beach wells for large scale ro plants-the sur oman case study

8/8/2019 Beach Wells for Large Scale RO Plants-The Sur Oman Case Study

1/14

IDA World Congress Atlantis, The Palm Dubai, UAE November 7-12, 2009

REF: IDAWC/DB09-106

Beach Wells for Large-Scale Reverse Osmosis Plants: The Sur Case Study

Authors: Boris David, Jean-Pierre Pinot, Michel Morrillon

Presenter: Boris DavidHydrogeologist Veolia Water France

Abstract

The Sur project involves the design, construction and 22-years operation of a new 80,200m3/day

capacity Seawater Reverse Osmosis (SWRO) desalination plant at Sur in Oman to replace the existing

12,000m3/day capacity plant. The new plant has recently been constructed and is currently being

commissioned. Like the existing plant it is to be fed 100% by water originating from beach wells drilled

at the site. This would make it by far the largest SWRO desalination plant in the world fed only by

beach wells and would contribute to show that the subsurface intake option is also feasible for largecapacity SWRO plants. The use of beach wells for such a large-scale plant however provides both

significant opportunities and challenges throughout the project delivery process, including at the design,

construction, and operational stage. These are discussed throughout this paper using the Sur project as acase study.


2/14

IDA World Congress Atlantis, The Palm Dubai, UAE November 7-12, 2009REF: IDAWC/DB09-106

-2-

I. INTRODUCTION

Seawater intake is the initial process of Sea Water Reverse Osmosis (SWRO) desalination and is ofutmost importance for desalination projects since it conditions other processes like pre-treatment,

membrane treatment and post-treatment, and it governs final water quality. The objective of seawater

intakes is to provide reliable and consistent high-quality feed water with lowest environmental impact.

Selecting the most appropriate type of seawater intake is therefore a critical step for the successful long-term operation and consistent performance of SWRO plants.

SWRO plants, especially the large capacity ones (>20,000m3/d), are traditionally and most frequently

fed by surface open intakes that pump water directly from the sea via a collecting pipe and an intake

screen. However, such intake systems provide unfiltered and often variable feed water quality (e.g. red

tides, oil spills) that requires costly pre-treatment and can lead to significant environmental impactduring operation (e.g. aspiration). In a quest to improve efficiency of SWRO plants and avoid some of

the drawbacks associated with surface intakes, the use of subsurface intakes to feed SWRO plant has

gained momentum in recent years. Although such systems have already been in operation for many

years in several countries around the world (e.g. Malta, Spain, Canary Islands, Greece, Israel, SaudiArabia, US, etc.), they have usually been restricted to smaller scale plants and it remains to be seen

whether subsurface intakes can be suitable for large scale plants [6, 8].

This article reports on a project in Sur (Oman), which involves the design and construction by Veolia

Water (VW) of a new 80,200m3/day capacity SWRO desalination plant fed by water originating entirely

from beach wells. This would make it the largest SWRO desalination plant in the world fed 100% bybeach wells and would contribute to show that the subsurface intake option may also be feasible for

large capacity SWRO plants. After initially discussing some of the key challenges and opportunities

associated with subsurface intakes, this paper seeks to illustrate those through a description of thevarious stages of the Sur project.

II. CHALLENGES AND OPPORTUNITIES OF SURFACE VS. SUBSURFACE INTAKES

There are various types and configurations of seawater intakes and as shown in Figure 1, these can be

classified into two main families [5]:

Surface water intakes (direct) Subsurface water intakes (indirect)

In the first case, water is withdrawn directly at different depths whereas in the second case, water

crosses through natural soil or sand bed and is naturally filtered before being withdrawn. Some of the

main advantages and disadvantages associated with both types of intakes are summarised in Table 1.This table shows that despite providing generally poorer water quality, surface intakes are technically

feasible almost anywhere along the coastline and offer greater certainty in terms of achieving the desired

capacity including for large scale SWRO plant. On the other hand, subsurface intakes generally provide better and less variable water quality but require favourable site conditions and are considered to be

more risky in terms of achieving the required capacity, particularly for large scale SWRO plants. Both

types of intakes also offer their own specific challenges and opportunities in terms of operation andmaintenance, as well as from an environmental impact point of view.


3/14


-3-

Figure 1 : Direct and indirect seawater intakes (after Cartier & Corsin, 2007)

Advantages Disadvantages

Surface Intakes

High flow capacity (virtually any capacitycan be designed for)

Suitable for most terrains and projects Relatively easy to build and rapid to

implement solution

Smaller footprint and less visual impact onthe seashore

Lower and more variable feed water quality(unfiltered) requiring costly pre-treatment

Vulnerable to oil spills and red tides Higher capital cost (significant for small units) Higher operational cost (maintenance) Significant environmental impact during

operation (aspiration, clogging)

Lower flexibility (all or nothing)

Subsurface Intakes

Better and more stable water qualitygenerally requiring less pre-treatment

(SDI


4/14


-4-

The decision on intake type and treatment process for SWRO projects relies on an economic

comparison. The first and main concern for comparing different water intakes is the resulting directfeed-water cost at the inlet of the SWRO plant (after pre-treatment), and the reduction of treatment cost

due to the improved feed-water quality. The second concern is the indirect cost representing the

environmental impacts of pumping seawater directly from the sea or from the groundwater system (i.e.

impact on the local ecosystem, impact on the sustainability of fresh groundwater for existing and planned pumping wells) [7]. The choice of seawater intake should therefore be based on technical,

economical and environmental considerations and is generally considered to be very site and project

specific.

As can be seen from Figure 1, there are different types of subsurface intakes, including vertical wells

and boreholes, radial collector wells, horizontal directional drains (HDD), infiltration trenches and basins. These all represent design variations that utilize the same principle of extracting filtered

seawater from below the surface near the shoreline. Each type has its own advantages, capabilities,

suitability, and cost-effectiveness for different site conditions. The feasibility, design, capacity and

performance of these types of intakes depend highly on site-specific conditions and in particular thelocal hydrogeological context. The hydrogeological properties of the site determine in particular the

most suitable type of subsurface intake, the intake structure size, the available water flows, the quality ofthe feed-water, and possible environmental impacts. Site suitability for the construction of beach wellstherefore requires that detailed hydrogeological investigations be carried out with the objectives to

establish and determine quantitatively relevant site properties. Examples of methods and survey

techniques commonly used for carrying out such site investigations are shown in Table 2.

Topographical mapping and bathymetric surveys Geological mapping and geological cross sections Review of existing well logs including oil wells and offshore wells Geophysical surveys (resistivity, electromagnetic). Remote sensing methods, aerial photographs and GIS Trial holes and geotechnical investigations Well pumping tests, including interference tests. Sampling and analyses of well water quality. Groundwater modelling

Table 2 : Examples of methods and survey techniques commonly used for site investigations

Favourable aquifers for beach wells are generally the same ones that are favourable for freshgroundwater withdrawal. This includes granular sedimentary rock aquifers (sandstones, beach and

alluvial deposits), which are the most commonly used for seawater withdrawal because they are morehomogeneous and thus less risky to develop. They also generally offer a good filtration potential,although there is often a compromise to be found between water quality and discharge rate. Fissured

and karstic sedimentary rock aquifers (limestone and dolomite deposits) are also generally favourable

because they can produce large quantities. They are however harder to develop and offer poorer natural

filtration potential (e.g. generally higher yield means lower water quality). Igneous and metamorphic


5/14


-5-

rock aquifers (basalts, lava, granites) on the other hands are usually very poor and unlikely to be

favourable for large scale subsurface intake projects.

The biggest advantages of subsurface intakes is better and more stable water quality notably in terms of

lower Silt Density Index (SDI), suspended solids, oil and grease, natural organic contamination and

aquatic micro-organisms. The water withdrawn from such intakes therefore generally requires less pre-

treatment, which in turn means lower capital costs (e.g. pre-treatment) and operational cost (e.g.chemicals and energy) for the SWRO plant. Other advantages may also include lower environmental

impact during operation and greater operational flexibility (e.g. multiple well fields). In addition,

subsurface intakes are generally less vulnerable to accidental pollutions (e.g. oil spills) and to algalblooms (e.g. red tides).

Depending on local conditions subsurface intakes may however provide only limited flow capacity andthere is always a higher risk of not obtaining the required capacity when implementing such systems (i.e.

yields need to be proven). Subsurface intakes may also be more complicated to build (e.g. HDD, radial

collector wells, tunnelling) and be slow to implement because of the need for extensive preliminary

studies. In addition subsurface intakes can have larger footprint and significant environmental impactduring construction. Finally, like their surface counterparts, subsurface intakes generally need some

form of monitoring and maintenance to prevent clogging and/or corrosion of the intake structure.

Under favourable hydrogeological conditions, beach wells are generally preferable to open intakes for

small SWRO plants, but for large plants, the distribution and large number of wells may render this

alternative less cost effective. According to a study carried out by MEDRC [6], beach well intakes canbe viable and cost effective solution for SWRO plants where:

Capacity of plant not exceeding 50,000 m3/day, The beach geological formations are granular, Aquifer transmissivity exceeds 1,000 m2/day, Impact on groundwater stocks inland does not exceed 10% of plants capacity.

The MEDRC study also indicates that many of the coasts along the Mediterranean, Red Sea, IndianOcean and the Arab/Persian Gulf meet those conditions.

III. THE SUR CASE TUDY

3.1 Context

The Sur project involves the design, construction and 22-years operation of a new 80,200m3/day

capacity SWRO desalination plant at Sur in Oman to replace the existing 12,000m3/day capacity plant.

The existing plant is fed entirely by seawater originating from 13 beach wells drilled in 3 successivephases and placed along the coastline at the Sur plant site. The capacity of the existing wells is about

30,000m3/day (i.e. 1250m

3/h).

According to the geological map of Oman shown in Figure 2, outcrops beneath the Sur area areessentially made of early tertiary (Palaeocene-Eocene) carbonates [1]. Such geological formations

usually form very productive but highly heterogeneous aquifers, as groundwater circulation in fractures

dissolves carbonates thereby creating networks of highly diffusive karstic drains and cavities. This


6/14


-6-

karstic development is well known to occur in Oman, where some of the largest cavities in the world

have been reported [2].

The local hydrogeological context of the Sur area was studied in more details for the project by a

specialist consultant appointed by the project team as early as the pre-tender stage. The studies indicated

that the Sur plant site is located at the edge of an unconfined coastal aquifer that spreads along the coast

from Bimah to Sur and beyond and that is made of early tertiary carbonated deposits disposed in sub-horizontal to slightly tilt layers [3]. The deposits comprise fossiliferous limestone with interbedded

conglomerates and belong to the Seeb, Shama and Tahwah formations that lay on top of the Rusayl marl

deposit.


7/14


-7-

Figure 2 : Simplified geological map of Oman

3.2 The Pre-Tender phase (January-June 2006)

The initial request for proposals (RFP) from the client, the Ministry of National Economy of the

Sultanate of Oman, was issued in January 2006 for the development, ownership and operation of a new

water desalination project at Sharqiyah and the privatisation of the existing Sur SWRO desalinationplant owned by the Rural Areas Electricity Company. The RFP indicated that the new plant was to be

fed by an open intake but offered the possibility to the developer to use the existing beach wells from the

existing plant at the site. Given the high quality of the water withdrawn from the existing beach wells,


8/14


-8-

VW decided at this stage to carry some preliminary hydrogeological investigations to evaluate the

feasibility of withdrawing additional quantities from the aquifer at the site thereby allowing reduce the

proportion of raw water coming from the open intake. These investigations were carried out at VWsown risk, as the costs of such studies was considered to be acceptable in view of the potential savings

that could arise from the use of naturally filtered seawater instead of unfiltered seawater for the plant

operation.

The preliminary hydrogeological investigations were carried out in May and June 2006 with the aim to

establish the potential yield of the aquifer at the site and in particular to determine whether an additional

yield of 7,800m3/h of seawater could be extracted from the site to feed the new plant. The objectives

were also to specify a technical solution (e.g. radial collector wells) capable of abstracting as much

seawater as possible. The investigations comprised an initial overview of the existing literature about

geology and hydrogeology of the Sur area, geophysical investigations (2D resistivity imaging surveys),and the drilling of 4 recognition boreholes. These investigations enabled to define the geological

structure of the area and to identify the spatial heterogeneity of the hydraulic properties of the geological

formations at the site. It was notably established that most of the structures (fractures or karstic drains)

were oriented North-South and that some were partially filled with sand and clay material.

The preliminary hydrogeological investigations led to the following conclusions [3]:

The withdrawal of large groundwater quantities at the Sur site could not be achieved with aradial collector well system, as initially envisaged. Due to the consolidated nature of the aquiferat the Sur site, several vertical beach wells would be more appropriate. Since the largest karstic

drains/cavities were found to be filled with sandy materials or clay, it was also considered that

the wells should imperatively be equipped with screened casing and gravel-pack.

The existence of high productivity zones at the site was not confirmed and the maximum yieldthat could be obtained from individual wells was estimated to be in the order of 250 to 350m

3/h.

The density of the fractures/karstic drains was found to be low with no more than 7 N-S

structures identified over the 500m of coastline. It was therefore considered that up to 10 to 15additional wells could be drilled along the coastline at the site, enabling to augment the capacity

of the existing well field by up to 5,500m3/h.

Overall, these investigations established that 75% of the seawater quantities required for the new plant

(i.e. about 9,000m3/h) could most probably be achieved by drilling new vertical beach wells at the site

(i.e. 5,500m3/h) and keeping the existing beach wells (i.e. 1,250m

3/h). However, these investigations

were not considered sufficient to validate an option relying 100% on subsurface intakes. On the basis of

those investigations, VW submitted a proposal to the client that involved feeding the new plant with

75% of raw water flow coming from subsurface intakes (i.e. vertical wells) and 25% from the open

surface intake.

3.3 The Tender evaluation to Contract award phase (June 2006 to January 2007)

During the tender evaluation phase, VW decided to carry out further hydrogeological investigations at

their own risk to determine whether the option of feeding the new plant with 100% groundwater wouldat all be feasible. These investigations took place from December 2006 to January 2007 and involved

[3]:


9/14


-9-

drilling and test pumping of 20 new investigation boreholes to determine more accurately thehydraulic properties of the aquifer (i.e. transmissivity) at various locations across the site,

geo-statistical analysis of the transmissivity data and the geophysical data obtained from thepreliminary investigations in order to obtain maps of aquifer transmissivity across the site, and

stochastic groundwater flow modelling in order to determine the maximum yield that could beobtained from wells at the site.

The pumping test schedule comprised constant yield discharge tests for each of the investigation

boreholes that were analysed using curve fitting methods. The transmissivity value obtained from the

pumping test data ranged from 260 to 26,000m2/d thereby illustrating the highly heterogeneous nature of

the aquifer at the site. The average transmissivity value obtained was in the order of 7,000m2/d, which

is quite high and confirmed the highly productive nature of the aquifer in Sur. The aquifer

transmissivity data were subsequently compared with the data obtained from the geophysical campaignof June 2006 and this showed that the transmissivity of the aquifer was well correlated with the

electrical resistivity data. Using this relationship and the geo-statistical analysis of the transmissivity

distribution, 100 maps of transmissivities across the site were generated. These maps were then

integrated into a groundwater flow model to calculate the yield that could be obtained from wells at thesite.

Numerous modelling runs then were performed for varying drawdown (5, 7.5 and 10m) and for varyingnumber (21, 78 and 140) and position of wells. These simulations showed that the maximum yield

which could be extracted from the site was very dependent on two main parameters: the number of wells

and their positions, and the allowed drawdown in each of the wells. The results of the simulationsnonetheless confirmed that the yield of 9,000m

3/h required for the 100% beach well option could most

probably be achieved at the site with a large number of wells and with a drawdown in the well

comprised between 5 and 10m (excluding the head loses due to the well itself). To explore this option

further and in particular to optimise the number and location of wells to be drilled, it was recommendedto refine the model calibration by carrying out further field investigations should the contract be

awarded to VW. It was also established at this stage that wells should be 10-14 diameter and equipped

with PVC screens in order to prevent corrosion and ageing.

3.4 Detailed design (February to December 2007)

VW was awarded the Sur project contract on 17th

of January 2007 based on the submitted proposal thatinvolved feeding the new plant with raw water coming from both subsurface and open surface intakes.

On the basis of the additional hydrogeological investigations carried out during the tender evaluation

phase, VW had however by then already taken the decision to go for the 100% subsurface intake optionand therefore proceeded to the detailed design of this option. Advanced hydrogeological investigations

were notably carried out from February to May 2007 in order to determine the number of wells that

would be needed to abstract the required 9,000m3/h of seawater for the plant and to propose optimal

locations for those wells at the site. These investigations included:

instrumentation of selected existing wells and topographic surveys, field measurement campaigns including sea level fluctuations monitoring and tidal response

analysis,

additional longer duration pumping tests,


10/14


-10-

more detailed numerical modelling in order to refine the characterisation of the spatial variabilityof the hydraulic properties of the aquifer at the site and determine the number of wells required

to achieve the target yield, and

further modelling work using genetic algorithms to determine the optimal configuration of thewell field.

These investigations enabled to compile a piezometric map of the study area, which confirmed that there

was virtually no recharge from the southwest border of the site and that the majority of the recharge was

coming from the sea. The field work also enabled to better characterise the spatial variability of thehydraulic properties of the aquifer at the site while the subsequent numerical modelling allowed to find

an optimal and robust configuration of the number, type, and location of the beach wells. Theoptimization of the wells position was based both on construction cost criteria and minimal drawdown

criteria in order to minimise both the operational costs and the environmental impacts of the facilities.

Based on this work, it was established that a well field comprising of 33 wells capable of producing 70-

100l/s each would be required to be able to withdraw 9,000m3/h from the aquifer at the site. The

configuration of the proposed well field, which included 8 of the 12 existing wells to be retained for the

project, is shown in Figure 3.

Figure 3 : Location of wells recommended at the design stage

The advanced hydrogeological investigations also enable to refine the design of the beach wells, a

typical layout of which is shown in Figure 4. It was in particular recommended that the 25 new wells be

drilled up to 100m in order to increase the contribution from the lower part of the aquifer and that the


11/14


-11-

open-holes (i.e. before casing) be developed in order to clean the karstic drains and thereby increase well

performance. It was also recommended to install 14 diameter PVC casing and screen in order to allow

sufficient clearance around the pump and ensure long term sustainability of the wells. The recommendedscreen slot size was 3 mm in order to facilitate horizontal flow through the gravel pack. The modelling

work also enabled to estimate that the average drawdown in the pumping wells would be in the order

12m, excluding the quadratic head loses caused by the wells themselves.

Figure 4 : Typical beach well layout

On the basis of those advanced investigations, VW therefore proposed to the client a solution for the Sur

project that involved feeding the Sur plant 100% with beach wells at the site. In order to reduce the riskof not obtaining the desired flow capacity from the well field it was nonetheless decided to construct the

open surface intake, but not to equip it unless development of the well field proved to be unsuccessful.

3.5 Construction (from June 2007 for plant, April 2008 for beach wells)


12/14


-12-

The drilling of the new beach wells at Sur took place between April and September 2008. The drilling

work was carried out by a local drilling contractor under the supervision of the specialist consultant

already contracted by VW for the previously described site investigations. Up to three drilling rigs weresimultaneously made available by the contractor to carry out the drilling operations. The drilling

operations involved the following tasks for each of the new wells:

ground truthing of individual well positions in order to ensure safe drilling operations andadequate well location

foam-flushed drilling of a pilot hole to full depth (i.e. 80-100m below ground) with 12 1/4 drillbit, including analysis of lithology (i.e. sampling of cuttings) and recording of critical drillingparameters (e.g. penetration rate),

airlift development of the pilot hole in order to clean up the karstic drains from clastic sedimentsand estimate the capacity of the well,

reaming of the pilot hole to full depth (if productive enough) and installation of the well casingand screen sections surrounded by gravel pack and a bentonite seal (well depth and exactposition of screen length were determined from the drilling records),

development and clearance pumping of the new well until water was sufficiently clear for pumptesting operations to commence,

carrying out of a step drawdown test and a constant rate pumping test in order to confirm theperformance and yield of each well.

Close supervision by the specialist consultant during the drilling work was considered of utmost

importance as it enabled design adaptation to be made in order to suit the ground condition encountered.

This allowed in particular relocating some of the wells that could not be drilled at the envisaged positionfor various reasons (e.g. inadequate space for safe drilling rig operation). This also allowed ensuring

correct positioning of casing and screen length in order to minimise well loses and thus drawdown.

At the time of writing all the 25 proposed new wells and three additional spare wells have beensuccessfully drilled. Table 3 shows a summary of the data obtained for each individual well during the

drilling and test pumping operations. Overall, this data suggest that aquifer and well losses are generallyboth lower than expected and thus these results are encouraging. However, the potential interferencesbetween pumped wells have not been properly evaluated yet and it is therefore too early at this stage to

attempt accurate yield/drawdown predictions. Combined test pumping of all the wells is scheduled

during commissioning of the plant in order to confirm the capacity of the Sur well field as a whole.

The new wells have all been equipped with submersible pumps and ancillary equipments. This includesa flowmeter and a pressure level transducer link to telemetry for each individual well in order to monitor

their performance. This will enable a continuous monitoring of the evolution of water levels, abstraction

rates and specific yield (i.e. flow/drawdown) of individual wells. Such rigorous monitoring is considerednecessary during full scale operation of the well field in order optimise abstraction from the well field

and to anticipate potential operational issues (e.g. well clogging, pump failure). This monitoring of well

hydraulic performance will also be combined with regular raw water sampling and analysis of key

parameters (e.g. temperature, pH, conductivity, turbidity, SDI, etc.) in order to monitor the evolution ofwater quality abstracted from each well. This well monitoring strategy will enable to optimise overall

plant performance by prioritising abstraction from the most productive and best water quality wells.


13/14

s

i

t

s

t

i

V CO

he use of

articularly i

heaper to burface inta

ntakes also

nowledgeeasibility o

ut in order

bstracted fr

lient himselhe SWRO

uch as the

he subsurfallowing S

nnovative a

IDA Wo

CLUSI

subsurface

n terms of

ild, provides. As illu

provides si

f the subssuch intake

o confirm

om such ty

f prior to thlant contra

ur project

ce intake oRO plant

d groundbr

ld Congress

T

N

intakes to

etter water

greater opstrated thro

nificant ch

rface grous. Extensiv

ith an adeq

e of intake

e bidding prtor to carry

ontract offe

tion can bconstruction

eaking solu

Atlantis, The

REF: ID

able 4 :New

feed SWR

quality and

rational flegh the Sur

llenges par

d conditioe and time c

uate level o

at any one

ocess, thereout such s

r the advan

e shared beand opera

ions to mee

Palm Dubai,

WC/DB09-10

each wells su

O plants g

lower opera

ibility andcase study

icularly for

ns is generonsuming s

certainty t

site. Unle

is generalludy. In thi

age that the

tween theion compa

their needs

UAE Novemb

6

mary data

enerally pr

tional costs.

esult is lesshowever, t

large-scale

ally requirete investiga

at the requi

s these inv

insufficiens respect D

cost incurr

onstructionies like V

.

er 7-12, 2009

ovides sign

Subsurfac

environmee impleme

plants. Thi

d to establtions theref

red quantiti

stigations a

time and fiesign Build

ed and the r

and operatto offer

ificant opp

intakes ma

tal impact ttation of s

s is because

sh and core need to b

s of seawat

re carried o

nancial reso& Operate

isks taken t

ional phaseto their cli

-13-

rtunities

y also be

han openbsurface

detailed

firm thee carried

er can be

ut by the

urces forcontracts

explore

, therebynts such


14/14


-14-

REFERENCES

1. Bechennec F et al. - Geological Map of the Sultanate of Oman, 1:1,000,000, with explanatory notes -Bureau de Recherches Gologiques et Minires, France - 1993.

2. Davison W.D. jr. - An Overview of Karst in the Sultanate of Oman NSS Bulletin, 47 (1),Huntsville (NSS) 62 1985.

3. BCEOM - Seawater catchment from drillings beneath the site of Sur (Oman) - Recognition of theextractible volume of (ground)water beneath the plant site 2007a.

4. BCEOM - Seawater catchment from drillings beneath the site of Sur (Oman) - Numerical evaluationof the extractible volume of (ground)water beneath the plant site and boreholes optimisation

2007b.

5. Cartier G., Corsin P. - Description of Different Water Intakes for SWRO Plants. IDA WorldCongress-Maspalomas, Gran Canaria Spain October 21-26, 2007 - REF: IDAWC/MP07-185.

6. Schwarz J. - Beach well intakes for Small Seawater Reverse Osmosis Plants MEDRC Project: 97-BS-015 August 2000.

7. Schwarz J. - Beach well intakes improve feed-water quality - Water & Wastewater International -November 2003.

8. Sunny Wang, Eric Leung, Robert Cheng, Tai Tseng, Diem Vuong, David Carlson, Jeff Henson,Srinivas Veerapaneni - Under Ocean Floor Seawater Intake and Discharge System - IDA World

Congress-Maspalomas, Gran Canaria Spain October 21-26, 2007 - REF: IDAWC/MP07-104.

9. Voutchkov - Desalination Challenges and considerations when using coastal aquifers for seawaterdesalination - Ultrapure Water

, September 2006 - UP230629.

beach wells for large scale ro plants-the sur oman case study

Documents