THE WATER REUSE PROGRAM AT THE COSTA BRAVA WATER AGENCY

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THE WATER REUSE PROGRAM AT THE COSTA BRAVA WATER
AGENCY

• Lluís Sala
• Consorci de la Costa Brava

Regional Training Course on Water Reclamation
and Reuse in the Mediterranean (WHO/UNEP Joint
Project, MED POL Phase III) Barcelona, Spain,
22-25 November 2004
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The Consorci de la Costa Brava

• Water agency formed in 1971 by 27 municipalities
• Deals with the whole water cycle
• Wholesale purveyor of drinking water to 14
  municipalities (3 external to CCB) - 18 hm3/year
• Biological wastewater treatment for 28
  municipalities (3 external to CCB) in 19 WWTP -
  35 hm3/year
• Reclamation and non-potable reuse of treated
  wastewater since 1989 - 5.5 hm3/year (2003)

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The Costa Brava in the 70s

• Decade of great increase in the touristic demand
  and urbanization
• The huge seasonal increase in population revealed
  the lack of efficient facilities
• Main problems
• Water supply Depletion of local resources and
  quality loss
• No wastewater treatment
• Faecal pollution in local rivers, streams and
  beaches

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The Costa Brava, year 2004

• Still greater degree of urban development and
  greater seasonal increase in population
• However...
• Water supply enough in quantity and quality
• Year 2004 98 of wastewater treated to
  biological level. Only pending the little
  villages of Sant Pere Pescador and LArmentera
• Treatment beyond secondary level of 15 of the
  wastewater produced
• Projects for the monitoring and recovery of the
  good ecological condition of the local streams
• Most of the beaches have excellent
  microbiological quality (independent control) and
  some awarded with the blue flag

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History of water reuse in the Costa Brava (I)

• First workshop in 1985 with the participation of
  experts such as Takashi Asano, James Crook and
  Rafael Mujeriego, among others.
• 1988 Newly constructed Golf Mas Nou was forced
  to use treated water from the Castell-Platja
  dAro WWTP for irrigation
• September 1989 Beginning of supply of
  disinfected secondary effluent from the
  Castell-Platja dAro WWTP for the irrigation of
  Golf Mas Nou
• 1989-1992 Demonstration project about the use of
  reclaimed water for golf course irrigation - Golf
  Mas Nou, UPC, Junta Sanejament (Regional Water
  Authority) and CCB

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History of water reuse in the Costa Brava (II)

• 1994 Beginning of supply of disinfected
  secondary effluent from the Lloret de Mar WWTP
  for the irrigation of Golf LÀngel
• 1994 First supply contracts with users.
  Criteria
• Microbiological quality non negotiable
• Supply included water analysis for adequate
  agronomic management
• 1995 Water reuse projects submitted to the EU
  Cohesion Funds and approved (80 funding)
• 1997 Beginning of supply of disinfected
  secondary effluent for the irrigation of a
  vineyard plantation in Colera

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History of water reuse in the Costa Brava (III)

• 1998 Start of operation of the environmental
  reuse project at the Aiguamolls de lEmpordà
  Nature Reserve with reclaimed water from the
  Empuriabrava WWTP (EU funded)
• 1998 Start of operation of the tertiary
  treatment at the Castell-Platja dAro WWTP (625
  m3/h) and improvement of the Ridaura river mouth
  (UE)
• 1998 Signing of contract and beginning of supply
  of reclaimed water to the Golf Costa Brava
• 1998 Beginning of reuse in the Parc de Sa Riera,
  in Tossa de Mar
• 2000 5 small tertiary treatments finished in the
  WWTP of northern Costa Brava (EU) (from 15 to 50
  m3/h)

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History of water reuse in the Costa Brava (IV)

• 2000 Signing of contract and beginning of supply
  of reclaimed water to the Golf Les Serres de Pals
• 2002 Construction of the tertiary treatment of
  the Blanes WWTP (800 m3/h), aimed at the recharge
  of the river Tordera aquifer
• 2003 Construction of the tertiary treatment of
  the Tossa (35 m3/h) and Torroella de Montgrí WWTP
  (1,000 m3/h)
• 2004 Beginning of supply of reclaimed water for
  corn irrigation (40 ha) in Solius and also for
  the irrigation of the Golf LEmpordà and the
  Pitch Putt facility of Castelló dEmpúries

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Rationale for water reuse in the Costa Brava

• Over the last 40 years local aquifers have been
  depleted due to touristic activities
• Increase in the non-potable urban demand, mostly
  due to golf course and landscape irrigation
• Expensive water transfers have been implemented
  during the late 80s and 90s. Half of the volume
  of the drinking water supplied in the Costa Brava
  comes from non-local sources
• After the also expensive wastewater collection
  and treatment to biological level, the reclaimed
  resource (secondary effluent) was simply wasted
  through sea disposal
• An additional treatment to make the water safe
  for non-potable uses allows a more efficient and
  logical management of water resources

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Goals of water reuse on the Costa Brava

• Decrease net water demand
• Reduce discharges into the sea
• Recycle nutrients
• Save energy
• Enhance environment
• Requirements
• Public health protection
• Technical and economical feasibility

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Key criteria

• Wastewater reclamation produces non-potable water
  for non-potable uses. Quality has to be put into
  perspective.
• Water reuse requires supply mentality, not
  discharge mentality
• Supply made according to written agreements which
  include monitoring and information dissemination
  - management of variability
• User as a client

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Conceptual evolution of water reuse on the Costa
Brava

• Discovery
• Learning to design and operate water reclamation
  and reuse systems
• Change of mentality, from discharge to supply
• Consolidation
• Establishment of operational protocols
• Trust in water reuse projects by agency,
  operators and users
• Beyond - What will 21st century bring?
• Development of dual distribution systems
• Full integration of water reuse into the water
  cycle
• Protection of local ecosystems and enhancement of
  biodiversity
• Action by modern, mature and responsible socities

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Evolution of wastewater reclamation on the Costa
Brava
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Reclaimed water uses on the Costa Brava

• Golf course and landscape irrigation
• Agricultural irrigation
• Recreation and/or restoration of aquatic
  ecosystems
• Aquifer recharge
• Urban non-potable reuse
• Discharge improvement

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Evolution of wastewater reclamation on the Costa
Brava
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Golf course irrigation

• Volume supplied in 2004 700,000 m3
• Forecast for 2005 1,000,000 m3 (new 27-hole
  course and a pitch putt facility added)

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Agricultural irrigation

• Volume supplied in 2004 200,000 m3
• Forecast for 2005 400,000 (up to 40 ha of corn
  added)

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Urban non-potable reuse

• Volume supplied in 2004 90,000 m3 (including
  internal uses in WWTP)
• Forecast for 2005 100,000 - 150,000 m3

19
Environmental reuse

• Volume supplied in 2004 1,500,000 m3 (includes
  discharge improvement)
• Forecast for 2005 1,500,000 m3

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Aquifer recharge

• Volume supplied in 2004 3,000,000 m3
• Forecast for 2005 3,000,000 m3

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Reclamation treatments

• Health protection criteria
• Disinfection is the essential step. Significant
  reduction of indicator microorganisms is needed
• Treatments for the conditioning of water before
  disinfection (coag, floc, sed, filt) may be
  needed
• Filters
• Open, pulsed bed (Hydroclear) 2
• Open, continuous backwash (Dynasand type) 1
• Closed, multilayer media (Culligan) 5
• UV systems
• Trojan low pressure 5
• Wedeco, low pressure high performance 1
• Berson medium pressure 3
• Environmental criteria
• Constructed wetlands 1

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Design of reclamation facilities on the Costa
Brava

• Historically, first reuse facilities only had
  disinfection of the secondary effluent
• Progressive improvement with treatments prior to
  disinfection coagulation, flocculation and
  filtration in several WWTP
• Recent reclamation treatments are the Title-22
  type, with sedimentation prior to filtration
• Disinfection combination of UV and chlorine in
  several facilities for a better overall
  performance

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Quality control

• Control parameters and strategies
• Physical and chemical parameters grab samples
  and/or on-line monitoring
• Biological treatment efficiency SS, turbidity,
  transmittance at 254 nm
• Disinfection efficiency residual chlorine
• Microbiological parameters use of indicator
  microorganisms
• Bacteria faecal coliforms, E. Coli (indicators
  of Salmonella sp. and Vibrio cholera)
• Viral bacteriophages (indicators of
  enteroviruses)
• Protozoa Clostridium spores (indicator of cysts
  of protozans such as Cryptosporidium and Giardia)
• Nematode eggs

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Effect of tertiary treatment
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Advantages of combined UV Cl2 disinfection

• UV alone cannot guarantee regularity in the
  bacteriological values unless a very high dose is
  given (high capital and operational costs)
• Chlorine is used only for microbiological
  polishing
• Alternative system in case of failure/maintenance
  of the UV system
• No microorganism is resistant to both systems
  applied simultaneously
• Cryptosporidium and Giardia are very sensitive to
  UV radiation and resistant to chlorine
• F-RNA phages, phages of Bacteroides fragilis and
  polioviruses are poorly affected by UV but
  sensitive to chlorine
• Redundancy of a key element of the tertiary
  treatment with a minor increase in the capital
  costs
• Conclusion UV allows the chlorine dose to be
  reduced and the combination of these two systems
  gives much greater consistency to the
  microbiological results

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Effect of combination of UV radiation Cl2 for
disinfection

• When UV doses are relatively low, action of
  chlorine is required in the more adverse
  situations (around percentile 90)

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Quality in year 2003
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Quality in year 2003
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Quality in year 2003
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Quality in year 2004
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Quality in year 2004
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Quality in year 2004
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Quality in year 2003
TRANSMITTANCE VALUES OF RECLAIMED WATER ON
THE COSTA BRAVA AREA. DATA FROM YEAR 2003
100
100
98
97
90
82
81
80
80
77
T254 nm,
77
74
73
73
71
71
70
70
70
68
68
68
66
66
66
63
62
62
61
60
60
60
59
57
54
54
53
53
50
Portbou
Colera
Port Selva
Cadaqués
Pals
Castell-
Castell-
Castell-
Tossa
Lloret
Blanes
Platja d'Aro
Platja d'Aro
Platja d'Aro
- UF
- OI
WWTP
P10
P50
P90
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Quality in perspective reclaimed water vs river
water
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Quality in perspective spores of Clostridium
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Quality in perspective spores of Clostridium
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Quality in perspective microorganism removal
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Quality in perspective Legionella and nematode
eggs

• Legionella
• Absence (lt 50 cfu/litre) of Legionella spp.,
  Legionella pneumophila serotype 1, and Legionella
  pneumophila serotype 2-14 in 8 samples of 2ary
  effluent and 8 of 3ary effluent from the Blanes
  WWTP (march-october 2004)
• Absencia (lt 50 cfu/litre) of Legionella
  pneumophila serotype 1 in 3ary effluents and
  sprinkler samples from Portbou, Torroella, Pals,
  Platja dAro and Lloret de Mar (juliol 2004).
• Nematode eggs (Laboratory of Parasitology,
  Faculty of Pharmacy, University of Barcelona)
• Absence in 25 litre samples both of 2ary and 3ary
  effluents (years 2002 and 2003 - one sample/year
  of each WWTP) and in 50 litre samples (year 2004
  - one sample/year of each WWTP). Only positive
  sample 1 egg/50 l in the 2ary effluent of the
  Palau-Saverdera WWTP

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Monitoring (I)

• In the WWTP Control of 2ary and/or 3ary effluent
• Daily (irrigation season) Turbidity, T254, EC,
  residual chlorine
• Twice per week (summer) or once/week (winter)
  BOD (only 2ary effluent), SS, nutrients (N and
  P), faecal coliforms
• Once/month Ca, K, Na, Mg and B
• Other parameters (Cd, Se, Mo, nematode eggs)
  once/year
• If reclaimed water is stored in ponds at the
  users site
• Same parameters dissolved oxygen
• Frequency proportional to the intensity of
  irrigation
• Once/month from november to march
• Twice/month april and may, and september and
  october
• Once/week june, july and august

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Monitoring (II)

• Monitoring allows the calculation of nutrient and
  salt contributions due to reclaimed water
• Necessary for adequate agronomic management
  (fertilization, soil preservation)
• Easy to integrate in the monitoring efforts of a
  larger WWTP or a sanitation district
• The operator of the WWTP gets the perception of
  the importance of reclaimed water quality
• Decisions are made based on quality

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Reuse improves sanitation
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Mentality change
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Other collateral benefits

• Reduction of discharges into the environment and
  nutrient recycling
• Light fertirrigation nutrients are absorbed
  progressively by the crops. Lower risc of aquifer
  pollution in comparison with traditional mineral
  fertilization

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Energy consumption (I)

• Water is a renewable resource, but many energy
  sources are not
• Main environmental burdens related to water
  management are due to energy consumption
• Reclamation treatment increases the energy
  consumption in wastewater treatment
• In urban non-potable reuse, need to evaluate the
  energy consumption of drinking water supply
• The comparison of the energy consumption of the
  DW supply and the RW supply will provide a new
  element to assess whether a given water reuse
  project increases the degree of sustainability

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Energy consumption (II)
Comparison of the energy consumption of the
different sections of the water cycle in the 27
municipalities belonging to the Costa Brava Water
Agency (Adapted from Serra and Sala, 2003)
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A few ideas on sustainability

• Water recycling projects will most likely
  contribute to greater sustainability when
• There is effective management of the total water
  demand, allowing re-allocation of resources and
  producing real freshwater savings
• The main pollutants in wastewater are being
  placed in the ecological compartment with the
  lowest adverse impact on the environment
• Treatment levels and reclaimed water quality
  correspond to the social and economic situation
  of a given community and are neither unrealistic
  nor pose an increased health hazard for the
  population
• The energy consumption of water recycling
  (reclamation plus distribution) is lower than
  that of some drinking water sources, so both
  water and energy are being conserved
• The positive externalities are being measured

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Conclusions

• Wastewater reclamation in a touristic area
  demands dealing with a permanent variability
• Wastewater reclamation and reuse needs a change
  of paradigm, from discharge to supply
• In the Costa Brava, improvements in the reclaimed
  water quality have been achieved after
• Improving the design and operation of reclamation
  treatments
• Establishing operational protocols for the
  operators
• Pro-active attitude and team work are fundamental

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Acnowledgements

• Other CCB staff
• Xavier Tristán, Carlos Nieto, Josep Cullell, Anna
  Arnau, Enric Pallarès
• Searsa Costa Brava Nord
• Anna Huguet, Marc Carré, Joan Colom
• Searsa Costa Brava Centre I
• Josep Ferrer, Jaume Pagès
• Searsa Costa Brava Centre II
• Jordi Muñoz, Sònia Costa, Andreu Bosch
• Netaigua-Passavant UTE
• Francisco Humbert, Maribel Marín, Estel Dalmau,
  Montserrat Soler
• Assistants
• UPC Rafael Mujeriego
• Free-lance Jordi Sala