Brine Discharge from Desalination Plants: a Modeling Approach to an Optimized Outfall Design

Desalination 214 (2007) 241–260

Brine discharge from desalination plants: a modeling approach to an optimized outfall design

I. Alameddine, M. El-Fadel* Department of Civil and Environmental Engineering, Faculty of Engineering and Architecture, American University of Beirut, Bliss Street, PO Box 11-0236, Beirut, Lebanon Tel. +961 (1) 374374, ext. 3470; Fax: +961 (1) 744462; email: [email protected]

Received 6 June 2005; Accepted 4 February 2006

Abstract Desalination was for long considered a technology too expensive to adopt in most arid countries except those with large reserves of fossil fuels and affluent economies. Recent advances in desalination technology have abolished this old paradigm and have increased its market share in many arid and semi-arid countries. Nevertheless, the introduction of a desalination plant will inevitably be associated with several potential adverse environmental impacts particularly on the marine ecosystem as a result of effluent (brine) discharge. This paper focuses on simulating the dispersion of the brine plume in the marine environment by considering the heated effluent from a desalination-power plant in the Gulf region. Various scenarios were defined and simulated using the CORMIX model to compare the mixing behavior and efficiency of surface, submerged single-port as well as submerged multi-port outfalls taking temperature variations as an indicator. The simulations capitalized on the inadequacy of widely used surface channel discharges in achieving the required dilution rates capable of minimizing potential environmental impacts on the Gulf. A sensitivity analysis was conducted to identify most influencing input parameters on simulation results as well as evaluate management options to minimize adverse impacts of desalination-related marine discharge.

Keywords: Desalination; Brine discharge; CORMIX; Discharge outfalls; Sensitivity analysis

1. Introduction Today 40% of the world’s population, most of In August 1999 the world human population whom live in arid countries, suffer from water exceeded the six billion mark signaling the ever- shortage. This ratio is expected to increase to increasing pressure on available water resources. 60% by the year 2025, due to population growth, improvements in lifestyle, increased economic *Corresponding author. activity, and increased contamination of existing

0011-9164/07/$– See front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2006.02.103 242 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 water supplies [1]. As a result, unconventional water resources such as desalination are increas- ingly becoming inevitable sources to alleviate water scarcity. The introduction of desalination plants, however, has been associated with several potential environmental impacts, the most important of which is perhaps the open discharge of the concentrated brine into the marine environment. Limited efforts have targeted the characterization of the impacts of brine discharge on the marine environment. Using a two-dimensional advection- diffusion equation, Purnama et al. [2] concluded that discharging brine through a surface outfall adversely impacts coastal waters and promotes Fig. 1. Brine discharge assessment methodology. saltwater intrusion. Biodiversity monitoring data collected within an area 100–200 m away from mental degradation. The general methodology the outfall of the Dhkelia RO plant in Cyprus adopted in the study is summarized in Fig. 1. revealed that littoral fauna and flora were affected by the brine discharge [3]. Conversely, a survey of the plankton community within the outfall bay 2. Brine characterization and impact of the Al-Jubail desalination plant in Saudi Arabia did not show significant change in the The main waste stream resulting from the distribution of phyto and zooplankton, which was desalination process is the concentrated effluent attributed to high dilution rates attained through that is referred to as brine or brine-blowdown. the use of a 1.8 km long cascading channel [4]. The brine is usually more saline than the raw The objective of the present study is to seawater and above its ambient temperature compare the effectiveness of various discharge although it reflects most of its chemical consti- outfalls on diluting the brine-blowdown gene- tuents. In addition to major constituents presented rated from desalination plants by taking a power in Table 1, the brine usually contains corrosion generation and water distillation station in the products, halogenated organic compounds, oxy- Gulf region as a case study. For this purpose, the gen scavengers, various acids, and a combination brine characteristics and potential impact were of anti-scaling/fouling/foaming/corrosion addi- first reviewed then the plants’ operating condi- tives at relatively low levels depending on the tions as well as the hydrodynamic characteristics desalination process involved [5]. of the area were defined. Various simulation Brine disposal has the potential to degrade the scenarios accounting for surface discharge chan- physical, chemical and biological characteristics nels, single-port outfalls, as well as multi-port of the receiving water body. The degree of degra- diffusers were assessed to determine the optimal dation is highly dependent on the total volume of outfall structure. A parametric sensitivity analysis the brine being released, its characteristics, the was conducted to evaluate the effect of the dilution rate prior to discharge, and the charac- various input parameters on the simulated results. teristics of the receiving waters. The effect of the Finally, management options were examined to brine on the environment is also highly dependent determine their effectiveness in reducing environ- on the geometric installation of the discharge I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 243

Table 1 Comparison between the chemical characteristics of the feed and brine water

Parameter Um-Alnar Planta Taweela A Planta Abu Dhabi Planta Doha West Plant Intake Brine Intake Brine Intake Brine Intake Brine water water water water water water water water Cations Magnesium (mg/l) 1,612 3,625 1,655 3,500 1,821 3,606 NR NR Sodium (mg/l) 11,806 21,750 13,250 26,142 12,103 22,437 NR NR Potassium (mg/l) 574 870 610 830 542 845 NR NR Calcium (mg/l) 516 1,850 659 1,775 563 1,818 NR NR Iron (ppb) NR NR NR NR NR NR 19.0 25.0 Copper (ppb) NR NR NR NR NR NR 4.3 8.0 Anions Chloride (mg/l) 26,921 37,223 28,113 38,821 27,135 37,779 25,134 41,748 Sulfate (mg/l) 3,723 4,560 3,227 4,319 3,115 4,321 NR NR Bicarbonate (mg/l) 115 190 131 187 126 185 NR NR TDS (mg/l) 45,340 70,278 47,737 71,689 45,490 71,204 46,710 79,226 pH 8.1 8.9 8.3 8.8 8.2 8.9 8.25 8.93 Temperature (EC) 40–44 reported for MSF plants operating in the Arabian Gulf b a[6]. b[7]. NR: Not reported.

outfall. In open and well-mixed environments, generating a total of 15,000 MW of electric adverse impacts have been noticed mostly within power and 11.99×106 m 3/day of desalinated water 300 m from the discharge point [8]. Impacts are [36,37]. These installations discharge their efflu- more pronounced in environments that are ents directly to the Arabian Gulf, which is a located in shallow and/or semi-closed bays. Areas shallow semi-enclosed and highly saline water inhabited by sensitive or high-value organisms body that has a water residence time of 2 to are also considered to be highly vulnerable to 5 years. The seawater characteristics of the brine discharge. Table 2 presents a brief overview Arabian Gulf differ from the world’s ocean of the characteristics, loads and environmental waters in many aspects including high salinity impacts of pollutants present in brine. Readers levels and elevated water temperatures that could interested in a more detailed assessment of the exceed 45EC. While the gulf is characterized with chemical and physical characteristics of the brine a very productive and diverse ecology, these should refer to Seawater Desalination: Impacts of harsh natural conditions stress the existing biota Brine and Chemical Discharge on the Marine and often expose them to conditions at the edge Environment [9]. of their tolerance limits. The uncontrolled discharge of brine blowdown can negatively affect the marine fauna and flora by compounding on 3. Area characteristics the existing harsh conditions resulting in the loss The Gulf area houses the highest density of of important sheltering, nursing, and feeding desalination and power plants in the world sites. 24 4 Table 2 Environmental impacts of brine constituents on the marine environment

Discharged Pollutant source characteristics and Potential environmental impact pollutants discharged load

Corrosion C Mainly resulting from the corrosion of copper alloy tubing used in C Heavy metals accumulate in sediments and tissues of products MSF plants and increases significantly under high temperature aquatic organisms [6, 5, 14, 19] I. Alameddine,M.El-Fadel/Desalination214(2007)241–260 (heavy metals) operations typical of such plants C Heavy metals can redistribute the trace metals in an area C The main corrosion products in the desalination industry are copper, and change the existing phytoplaktonic and fish iron, nickel, chromium, zinc and molybdenum [1,5–7,10–13]. communities in an area [15] C Copper is the most significant heavy metal discharged from desalination. Reported copper concentrations in the effluent can exceed 0.02 ppm (200 times higher than natural marine concentrations) [5]. C Estimates indicate that desalination is responsible to the input of 2 to 13% of the natural copper load in the Arabian Gulf [9] Antiscaling C Used to remove the scale formations on the plant’s tubing C The use of orthophosphate enhances the primary additives C The main antiscalants used in the desalination industry are productivity in oligotrophic seas and increases the orthophosphate, and biodegradable polymeric additives based on occurrence of acute red and green algae blooms which in maliec anhydride or polyacrylate [9, 14, 15] turn depletes the dissolved oxygen levels [5,11,14] C Reported dosing rates for polymeric additives do not exceed C While polymeric additives are not linked with toxic 0.53 mg/L [16]. hazards their potential to cause biogenic and/or abiogenic C Anti-scaling additive concentrations at the point of discharge of MSF toxicity has not been completely analyzed [5,11] plants range between 0.53 and 1 ppm [9] Antifouling C Used to hinder the potential of bacterial, algal and other marine C Transforms stable bromides to reactive bromines additives organisms to foul the desalination plant C Forms halogenated hydrocarbons some of which are C Chlorine or hypochlorite are the main antifouling agents in use known carcinogens and mutagens [5,12,] C Chlorine dosing ranges between 2 and 5 ppm, while shock C Forms chloroamines and bromoamines which are toxic chlorination can reach up to 8 ppm [7, 17] stable compounds [5] C Chlorine concentrations at the point of discharge of MSF plants range C Results in the formation of hypochlorite ions that disrupt between 0.2 and 0.5 ppm [18] normal enzymatic and biological processes in organisms [11] C Can induce the migration of intolerant species from the affected area [11,20] I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 245 the 23] ,19,27, late in tagenic from ] 7 of the gen, u species u 3 sters [ e s [ rine a gen in the the affected area 22] in m increase [ s from stem sters [ tagens prus showed that littoral u rate of larval oy salinity 28] aquatic organism carcinogenic and m of water to hold oxy e rane sy pounds can bioaccum b tabolic rate of cold-blooded rtality e m o 25] e within an area 100–200 m [ ical reactions, changes the available s even at low concentrations pacted by of the seawater in vicinity gration of organism i pacts on som istry rphological characteristics of som o pacts 25] ] 5 increase the m increases the m reduce the levels of dissolved oxy , rine organism a s 29, 30, 6, 31, 32, 33, 11, 34, 35] ental im 11] 24] are known carcinogens and m halogenated organic com als [ e pounds [ ect heat decreases the ability pacts the reproductive organs of oy 28] anim fauna and flora were im increases the rate of chem biodiversity outfall of the Dhkelia RO plant in Cy Rej thus reducing biodiversity [ Monitoring of biodiversity discharge area [ Can affect the m Som com Can slightly tissue [ Disrupts the intracellular m Changes the chem Im Significantly outfall [ Can result in the m Can have lethal im 28] Can retard hatching of fish eggs [ Can react with halogens to form organism Stresses m Many C C C C C C C Environm C C C C C C C C ] 5 ] ] 9 9 [ bient sis. gen scavenger [ o re concentrated than o col blends [ l pollution ly a s m g in MSF plants e C above am E used oxy re concentrated than the original o 21] pounds in the Arabian Gulf is ation in MSF units s m e ical constituents of the feedwater st widely o form ol concentrations at the point of discharge c ng additives are poly i as an antiscalant 16] lene gly inly reflects the chem sulfite is the m a ed as a result of the reaction residual chlorines and ines with natural and anthropogenic organic sources propy pical dosing rates are around 0.1 ppm MSF plants have effluents 8 to 15 RO plants do not contribute to therm Usually MSF effluents are 1.1 tim feedwater [ Seawater RO effluents can be 2 tim Ty 90 % degradation is expected before discharge Poly of MSF plants range between 0.04 and 0.05 ppm Used m Acid washing can produce effluents with pHs as low 2 the original feedwater Sodium Used to reduce corrosion especially Used to prevent foam Main antifoam Form brom Main source of organic com anthropogenic releases of oil [ C C C C C C C C C C Pollutant source characteristics and discharged load C C C C C C lti-stage flash distillation plants. RO = reverse osm ing u en g pounds ect heat Rej Concentrate Acid Discharged pollutants Oxy scavengers Antifoam additives Halogenated organic com MSF = m Table 2 (continued) 246 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260

In the area proper of the desalination plant average temperature to a mixing zone of 300 m under study, seven coastal sites have been from the point of discharge beyond which the developed to produce distilled water and elec- heated discharge is expected to decrease to less trical energy. The total current installed nominal than 1EC above the ambient temperature. The capacity reaches to 1.4×106 m3/day at an opera- standard also stipulates that the effluent should ting temperature of 90EC. Most plants discharge not exceed the summer maxima nor the daily fre- their brine blowdown into a narrow bay via quency and amplitude of the ambient temperature ordinarily surface and near-shore outfalls as is the cycle beyond the 300 m mixing zone [8]. case in most desalination plants operating in the Gulf region [5]. The closed nature of the bay and the restricted hydraulic circulatory currents 5. Brine discharge modeling hinder the mixing and dilution processes and may 5.1. Model description result in the recirculation of the discharged pollutants [38]. This situation is especially exa- The CORMIX–GI model was used to simulate cerbated at the plant site due to the shallowness of the development of the brine plume resulting its area within the bay and characterized with from the continuous discharge of the brine blow- more limited circulation patterns and is mostly down from the MSF desalination power plant. composed of intertidal mud beds. This shallow CORMIX is a United States Environmental bay is utilized to discharge the resulting brine Protection Agency (USEPA) approved simulation blowdown after mixing with the once-through and decision support system that has been cooling water (the plant follows a combined adopted for assessing the environmental impacts distillation-power cogeneration and its exact resulting from point source discharges within coordinates are kept anonymous at the request of their mixing zones [41]. The model is subdivided the plant management; it is of the MSF type and into three separate sub-systems namely: COR- was built in the early 1980’s to supplement the MIX 1 for the analysis of submerged single port area’s increasing power and water demands). discharges, CORMIX 2 for the analysis of submerged multi-port diffuser discharges and CORMIX 3 for the analysis of buoyant surface 4. Standards and regulations discharges. It is capable of predicting the effluent dilution rate and the plume trajectory from the In general, the development of specific and point of release into the far-field by analyzing and comprehensive standards regarding the discharge combining the solutions of several flow patterns of brine concentrate to water bodies is still lack- [42]. ing because the desalination industry-regulatory interface is relatively new and in developmental stages [10,39,40]. Current regulatory attempts 5.2. Simulation scenarios focus on defining plant-specific mixing zones at Three basic scenarios were examined to com- the point of discharge. These zones take into pare the mixing behavior and efficiency of sur- account the capacity of the receiving water to face, submerged single-port as well as submerged dilute the effluent and limit aquatic degradation multi-port outfalls into shallow waters typical of spatially and temporally. the Arabian Gulf, with the subject plant as a case The adopted mixing zone standard in this study (Table 3). The first scenario, S1, evaluates study was proposed by Khordagui [7]. This the adequacy of surface discharge outfalls widely standard restricts the increase in the weekly used in most desalination plants along the I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 247

Table 3 Simulated scenarios and sub-scenarios

Scenario Module Description of scenario Sub-scenario S1 CORMIX-3 Simulates current brine discharge conditions practiced in the plant, i.e. surface discharge into the bay at an average depth of 0.6 m, an ambient velocity 0.182 m/s, and a heat loss rate of 40 W/m2/EC S2 CORMIX-1 Simulates discharge of brine through a single-port submerged outfall extended deep into the bay 4 m from the nearest bank at a depth of 20 m, an ambient velocity 0.182 m/s, and a heat loss rate of 40 W/m2/EC S3 CORMIX-2 Simulates discharge of brine through a multi-port S3.1: Staged multi-port submerged outfall extended to the bay, at an average submerged outfall depth of 5 m, an ambient velocity 0.182 m/s, and a heat S3.2: Vertical multi-port loss rate of 40 W/m2/EC submerged outfall S3.3: Alternating-fanned multi- port submerged outfall

Table 4 Characteristics of the simulated outfall structures

Parameter Outfall type Surface Single Vertical Staged Alternating (flush type) port fanned Port discharge velocity (m/s) 18 m/s 5 5 5 5 Distance to nearest bank (km) 0 4 2 2 2 Angle of discharge (E)90NA Alignment angle (E)NA909090 Vertical angle (E)NA9000NA Relative orientation angle (E)NANA900NA Horizontal angle (E)NA0090NA Diffuser length (m) NA NA 1,464 813 1,342 Number of ports 1 1 244 125 244 Port spacing (m) NA NA 6 6.5 5.5 Port(s) diameter (m) 13a 60.38b 0.53b 0.38b Port height (m) 0 1 0.7 0.7 0.7 Discharge depth (m) 0.6 20 5 5 5 aPort width. bDiameter of diffusers. NA, not applicable since the angles vary from one port to another.

Arabian Gulf. In the case of the subject plant, discharged deep into the bay 4 km away from the discharge occurs through a channel located within coast. The third scenario, S3, evaluates the dilu- the inter-tidal zone of the bay. The second tion rates experienced through the adoption of scenario, S2, examines the development of the multi-port diffusers. It is divided into three sub- brine plume through the use of a single-port scenarios: S3.1 to determine the dilution rates submerged outfall. In this scenario, the brine is generated through the use of a staged multi-port 248 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260

Fig. 2. Achieved plume temperature drop and dilution rates for the simulated scenarios. I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 249 submerged diffuser; S3.2 to assess the effect of a discharge thus blocking the ambient current and vertical multi-port submerged diffuser; and S3.3 reducing dilution potential. The use of a single to assess the adequacy of an alternating-fanned port submerged outfall increased dilution rates multi-port submerged diffuser for brine dilution. significantly but still failed to achieve the The spatial orientation of the adopted discharge required dilution rate within the adopted mixing ports is presented in Table 4. zone, whereby the plume temperature profile The elevated temperature of the brine blow- reaches the differential 1EC standard after down was selected as an indicator for simulating 2,685 m downstream of the initial point of dis- the dilution and mixing rates of the brine upon charge (Fig. 2c, 2d). The highest dilution rates discharge. The temperature was selected since it were obtained under the three sub-scenarios S3.1, is a conservative pollutant that has no side S3.2, and S3.3, which were able to accomplish interactions with other pollutants thus providing the required dilution rates and hence minimize an accurate description of the dilution and mixing potential environmental damage (Fig. 2e, 2f). The processes. length of the diffuser line being an important parameter affecting the total cost of multi-port outfalls renders sub-scenario S3.1 an economic- 5.3. Simulation results and analysis ally desirable option to adopt since it achieves the Simulation results in terms of achieved required temperature drop with the shortest dilution rates and the spatial drop in plume diffuser line (813 m). Fig. 3 compares the plume temperature are presented in Fig. 2. The results temperature drop under the three considered indicate that the use of a surface discharge outfall scenarios S1, S2, and S3. Evidently, the single fails to achieve the required dilution rates within and multi-port outfalls offer more effective alter- a mixing zone of 300 m under conditions typical natives in attaining the desired temperature drop of the bay (Fig. 2a, 2b). The low dilution rates are with S3 being the optimum alternative. due to the dynamic attachment of the plume to the downstream bank resulting in the formation of a 5.4. Sensitivity analysis zone in which the effluent undergoes recirculation. In addition, the shallow nature of the bay The parametric sensitivity analysis focused on leads to the bottom attachment of the plume upon the effect of varying model parameters on

Fig. 3. Comparison of the plume temperature drop under scenarios S1, S2 and S3. 250 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 nt e by . was attachm increasing 50 %. . Multi-ports affect drop in by oderately e significantly e centerline. bient velocity lations did not show xing process and the i erged outfalls. u 20 % while increasing . Flow rate variations thus resulting in a slight lti-port sim . eratures. e u lti-port subm p xing and hence m lated concentrations by u i u eratures as the am of the outfall will decrease p eratures along the plum tem erature profile of surface discharge only affects its dissipation greatly erature profile of the plum p e with the receiving water body p p e and the bottom ined the sam a e attaches to the bank. Increasing distance tem lated concentrations by u to depth changes. nt and thus is expected to enhance the dilution rate. nts. Single-port discharges showed a decrease in e e C increased the sim eratures. Single and m o increasing the dilution rates, reducing bottom p increased tem 5 eratures rem p e by of currents will enhance m ing the friction coefficient. eratures and increase the dilution rate in case of surface p erature of the effluent p xing and reducing centerline tem C reduced the sim i erature by o erature until the plum p p 2 e tem the dilution rates of single and m enhanced dilution rates. stly o bient current slightly erature by erature of the plum erature in scenarios S2 and S3, while increasing the distance case of S1 lated centerline tem p p p change while vary u lti-port discharge arrangem u ecreasing the flow rate reduces tem ncreasing the velocity Increasing the tem any Decreasing the roughness of channel in case surface discharge decreased the friction between plum decrease in the reported tem exhibited the highest sensitivity decrease plum m dilution rates and a subsequent increase in increased. the am and increasing the interaction of plum the load being discharged. In all three discharge cases, decreasing effluent tem reducing the heat load and its respective discharge velocity affect m Observations Increasing the depth of water in vicinity tem Changes in the area of single port outfall did not affect m sim thus enhancing m Changing the distance of outfall with respect to nearest bank does not affect the drop in tem the bank would retard attachm However, changing the distance to nearest bank did not significantly tem significantly the effluent tem Reducing the angle of discharge between surface outfall centerline and Decreasing the width of surface discharge outfall increased velocity D I Changes in Manning’s n affected the d ters e 0.06–1.5 Variation range 1–5 15–30 3–10 1–5 2,000–5,000 1,000–4,000 69.5–277.8 8–15 0–45 17.4–46.3 3–10 0.05 ase 0 2 0.182 0.182 0.182 0.08 0.6 20 5 case 0 4,000 2,000 27.8 138.9 138.9 138.9 10 10 10 9 1 B ) /s) C) (m E ) E ) ) ( ) a 2 is of CORMIX1, 2 and 3 to input param (m s a (m b /s) 3 n bient velocity analy ter e Surface discharge Single port Multi-port Surface discharge Single port Multi-port Surface discharge Single port Multi-port Surface discharge Single port Multi-port Surface discharge Single port Multi-port dth of outfall i Flow rate (m Current am Manning’s W Area of outfall Indicator concentration ( Average depth/ discharge depth (m Distance to bank (m Angle of discharge Param Table 5 Sensitivity I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 251 st o xing i l effect on is a s xing process ent is the m i erature in the p nim i analy all plugging. lti-port outfalls resulted in an increase u lti-port outfalls had a m u xing and dissipate the excess tem i lation efforts and the sensitivity u ent of the m eratures indicating that a perpendicular alignm p ited the sim ent to enhance m ent angles considered for the m nded to reduce deposition, pipe scouring, and outf e m xing and dilution processes. i hanges in port height of the single outfall did not affect m Observations All alignm in the centerline tem conditions that lim Variations of the outfall orientation resulted in generation unstable m suitable alignm effluent in the three cases. Changing the nozzle alignm the m C sec, recom / m direction e ariation range V 0–45 0–270 0–135 NA Fanned Sam 0.5–2.0 direction e ase case 0 90 90 90 90 NA Sam Fanned 1 B lti-port discharge (CORMIX-2) ) u E ) ) ) E E E b ( c ( for single port discharge (CORMIX-1) for m for surface discharge (CORMIX-3) c ) ent (m b ent angle ter e Vertical angle ( Single port Horizontal angle ( Staged Vertical Alternating fanned Staged Vertical Alternating fanned Applicable only Areas that translate into discharge velocities between 3 and 8 Applicable only Applicable only Outfall orientation Port height Alignm Nozzle alignm Param a b c d NA: Not applicable Table 5 (continued) 252 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 20.0 32.1 48.5 18.2 0 0.0 NA NA ND ND ! +49.8 NA NA +30.6 ! 2 NA NA NA +7.3 0.0 ! +92.1 ! +121.5 +149.7 19.7 31.5 48.0 25.2 .0 5 0 NA NA NA ND ND ! +50.4 NA NA +30.8 ! 1 NA NA +0.9 0.0 ! +89.7 ! +118.0 +140.2 20.4 31.1 1.5 47.6 30.6 0 0.0 NA NA NA ND ND ! +49.5 NA NA +29.1 ! NA NA ! 0.0 ! +84.0 ! +110.2 +21.8 (CORMIX-1 and 3) 19.9 30.2 46.2 39.2 .0 0 NA NA NA ND ND ! +49.9 NA NA +27.8 ! NA NA +0.9 0.0 ! +79.2 ! +102.4 +103.9 lations. u base case 19.9 28.9 0.8 44.7 37.9 0.0 NA NA NA ND ND ! +50.0 NA NA +26.4 ! NA NA ! 0.0 ! +73.2 ! +93.7 +85.0 20.0 26.7 4.5 41.9 35.2 .0 0 NA NA NA ND ND ! +49.6 NA NA +22.7 ! NA NA ! 0.0 ! +62.5 ! +77.6 +55.0 20.1 18.9 3.1 31.7 25.3 0.0 NA NA NA ND ND ! +50.2 NA NA +14.7 ! 13571 NA NA ! 0.0 ! +35.1 ! +41.3 +0.8 5 20.0 13.4 23.2 12.9 20.0 .0 . xing conditions that stop further sim 0 Single-port outfall NA NA NA ND ND ! +50.0 NA NA +9.1 ! 0 NA NA +0.3 0.0 ! +21.2 ! +23.2 ! i 0.7 20.1 6.4 13.9 78.8 13.9 78.8 11.0 .7 8 ND ND ! ! +50.1 ! ! ! ND ND ! ! NA NA ! ND ND ND ND e-port diffusers expressed in percent variation from on of unstable m 0.4 19.9 6.5 12.1 78.0 12.1 78.0 7.7 7.7 ND ND ! ! +49.7 ! ! ! ND ND ! ! NA NA ! +3.6 ND ND ND ) 1 8.3 3.4 0.1 11.6 19.9 6.6 11.6 77.8 77.8 7.0 14.9 .4 7 ! ! ! ! ! ND +50.4 ! ! ! ND ND ! NA NA +3.4 ! ND ! distance (Km is for surface and singl 8.9 3.9 0.5 11.2 77.1 20.0 6.7 11.2 77.1 5.5 22.8 s ! ! ! ! ! NA NA 6.3 ! +50.3 ! - ! ! ND ND 1357 ! +2.5 ined due to the generati analy 5 ownstream 9.1 4.3 0.5 10.5 76.4 20.1 6.6 10.5 76.4 3.3 . ! ! ! ! ! NA NA -18.5 ND +0.8 ! +50.0 ! ! ! ND ND 0 Surface outfall ! +2.2 D ) ) tric sensitivity e /s 3 n /s s bient velocity 3 / s / s / C ter e E C E E E 3 5 10 1 5 2,000 5,000 1 m 1.5 m 69.5 m 0.06 m 0 45 8 15 0.05 1 m 5 m 15 m 30 m 277.8 m dth of outfall (m i W Distance to bank (m Flow rate Current am NA: Not applicable; ND: determ Angle of discharge Indicator concentration Manning’s Average depth Param Table 6 Results of param I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 253 94.3 10.1 26.1 93.7 50.0 39.9 49.8 0 ! 11.7 ND ! ! 16.6 16.7 ! ! +100 2 ! ND ! +100 89.2 21.7 38.2 87.1 50.0 43.0 50.0 5 ! ND ! ! 16.4 16.5 ! 8.4 ! +100 1 ! ND ! +100 94.9 35.0 50.7 97.5 50.4 40.7 50.1 .6 6 5 0 ! 6 ND ! ! 1 1 ! ! +98.6 ! ND ! +99 102 99.4 104 49.6 38.8 50.1 ! ! 17.7 ! 14.1 5.3 ! +102 ! ND ! +100 base case (CORMIX-2) lations. u 105 4.7 50.5 64.2 109 50.3 37.0 49.8 .8 6 ! 3 ! ! ! 1 16.8 ! ! +99.6 ! ND ! +101 89.4 10.5 57.3 69.9 91.5 49.5 34.4 49.9 ! ! ! ! ! 15.6 15.1 2.8 ! +102 ! +1.5 ! +100 ) 30.6 5.6 64.5 75.5 33.7 50.5 30.4 50.0 .2 1 ! ! ! ! ! 14.5 16.3 ! +98.0 13571 ! +6.5 ! +100 distance (km sers expressed in percent variation from xing conditions that stop further sim i ble m 3 ownstream 126 49.9 28.4 49.9 . 10.5 ! 11.4 0.4 17.5 16.9 ! +100 0 ! +26.4 ! +100 D lti-port diffu u is for m s fanned fanned fanned ! ! ! analy 0.06 1 1.5 0.06 1 1.5 0.06 1 1.5 3 10 3 10 3 10 69.5 277.8 69.5 277.8 69.5 277.8c ulti port diffuser ertical V Alternating Staged M Vertical Staged Alternating Vertical Staged Alternating tric sensitivity e ined due to the generation of unsta /s) 3 /s) bient ) (m ter e Flow rate (m Current am velocity Average discharge depth (m Param ND: Not determ Table 7 Results of param 254 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 .9 .2 .9 0 0.0 0 9 0 +1.8 +5.9 0.0 ND ND ND 2 -19.8 +49.8 -19.8 +49.8 -19.9 +50.0 12.5 NA lations. 2.3 u .0 5 0 + 15.8 12.3 18.6 12.3 0.0 0.0 ND ND ND 1 -20.2 +49.6 -20.2 +49.6 -20.0 +50.0 NA 4.8 0 0.0 + 25.2 34.8 0.0 0.0 ND ND ND 7.1 -20.2 +49.6 -20.2 +49.6 7.1 -20.7 +50.0 NA 5.8 .0 4 that stop further sim 0 + 41.9 8 0.0 0.0 ND ND ND -0.4 0.0 71 -19.5 +50.1 -19.5 +50.1 -0.4 -0.2 -19.4 +51.3 NA base case (CORMIX-2) 6.4 1 0.0 + 5 105.9 -0.2 0.0 0.0 ND ND ND -0.2 0.0 -19.9 +50.2 -19.9 +50.2 0.0 -20.3 +49.4 NA xing conditions ) i 7.6 .0 0 + 68.6 83.8 -0.9 0.0 0.0 0.0 ND ND ND -0.9 0.0 -20.0 +50.4 -20.0 +50.4 -19.2 +50.9 NA 9.3 distance (Km 0.0 + 95.1 114.6 0.0 0.0 0.0 0.0 +59.7 ND ND 0.0 0.0 -20.0 +49.5 135 -20.0 +49.5 -20.9 +47.9 NA on of unstable m 3 ownstream 10.1 .0 . 0 + 0.0 0.0 229 0.0 0.0 +67.8 +66.8 ND 0.0 0.0 -20.0 +50.5 203 -20.0 +50.0 0 -19.9 +50.3 NA D sers expressed in percent variation from lti-port diffu u direction e ined due to the generati Sam 1000 4000 0 45 135 1000 4000 0 45 135 1000 4000 8 15 0 45 135 8 15 8 15 ulti-port diffuser ertical ertical is for m s V Vertical Staged, fanned Alternating-fanned Vertical M Alternating-fanned Alternating-fanned Staged Staged Alternating-fanned V Staged analy C) E ) ) E tric sensitivity e direction) e ent angle ( ter e Nozzle direction (Fanned/sam Distance to bank (m Alignm Param Indicator concentration ( Table 7 (continued) Results of param NA: Not applicable; ND: determ I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 255 simulated temperature drop and/or dilution rates. for local circulation patterns, hydrographic The simulations were conducted by varying one currents, and the hydrodynamic characteristics of parameter at a time while holding the rest the discharge area. Outfalls should avoid lagoons, constant. Table 5 summarizes the effect of input shallow water and inter-tidal areas with limited parameters on simulated temperatures with circulations and look for rather exposed coastal respect to downstream distance. The temperature stretches with strong flushing capabilities [5,7,8, variations at different downstream locations are 15]. In fact, the USEPA prohibits the discharge of reported in the form of percent change from base any effluent in shallow near-shore water bodies case and presented in Tables 6 and 7. Note that and requires the construction of offshore outfalls. variations in wind speed and in the heat loss In Cyprus, the new Larnaca RO plant (capacity coefficient did not affect concentrations and dilu- 54,000 m3/day) was required to be equipped with tion rates and thus were not reported. The results an outfall exceeding 1 km in length and discharg- indicate that the adopted flow rate, ambient ing at least 10 m below sea surface to limit brine current velocity, discharge depth, indicator level impact on existing biota [3]. Submerged dis- and the alignment angle of multi-port outfalls charge outfalls however are more costly, parti- were the most significant parameters affecting the cularly in the Gulf region since the distance development of the plume, while the roughness of required for laying down the pipes is relatively the seabed and the distance of the outfall from the long due to the shallowness of the Arabian Gulf. bank seemed to have the least significant effect The adoption of submerged multi-port diffusers is on model simulation results. expected to be cheaper than single-port submerged outfalls in the case of the Arabian Gulf since multi-ports are capable of ensuring rapid 6. Management options mixing even in shallow water bodies thus reducing the costs associated with placing pipes 6.1. Brine disposal over long distances. This is attributed to the The mitigation of environmental implications presence of a multitude of nozzles in the diffuser of concentrate disposal is most closely related to that increase the plume’s contact area with the the means through which it is managed. Several ambient water, increase initial mixing rates, and means for disposal of the concentrate are prac- reduce the downstream distance traveled by the ticed worldwide including: direct surface water plume before meeting the environmental regula- discharge, discharge to a sewage treatment plant, tory requirements [45,46]. deep well disposal, land application, evaporation Based on the simulation results presented in ponds, brine concentrators as well as mixing with this study, Table 9 outlines design recommen- the cooling water or sewage treatment effluents dations that can enhance the dilution rates of the prior to surface discharge. Table 8 outlines discharge and reduce the pollutant concentrations advantages and disadvantages of various brine for direct surface, single-port and multi-port disposal methods. Evidently, brine discharge into outfall discharges. The adoption of surface surface water bodies is the most commonly used channels for brine discharge in shallow areas with and least expensive disposal method in practice limited circulation is not adequate to achieve today [10,40,43]. Minimal adverse impacts are acceptable mixing and dilution rates. Mitigation expected if rapid mixing and dilution are ensured of adverse impacts of the direct surface discharge in the discharge zone [5,44]. These optimal of brine on the local marine environment can be mixing conditions can be attained by the careful achieved either by the construction of several design and construction of outfalls that account long single port outfalls or a multi-port diffuser. 256 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260

Table 8 Advantages and disadvantages of brine disposal options [44, 7, 10, 42, 40, 47]

Disposal method Advantages Disadvantages

Direct surface water C Least expensive C Depends on natural circulation patterns discharge C Can accommodate large volumes and hydrographic currents in the area Discharge to a sewage C Lowers the BOD of the resulting effluent C Can inhibit bacterial growth treatment plant C Dilutes the brine concentrate C Can hamper the use of the treated sewage for irrigation due to the increase in TDS and salinity of the effluent C Overload the existing capacity of the sewage treatment plant Deep well disposal C Viable for inland plants with small volumes of C Expensive brine C Needs a structurally isolated aquifer C No marine impact expected C Increases the salinity of groundwater Land applications C Can be used to irrigate salt tolerant species C Requires large parcels of land C Viable for inland plants with small volumes of C Can affect the existing vegetation brine C Can increase the salinity of groundwater C No marine impact expected C Can increase the salinity of underlying soil Evaporation ponds C A viable option for inland plants in highly arid C Expensive option regions C Can increase salinity of groundwater C Can commercially exploit the concentrate C Can increase salinity of underlying soil C No marine impact expected C Needs dry climates with high evaporation rates C Requires large parcels of land with a level terrain C Needs regular monitoring Brine concentrators/zero C Can produce zero liquid discharge C Expensive discharge C Can commercially exploit concentrate C High energy consumption C No marine impact expected C Production of dry solid waste Mixing with the cooling C Achieve dilution of both effluents prior to C Dependent on the presence of a nearby water discharge discharge thermal power plant C Combined outfall reduces the cost and environmental impacts of building two outfalls C Necessary to reduce salinity if disposing in fresh water bodies Mixing with the sewage C Achieve dilution of brine effluent prior to C The brine could enhance the aggregation treatment effluent discharge and sedimentation of sewage C Does not overload the operational capacity of particulates that can impact benthic sewage treatment plant organisms and interfere with the passage C Necessary to reduce salinity if disposing in of light in the receiving water body fresh water bodies I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 257

Table 9 Design recommendations for brine discharge

Discharge type Design recommendation a

Surface discharge Increasing the width of the channel coupled with reducing its depth is expected to increase the dilution process of the plume and enhance its ability to spread horizontally Single-port outfall Splitting the effluent flow rate between 2 or more outfalls that are adequately spaced is expected to enhance the dilution process Multi-port outfall Adopting a perpendicular alignment of the diffuser line with respect to the ambient velocity is expected to enhance the dilution process aRelevant to conditions similar to those simulated and should not be implemented to discharges under different conditions without prior verification.

Table 10 Environmental concerns and the possible mitigation measures resulting from brine discharge into a surface water body [10,15]

Environmental impact Desalination process Mitigation measure Low pH Mainly SWRO Raise pH prior to discharge Residual chlorine MSF Dechlorination prior to discharge; improved chemical control Increased temperature MSF Blending; using diffusers; using cooling pond or cooling tower prior to discharge Metal ions MSF Blending; improved chemical control, using different equipment materials (polyethylene or titanium rather than copper nickel pipes) High salinity SWRO and MSF Using diffusers; blending

SWRO = Seawater reverse osmosis; MSF = multi-stage flash.

6.2. Reducing pollutant load the desalination industry. The blow-down contains a variety of environmental pollutants that The effects of brine can also be minimized may impact the receiving water bodies. Simula- prior to the discharge phase by reducing the tions of the brine plume dispersion from a pollutant load of the effluent. Pollutant specific desalination-power plant in the Gulf region re- mitigation measures that are most commonly vealed the inadequacy of using surface discharge practiced in the desalination industry are pre- outfalls for brine disposal. Using multi-ports sented in Table 10. proved to be adequate to enhance dilution rates and limit the potential environmental impacts, 7. Conclusions and limitations whereby a tenfold dilution rate was achieved within a 300 m mixing zone. Like all models, The disposal of the brine blow-down is one of CORMIX has several inherent limitations. One the major environmental concerns associated with major limitation results from the use of hydro- 258 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 dynamically significant length scales to determine integrated water management in the ESCWA region. the flow class of the effluent and its subsequent United Nations, New York, 1996. dilution, spatial and temporal development in the [2] A. Purnama, H.H. Al-Barwani and M. Al-Lawatia, receiving water body. As such a small change in Modeling dispersion of brine waste discharge from a an input variable may result in the identification coastal desalination plant. Desalination, 155 (2003) 41–47. of a different flow class with quite different pre- [3] R. Einav, K. Harussi and D. Perry, The footprint of dictions leading to a sharp shift in the simulated the desalination processes on the environment. trajectory and mixing rates causing potential in Desalination, 152 (2002) 141–154. discontinuities in the prediction results [45]. [4] P.K. Abdul-Azis, I.A. Al-Tisan, M.A. Daili, T.N. Another limitation common to all three CORMIX Green, A.G.I. Dalvi and M.A. Javeed, Chlorophyll modules is the need to describe the actual cross- and plankton of the Gulf coastal waters of Saudi section of the water body as a rectangular straight Arabia bordering a desalination plant. Desalination, uniform channel that may be bound laterally or 154 (2003) 291–302. unbound and where the current velocity is [5] T. Höpner, A procedure for Environmental Impact assumed to be uniform thus simplifying the pre- Assessment (EIA) for seawater desalination plants. Desalination, 124 (1999) 1–12. vailing hydrodynamic regimes within an area. A [6] H.A. Abu Qdais, Environmental impacts of desali- limitation inherent to the CORMIX-3 module is nation plants on the Arabian Gulf. Proc. International its inability to simulate negatively buoyant dis- Desalination Association World Congress on Desali- charges thus limiting its applicability for brine nation and Water Reuse, Vol. 3, San Diego, 1999, dispersion [42]. Furthermore, the CORMIX pp. 249–260. model exhibited a limited capability for simu- [7] H. Khordagui, Environmental aspects of brine reject lating the discharge of large flow volumes in from desalination industry in the ESCWA region. shallow areas. Finally, model simulations could Groundwater recharge from treated wastewater. not be verified with field measurements since Expert group meeting on development of non- data concerning pollutant concentrations along conventional water resources and appropriate technologies for groundwater management in the the brine plume were not available. ESCWA member countries, Manama, 1997. [8] ESCWA (Economic and Social Commission for Western Asia). Water desalination and wastewater Acknowledgements reuse: Review of technology, economics and application in the ESCWA region. Expert group Special thanks are extended to the United meeting on development of non-conventional water States Agency for International Development for resources and appropriate technologies for ground- its support to the Water Resources Center and the water management in the ESCWA member coun- Environmental Engineering and Science Pro- tries, Manama, 1997. grams at the American University of Beirut. [9] S. Latteman and T. Höpner, Seawater desalination: Impacts of brine and chemical discharge on the marine environment. Balaban Desalination Publi- cations, Italy, 2003. References [10] M. Mickeley, Environmental considerations for the disposal of desalination concentrates. Proc. Inter- [1] ESCWA (Economic and Social Commission for national Desalination Association World Congress Western Asia) and UNEP (United Nations on Desalination and Water Sciences, 37 (1995) 351– environmental program). Proc. Expert Group Meet- 368. ing on the Implementation of Agenda 21 for the [11] A.M. Shams El Din, S. Aziz and B, Makkawi, I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260 259

Electricity and water production in the Emirates of [24] G.L. Scott, D.P. Middaugh, A.M. Crane, N.H. Abu Dhabi and its impact on the environment. McGlothin and Eatabe, in: Jolley, R.L., Brungs, Desalination, 97 (1994) 373–388. W.A. and Cumming, R.B. eds., Water Chlorination: [12] F.M.A. Al-Awadhi, The year of the ocean and its Environmental Impact and Health Effects, Vol. 3, crucial importance to the Gulf. Desalination, 123 Ann Arbor Science, 1980, pp. 501–516, cited in (1999) 127–133. Saeed et al., 1999. [13] I.D. McGregor, A.H. Sultan and A. Al-Radif, Fifty [25] A.M. Altayaran and I.M. Madany, Impact of a common misconceptions in the desalination industry. desalination plant on the physical and chemical Proc. International Desalination Association World properties of seawater, Bahrain. Water Res., 26(4) Congress on Desalination and Water Sciences, Abu (1992) 435–441. Dhabi, 1995, pp. 185–195. [26] B. Mabrook, Environmental impact of waste brine [14] M. Abdel-Jawad and M. Al-Tabtabaei, Impact of disposal of desalination plants, Red Sea, Egypt. current power generation and water desalination Desalination, 97 (1994) 453–465. activities on Kuwaiti marine environment. Proc. [27] R.A. Kryzhanovsky, Effectiveness of processing International Desalination Association World Con- resources of the continental shelves of world oceans. gress on Desalination and Water Reuse, San Diego, Nedra, Leningrad, Russia, 1989. Cited in Abu Qdais, 3 (1999) 231–240. 1999. [15] California Coastal Commission. Seawater desalina- [28] S. Iso, S. Suizu and A. Maejima, The lethal effect of tion in California, 1993. Available from: hypertonic solutions and avoidance of marine organ- http://ceres/ca.gov/coastalcomm/web/desalrpt/ isms in relation to discharged brine from a desali- dtitle.html. nation plant. Desalination, 97 (1994) 389–399. [16] A.J. Morton, I.K. Callister and N.M. Wade, Environ- [29] R.A. Hinrichs and M. Kleinbach, Energy Its Use and mental impacts of seawater distillation and osmosis the Environment, 3rd ed., Harcourt College, Phila- processes. Desalination, 108 (1996) 1–10. delphia, 2002. [17] H.K. Khordagui, A conceptual approach to the [30] GESAMP (Group of Experts on the Scientific selection of a control measure for residual chlorine Aspects of Marine Environmental Protection). discharge in Kuwait Bay. Environ. Management, IMO/FAO/UNESCO/WMO/WHO/IAEA/UN/UNEP 16(3) (1992) 309–316. joint group of experts on the scientific aspects of [18] T. Höpner and S. Lattemann, Chemical impacts from marine pollution, thermal discharges in the marine seawater desalination plants — a case study of the environment. Report Study GESAMP, Number 24, northern Red Sea. Desalination, 152 (2002) 133–140. 1984. Cited in Altayaran and Madany, 1992. [19] T. Höpner and J. Windelberg, Elements of environ- [31] L. Jensen, R. Davies, A. Brooks and C. Meyers, The mental impact studies on coastal desalination plants. effects of elevated temperatures upon aquatic inverte- Desalination, 108 (1997) 11–18. brates. Johns Hopkins University, Cooling Water [20] G.L. Seegert, Observation on fish distribution below Research Project, Report No. 4, Edison Electric sewage treatment plants in relation to chlorinated Institute, New York, 1969. Cited in Altayaran and effluents. Water chlorination-environmental impact Madany, 1992. and health effects. Ann Arbor Science, Ann Arbor, [32] C. Coutant, Biological aspects of thermal pollution. Michigan, 1979. Entrainment and discharge canal effects. In Brook [21] R. Golob and E. Brus, UNEP Regional Seas Reports A.J., ed., CRC Critical Review of Environmental and Studies, 1984, p. 7. Control Union, Carbide Corp, Oak Ridge, Tennessee, [22] M.Y. Ali and J.P. Riley, The distribution of bromi- 1970, pp. 341–381. Cited in Altayaran and Madany, nated methanes in desalination plants in Kuwait. 1992. Water Res., 23(9) (1989) 1099–1106. [33] R.M. Davies and L. Jensen, Effects of entrainment of [23] M.E. Stewart, W.J. Biogoslawski, R.Y. Hsu and G.R. zooplankton at three Mid-Atlantic power plants. Helzz, Marine Pollution Bull., 10 (1979) 166, cited Report No. 10, Electrical Power Research Institute, in Saeed et al., 1999. Cooling water discharge research project (RP-49), 260 I. Alameddine, M. El-Fadel / Desalination 214 (2007) 241–260

Palo Alto, California, 1974. Cited in Altayaran and [41] R.L. Doneker and G.H. Jirka, CORMIX-GI systems Madany, 1992. for mixing zone analysis of brine wastewater [34] J. Baum, Environmental impacts and regulatory disposal. Desalination, 139 (2001) 263–274. issues from seawater desalination: Meeting the needs [42] G.H. Jirka, R.L. Doneker and S.W. Hinton, User’s of California’s coastal communities, seminar, Uni- Manual for CORMIX: A hydrodynamic mixing zone versity of California at Santa Barbara (USCB), 1991. model and decision support system for pollutant Cited in California Coastal Commission, 1993. discharges into surface waters. DeFrees Hydraulics [35] R.O. Smith, Ecology and Field Biology, 5th ed., Laboratory, School of Civil and Environmental Addison Wesley, Longman, Menlo Park, California, Engineering, Cornell University, Ithaca, New York, 1996. 1996. [36] P. Azoury, Power and desalination in the Arabian [43] D. Squire, Reverse osmosis concentrate disposal in Gulf region: an overview. Proc. Institution of the UK. Desalination, 132 (2000) 47–54. Mechanical Engineers, 215(A) (2001) 405–419. [44] M. Ahmed, W.H. Shayya, D. Hoey, A. Mahendran, [37] IDA (International Desalination Association), The R. Morris and J. Al-Handaly, Use of evaporation biggest turnout for WSTA 6th water conference. ponds for brine disposal in desalination plants. IDA News, 12(3–4) (2003) 6–8. Desalination, 130 (2000) 155–168. [38] T. Saeed, H. Khordagui and H. Al-Hashash, Contri- [45] L.R. Davis, Fundamentals of Environmental Dis- bution of power/desalination plants to the levels of charge Modeling. CRC Press, Boca Raton, Florida, halogenated volatile liquid hydrocarbons in the 1999. coastal areas of Kuwait. Desalination, 121 (1999) [46] H.B. Fischer, E.J. List, R.C.Y. Koh, J. Imberger and 49–63. N.H. Brooks, Mixing in Inland and Coastal Waters. [39] R.L. Doneker, Personal communication. Department Academic Press, Boston, 1979. of Environmental Science and Engineering, OGI [47] J. Truesdall, M. Mickley and R. Hamilton, Survey of School of Science and Engineering, Oregon Health membrane drinking water disposal methods. Desali- and Science University, 2002. nation, 102 (1995) 93–105. [40] J.V. Del Bene, G. Jirka and J. Largier, Ocean brine disposal. Desalination, 97 (1994) 365–372.