STRENGTHENING THE SCIENTIFIC FOUNDATION OF WATER QUALITY PROGRAMS IN CYPRUS; DECISION ASSIST MODELS FOR THE LARNACA SALT LAKES

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1 STRENGTHENING THE SCIENTIFIC FOUNDATION OF WATER QUALITY PROGRAMS IN CYPRUS; DECISION ASSIST MODELS FOR THE LARNACA SALT LAKES Chrstos C. Anastasou*, and Charalambos Panayotou** *Assstant Professor. Dept. of Cvl Engneerng; Frederck Unversty, 7 Y. Frederckou Street; 1036 Ncosa, Cyprus. E-mal: c.anastasou@frederck.ac.cy ** Managng Drector, Atlants Consultng Cyprus, Ltd. ABSTRACT In the framework of an EU funded, LIFE+, project, enttled Strengthenng the Scentfc Foundaton of Water Qualty Programs n Cyprus, a quanttatve methodology for the ntegrated management of water qualty, at the watershed level, s beng developed, and wll be demonstrated for the rver basn of Kalo Horo, Larnaca, whch feeds the unque aquatc ecosystem of the Larnaca Salt Lakes n Cyprus. One of the central themes of ths effort s the ntroducton of the concept of the Total Maxmum Daly Load (TMDLs) as a means of enhancng the procedures for water qualty management. In our procedure, essental descrptors of an ecosystem, such as hydrologc parameters, water quantty nflow, are smultaneously consdered wth polluton source descrptors, such as key pollutants, polluton sources. The actual development of TMDLs wll be accomplshed through the use of quanttatve, optmzaton, models that can ntegrate polluton sources wth ecosystem functons. Wthn ths context, ths paper presents an optmzaton model for supportng decsons concernng water qualty n watersheds, appled to the Kalo Horo, Larnaca watershed. From the development of a rudmentary form of the decson models, t proved to be exceptonally challengng to quantfy the manner n whch such thngs as bodversty, or aesthetc value, can be nfluenced by basc factors such as nutrent and BOD nflows to the system. The decson varables of the model were defned to be the area of new development n the regon (e.g. the land area to be devoted to agrcultural actvty), the number of anmals to be permtted for the regon (e.g. the number and sze of anmal farms to be allowed), or the number of new resdental space that could be permtted n the regon. These decson varables are connected to one another through a set of basc parameters that nclude water quantty flows n the watershed (affectng salnty regmes), nflow of basc macro-nutrents (Ntrogen and Phosphorus) and BOD. Among objectves to be examned, reducton of treatment costs, maxmzaton of economc proft, maxmzaton of bodversty (and/or bomass productvty), and mnmzaton of aesthetc deteroraton, are sngled out. Among the constrants, envronmental laws and regulatons are mperatve, as well as possble budget constrants, or town-plannng zonng constrants. KEYWORDS Water Qualty Management, TMDL, Regonal Envronmental Management Optmzaton, Watershed Management, Decson Support Model, Cyprus, Salt Lake. 1

2 1. INTRODUCTION The overall project targets the problem of ensurng the good ecologcal status of water bodes n Cyprus. In general, t ams to create the capactes and tools to facltate the desgn and montorng of cost effcent water qualty management programmes and measures. Water systems n Cyprus are facng ncreasng pressures both from human nduced actvty and natural weather / hydrologcal changes. Water avalablty has n recent years been the most pressng ssue due to the ongong drought. A sgnfcant porton of aqufers are facng depleton and or water qualty problems, wth salne ntruson beng a major concern. At the same tme urban non pont polluton has been one of the man sources of pressure and, though the mplementaton of drectve (91/271/EEC) wll help to mnmse urban polluton mpacts, such pressures wll lkely contnue to exst. Agrculture s a major contrbutor to non-pont polluton regardng nutrents, BOD and bocdes, whle t s puttng tremendous pressure on water avalablty. Measures for the control of non-pont polluton such as the Code of Good Agrcultural Practce help to reduce pressures from agrcultural polluton. However such measures concentrate on the mplementaton of prescrbed pollutant control measures, usually homogeneously n applcable actvtes, and do not extend to wder polcy level control. The severty of measures also s not drectly lked to ntegrated mpact of beneft analyss thus effcency and cost effectveness are not ensured. Measures stemmng from legslaton such as drectve 91/271/EEC, the sold waste drectve, the Ntrates drectve, IPPC, EIA and SEA drectves etc are all contrbutng towards mnmzng polluton. However, at present, each of these drectves s treated ndvdually and an ntegrated strategy that can gude the mplementaton of an effcent and cost effectve ntegrated management plan s absent. Water abstracton, for example, s generally montored and controlled. However, there are no techncal tools to lnk abstracton rates to overall water avalablty (based on ranfall patterns) and water qualty. Water body management requrements stem from a varety of legslaton, the Water Framework drectve beng the major drver for preparng rver basn scale management plans. Despte the fact that a rver basn management plan s currently under development n Cyprus, t s antcpated that a gap wll reman concernng the ntegraton of polces and measures drectly related to envronmental and bodversty management. For example EIAs, Bodversty Management Plans, effluent emsson permts, changes n agrcultural crops all can place requrements on water bodes that wll need to be ncorporated n an ntegrated water qualty management system. One of the central themes of ths effort s the ntroducton of the concept of the Total Maxmum Daly Load (TMDLs) as a means of enhancng the procedures for water qualty management. A TMDL s the maxmum quantty of a pollutant, whch a water body can receve, wthout jeopardzng ts desred functons. TMDLs are currently used n the USA as a tool for allevatng envronmental pressure on ecosystems that are already consdered perturbed. A novelty of our work les n the fact that we wll use TMDLs as an umbrella tool that wll assst the management of water qualty by adoptng a top-down approach, as opposed to a bottom-up approach, currently used, for all watersheds, regardless of ther current condton. In ths procedure, essental descrptors of an ecosystem, such as hydrologc parameters, water quantty nflow, are smultaneously consdered wth polluton source descrptors, such as key pollutants, polluton sources. These are coupled wth ecosystem functons, when devsng a management scenaro. 2

3 The actual development of TMDLs wll be accomplshed through the use of quanttatve, optmzaton, models that can ntegrate polluton sources (rver-basn users and uses) wth ecosystem functons, as opposed to the tradtonal approach that solates sngle pollutants and the respectve ecosystem functons affected. The decson models wll have the capablty of beng used n the development and examnaton of water qualty management scenaros for the area. Specfcally, these models seek to assst the Department of the Envronment of the Republc of Cyprus n the examnaton of Envronmental Impact Assessments, as well as for the ssue of permts/lcenses for possble new developments n an area. The once smplfed scheme of ssung dscharge lcenses, for any gven area n Cyprus, has evolved nto an mportant and dffcult task, f one s to consder new restrctons stemmng from EU drectves and procedures, as well as the comng-nto-the-foreground of a broad spectrum of stakeholders. To ths end, decson support tools have to be developed n order to assst such top management, or regulators, n takng the best possble decsons. The best possble decson, or the optmum decson, can be dentfed prmarly wth the use of optmzaton technques. Optmzaton plays an essental role n modern world. Arsng problems that nvolve mnmzng treatment cost, mnmzng the dscharge of a specfc pollutant, or, on the other hand, maxmzng beneft (however ths may be defned by the varous stakeholders), seek for solutons n the optmzaton theory. Some of these problems can be expressed n the form of lnear optmzaton problems wth constrants and can be solved by the Smplex method (Rardn, 2009). The method was ntroduced by the Amercan mathematcan George Dantzg n 1947 and ts contrbuton n optmzaton theory has classfed t as one of the top ten algorthms of the century (Dongara & Sullvan, 2000 and Cpra, 2000). Other problems though possess addtonal complexty n the sense that they enjoy nteger solutons or can only be expressed n terms of nonlnear expressons. To ths end, several technques have been developed to tackle these ssues (Ruszczynsk, 2006) but no unfed methodology exsts for fndng unque solutons for all cases. The objectve of the research team, for ths project, s to ntroduce a new method to whch state of the art analytcal tools and supplementary decson support nstruments (stakeholder partcpaton, optmsaton tools) are brought together to enhance the scentfc base of water qualty management. The paper s structured as follows: In secton 2 the area, used as the case study for ths work, alongsde pressures and set objectves, s descrbed. In secton 3 the decson support framework s defned and the mathematcal expressons calculatng overall beneft for the watershed are derved. The optmzaton problem that mnmzes cost subject to qualty s presented and t s explaned how ths transforms to a mxed nteger mult-objectve problem. Further, model lmtatons and challenges are elaborated. 2. DESCRIPTION OF STUDY AREA The selected study area (Kalo Horo catchment) drans nto the Larnaka Salt lakes (Fgure 1). The two salt lakes of Larnaka are the second n sze and mportance n Cyprus after the salt lake of Akrotr n Lmassol. The area supports a large varety of extended and representatve halophlous wetland habtat types whle s host to more than 100 brd speces and s mportant at Natonal as well as nternatonal level. For these reasons the ste s ncluded n the NATURA 2000 network and desgnated as a Ramsar ste. 3

4 Fgure 1. Satellte mage of Study Area (Google Maps, February 2011) Despte ts ecologcal mportance the ste s severely stressed by human actvtes. Industral polluton from the Aradpou ndustral zone, non-pont polluton from agrcultural and farmng actvty, the Larnaca arport and the Larnaca Sewerage Treatment Staton all threaten the ntegrty of the ecosystem. Lastly, the lakes are recpents of surface ranwater runoff from the cty of Larnaca. A further ssue arses wth the constructon of the Larnaca storm water dranage system. At present a large part of the Larnaca Western area drans n the salt lakes. It thus appears that storm dranage management optons can have a sgnfcant mpact on the lakes. Dsposal of the storm water at sea may have mpacts of water avalablty and the duraton each year durng whch the lake area s flooded. Ths s a vtal aspect for the survval of many of the speces hosted n the area. On the other hand, dvertng the water to the lake may have other mpacts from ntensfed peak flows due to a more effcent dranage regme than at present and ncreased nflow of urban area related pollutants (hydrocarbons, ols, partculates etc). Further concerns over water avalablty are caused by ncreasng demand for water dverson and abstracton wthn the catchment as well as the decreasng amounts of ranfall recorded over the last years. 3. DECISION SUPPORT FRAMEWORK In ths secton a basc descrpton of the water qualty decson support framework, as developed for the Kalo Horo Watershed, s provded. 3.1 PROCEDURE OVERVIEW The quanttatve methodology, for the ntegrated management of water qualty, at the watershed level, that s beng developed, utlzes state-of-the-art software (ArcGIS), computer models (such as US EPA s HSPF and AQUATOX), and Decson-Support Optmzaton Models. Wth the ntaton of ths procedure, t s antcpated that the capacty for the development of scentfcally-sound water qualty management scenaros, based on quanttatve procedures, wll be provded and demonstrated. Essentally, whle the optmzaton procedures wll empower decson-makers to examne 4

5 a varety of management scenaro, nformaton that wll feed nto the optmzaton models wll come from smulaton models and from GIS, or other databases (Fgure 2). Fgure 2. Overvew of Decson Support Framework. 3.2 MATHEMATICAL MODEL DEVELOPMENT Optmzaton technques are often used n producng solutons to problems nvolvng multple crtera. However, such tools are often controversal as results greatly depend on subjectve opnons regardng crtera values and weghts. In the course of the project, applcaton of an optmzaton methodology ams ndeed to demonstrate the senstvty of decson makng methods to crtera values as well as perceved opnons regardng the relatve mportance assgned to conflctng water use requrements. A water qualty decson support model for the Larnaca Salt lakes was developed followng major stakeholders contrbuton clarfcaton. To enable robust elctaton process a focus group, representng academa, regulators (Department of Envronment), and the consultng ndustry, has been formed. Engneers and scentsts from dfferent academc backgrounds, ncludng bologsts, envronmental engneers, hydrologsts, and economsts, were represented n ths group. The fact that a number of dfferent users are wthn the watershed of nterest, complcates thngs, wth regards to what weght one may place on any gven use. For nstance, t s not an easy matter for an actvst group that wants to mnmze any perturbaton to the natural functons of the salt lakes to agree wth an anmal farmer who wants to mplement yet another anmal husbandry unt wthn the vcnty of the lakes. In order to develop the optmzaton model concept, the functons of the Larnaca Salt Lakes that are consdered essental to mantan were elcted. Further, the varous actvtes/uses n the gven watershed were elaborated. The decson varables chosen for the model were the area that could be devoted to a certan use/actvty n the watershed. For example, a decson varable would be the area (.e. hectares) for X crop to be cultvated, or the area for Y type of constructon development (resdental, commercal, etc.). Also, concernng anmal farmng, the Z number of anmals to be 5

6 housed n a new farm n the area consttutes a decson varable. Other uses, that are ncluded as decson varables n the model nclude the number of new ndustral plants that may be permtted wthn an area of nterest, or any new tourst development that may be allowed. Each of these decson varables s related to a set of basc parameters (specfcally, nutrents, BOD, salnty) that then map onto watershed functons that were chosen to be mantaned (e.g. bodversty, ecosystem productvty, aesthetc value). However, snce t s one of the goals of ths effort to be able to assst decson-makng by consderng the overall beneft for the regon, a scheme through whch weghts to each one of the man, possble, land uses and system functons (.e. crop cultvaton, anmal farmng, ndustral actvty, commercal and resdental development, tourst development, bodversty, productvty, etc.) for the area of nterest was devsed. Specfcally, the overall beneft for the area can be expressed by Beneft = W S (1) n C C s the set that contans the varous watershed uses/user categores, W stands for the qualty weghtng factor of category and S s the score of the correspondng category. W s a globally known weght whle the score S s calculated usng the expresson: S = W S (2) jn C In ths case, C s the set that contans the specfc components of use-category, W stands for the weghtng factor of component j of the correspondng use-category and S s the score of the correspondng component. Combnng all formulas together we get that the overall beneft for the watershed s gven by: Beneft = n C W j n C W S Although the overall objectve of ths model was to Maxmze Beneft, as stated above, t remans that there are a seres of ndvdual objectves that can be examned separately, consttutng ths as a multobjectve optmzaton model. Indvdual objectves nclude the mnmzaton of cost of treatment, for the area, to meet a certan envronmental crteron, or regulaton. Ths objectve functon could be expressed n the followng mathematcal formulaton: (3) Mnmze: N n S = 1 t= 1 C S X, t S, t (4) N n p p Subject to: [ X S, t ( % R ) W ] t S S = 1 t= 1 S, t { 0, 1} p 100 T p (5) X S, t (6) 6

7 where C S,t s the cost of usng treatment method t at watershed use-category S, X S,t s a bnary varable ndcatng whether or not a specfc treatment method t s used wthn the context of use category S. R t p s the percent removal of pollutant p by technology t, W S p s the waste load of pollutant p for use-category S, T p s the collectve loadng target for pollutant p, n s the number of avalable alternatve technologes, and N s the total number of watershed uses consdered n the study area. Eq. 4 represents the total cost of the waste reducton strategy. Eq. 5 ensures that the total release of pollutant p from the collecton of farms s wthn a specfed target. Eq. 6 lmts the varable X S,t to be bnary (X S,t = 1 f treatment system t s allocated to watershed use-category S). 3.3 POSSIBLE SCENARIOS TO BE EXAMINED Ths model can be extended to analyze a range of dfferent scenaros. For example, to examne the effect of dfferent pollutant dscharge targets (whch can be any Water Qualty Crteron.e. nutrents or organcs loadngs, other rules & regulatons stemmng from Cyprus or EU legslaton, or varous Red-lnes as these are artculated by stakeholders) on cost, the model can be resolved for dfferent values of the loadng target T p for each pollutant n the pollutant constrant (Eq. 5). These solutons would represent the non-nferor tradeoff between cost and allowable loadng of a pollutant. By repeatng ths for dfferent pollutants whle constranng the loadng from the other pollutants, the effectveness of a technology allocaton strategy n reducng dfferent pollutants smultaneously can be evaluated. Ths s crtcal n regons where more than one envronmental goal must be met at mnmum cost. Ths capablty of the model s especally mportant, consderng that one of the man objectves of ths work s to help develop TMDLs whle examnng, smultaneously, the overall beneft for the gven regon, and not ndvdual objectves, whch can be altered based on a stakeholder category wants. The results expected from the mplementaton of the decson models, other than the management scenaros that wll be developed, wll nclude a set of trade-off curves, between the varous objectves for the studed area (as these are dentfed by the varous stakeholders). 3.4 MODEL CHALLENGES AND LIMITATIONS From the development of a rudmentary form of the decson models, t proved to be exceptonally challengng to quantfy the manner n whch such thngs as bodversty, or aesthetc value, can be nfluenced by basc factors such as nutrent and BOD nflows to the system. The decson varables of the model were defned to be the area of new development n the regon (e.g. the land area to be devoted to agrcultural actvty), the number of anmals to be permtted for the regon (e.g. the number and sze of anmal farms to be allowed), or the number of new resdental space that could be permtted n the regon. These decson varables are connected to one another through a set of basc parameters that nclude water quantty flows n the watershed (affectng salnty regmes), nflow of basc macro-nutrents (Ntrogen and Phosphorus) and BOD, as well as toxc substances such as heavy metals from ndustral and other actvtes. Among objectves to be examned, reducton of treatment costs, maxmzaton of economc proft, maxmzaton of bodversty (and/or bomass productvty), and mnmzaton of aesthetc deteroraton, are sngled out. Among the constrants, envronmental laws and regulatons are mperatve, as well as possble budget constrants, or town-plannng zonng constrants. 7

8 4 CONCLUSIONS Operatng n a complex envronment such as the one that prevals today, where many uses n a gven watershed often come nto conflct wth desred functons of a system, mposes the need for agle and vglant regulaton behavor to mnmze costs and delver solutons that satsfy many dfferent stakeholders. More mportantly, such optmzaton frameworks can provde, not the optmal soluton, but good startng ponts for dscusson for stakeholders n focusng on the real ssues wthout becomng entrenched n ther respectve postons. Further, t s essental that new management tools, such as the use of TMDLs, whch we envson to ntroduce for Cyprus, are steeped n quanttatve data that encapsulate whole concepts, as opposed to ndvdual parameters that can often lead to sub-optmal drectons. Asde from the management strateges developed through the proposed framework, alternatve management approaches are currently used n other envronmental felds. For example, transferable (tradable) permts are an economc polcy nstrument under whch rghts to dscharge pollutants or explot resources can be exchanged through ether a free or a controlled permt-market. Transferable permts could be excellent nstruments to meet regonal envronmental goals whle allowng more freedom to regulators n mplementng watershed-use optons, thus addressng equty concerns. Past mplementatons showed that transferable permts lead to cost-effectve and equtable solutons for regons (Musole, 2009). Ths modelng effort s stll n ts nfancy. Despte the fact that ntal thoughts have been put to paper, t remans that the model s mplemented, usng data that s currently beng collected / developed for the case study, on an optmzaton platform. Further, work that stll can be undertaken under ths project would be to run extensons of ths model to examne a number of dfferent management scenaros, as well as nclude alternatvegeneraton capabltes plus uncertanty analyss capabltes to the optmzaton framework. 5 ACKNOWLEDGEMENTS We would lke to acknowledge the fnancal support, for ths project, from the LIFE Programme of the European Unon (Project: LIFE 08 ENV/CY/000460). 6 REFERENCES Cpra, A., B., (2000). The Best of the 20th Century: Edtors Name Top 10 Algorthms. Sam News Volume 33, Number 4. Dongarra, J. and Sullvan, F., (2000). Guest Edtors' Introducton: The Top 10 Algorthms. Computng n Scence and Engneerng, January/February, 2 (1). Musole, M Property rghts, transacton costs and nsttutonal change: Conceptual framework and lterature revew. Progress n Plannng, Volume 71(2): Rardn L. R. (1998). Optmzaton n Operatons Research. Prentce Hall, New Jersey. Ruszczynsk A. (2006). Nonlnear Optmzaton. Prnceton Unversty Press, New Jersey. 8