et al. (2006) found signi?cant correlations between DOC and some
active substances frequently detected in water (monensin and
carbamazepine), with concentration variations of monensin, linco-
mycin, sulfamethazine, trimethoprim and carbamazepine depending
on ?ow rate and precipitation amount. Furthermore, clo?bric acid and
iopromide are found to have an important leaching potential which
could represent a long term risk for groundwater contamination from
river water through sediment and subsoil (Oppel et al., 2004),
especially in case of heavy rainfalls events.
Waterborne pathogens could be spread within the freshwater after
a contamination by animal or human waste due to heavy rainfall
discharge in combined sewer systems (CSS). When the ?ow exceeds
the CSS capacity, the sewers over?ow directly into surface water body
(Charron et al., 2004). Pednekar et al. (2005) have studied coliform
load in a tidal embayment and shown that stormwater coming from
the surrounding watershed is a primary source of coliform. Moreover,
higher water temperatures will probably lead to a pathogen survival
increase in the environment, although there is still no clear evidence
Floods often led to a contamination of groundwater and additional
disease outbreaks like Acanthamoeba keratitis in Iowa (USA) in 1994
(Hunter, 2003). According to Curriero et al. (2001), half of the
waterborne disease outbreaks in the US during the last half century
followed a period of extreme rainfall. Even though the risk of diseases
outbreaks linked to mains drinking waters is low in developed
countries, private supplies would be at risk (Hunter, 2003). In
addition, an increase in temperature threats water quality with regard
to waterborne diseases especially cholera disease in Asia and South
America (Hunter, 2003). Lastly, it was shown that with increased UV
radiation due to ozone layer depletion, NOM trap higher levels of UV
energy and breaks down to more bioavailable organic compounds,
minerals and micronutrients. All these processes could stimulate
bacterial activity in aquatic ecosystems (Soh et al., 2008 ).
2.7. Cyanobacteria and cyanotoxins
Competition between phytoplankton and cyanobacteria could be
switch in favor of cyanobacteria in a warmer climate (Arheimer et al.,
2005) and could also increase their dominance. A higher phosphorus
?ux in the epilimnion can promote phytoplankton growth in the
euphotic layer and lead to an evolution from a macrophyte-dominated
clear water state to a phytoplankton-dominated turbid state. Increase in
water temperatures and nutrient concentration causes massive cyano-
bacteria bloom in many waterbodies (Hunter, 2003). Summer heat-
waves could also boost the cyanobacteria development in lakes through
reducing vertical turbulent mixing and increasing growth rates (J?hnk
et al., 2008). Moreover, new cyanobacterium species as Cylindrosper-
mopsis raciborskii have colonized northern habitats due to effects of
rising temperatures. This tropical cyanobacterium, known to produce
Cylindrospermopsin, is now detected in South and Western Europe
freshwaters (Italy, Spain and France) (Brient et al., 2008) and has been
detected in German lakes (Wiedner et al., 2007). Moreover, an earlier
annual warming in temperate countries permits an earlier and more
important growth of this alga (Wiedner et al., 2007). Lastly, other
cyanobacteria, like Microcystis which can produce microcystin, could
become invasive with climate warming (J?hnk et al., 2008).
2.8. Water quality indicators
Fishes, green algae and diatoms are often used as water quality
indicators. Daufresne and Bo?t (2007) observed an increase related to
global warming in total abundance and in proportions of warm-water
species and size-structures changes in ?sh communities in French
rivers. Southern thermophilic ?sh species progressively replaced
northern cold water species in the upper Rh?ne River (Daufresne
et al., 2003). Furthermore, high temperature and low turbulent
diffusivities in lakes could suppress the population abundances of
green algae and diatoms ( J?hnk et al., 2008). High temperatures seem
to favor the cyanotoxins dominance, as Microcystis, over diatoms and
green algae (J?hnk et al., 2008).
The climate change impacts on surface water quality can be
summarized in Fig. 1, which consider the effects (droughts and ?oods)
of the two main factors (temperature and rainfalls). These impacts
depend on natural or man built environment, and the consequences
can be different according to water body type (rivers, lakes, dams,
ponds, wetlands...) and characteristics (water residence times, size,
shape, depth…). For streams, the main parameters affected are DOM
and nutrients meanwhile pathogens and cyanobacteria/cyanotoxins
are more related to lakes. In between, micropollutants, inorganic or
organic are also frequently affected.
1229I. Delpla et al. / Environment International 35 (2009) 1225–1233
3. Expected impacts on drinking water production
Research undertaken in the 1970s, indicated the presence of
disinfection by-products (DBPs) in drinking water (Rook, 197 4;
Symons et al., 1975). Special attention was given to the concentration
of trihalomethanes (THMs) because of their potential carcinogenic
effects (Singer, 1993). The study on the occurrence of DBPs in drinking
water distribution systems has increased in the recent years, focusing
?rstly on natural organic matter transformation. Concerning emerging
DBPs linked to pharmaceuticals and new pesticides, very few studies
have been published in order to understand their formation and fate
during water treatment. For pharmaceutical by-products, most of
studies are limited to parent's pharmaceutical products (PPs) (Fent
et al., 20 06; Mompelat et al., 2009).
This part aims at reviewing the main known determinants on DBPs
formation under usual water treatment conditions. Then we consider
the expected impacts of climate change on these parameters and the
degradation of drinking water quality. Lastly, we present some further
monitoring needs for a better knowledge.
3.1. DBPs determinants
Several factors such as temperature, dissolved organic carbon
(DOC), pH, bromide concentrations, and operational factors or
chlorine doses and contact time were reported to signi?cantly affect
the formation of DBPs (Nikolaou et al., 2004; Teksoy et al., 2008).
Temperature and organic matter matrix, in?uen ced by climate
change, are considered hereafter.
Concerning the in?uence of the water temperature on the DBPs
formation, the general trend shows that for natural surface water
temperatures (5–30 °C), increased temperatures promote the DBPs
formation rate. Some studies (Rodriguez and Serodes, 2001) showed
that THM concentrations vary signi?cantly (from 1.5 to 2 times,
depending on the utility) between drinking water plant and tap (the
most distant). When water temperature exceeds 15 °C, spatial THM
variations are particularly high (from 2 to 4 times, depending on the
utility). In the same way, others authors reported that increasing
temperature (10–33 °C) generally increased the formation of bro-
moorganic DBPs (Zhang et al., 2005). However, this general trend
should be moderated for certain unstable DBPs. Indeed, Yang et al.
(2007) studied the formation of DBPs after 3 days of chloramination
with monochloramine (NH
Cl) at three temperatures (10 °C, 20 °C
and 30 °C). They showed that chloroform formation increases with
temperature from 10 to 30 °C. However, for more unstable DBPs as
dichloroacetonitrile (DCAN) and 1,1-dichloro-2-propane (1,1-DCP),
this general trend should be moderated, since their decomposition
could increase with temperature.
In terms of water quality, it has been established that fulvic and
humic constituents of organic matter constitute important precursors
for THMs (Christman et al., 1990). Total organic carbon (TOC), as well
as UV absorbance, have been used as indicators of the presence of
organic matter in drinking water (Thomas, 2007). Some authors
pointed out that the minimum effective alum dose shows a strong
stoichiometric relationship with DOC concentrations in model waters
(Shin et al., 2008). Moreover, several studies have mentioned that
dissolved organic carbon (DOC) concentration in alum or iron treated
water was directly related to the THM formation potential (van
Leeuwen et al., 2005; Uyak and Toroz, 2007). Some research projects
based on laboratory bench-scale and ?eld data have shown that the
higher values are for these parameters, the higher the concentrations
of THMs formed (Rodriguez et al., 2000; Gol?nopoulos et al., 1998;
Garcia-Villanova et al., 1997; Montgomery, 1993). For DBPs formation,
the determinant factor could be the aromatic part or hydrophobic
fraction of NOM and molecular weight distribution (Randtke and
Jepsen, 1981; Bose and Reckhow, 1998; Croue et al., 1999; Singer,
1999). Moreover, some studies have already showed that for waters
that are not governed by sweep ?occulation, coagulant doses are
determined by the concentrations of both NOM and particles, silica
being the dominant factor for coagulant demand at high particle
concentrations (N100 mg/L) (Shin et al., 2008). Consequently,
mineral-bound humic substances increase the intrinsic complexation
properties of mineral substances for organic and inorganic pollutants
(Murphy and Zachara, 1995) and directly impact on DBPs formation
3.2. Potential impacts
Concerning climate change issues o n DBPs fo rmation, past
investigations have already observed that the occurrence of THMs in
chlorinated water may vary signi?cantly according to season and
geographical location in the distribution system (Williams et al., 1997;
Garcia-Villanova et al., 1997; Arora et al., 1997; Singer et al., 1995;
Clark, 1994). These temporal and spatial variations are due to changes
in raw and treated water quality as well as in operational parameters
(pH, chlorine dose, contact time…) related to chlorination.
Rainstorm events lead to elevated levels of turbidity and organic
matter found in river waters which cause deterioration in treatment
performance. However, it has been shown that this effect is not
uniform. This could be due to a combin ation of lower water
temperatures and a change in the nature and increased concentrations
of NOM in the natural water (Hurst et al., 2004). This could also
explain why these authors observed that seasonal differences have a
signi?cant impact on process robustness, independent of the raw
water turbidity. Rodriguez and Serodes (2001) showed that when
water temperature is lower than 15 °C, THMs in treated water will not
be higher than initial THM concentration, even if these ones are high
(60 μg/L). The latter situation may be typical in spring or fall, when
the organic content of raw water and treated water tends to increase
following rain or ?eld runoff. For typical summer water temperatures
(N18 °C), the THM concentration within the system treatment may
rise from 2 to 4 times, depending on the utility (Rodriguez and
DOC nature and concentration are not the only parameters which
drastically change during rainstorm e vents and the biolo gical
compartment contribution should be taken into account too. Chen
and Zhang (2008) globally showed that algae contributed much more
to the HAA (haloacetic acids) formation than the THM during the
summer and autumn blooms. During these special events, when the
algal concentration is 20–80 million per liter, the DBP precursors
originating from algae would account for about 20% to 50% of the total
Fig. 1. Impacts of climate change on water resources and drinking water quality.
1230 I. Delpla et al. / Environment International 35 (2009) 1225–1233
Variations of temperature, pH and aqueous composition occurring
during climate change could also have an in?uence for contaminants
on their sorption on mineral phases. When assessing the leaching
behaviour of anthropogenic compounds, the in?uence of the proper-
ties of soils has to be taken into account (Oppel et al., 2004; Yu et al.,
2009). Moreover, especially during rainfall events, mineral particles
leaching could lead to high concentrations in natural waters, having a
direct impact on coagulant demand during water treatment as seen
before (Shin et al., 2008) and on DBPs formation.
Concerning the occurrence and fate of micropollutants with
respect to drinking water treatment, the main (recent) studies are
related to pharmaceuticals. Actually, studies on pharmaceuticals are
principally linked to wastewater treatment, the ef?ciency of which
may affect the quality of water resources downstream a treated
ef?uent discharge. Even if they are pa rtially removed, residual
quantities may remain in treated water, and have been found in
drinking (tap) water (Al-Ahmad et al., 1999; Hernando et al., 2006).
The ef?ciency of pharmaceuticals removal varies with treatment
processes and also with temperature and weather (Choi et al., 2008).
For instance, diclofenac showed largely different elimination rates
between 17% (Heberer et al., 2002), 69% (Ternes et al., 1998), and 100%
(Thomas and Foster, 2004) depending on these two last parameters.
Finally, for pesticides elimination in conventional physi-cochemical
drinking water treatment processes, such as ?occulation, sedimenta-
tion, ?ltration, or lime softening, only certain lipophilic substances are
removed adequately (Baldauf, 2006).
Natural micropollutants, mainly represented by cyanotoxins may
also have a huge impact on drinking water treatment. Chlorination,
micro-/ultra?ltration and especially ozonation are the most effective
water treatment procedures in destroying cyanobacteria and in
removing microcystins (Hitzfeld et al., 2000). During cyanobacterial
bloom events, ozonation may be an appropriate process to eliminate
peptide toxins like microcystin-LA and-LR (Rositano et al., 1998, 2001;
Brooke et al., 2006). Lots of studies concerning removal of cyano-
bacterial toxins from water showed that the effectiveness of the
oxidation process is not only dependant on the reactant concentration,
but also on temperature, pH, ionic composition (Rositano et al., 1998;
Shawwa and Smith, 2001) and NOM concentration (Al Momani et al.,
2008). Although very few studies reported the relationship between
algae and DBPs precursors, some authors pointed out the algal
contribution to some DPBs formation (Chen and Zhang, 2008). Some
studies tried to improve new by-products identi?cation for cyanotox-
ins ( Rodriguez et al., 2007; Merel et al., 2009). However, DBPs
formation has largely not been investigated.
3.3. Monitoring and modeling of impacts
Face to the previous expected impacts on the degradation of
(drinking) water quality, several monitoring tools are proposed.
The ?rst way is to incorporate on-line TOC (or DOC) measurements
into coagulation control algorithm for pH control and coagulant dose
to prevent uncontrolled variation especially during storm/raining
events (Hurst et al., 2004). In the same area, the development of ?eld
monitoring procedures or system may be useful for improving DOM
knowledge in order to evaluate bulk properties mainly in?uencing
disinfection by products formation such as biological activities (algal
contribution, photosynthetic evolution…) or molecular polarity.
Fluorescence analysis could help in the assessment of DOM sources
by spectral signatures related to waters affected by microbial activity,
either by wastewater in?uence or by autochthonous processes and
could correlate some of these data with DOC for instance (Parlanti
et al., 20 00; Jung et al., 2005; Rosario-Ortiz et al., 2007).
Another solution is the prediction of the occurrence or fate of some
physico-chemical parameters through modeling. Uyak and Toroz
(2007) have proposed a model for the concentration estimation of
THM and HAA in chlorinated raw water of surface water supplies for
instance. Other models have already been developed that relate
coagulant dose to the concentration and character of organics present
in natural waters. These models enable prediction of inorganic
coagulant doses that maximize removal of organics at a particular
coagulation pH (van Leeuwen et al., 2005). As we have seen before,
model development studies taking into account temperature should
be continued. The complexity of DBP formation reactions makes it
dif?cult to develop universally applicable models. This research ?eld
should however be considered with special attention for the future.
A last point to consider is the analytical development for emerging
substances and by-products. Concerning pharmaceuticals and pesti-
cides, there is a real need for identi?cation and toxicity assessment on
the degradation byproducts formed during water treatment. The
removal of pharmaceuticals and other polar micro-pollutants can only
be assured using advanced techniques such as ozonation, activated
carbon or membrane ?ltration (Ternes et al., 2002) or eventually UV
treatment (Canonica et al., 2008). However, developing only the best
available treatment techniques to remove these substances without
taking into account DBPs formation is not the actual challenge.
Comparison on emerging substances consumption (such as pharma-
ceuticals) and occurrence in water based on a reference methodology,
health and ecotoxicological risk assessments should be developed in
parallel with analytical methods permitting identi?cation and quan-
ti?cation of by-products.
The climate change impacts on drinking water treatment issues
can be summarized in Fig. 2. Remind that climate change may cause at
the resource level (surface water), huge hydrologic variations, water
temperature rise and increases of pollution load (chemical and
microbiological). For treatment plants, considering that all remedia-
tion actions have been made (pollution source reduction, run off
limitation, fertilizers and pesticides reduction management, etc.),
adaptation measures must be envisaged for a better ef?ciency,
particularly with regards to extreme events (heavy rainfalls and
droughts). These measures integrate complementary treatment steps
and process control even for small water supply systems. Moreover,
water quality monitoring with analysis of micropollutants among
which emerging substances and treatment by products must be carry
out, as well as health risk assessment (following the water safety plan
procedure). Obviously, in case of severe ?oods, transportation of
bottles or tanks may be the only solution for safe drinking water
Fig. 2. Climate change impacts and drinking water treatment issues.
1231I. Delpla et al. / Environment International 35 (2009) 1225–1233
The main outcome of this literature review on climate change impact
on surface water quality (from resources to tap) is that there is a
degradation trend of drinking water quality leading to an increase of at
risk situations with regard to potential health impact, mainly during
extreme meteorological events. Among water quality parameters,
dissolved organic matter, micropollutants and pathogens are susceptible
to rise in concentration or number as a consequence of temperature
increase (water, air and soil) and heavy rain falls in temperate countries.
Another conclusion is the lack of information on micropollutants
occurrence and fate with regard to climate change impacts and
treatment ef?ciency, including potentially association and transporta-
tion with natural organic matter. Disinfection by products of
micropollutants not removed during treatment and of residues must
be identi?ed and their toxicity assessed. Last conclusion concerns
water borne diseases potentially highly linked to climate change
impacts but still rarely studied at least for temperate countries. Finally,
there is a huge need for water quality monitoring and predictive tools
as models and decision support systems mainly with the aim of health
risks assessment and remediation and adaptation actions.
The authors would like to thank Sophie Mompelat and Sylvain
Merel, PhD students of the Laboratoire d'Etude et de Recherche en
Environnement et Santé (LERES), for their fruitful discussions on
cyanotoxins and pharmaceuticals occurrence and persistence in the
environment. They also thank André Lavoie from Sherbrooke
University for his help as well as the reviewers of the manuscript,
suggesting us very relevant improvements.
Al Momani F, Smith DW, El-Din MG. Degradation of cyanobacteria toxin by advanced
oxidation process. J Hazard Mater 2008;150:238–49.
Al-Ahmad A, Daschner FD, Kummerer K. Biodegradability of cefotiam, cipro?oxacin,
meropenem, penicillin G, and sulfamethoxazole and inhibition of waste water
bacteria. Arch Environ Contam Toxicol 1999;37:158–63.
Arheimer B, Andreásson J, Fogelberg S, Johnsson H, Pers CB, Persson K. Climate change impact
on water quality : model results from southern Sweden. Ambio 2005;34(7):559 –66.
Arora A, LeChevallier MW, Dixon KL. DBP occurrence survey. J Am Water Works Assn
Baldauf G. Removal of pesticides in drinking water treatment. Acta Hydrochim
Bates BC, Kundzewicz ZW, Wu S, Palutikof JP. Climate change and water. Geneva:
Technical paper of th e Intergovernmental Panel on Climate change. IPCC
Bhat S, Hat?eld K, Jacobs JM, Lowrance R, Williams R. Surface runoff contribution of
nitrogen during storm events in a forested watershed. Biogeochemistry 2007;85:
Bloom?eld JP, Williams RJ, Gooddy DC, Cape JN, Guha P. Impacts of climate change on
the fate and behaviour of pesticides in surface and groundwater—a UK perspective.
Sci Total Env 2006;369:163–77.
Boreen AL, Arnold WA, McNeill K. Photodegradation of pharmaceuticals in the aquatic
environment: a review. Aquat Sci 2003;65(4):320–41.
Bose P, Reckhow DA. Adsorption of natural organic matter on preformed aluminium
hydroxide ?ocs. J Environ Eng 1998;124:803–11.
Brient L, Lengronne M, Bormans M, Fastner J. Short communication: ?rst occurrence of
Cylindrospermopsin in freshwater in France. Environ Toxicol 2008;24(4):415–20.
Brooke S, Newcombe C, Nicholson B, Klass G. Decrease in toxicity of microcystins LA and
LR in drinking water by ozonation. Toxicon 2006;48:1054–9.
Brunetti M, Maugeri M, Nanni T. Changes in total precipitation rainy days and extreme
events in northeastern Italy. Int J Climatol 2001;21:861–71 .
Buerge IJ, Buser HR, Poiger T, Müller MD. Occurrence and fate of the cytostatic drugs
Cyclophosphamide and Ifosfamide in wastewaters and surface waters. Environ Sci
Canonica S, Meunier L, von Gunten V. Phototransformation of selected pharmaceuticals
during UV treatment of drinking water. Water Res 2008;42:121–8.
Charron DF, Thomas MK, Waltner-Toews D, Aramini JJ, Edge T, Kent RA, et al. Vul-
nerability of waterborne diseases to climate change in Canada: a review. J Toxicol
Environ Health Part A 2004;67:1667–77.
Chen C, Zhang X-J, Zhu L-x, Liu J, He W-j, Han H-d. Disinfection by-products and their
precursors in a water treatment plant in North China: seasonal changes and fraction
analysis. Sci Total Environ 2008;397:140–7.
Choi K, Kima Y, Park J, Park CK, Kim M, Kim HS, et al. Seasonal variations of several
pharmaceutical residues in surface water and sewage treatment plants of Han
River. Sci Total Environ 2008;405:102–28.
Christman RF, Kronkerg L, Sing R, Ball LM, Johnson JD. Identi?cation of mutagenic
byproducts from aquatic humic chlorination. Denver: AWWA Research Foundation
and AWWA; 1990.
Clark RM.Modelling water qualitychanges and contaminant propagation in drinkingwater
distribution systems: a US perspective. J Water Supply Res Technol 1994;43:133–43.
Clark JM, Lane SN, Chapman PJ, Adamson JK. Link between DOC in near surface peat and
stream water in an upland catchment. Sci Total Environ 2008;404:308–15.
Croue JP, Debroux JF, Aiken G, Leenheer JA, Amy GL. Natural organic matter: structural
and reactive properties. In: Singer PC, editor. Formation and control of disinfection
by-products in drinking water. Denver, CO: American Water Works Assn; 1999.
Curriero FC, Patz JA, Rose JB, Lele S. The association between extreme precipitation and
waterborne disease outbreaks in the United States, 1948–1994. Am J Public Health
Daufresne M, Bo?t P. Climate change impacts on structure and diversity of ?sh
communities in rivers. Glob Chang Biol 2007;13:2467–78.
Daufresne M, Roger MC, Capra H, Lamouroux N. Long-term changes within the inver-
tebrate and ?sh communities of the Upper Rh?ne River: effects of climatic factors.
Glob Chang Biol 2003;10:124–40.
Drewry JJ, Newham LTH, Croke BFW. Suspended sediment, nitrogen and phosphorus
concentrations and exports during storm-events to the Tuross estuary, Australia.
J Environ Manag 2009;90:879–87.
Ducharne A, Baubion C, Beaudoin N, Benoit M, Billen G, Brisson N, et al. Long term
prospective of the Seine river system: confronting climatic and direct anthro-
pogenic changes. Sci Total Environ 2007;375:292–31 1 .
Evans CD, Monteith DT, Cooper DM. Long-term increases in surface water dissolved
organic carbon: observations, possible causes and environmental impacts. Env Poll
Evans CD, Monteith DT, Reynolds B, Clark JM. Buffering of recovery from acidi?cation by
organic acids. Sci Total Environ 2008;404:316–25.
Fent K, Weston AA, Caminada D. Review: ecotoxicology of human pharmaceuticals.
Aquat Toxicol 2006;76:122–59.
Garcia-Villanova J, Garcia C, Gomez JA, Garcia MP, Ardanuy R. Formation, evolution and
modelling of trihalomethanes in the drinking water of a town: II. In the distribution
system. Water Res 1997;31:1405–13.
George G, Hurley M, Hewitt D. The impactof climate change on the physical characteristics
of the larger lakes in the English Lake District. Freshw Biol 2007;52:1647–66.
Gol?nopoulos SK, Xilourgidis NK, Kostopoulou MN, Lekkas TD. Use of a multiple
regression model for predicting trihalomethane formation. Water Res 1998;32:
Heberer T, Reddersen K, Mechlinski A. From municipal sewage to drinking water: fate
and removal of pharmaceutical residues in the aquatic environment in urban areas.
Water Sci Technol 2002;46:81–8.
Hejzlar J, Dubrovsky M, Buchtele J, Ru?i?ka M. The apparent and potential effects of
climate change on the inferred concentration of dissolved organic matter in a
temperate stream (the Mal?e River, South Bohemia). Sci Total Environ 2003;310:
assessment of pharmaceutical residues in wastewater ef?uents, surface waters
and sediments. Talanta 2006;69:334–42.
Hitzfeld BC, H?ger SJ, Dietrich DR. Cyanobacterial toxins removal during drinking water
treatment and human risk assessment. Environ Health Perspect 2000;108:113–22.
Hunter PR. Climate change and waterborne and vector-borne disease. J Appl Microbiol
Hurst AM, Edwards MJ, Chipps M, Jefferson B, Parsons SA. The impact of rainstorm
events on coagulation and clari?er performance in potable water treatment. Sci
Total Environ 2004;321:219
Jackson LJ, Lauridsen TL, S?ndergaard M, Jeppesen E. A comparison of shallow Danish
and Canadian lakes and implications of climate change. Freshw Biol 2007;52:
J?hnk KD, Huisman J, Sharples J, Sommeijer B, Visser PM, Stroom JM. Summer heatwaves
promote blooms of harmful Cyanobacteria. Glob Chang Biol 2008;14: 495–512.
Jung A-V, Frochot C, Parant S, Lartiges BS, Selve C, Viriot M-L, et al. Synthesis of amino-
phenolic humic-like substances and comparison with natural aquatic humic acids:
a multi-analytical techniques approach. Org Geochem 2005;36:1252–71 .
Kaste ?, Wright RF, Barkved LJ, Bjerkeng B, Engen-Skaugen T, Magnusson J, et al. Linked
models to assess the impacts of climate change on nitrogen in a Norwegian river
basin and fjord system. Sci Total Environ 2006;365:200–22.
Komatsu E, Fukushima T, Harasawa H. A modeling approach to forecast the effect of
long-term climate change on lake water quality. Ecol Model 2007;209:351–66.
Lennartz B, Louchart X. Effect of drying on the desorption of diuron and terbuthylazine
from natural soils. Environ Pollut 2007;146:180 –7.
Lissemore L, Hao C, Yang P, Sibley PK, Mabury S, Solomon KR. An exposure assessment
for selected pharmaceuticals within a watershed in Southern Ontario. Chemo-
Malmaeus JM, Blenckner T, Markensten H, Persson I. Lake phosphorus dynamics and
climate warming: a mechanistic model approach. Ecol Model 2006;190:1–14.
Merel S, Lebot B, Clement M, Seux R, Thomas O. MS identi?cation of microcystin-LR
chlorination by-products. Chemosphere 2009;74:832–9.
Mompelat S, Lebot B, Thomas O. Occurrence and fate of pharmaceutical products and
by-products, from resource to drinking water. Environ Int 2009;35:805–14.
Monteith DT, Stoddard JL, Evans CD, de Wit HA, Forsius M, H?g?sen T, et al. Dissolved
organic carbon trends resulting from changes in atmospheric deposition chemistry.
Nature 2007;450:537–41 .
1232 I. Delpla et al. / Environment International 35 (2009) 1225–1233
Montgomery W. Mathematical modeling of the formation of THMs and HAAs in
chlorinated natural waters. Denver, CO: Am. Water Works Ass; 1993.
Mooij WM, Hülsmann S, De Senerpont Domis LN, Nolet BA, Bodelier PLE, Boers PCM,
et al. The impact of climate change on lakes in the Netherlands: a review. Aquat
Murphy EM, Zachara JM. The role of sorbed humic substances on the distribution of
organic and inorganic contaminants in groundwater. Geoderma 1995;67:103–24.
Nikolaou AD, Gol?nopoulos SK, Lekkas TD, Arhonditsis GB, Kolovoyiannis V, Lekkasa TD.
Modelling the formation of chlorination by-products in river waters with different
quality. Chemosphere 2004;55:409–20.
Olivie-Lauquet G, Gruau G, Dia A, Riou C, Jaffrezic A, Henin O. Release of trace elements
in wetlands: role of seasonal variability. Water Res 2001;35(4):943–52.
Oppel J, Broll G, L?f?er D, Meller M, R?mbke J, Ternes Th. Leaching behaviour of
pharmaceuticals in soil testing systems: a part of an environmental risk assessment
for groundwater contamination. Sci Total Environ 2004;328:265–73.
Parlanti E, W?rz K, Geoffroy L, Lamotte M. Dissolved organic matter ?uorescence
spectroscopy as a tool to estimate biological activity in a coastal zone submitted to
anthropogenic inputs. Org Geochem 2000;31:1765–81.
Pednekar AM, Grant SB, Jeong Y, Poon Y, Oancea C. In?uence of climate change, tidal
mixing, and watershed urbanization on historical water quality in Newport Bay, a
saltwater wetland and tidal embayment in southern California. Environ Sci Technol
Pédrot M, Dia A, Davranche M, Bouhnik-Le Coz M, Henin O, Gruau G. Insights into colloid-
mediated trace element release at the soil/water interface. J Colloid Interface Sci
Petrovic M, Barceló D. LC-MS for identifying photodegradation products of pharma-
ceuticals in the environment. Trends Anal Chem 2007;26(6):486–93.
Petterson K, Grust K, Weyhenmeyer G, Blenckner T. Seasonality of chlorophyll and
nutrients in Lake Erken—effects of weather conditions. Hydrobiologia 2003;506–
Prathumratana L, Sthiannopkao S, Kim KW. The relationship of climatic and hydro-
logical parameters to surface water quality in the lower Mekong River. Environ Int
Probst M, Berenzen N, Lentzen-Godding A, Schulz R. Scenario-based simulation of
runoff-related pesticide entries into small streams on a landscape level. Ecotox
Environ Safe 2005;62:145–59.
Psenner R, Schmidt R. Climate-driven pH control of remote Alpine lakes and effects of
acid deposition. Nature 1992;356:781–3.
Randtke SJ, Jepsen CP. Chemical pre-treatment for activated carbon adsorption. J Am
Water Works Assn 1981;73:411–20.
Rodriguez MJ, Serodes JB. Spatial and temporal evolution of trihalomethanes in three
water distribution systems. Water Res 2001;35:1572–86.
Rodriguez MJ, Serodes JB, Morin M. Estimation of water utility compliance with
trihalomethane regulations using a modelling approach. J Water Supply Res
Rodriguez E, Sordo A, Metcalf JS, Acero JL. Kinetics of the oxidation of cylindosper-
mopsin and anatoxin-a with chlorine, monochloramine and permanganate. Water
Rook JJ. Formation of haloforms during chlorination of natural waters. Water Treat
Rosario-Ortiz FL, Snyder SA, Suffet IH. Characterization of dissolved organic matter in
drinking water sources impacted by multiple tributaries. Water Res 2007;41:
Rositano J, Nicholson BC, Pieronne P. Destruction of cyanobacterial toxins by ozone.
Ozone-Sci Eng 1998;20:223–38.
Rositano J, Newcombe G, Nicholson B, Sztajnbok P. Ozonation of NOM and algal toxins in
four treated waters. Water Res 2001;35:23–32.
Rothwell JJ, Evans MG, Daniels SM, Allott TEH. Base?ow and storm?ow metal
concentrations in streams draining contaminated peat moorlands in the Peak
District National Park (UK). J Hydrol 2007;341:90–104.
Sardans J, Pe?uelas J, Estiarte M. Changes in soil enzymes related to C and N cycle and in
soil C and N content under prolonged warming and drought in a Mediterranean
shrubland. Appl Soil Ecol 2008;39:223–35.
Shawwa AR, Smith DW. Kinetics of microcystin-LR oxidation by ozone. Ozone-Sci Eng
Shin JY, Spinette RF, O'melia CR. Stoichiometry of coagulation revisited. Environ Sci
Singer JJ. Formation and characterization of disinfection by-products. In: Craun GF, editor.
Safety of water disinfection: balancing chemical and microbial risks. Washington: ILSI
Singer PC. Humic substances as precursors for potentially harmful disinfection by-
products. Water Sci Technol 1999;40:25–30.
Singer PC, Obolensky A, Greiner A. DBPs in chlorinated North Carolina drinking waters.
J Am Water Works Assn 1995;87:83–92.
Soh YC, Roddick F, van Leeuwen J. The future of water in Australia: the potential effects
of climate change and ozone depletion on Australian water quality, quantity and
treatability. Environmentalist 2008;28:158–65.
Symons JM, Bellar TA, Carswell JK, DeMarco J, Kroop KL, Robeck GG, et al. National
organics reconnaissance survey for halogenated organics. J Am Water Works Assn
Teksoy A, Alkan U, Baskaya HS. In?uence of treatment process combinations on the
formation of THM species in water. Sep Purif Technol 2008;61:447–54.
Ternes T, Hirsch R, Mueller J, Haberer K. Methods for the determination of neutral drugs
as well as betablockers and alpha2-sympathomimetics in aqueous matrices using
GC/MS and LC/MS/MS. Fresen J Anal Chem 1998;362:329–40.
Ternes T, Meisenheimer M, McDowell D, Sacher F, Brauch H-J, Haist-Glude B, et al.
Removal of pharmaceuticals during drinking water treatment. Environ Sci Technol
Thies H, Nickus U, Mair V, Tessadri R, Tait D, Thaler B, et al. Unexpected response of high
Alpine Lake waters to climate warming. Environ Sci Technol 2007;41:7424–9.
Thomas O, Burgess C. Elsevier ed. UV–Visible spectrophotometry for water and
Thomas PM, Foster GD. Determination of nonsteroidal anti-in?ammatory drugs,
caffeine, and triclosan in wastewater by gas chromatography-mass spectrometry.
J Environ Sci Health A 2004;39:1969–78.
Uyak V, Toroz I. Disinfection by-product precursors reduction by various coagulation
techniques in Istanbul water supplies. J Hazard Mater 2007;141:320–8.
Van Leeuwen J, Daly R, Holmes M. Modelling the treatment of drinking water to
maximize dissolved organic matter removal and minimize disinfection by-product
formation. Desalination 2005;176:81–9.
Van Vliet MTH, Zwolsman JJG. Impact of summer droughts on the water quality of the
Meuse river. J Hydrol 2008;353:1–17.
Weyhenmeyer GA. Rates of change in physical and chemical lake variables—are they
comparable between large and small lakes? Hydrobiologia 2008;599:105–10.
Wiedner C, Rücker J, Brüggemann R, Nixdorf B. Climate change affects timing and size of
populations of an invasive cyanobacteri um in temperate regions. Oe cologia
Wilby RL, Whitehead PG, Wade AJ, Butter?eld D, Davis RJ, Watts G. Integrated modelling
of climate change impacts on water resources and quality in a lowland catchment:
River Kennet, UK. J Hydrol 2006;330:204–20.
Wilhelm S, Adrian R. Impact of summer warming on the thermal characteristics of a
polymictic lake and consequences for oxygen, nutrients and phytoplankton. Freshw
Williams DT, Lebel GL, Benoit FM. Disinfection by-products in Canadian drinking water.
Worrall F, Burt T. Trends in DOC concentration in Great Britain. J Hydrol 2007;346:
Worrall F, Burt T, Adamson J. Can climate change explain increases in DOC ?ux from
upland peat catchments? Sci Total Environ 2004;326:95–112 .
YangX, Shang C, Westerhoff P. Factors affecting formationof haloacetonitriles, haloketones,
chloropicrin and cyanogens halides during chloramination. Water Res 2007;41:
Yu L, Fink G, Wintgens T, Melin T, Ternes TA. Sorption behaviour of potential organic
wastewater indicators with soils. Water Res 2009;43:951–60.
Zhang X, Echigo S, Lei H, Smith ME, Minear RA, Talley JW. Effects of temperature and
chemical addition on the formation of bromoorganic DBPs during ozonation. Water
Zhu Z, Arp PA, Mazumder A, Meng F, Bourque CPA, Foster NW. Modeling stream water
nutrient concentrations and loadings in response to weather condition and forest
harvesting. Ecol Model 2005;185:231–43.
Zwolsman JJG, van Bokhoven AJ. Impact of summer droughts on water quality of the
Rhine River—a preview of climate change? Water Sci Technol 2007;56:44–55.
1233I. Delpla et al. / Environment International 35 (2009) 1225–1233