world water nov-dec pdf of chris d article

7/27/2019 World Water Nov-Dec PDF of Chris D Article

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Volume 33 / Issue 6November/December 2010

AfricaUtility operations: challenges and

priorities. Page 13

DesalinationPump energy cost reductions. Page 27

Potable Water Arsenic removal. Page 31

Formerly World Water & Environmental Engineering

Breaking traditionin flood control


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Other information

Subscription rates1 Year: UK 100, Rest of the World 125

WEF Publishing UK Limited 2009

No part of this publication may be reproduced byany means without prior written permission fromthe publishers. Every effort is made to ensurethe accuracy of material published in WorldWater & Environmental Engineering. However,WEF Publishing UK Ltd will not be liable for any

inaccuracies. The views expressed by contributorsare not necessarily those of the Editor or publishers.

The title WORLD WATER & ENVIRONMENTALENGINEERING is registered at Stationers Hall.

The magazine is printed on environmentallyfriendly paper. Both text paper and cover stock areelementary chlorine free and sourced from papersuppliers with a well planned environmental policy.

The magazine includes editorial photographsprovided and paid for by suppliers.

World Water is published 6 times a year.Periodicals postage paid at Emigsville, PA.POSTMASTER: send address changes to WorldWater and Environmental Engineering ,C/O PO Box 437, Emigsville PA 17318

ISSN 1354-313X

Repro by J Graphic & Digital Design

Printed by Buxton Press Ltd, Buxton,Derbyshire UK

Cover image: Erg Chebbi, Morocco,Photo by: Rest, istockphoto

In this issue

13 18

31 35

Features

13 Market ReportReform necessary to strengthen Russian water sector

18 Regional Focus: Middle EastTo fathom the Middle East, think water; Task forceto explore desalination effects on Gulf

22 Wastewater TreatmentReed bed technology helps utility comply withEU directive

26 Advanced Water TreatmentSmart design yields sustainable recycled watersupply in Singapore; From conception to deliveryin 30 months

33 DesalinationGRP pipe system designed for Abrera EDRdesalination plant

35 Laboratory AnalysisMonitoring method targets unexpected pollutants;New approach improves laboratory productivity

37 Asset ManagementData without frontiers

39 Sewer infrastructureMapping reveals private sewer networks

41 Mining WastewaterWater treatment technology improves gold yields

Regulars

6 Commentary8 Global News10 Milestones

43 Innovations49 Events

Editorial AdvisoryBoard

Bjorn von EulerDirector of CorporatePhilanthropy, ITT

Thierry MalletChief Executive Officer of Degrmont

Daniel W. McCarthyPresident & Chief ExecutiveOfficer of Black & VeatchCorporation

Lisa SorginiGlobal Director for Municipal Strategic Marketing, Siemens WaterTechnologies

Corrado SommarivaManaging Director, ILF Consulting Engineers Middle East

Published by

WEF Publishing UK Ltd46 Lexington, 40 City RoadLondon EC1Y 2ANUnited KingdomTel. +44 207251 8778, Fax.+44 207 336 0377www.wefworldwater.com

WEF Head Office601 Wythe Street, Alexandria VA22314-1994,USAwww.wef.org

Executive Director William BerteraWater Environment Federation

Group Publisher Jack Benson [email protected]

Editor-in-Chief Pamela Wolfe

[email protected] Nic [email protected]

Subscription EnquiriesPortland ServicesTel: +44 (0) 1206 [email protected]

Global Advertising Representatives

Europe excluding UK and Italy Tony SearTel: +44 (0)1702 258490, Cell:+44 (0) 7956 [email protected]

Italy Fabio PotestaMediapoint & Communications SRLCorte Lambruschini, Corso Buenos Aires,85 piano -interno 7/6, 16129Genova, ItalyTel: +39 010 5704948, Fax: +39 010 [email protected]

IsraelZvi Segal Direct Media Marketing Services24 Hayovel Street, Raanana 43401(PO Box306, Raanana43103) IsraelTel: +972 9 748 1806, Fax: +972 9 741 [email protected]

UK and AsiaNick OrnstienTel: +44 (0) 1223 [email protected]

North Eastern U.S. and CanadaDave Mathews or Robin Misner2420 Oak Street West,Cumming, GA30041, USAToll Free: 866 756 7811Tel: +1 678 947 9950, Fax: +1 678 947 [email protected], [email protected]

Western U.S. and CanadaTom Brun and Janice Jenkins Arnold PalmerRegionalAirport148 Aviation Lane, Suite 307Latrobe, PA 15650Tel: 724 539-2404, Fax: 724 539-2406

[email protected] Jenkins direct 724 929-3550 [email protected]

South East US and Latin AmericaCari Zimmerman601 Wythe St., Alexandria, VA22314USAOffice phone: (703) 535-5266Mobile: (703) 795-2518, Fax: (703) 684 [email protected]

Other information

Subscription rates1 Year: UK 100, Rest of the World 125

WEF Publishing UK Limited 2010

No part of this publication may be reproduced byany meanswithout prior written permission fromthe publishers. Every effort is made to ensurethe accuracy of material published in WorldWater & Environmental Engineering. However,WEF PublishingUK Ltd willnot be liablefor anyinaccuracies. The views expressed by contributorsare not necessarilythose of theEditor or publishers.

The title WORLD WATER & ENVIRONMENTALENGINEERING is registered at Stationers Hall.

The magazine is printedon environmentallyfriendly paper. Both text paper and cover stock areelementary chlorine free and sourced from papersuppliers with a well planned environmental policy.

The magazine includeseditorial photographsprovided and paid forby suppliers.

World Water is published 6 times a year.Periodicals postage paid at Emigsville, PA.POSTMASTER: send address changes to WorldWater and Environmental Engineering,C/O PO Box 437, Emigsville PA 17318

ISSN 1354-313X

Repro by j-graphicdesign.co.uk

Printed by Buxton Press Ltd, Buxton,Derbyshire UK

Cover image: A oodedroadnearRichmond in London.

Photo by: MikeGR, istockphoto.

In this issue

14 20

26 37

Features

13 Area Focus: AfricaUtility operators challenges and priorities in East Africa

14 Drainage & Flood ControlNo space is useless; Tunnel channels stormwaterdrainage to the sea

20 Water SupplyFinancial and environmental returns crucial to watersupply strategy; Seawater for toilet ushing incoastal cities

27 DesalinationReducing pump energy costs in SWRO

desalination plants

29 Potable WaterUF membranes pass test for Cryptosporidiumremoval; Progress in arsenic removal with selectivehybrid adsorbers

33 MonitoringOnline suspended solids monitoring contributes toreduced operating costs

35 StorageSpill protection depends on effective coating

37 Pump TechnologyMaking maintenance easy

Regulars

6 Commentary8 Global News42 Innovations

49 Events

Editorial AdvisoryBoard

Bjorn von EulerDirector of CorporatePhilanthropy, ITT

Thierry Mallet

Chief Executive Officer of Degrmont

Daniel W. McCarthyPresident & Chief ExecutiveOfficer of Black & VeatchCorporation

Corrado SommarivaManaging Director, ILF Consulting Engineers Middle East

World Water November/December 2010


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Chris Digman , senior principal engineer at MWH, reviews the reasonswhy an integrated, sustainable approach to managing surface water should be adopted instead of investing in traditional solutions.

No spaceis useless

14 Drainage & Flood Control

November/December 2010 World Water


4/5World Water November/December 2010

Drainage & Flood Control 15

The traditional approach o ood managementand water quality protection during major rainevents is unsustainable given the increasinglydi fcult challenges o managing greater oodrisks, complying with water quality standards,and a ording the construction o large-scalein rastructure.

Alternatively, a more easible solution is tokeep water on the sur ace. I ows are managedat source, close to where it alls, they can beslowly released downstream or returned to theground. Sur ace water once conveyed across theurban area becomes polluted, so this approachcan prevent pollution and acilitate treatment ator as close to the source as possible. Typically thisapproach may use sustainable drainage systemsand hard-engineered aboveground channels, butmost importantly they are integrated into theurban space. Australia, the United States, andsome European countries have adopted thisapproach by retroftting sustainable measuresinto urban areas.

CIRIA, the construction industry research andin ormation association, has recognized the needto help implement these measures in the UnitedKingdom. It appointed the global consultancyMWH along with the University o She feld todevelop guidance to help decision makers andpractitioners achieve this goal. CIRIA is based inLondon, England, UK.

Major ooding in the UK in recent years hashighlighted the limitations o the currentapproach to drainage. Some o the challengesthat need to be considered while developinguture water management policy and practicesare: Urban sur ace water management systems are

built upon an aging legacy o combined andsur ace water pipes.

Climate change and historical planningdecisions require the in rastructure to cope withan increasing challenge o managing greaterood risk in urban areas and pollution towatercourses and rivers.

Tighter standards through Europeanlegislation.

The traditional approach to manage oodingand limit its e ects on water quality has been tobuild large storage tanks to hold storm or oodwater within piped systems. This water isreturned to the system to eventually be treated at

the wastewater treatment works; however thisapproach is unsustainable due to the high capitaland environmental costs o continually buildingnew and larger in rastructure. Many currentsolutions will also increase operational costs byincreasing the volume o water to be treated. Thereasoning is that in rastructure assets should beconstructed in larger scale to accommodatechanging rain all patterns, which will increase theembedded and operational carbon ootprint.

Reasons for retro ttingThere are many reasons to retroft moresustainable, cost-e ective measures to managesur ace water, so the combination o these

reasons and multiple benefts created by thesemeasures are likely to drive the change inapproach. Retroftting could reduce sur acewater in combined sewerage systems, sur acewater sewers, culverts and watercourses toreduce ood risk; and reduce sur ace water incombined sewerage systems by reducing

discharges rom combined sewer over ows.These measures can provide a secondary

source o water and control pollution romsur ace water out alls including highwaydrainage that can enter rivers. They can helpmanage the impact o urban creep (propertyextensions and paving over gardens) on existingsystems; the impact o climate change on existingsystems rom increasing rain all, such as intensesummer rain storms and warmer, wet winters;impact o groundwater discharges; and extremeevents to minimize ood risk. In addition, the

retroft o sustainable measures could improvethe urban landscape o regeneration projects andcreate biodiversity and increasing greenin rastructure while minimizing the heat islande ect. This is where urban areas temperaturescan typically be 3-4C higher and lead to higherlevels o air pollution.

The UK has started to increase the use o sustainable drainage systems in newdevelopment, mainly using above groundmeasures to manage water quantity and quality,rather than installing traditional piped systems.However the rate o redevelopment o existingareas will not be enough to change watermanagement in order to reduce the volume and

avoid the repeat o ooding, pollution, and otherproblems. There ore retroftting these newmeasures into the existing urban environmentrather than increasing pipe sizes and placingstorage within the below ground system will becritical or sustainable management o oodingand water quality impacts.

Integrated approach on street levelMeasures that complement and enhance theurban space need to be sensitively introduced inorder to change the current approach to urbanwater management. Urban designers, planners,and sur ace water engineers must work togetherto success ully retroft measures. Over time,urban streetscapes could be trans ormed to re ectthe emphasis on keeping water on the sur ace.

In Australia, parts o Europe, and the USA,more sustainable ways are used to managesur ace water. This approach ensures that thepublic health benefts o traditional drainage aresustained while addressing the drivers orretroftting. To achieve this in the UK, theollowing guiding principles should be adopted. Sur ace water will be kept separate rom

wastewater. Sur ace water will be managed on the sur ace. Drainage systems will mimic natural processes,

maximizing the quantity o water andpollutants that are retained and managedat source.

The impact o sur ace water on downstreamsystems in terms o quantity and quality will bekept to a minimum.

Urban areas will be designed to accommodatesur ace ood ow at times o extreme eventsthrough the dual use o roads and pathways asood conveyance channels, and low value areas(parkland etc) used as sacrifcial ood areas.

Buildings will be designed to be resistant toooding by using materials and constructionmethods resilient to ood water.

The ull amenity and bio-diversity potential o sur ace water management systems will berealized in the context o creating good qualityurban space.

Sur ace water management will accord with thebest practices or the management o the wholeurban water cycle.

Measures will be su fciently adaptable toaddress the needs o climate change.

Finding opportunitiesRetroftting presents other opportunities that alsoenable urban planners to expand beyond betterurban drainage. This means taking a moreholistic approach to retroftting by looking acrossan entire neighbourhood or a catchment areainstead o solving only one problem. Thisapproach may consider a range o measures

across an area, which together would managesur ace water and take pressure o theunderground system.

Alternatively, opportunities may occurperiodically where we see a slow progressive, butnot necessarily joined-up suite o measuresbeing retroftted. This is likely to happen when astakeholder, particularly a local authority,recognizes the benefts o retroftting and usesmore sustainable measures during general urbanimprovements. This may include retrofttingbioretention areas such as local rain gardens in adamaged verge, or permeable pavement wherelocal parking areas are renewed. This approachcould also be used during the re urbishment and

regeneration o areas. Installation o suchmeasures should be done sensitively to enhanceand add value to the existing urban area.

The broader needs o urban society should beconsidered when exploring water managementsolutions. It is a antastic opportunity to enhanceurban living space while also managing excess

An aboveground channel designed to convey ow to a storage pond.


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16 Drainage & Flood Control

November/December 2010 World Water

ows and improving rivers. Certain measuresmay more appropriately ft into di erent types o land use; or example retroftting swales may notbe appropriate in a terraced street with limitedwidth, but easible in a housing estate with widergrass verges. The philosophy that no space isuseless should be considered when designingmulti- unctional measures to improve the level o biodiversity and quality o urban li e or people.

These urban design principles, describedabove, should be taken into account whenconsidering potential uture measures to dealwith sur ace water. Three categories o measures source, pathway, and receptor are widelyused to describe the sur ace water management

process and the ollowing advice helps workout where such measures can be used.Source re ers to measures that manage sur ace

water in the vicinity where the rain ell and romwhich sur ace water runs o into downstreamsystems. Source control includes infltrationmeasures that re-direct sur ace runo either by

disconnecting down-pipes or diverting it intotemporary storage, or example, rom permeablepavements rom where it is infltrated into theground. Opportunities or infltration into theground arise in all areas with permeable groundwhere infltration would not a ect the qualityo protected aqui ers, waterlog the ground orcreate groundwater ooding elsewhere.

Alternatively, ow can be held back inunderground or sur ace storage such as rainwater butts. This water can be slowly releasedinto the downstream system or used as a valuablewater resource. Sur ace storage can alsoincorporate vegetation to give a degree o treatment to pollutants, and provide amenity andbiodiversity. Green roo s and rainwater gardenscan help to manage part o the ow rom a rainevent. Source control can be very e ective orroutine storm events, but have a limited e ectduring extreme events.

Pathway relates to the natural and constructedpathways along which sur ace water is conveyedand may be below ground (pipes and culverts)or above ground (channels, rivers, and streams).Above ground channels such as swales andstorage ponds are pre erred to pipes as ow isslowed down and attenuated. They can alsoprovide treatment by working in series to reducethe pollutant load. Other opportunities that can

enhance an area can be day-lightingwatercourses.Drainage in rastructure has a defned capacity

and sometimes it can be exceeded when there istoo much runo . Current practice in developedareas does not address this exceedance. Thisresults in sur ace water escaping rom the existingdrainage and being conveyed on the sur acealong routes determined by topography suchas streets, pathways, and open spaces in urbanareas. Most places are not designed or thispurpose, which can lead to indiscriminateooding o properties, damaged in rastructure,lives put at risk, and public health beingcompromised. The economic, social, and

environmental consequences can be severe;thus an important part o uture sur ace watermanagement will be managing exceedance.These measures are likely to have a dual usesuch as highways, above ground channels,and sacrifcial storage areas.

Receptors re er to parts o the area that are

a ected by sur ace water. This may includeareas subject to ooding or a watercourse beingpolluted. Measures may be incorporated toincrease the ood resistance and resilience o a property, to reduce the time taken to recoverrom ooding, or to mitigate the e ectso pollution.

ChallengeAchieving sur ace water management orrequent and extreme events will requirepro essions to work closer together. CIRIAstechnical guidance will help remove some o the hurdles to retroftting while highlightingthat such measures need to be implementedand unded holistically. Funding remains abig challenge or the di erent stakeholdersresponsible or sur ace water in the UK todeliver holistic solutions and use non-traditionalsur ace water management measures.

Cities need a high level o retroftting to reduceood and pollution risks and to increase thegreen areas o cities. This requires an e orto many years to deliver retroft solutions, butuntil more unding is available, it is vital totake advantage o every opportunity whenre urbishment and redevelopment occurs toretroft measures and manage sur ace waterdi erently.

By managing sur ace water di erentlyand recognizing that no space is useless,urban areas will be able to embrace the widerbenefts made possible through an integrated,sustainable approach.

Authors NoteChristopher J. Digman, a chartered civil engineer, is a senior principal engineer at MWH,who has worked for more than 13 years in thewater and wastewater industry. Currently thetechnical leader in the eld of urban drainage forMWH, he is heading up the project to developand write CIRIAs Retro tting Surface WaterManagement Measures. With approximately

7,000 employees worldwide, MWH provideswater, wastewater, energy, natural resource, program management, consulting, and construction services to industrial, municipal,utility, and government clients in Europe, theAmericas, Middle East, India, Asia and thePaci c Rim. www.mwhglobal.com

Left: An example of changing the street to managewater on the surface through shallow above groundchannels, planter, and bio-retention areas (Courtesy of CIRIA)

Above: Underground storage and in ltrationbasin retro tted to existing development inDelft, Netherlands.

Retro tting could reducesurface water in combinedsewerage systems,surface water sewers,culverts and watercoursesto reduce ood risk; andreduce surface water incombined sewerage

systems by reducingdischarges from combinedsewer over ows.

world water nov-dec pdf of chris d article

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