Kemira Oyj/Kemira M&I ABSTRACT Vesa Kettunen ... - Svenskt Vatten
Kemira Oyj/Kemira M&I ABSTRACT Vesa Kettunen ... - Svenskt Vatten
Kemira Oyj/Kemira M&I ABSTRACT Vesa Kettunen ... - Svenskt Vatten
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<strong>Kemira</strong> <strong>Oyj</strong>/<strong>Kemira</strong> M&I <strong>ABSTRACT</strong><br />
<strong>Vesa</strong> <strong>Kettunen</strong> 17th Jan 2013<br />
Author: <strong>Vesa</strong> <strong>Kettunen</strong><br />
Application Manager<br />
<strong>Kemira</strong> <strong>Oyj</strong> / Municipal&Industrial<br />
vesa.kettunen@kemira.com<br />
This abstract is meant for platform presentation. Presentation language is<br />
English.<br />
CHEMICAL METHODS IN THE CONTROLLING OF<br />
CORROSION AND ODOURS IN MUNICIPAL SEWERS<br />
Due to the new wastewater purification demands and cost optimisation, the<br />
number of municipal wastewater treatment plants is decreasing. This means<br />
that longer sewer systems need to be constructed. Today even 10-20km<br />
long sewers are not rare any more.<br />
In the long sewers there is more time for microbiological activity and this<br />
may cause problems. The most common problems in sewers are odour<br />
formation and corrosion. Hydrogen sulphide(H2S) formation in the sewer<br />
systems is the main reason for problems.<br />
H2S gas is toxic to humans in high concentrations and causes unpleasant<br />
odours even at very low concentrations. These odours may be released to<br />
air in sewer pumping stations causing odour problems.<br />
In the existing sewer network concrete is widely used construction material.<br />
H2S gas may cause severe corrosion to concrete, because in contact with air<br />
and moisture, H2S gas will react and form sulphuric acid.<br />
H2S formation in municipal sewer systems can be controlled in several<br />
ways. Aeration and the use of oxidative chemicals provide the oxygen to<br />
the water and will prevent H2S formation. However, many times the<br />
problem with these methods is very short effect. Microbiological activity<br />
consumes oxygen fast and then H2S formation starts again.<br />
The addition of iron is efficient in H2S control, because iron can chemically<br />
bind sulphide and this way prevent H2S release and sulphuric acid<br />
formation. Iron also gives clearly longer lasting effect compared to oxygen.<br />
The efficiency of iron can be further improved by combining it with nitrate.<br />
Nitrate will function like oxygen, will release oxygen and this way prevent<br />
H2S formation.<br />
H2S Guard is <strong>Kemira</strong>s concept for corrosion and odour control is sewers. It<br />
provides continuous H2S measurement from sewer. Iron (and nitrate)<br />
containing chemicals can be dosed to the sewer in order to decrease H2S to<br />
the target level.
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Wastewater Overflow Reduction Project in Vantaa River Catchment Area<br />
Aninka Urho, project coordinator, Helsinki Region Environmental Services<br />
Authority<br />
Aninka.urho@hsy.fi, Platform presentation in English<br />
Vantaa River catchment area is located in the most densely populated area of Finland. Wastewater overflows<br />
into the river have been a matter of great public interest of great interest recently. The current method of<br />
leading untreated wastewater into the nearest watercourse when there is a fault or overload in the sewer<br />
system has faced strong resistance among environmentalists.<br />
There are 9 participating organisations in this project:<br />
Helsinki Region Environmental Services Authority, Project coordination<br />
Municipal utilities from Riihimäki, Hyvinkää, Nurmijärvi, Kerava, Tuusula and Järvenpää<br />
Keski-Uusimaa Joint Municipal Board for Water Pollution Control (KUVES)<br />
The Water Protection Association of the River Vantaa and Helsinki Region<br />
This cooperation project is financed by Regional Development Fund of Uusimaa (national allowance) and<br />
Water Utilities Development Fund. Project duration is 2 years (2012-2013) and total budget 170 000 €.<br />
The aim of the project is to decrease wastewater overflows by various means:<br />
1. The project was started by defining a Vision, a Strategy and an Action Plan for stopping<br />
wastewater discharges into the Vantaa River. The vision is: “No untreated wastewater spills into<br />
waters”. Significant investments and an attitude change within the utilities are demanded to reach<br />
this challenging vision.<br />
The Strategy and Action programme is divided into three themes: a) Reliable pumping stations, b)<br />
adequate condition and correct sizing of wastewater networks c) I/I control management. The cost<br />
impacts of the Action Plan will be assessed by consultant.<br />
2. Reliable pumping stations are the key aspect when fighting against sewer overflows. In this project<br />
the pumping specialists from the utilities defined together the best practices concerning a) pumping<br />
station equipment and b) operation and maintenance procedures.<br />
3. The performance of utilities can be enhanced by developing staff training, interest group<br />
cooperation and customer guidance. Small pilot projects related to these topics are to be launched<br />
during 2013.<br />
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Distribueret temperatur måling til opsporing af<br />
fejlkoblinger i spildevandsledninger<br />
Mads Uggerby 1 , Anne Laustsen 2 , Bo Snediker Jacobsen 2 , Peter Hjortdal 2 , Jes Vollertsen 3 , Carsten Jensen 4 ,<br />
Rémy Schilperoort 5 , Jeroen Langeveld 6<br />
1 EnviDan A/S; 2 Aarhus Vand A/S; 3 Aalborg Universitet; 4 Per Aarslef A/S; 5 Royal HaskoningDHV; 6 Delft<br />
University of Technology<br />
E-mail of presenting author, Mads Uggerby: mau@envidan.dk<br />
Platform presentation<br />
Danish language<br />
Fejlkobling af spildevand og regnvand er et hyppigt forekommende problem i separatkloakerede oplande.<br />
Undersøgelser udført af Aarhus Vand viser, at en fejlkoblingsgrad på 5-10% ikke er ualmindelig, hvilket<br />
betyder hydraulisk overbelastning af spildevandsledninger, såvel som uønsket miljøbelastning via<br />
regnvandsledninger. Specielt førstnævnte er et væsentligt problem for forsyningen, idet folk i<br />
separatkloakerede oplande oplever kælderoversvømmelser via spildevansledningen.<br />
Fejlkoblet regnvand kan spores på en række måder, hvor den hyppigst anvendte er at hælde vand i nedløb<br />
og riste samtidigt med, at spildevandsstik inspiceres med tv. Metoden kræver, at den udførende<br />
entreprenør får adgang til privat grund, samt at alle nedløb og riste er tilgængelige. Metoden er derfor ikke<br />
uproblematisk, og man har derfor været på udkik efter alternativer hertil.<br />
Ny forskning udført i især Holland har vist, at distribueret temperatur måling (Distributet Temperature<br />
Sensor, DTS) – som det kendes fra en række applikationer indenfor fx olie- og gasindvinding – også kan<br />
anvendes til at opspore fejlkoblinger i afløbssystemer. En DTS måling foretages med et fiberoptisk kabel,<br />
der installeres på bunden af en regnvands- eller spildevandsledning. Kablet forbindes med et instrument,<br />
der sender laserimpulser ind i kablet, og analyserer på det signal, der reflekteres af glassets amorfe<br />
struktur. Mønsteret med hvilken signalet reflekteres bestemmes bl.a. af kablets temperatur, og kablet<br />
fungerer herved som én lang temperaturføler, hvor temperaturen kan registreres kontinuert i hele kablets<br />
længde. Der anvendes et specialbygget instrument, der integrerer laser, dataopsamling og computer i én<br />
enhed. I praksis er det computerens ydeevne, der sætter grænsen for den nøjagtighed med hvilken<br />
temperaturen kan måles, og den opløsning, der kan opnås i tid og sted. Typiske nøjagtigheder er en<br />
temperaturopløsning på 0,1°C, en stedslig opløsning på 1-2 meter og en tidslig opløsning på 15-60<br />
sekunder. Typiske maksimale kabelængder er i praksis knap 2 km.<br />
EnviDan A/S, Aarhus Vand A/S, Aalborg Universitet og Per Aarslef A/S har, i samarbejde med Royal<br />
HaskoningDHV iHolland, og støttet af Vandteknologiudviklingsfonden (VTUF), igangsat et forsknings- og<br />
udviklingsprojekt hvor vi videreudvikler DTS teknologien og implementerer den i et forsøgsopland i Aarhus<br />
kommune. Vi udvikler teknologien til danske forhold, og anvender den i et antal separate<br />
spildevandssystemer, hvor vi benytter temperaturmålingen til at identificere lokaliteter, hvor
uvedkommende regnvand er koblet på spildevansledningen. En sådan tilledning vil ses som en pludselig<br />
temperaturstigning eller –fald når regnvand når ned i ledningen. Endvidere vil vi kunne se hvor der sker<br />
anden sporadisk tilledning af uvedkommende vand, så som overlækning og omfangsdræn.<br />
DTS giver en meget stor datamængde, der efterfølgende kræver systematisk behandling. Således vil en<br />
enkelt målekampagne let føre til i størrelsesorden 100 millioner individuelle temperaturregistreringer. I<br />
projektet udvikler vi et GIS baseret værktøj, der automatisk analyserer disse datamængder og fortæller<br />
brugeren hvor der sker tilledning af uvedkommende vand, samt tilledningens natur.<br />
I nærværende præsentation viser vi resultaterne af den første målekampagne udført på cirka 1½ km<br />
spildevandsledning i en mindre by nord for Aarhus. Vi viser hvordan metoden kan benyttes til at<br />
identificere forskellig former for uvedkommende vand, og viser detaljer af værktøjet til dataanalyse. På<br />
samme opland identificere vi endvidere uvedkommende vand på traditionel vis – altså ved at hælde vand i<br />
nedløb og riste under samtidig visuel inspektion med kloak-tv. Vi sammenligner herpå de to metoder og<br />
diskuterer praktisk og økonomisk fordele og ulemper ved DTS.
Inlägg 13:e Nordiska Avloppskonferensen, Malmö 8-10 oktober 2013<br />
Annika Malm, kretslopp och vatten<br />
David Jacobsson, kretslopp och vatten<br />
Karin Thörnqvist, kretslopp och vatten*<br />
*karin.thornqvist@kretsloppochvatten.goteborg.se<br />
KRITISKA LEDNINGSNÄTET I GÖTEBORG<br />
Bakgrund<br />
Riskanalyser är en tillgång inom förebyggande arbete, och genom att använda riskanalyser<br />
kan man hitta svaga punkter i avloppsledningsnätet innan något akut inträffar. Kretslopp och<br />
vatten bedömer att ett effektivt förebyggande arbete inte innebär att utföra riskanalyser för<br />
hela ledningsnätet, utan att riktade insatser inom vissa strategiska områden är mer effektivt.<br />
De riktade insatserna skall göras för de ledningar som, vid problem, ger stor påverkan på<br />
samhälle, verksamhet och brukare. Dessa ledningar, som kallas kritiska ledningar, skall<br />
inspekteras i förebyggande syfte, med målsättningen att samtliga kritiska ledningar skall<br />
inspekteras under en tioårsperiod med start 2010. Övriga ledningar inspekteras inte i<br />
förebyggande syfte, utan åtgärdas efter driftstörningar.<br />
Metodik<br />
Ledningar, där sannolikheten att något allvarligt kommer att ske är hög, kallas<br />
sannolikhetsledningar, och kan exempelvis vara ledningar där många stopp inträffar eller<br />
ledningar där problem med svavelväte förekommer. Sannolikhetsledningar har tagits fram på<br />
erfarenhetsbasis. Utfallet är lågt då många av dessa ledningar åtgärdats när väl problemen<br />
upptäckts. Det är i många fall inte effektivt att ta fram alla sannolikhetsledningar på förhand,<br />
utan bättre att lösa problemen när de väl uppstår.<br />
Exempel på sannolikhetsledningar:<br />
• Ledningar med mycket stopp<br />
• Träledningar<br />
• Lergodsledningar med större dimension än 300 mm<br />
Ledningar, som vid driftavbrott ger stora konsekvenser, t.ex. ledningar i hårt trafikerade gator<br />
eller ledningar som vid driftavbrott drabbar många brukare, kallas konsekvensledningar. Ju<br />
större konsekvens desto mer kostar det. Konsekvensledningarna har tagits fram ur GISdatabasen<br />
samt kompletterats med erfarenheter från både kretslopp och vatten och Göteborg<br />
Energi.<br />
Exempel på konsekvensledningar:<br />
• Dagvattenledningar med större dimension än 1 500 mm<br />
• Kombinerade ledningar med större dimension än 1000 mm<br />
• Spillvattenledningar med dimension som är större eller lika med 500 mm<br />
• Ledningar under järnväg, spårväg, motorväg, vattendrag och byggnader<br />
• Ledningar som vid störning ger konsekvenser för råvattnet<br />
En risk definieras som en konsekvens sammanvägt med sannolikhet. Stor konsekvens och hög<br />
sannolikhet innebär en hög risk. Kritiska ledningar kan vara antingen sannolikhetsledningar,
konsekvensledningar eller både och. Detta kan redovisas i en riskmatris, se figur, där de<br />
kritiska ledningarna hamnar inom rött område.<br />
Resultat<br />
Kretslopp och vatten har totalt 2 500 km avloppsledningar, av vilka kritiska ledningsnätet<br />
utgör 265 km, dvs. omkring 10 %. För att uppfylla målsättningen skall drygt 25 km av dessa<br />
inspekteras varje år. De kritiska ledningarna finns redovisade i kretslopp och vattens GISdatabas.<br />
Prioritering av vilka ledningar som skall inspekteras när, görs på följande kriterier:<br />
• Kritiska ledningar med störst konsekvens<br />
• Driftstörningar i det kritiska ledningsnätet<br />
• Kommunens beläggningsprogram<br />
• Planerade spårvägsavstängningar<br />
• Remisser<br />
• Detaljplaner och bygglov<br />
• Kritiska ledningar i investeringsprojekt eller planerat underhåll<br />
• Planlagda inspektioner av ledningar som skall inspekteras för andra gången<br />
Ledningarna inspekteras med hjälp av filmkamera eller okulärt, genom att en person går i<br />
ledningen. Okulär besiktning är dock enbart möjligt i stora ledningar som ej står dämda. När<br />
en ledning inspekteras bedöms status, om åtgärder krävs samt när nästa inspektion skall göras.<br />
Resultaten dokumenteras väl och skall följas upp. Grundtanken är att samtliga kritiska<br />
ledningar skall besiktas vart tionde år, men detta bedöms från fall till fall.<br />
Kretslopp och vatten anser att detta arbetssätt ger en bra uppfattning om ledningsnätets status.<br />
Det anses inte motiverat att regelbundet inspektera hela ledningsnätet, utan det är fullt<br />
tillräckligt att besiktiga de kritiska ledningarna. Man har möjlighet att hitta problem och hinna<br />
åtgärda ledningar innan något händer, och slipper på så sätt de stora konsekvenser för<br />
samhället som en driftstörning hos en kritisk ledning skulle innebära.
Pres_Agertved_Samstyring_ Reneseanlæg og afløbssystem_regnprogose.docx<br />
13 th Nordic Wastewater Conference, 2013<br />
Abstract til mundtlig præsentation under temaet:<br />
“Integrated wastewater systems – a holistic approach”<br />
Sprog -Dansk<br />
Titel<br />
”Intelligent Spildevandshåndtering – regnprognose og integreret styring af afløbssystem og renseanlæg”<br />
Forfattere<br />
Jeanette Agertved 1* , Henrik Sønderup 2 , Henrik Dehn 3 , Lorenzo Benedetti 4 , Carsten Thirsing 5 og Kim<br />
Rindel 5<br />
1 EnviDan A/S, Fuglebækvej 1A, 2770 Kastrup, Danmark * e-mail adresse: jam@envidan.dk<br />
2 Rambøll, Hannemanns Alle 53, 2300 København, Danmark<br />
3 HOFOR A/S, Ørestads Boulevard 35, 2300 København S, Danmark<br />
4 WATERWAYS srl Via del Ferrone 88 50023 Impruneta (FI) Italy<br />
5 Lynettefælleskabet, Refshalevej 250, 1432 København K<br />
Stikord<br />
MIKE URBAN, WEST, Integrering af matematiske modeller, styring og regulering, reduktion af bypass,<br />
regnprognose, forvarsling, tilbageholdelse i afløbssystem, driftsomkostninger<br />
Abstract<br />
Modelberegninger viser, at tilbageholdelse af spildevandvand i afløbssystemet på Amager ved styring<br />
af pumpestationer kombineret med anvendelse af radarbaseret prognose for indløbsflow til<br />
Renseanlæg Lynetten samlet set kan halverer aflastningerne fra anlægget, hvormed den stofmæssige<br />
belastning af recipienten reduceres betragteligt.<br />
EnviDan Øst, A/S • Fuglebækvej 1A • DK-2770 Kastrup • Tlf.: 32 50 79 44• www.envidan.dk
Pres_Agertved_Samstyring_ Reneseanlæg og afløbssystem_regnprogose.docx<br />
EnviDan Øst, A/S • Fuglebækvej 1A • DK-2770 Kastrup • Tlf.: 32 50 79 44• www.envidan.dk<br />
Side 2 af 4<br />
Projektet Intelligent Spildevandshåndtering blev i gangsat af Lynettefællesskabet I/S i samarbejde<br />
med de otte ejerkommuner og deres respektive Forsyningsselskaber i 2008. De otte kommuner afleder<br />
regn-og spildevand til to renseanlæg med en kapacitet på hhv. Renseanlæg Damhusåen (350.000<br />
PE) og Renseanlæg Lynetten (750.000 PEProjektet har haft til formål;<br />
At udvikle en optimal driftsmæssig styring af det samlede eksisterende spildevandssystem i<br />
Lynettefællesskabets opland<br />
At gøre Lynettefællesskabet og dets ejerkommuner som centrale udførende virksomheder<br />
indenfor udvikling af området<br />
Projektet er gennemført i 4 faser, og projektforløbet fremgår af nedenstående figur:<br />
Figur 1: Faseopdelt projektforløb<br />
Renseanlæg Lynetten aflaster forrenset spildevand efter primærtankene via et bypass til recipienten<br />
Øresund. Aflastningerne sker næsten hver gang det regner og udgør typisk 1-2 mio m 3 på årsbasis.<br />
Vandkvalitetsmålinger viser, at koncentrationerne af forureningsparameter i bypass er meget<br />
høje i betragtning af, at der er tale om fortyndet spildevand og at vandet har passeret primærtankene.<br />
Der er identificeret to årsager aflastningerne fra Lynetten:<br />
1. Den samlede kapacitet af de tre hovedpumpestationer, der pumper vand fra oplandet til<br />
renseanlægget, er væsentlig større end den biologiske kapacitet på Lynetten. Der er således<br />
tale om trykledninger, hvormed der ved en stigning i flowet indledningsvist aflastes ufortyndet<br />
spildevand.<br />
2. Omstilling til regnstyring på anlægget sker i dag, når indløbsflowet til anlægget overskrider<br />
den biologiske kapacitet. Herved øges den hydrauliske kapacitet fra 17.000 m 3 /h tl 23.000<br />
m 3 /h over to timer. En rettidig omstilling kan potentielt reducere aflastning via bypass.<br />
I projektet er det undersøgt to tiltag til reduktion af hyppigheden af bypass:
Pres_Agertved_Samstyring_ Reneseanlæg og afløbssystem_regnprogose.docx<br />
EnviDan Øst, A/S • Fuglebækvej 1A • DK-2770 Kastrup • Tlf.: 32 50 79 44• www.envidan.dk<br />
Side 3 af 4<br />
1. Øget tilbageholdelse af spildevand i store magasineringsvoluminer på Øst- og Vestamager<br />
gennem styring af pumpestationer, således at afledningen herfra begrænses, når tilløbshydrografen<br />
til Lynetten overskrider anlæggets biologiske kapacitet.<br />
2. Anvendelse af prognose for indløbsflow til Lynetten til omstilling til regnstyring. Der er regnet<br />
på forvarsling fra regnmålere samt forvarsling på basis af egentlig flowprognose, der<br />
forudsiger indløbet til Lynetten en eller to timer i forvejen.<br />
Vurderingen af tiltagene er gennemført ved at anvende modeller for hhv. renseanlægget (WEST) og<br />
for afløbssystemet (MIKE URBAN).<br />
Modelberegningerne viser et stort potentiale for en miljømæssig optimering af det samlede spildevandssystemet<br />
gennem bedre udnyttelse af magasineringsvolumner på Amager og forvarsling for<br />
omstilling til regnstyring på renseanlæget, se figur 2 og 3.<br />
Figur 2: Beregnet reduktion af aflastede stofmængder ved optimering af tilløbshydrografen til Renseanlæg<br />
Lynetten.
Pres_Agertved_Samstyring_ Reneseanlæg og afløbssystem_regnprogose.docx<br />
EnviDan Øst, A/S • Fuglebækvej 1A • DK-2770 Kastrup • Tlf.: 32 50 79 44• www.envidan.dk<br />
Side 4 af 4<br />
Figur 3: Beregnet reduktion af aflastede stofmængder til recipienten ved forvarsling til omstilling af<br />
regnstyring på renseanlæg Lynetten.<br />
Ved at optimere i forhold til vandmiljøet gennem reduktion af bypass mængden ledes en tilsvarende<br />
øget mængde spildevand til renseanlægget. Dette resulterer i ekstra driftsomkostninger samt en<br />
øget statsafgift for afledning af forureningsparameterne (BOD, Total-N og Total-P).<br />
Ud over disse resultaterne er der i projektgruppen foregået en løbende erfaringsudveksling og dermed<br />
en bedre forståelse for funktionen af det samlede spildevandssystem og hvilke potentialer der<br />
eksistere for optimering af spildevandssystemet.<br />
De beregningsmodeller, der er opstillet i projektet Intelligent Spildevandshåndtering, er sideløbende<br />
blevet anvendt til projektering og planlægning hos flere af forsyningsselskaberne til andre projekter,<br />
bl.a. til klimatilpasningsplan for Københavns Kommune, projekter for reduktion af aflastninger<br />
til Damhusåen, spildevandsplanlægning i Gentofte og Gladsaxe, projekter på DTU og til udviklingsprojekterne<br />
METSAM og SWI.
Presentation på svenska<br />
Rubrik: ”Är bräddning från avloppsledningsnät ett hot mot miljökvalitetsnormer och<br />
dricksvattenförsörjning?”<br />
Författare: Åsa Bengtsson Sjörs, Daniel Larson, Lena Thyberg och Sofia Billvik<br />
Föredragshållare: Åsa Bengtsson Sjörs och Daniel Larsson<br />
Organisation: WSP Samhällsbyggnad<br />
Epost: asa.bengtsson.sjors@wspgroup.se daniel.larson@wspgroup.se<br />
Nyckelord: Bräddning miljöpåverkan avloppsledningsnät<br />
WSP utför under våren 2013 en förstudie inom bräddningars påverkan på recipienter med<br />
avseende på övergödning och hygieniska risker. Metoden som vi vill presentera på<br />
NORDIWA 2013 kommer att användas vid en huvudstudie där den nationella problembilden<br />
av bräddning ska kartläggas.<br />
Abstract<br />
Bräddning från avloppsledningsnät leder till utsläpp av näringsämnen och smittoämnen som<br />
kan bidra till både övergödning och att försämra vattenkvaliteten i dricksvattentäkter. Det<br />
finns ingen rikstäckande kvantifiering av bräddproblemets omfattning och riskerna med<br />
bräddning från avloppsledningsnäten är oftast inte kartlagda. Samtidigt finns en fara att<br />
klimatförändringar kommer att innebära en ökning av mängden avloppsvatten som bräddas.<br />
Det finns idag inga utarbetade riktlinjer om hur kvantifiering av bräddning från ledningsnät<br />
ska utföras. Många VA-huvudmän har bräddregistrering eller utför någon form av<br />
bräddberäkning idag, men man använder många olika metoder och det finns ingen säkerhet<br />
för hur tillförlitliga metoderna är. För att få ett samlat grepp har en tillämpbar metodik<br />
arbetats fram.<br />
<strong>Svenskt</strong> <strong>Vatten</strong> har med hjälp av WSP arbetat fram en metodik för kartläggning och<br />
kvantifiering av bräddningars påverkan. I metodiken ingår att kartlägga bräddningens<br />
omfattning samt att koppla omfattningen till påverkan på recipient och<br />
dricksvattenförsörjning. För påverkan på recipient utgår metoden från bedömningssystemet<br />
för miljökvalitetsnormer i ytvatten.<br />
Inom tillsyn och prövning har miljökvalitetsnormer för vatten fått ett allt större fokus. Målet<br />
är att samtliga ytvatten ska uppvisa en god ekologisk status. Ett av de miljöproblem som<br />
särskilt uppmärksammats är övergödning, där avloppsförsörjning pekats ut som en viktig<br />
källa. Eftersom bräddning kan utgöra en betydande, men ofta okänd del, av<br />
näringsämnesbelastningen från avloppsförsörjningsanläggningar så är det troligt att krav på<br />
utredningar och åtgärder som avser bräddning kommer att öka. Det är också av intresse att få<br />
fram underlag som kan användas i kommunernas arbete med lokala åtgärdsprogram som en<br />
del i vattenförvaltningsarbetet.<br />
Den brädddata som nu kommer att tas fram i Sveriges kommuner kan analyseras på många<br />
sätt. Exempel på detta är en bedömning av vilken utsträckning som bräddning i ledningsnät<br />
orsakas av påkopplade takavlopp, brister på privata fastigheter eller otäta självfallsledningar.<br />
Att identifiera de olika skälen för bräddning ger en uppfattning om hur kostnaden för att<br />
åtgärda problemet kan räknas fram. Tidpunkt på året då bräddningen sker kan ge en hint om<br />
lämplig åtgärd, och kan också ställas i relation till hur känslig en recipient är för orenat<br />
avloppsvatten vid denna tidpunkt.
Disinfection of Combined Sewer Overflow with Micro-Screening<br />
Combined with Ozone or Chlorine Dioxide<br />
F. Nilsson A , J. Väänänen B , S. Haghighatafshar C , M. Hagman D , G. Hey E & K. Jönsson F<br />
A: Corresponding Author, Ind. Ph.D student, Water & Env. Eng. at Dep. Chem. Eng. Lund University and<br />
Primozone Production AB, Terminalvägen 2, SE-24642, Löddeköpinge, Sweden, filip.nilsson@primozone.com<br />
B: Ind. Ph.D student, Water & Env. Eng. at Dep. Chem. Eng. Lund University and Hydrotech AB<br />
C: Project Assistant, Water & Env. Eng. at Dep. Chem. Eng. Lund University<br />
D: Ph.D, NSVA (municipal company operating Öresundsverket WWTP)<br />
E: Ph.D student, Water & Env. Eng. at Dep. Chem. Eng. Lund University<br />
F: Associate professor, Water & Env. Eng. at Dep. Chem. Eng, Lund University<br />
Abstract<br />
During wet weather flow (WWF) the capacity of a wastewater treatment plant (WWTP) can<br />
be exceeded, leading to a portion of the flow being discharged into the recipient either untreated<br />
or only partially treated . This flow, combined sewer overflow (CSO), can be a major<br />
contributor of pathogens found in receiving waters. It is possible to disinfect CSO with a<br />
number of methods including UV, ozone, hydrogen peroxide, chlorine, chlorine dioxide etc.<br />
But due to the fickle nature of the appearance of CSO, high chemical oxygen demand (COD)<br />
and particle content, it can be difficult and costly to implement [1]. In 2006, the EU issued a<br />
new bathing water directive which specifies that for sufficient quality coastal bathing water,<br />
Escherichia Coli and intestinal Enterococci levels cannot exceed 500 and 185 cfu/100 ml,<br />
respectively [2]. The aim of this study is to evaluate the efficiency of ozone and chlorine<br />
dioxide for reducing Escherichia Coli, intestinal Enterococci and total coliform bacteria in<br />
CSO to comply with the EU directive.<br />
A pilot plant was set up in order to treat the incoming wastewater at Öresundsverket WWTP<br />
in southern Sweden. The wastewater passed through screens and aerated grit chambers before<br />
being pumped into the pilot plant. The pilot plant consisted of chemical phosphorus<br />
precipitation (coagulation/flocculation) and 100 µm screening as a primary treatment<br />
followed by ozone injection for disinfection. In parallel to the ozone treatment, the screened<br />
water was treated in lab-scale with chlorine dioxide. Since the CSO had been treated by<br />
micro-screening prior to addition of disinfection agent it was hypothesised that the dose<br />
needed would be in a range of 3-12 g O3/m 3 for ozone and 5-15 g ClO2/m 3 for chlorine<br />
dioxide, with 8 minutes hydraulic retention times for both disinfection agents. Along with<br />
microbiological analysis of the three target organisms, the pilot plant was evaluated for<br />
phosphorus-, SS-, COD-, BOD- and turbidity reductions.
The trial experiments showed that lab-scale chlorine dioxide addition to chemically<br />
precipitated and screened wastewater was the most effective disinfectant, achieving a<br />
reduction of all three target organisms down to
Jukka Yli-Kuivila, project manager, investments for water services<br />
Helsinki Region Environmental Services Authority HSY<br />
jukka.yli-kuivila@hsy.fi<br />
NORDIWA 2013 13th Nordic Wastewater Conference, platform presentation, English<br />
No prolonged maintenance breaks in a sewer rocktunnel<br />
A general plan for a new 150 000 m 3 /d wastewater treatment plant in Espoo, Finland was completed in<br />
October 2011. Purified wastewater should be transferred 8,5 km via a rocktunnel to the outlet tunnel of the<br />
present WWTP. The tunnel would be below a river at -20 m depth and further below a metro at -60 m. If<br />
water could not pass through the tunnel, a six months period was estimated to be needed for fixing it.<br />
Meanwhile the water would be discharged to the crossing river. This was estimated to happen once within a<br />
hundred years.<br />
The river leads to the Gulf of Espoo (Baltic Sea), where lives a population of Macroplea pubipennis– very<br />
rare water insect, protected by a national law and Natura-2000 program. Regional environmental authorities<br />
wrote in November 2012, that no major risk for that insect population could be allowed. This meant a delay<br />
risk for the whole 286 million euros WWTP project, and possible 20 million euros extra investment costs for<br />
an emergency outlet tunnel. Therefore the outlet tunnel plans are updated as follows and extra costs limited<br />
to about 2 million euros.<br />
The part of the outlet tunnel from the new WWTP to the river will be blasted above the sea level. This part<br />
can be reached by men and vehicles whenever needed. Most inspection and maintenance can take place,<br />
while the WWTP and the outlet tunnel are operated normally. If those duties can’t be completed when water<br />
is flowing on the bottom of the tunnel, treated wastewater can be turned back to the inlet tunnel to avoid a<br />
total break in the WWTP. The storage capacity of the inlet tunnel enables one to two days break for the<br />
WWTP use, or running it with diluted wastewater. Excellent purification results are easier to maintain, if the<br />
exception period doesn’t last longer than 8 h/d. That enables repeatedly one working shift for tunnel<br />
maintenance and two shifts for emptying the inlet tunnel storage. The fixing of the tunnel bottom can be<br />
done part by part while the flow is isolated from the part under construction. Therefore no prolonged<br />
maintenance breaks are needed for this part of the tunnel.<br />
Before the tunnel would cross the river, a 20 m vertical shaft is needed to remain the tunnel in a solid rock.<br />
After that the slope of the tunnel is towards the seashore, where another vertical shaft is needed from -60 m<br />
to the present outlet tunnel. Normally this 7,5 km part of the tunnel is full of water. A pumping station will<br />
be built beside the tunnel before it dives deed because of the metro. This pumping station can raise water<br />
about 30 m, from tunnel bottom level to sea level behind a pressure wall in the tunnel. If the tunnel from the<br />
pumping station to the present outlet tunnel should be emptied, water would be pumped via another pipe to<br />
the street level above and from there further to a nearby ditch and seashore. When inspections or<br />
maintenance is needed, water level could be kept low in the tunnel and vehicles driven in.<br />
The normal outlet tunnel discharge is 7.5 km to deeper sea and a discharge to seashore should also be<br />
avoided. Therefore the last tunnel part will be inspected by a diving robot and kept empty only during<br />
essential maintenances.<br />
Another benefit of the pumping station is the adaptation to climate change. The WWTP can be built to lower<br />
position and booster pumps used only, when the sea level or water flow is too high for gravity discharge.
Wastewater pipes in Oslo: from condition monitoring to<br />
rehabilitation planning<br />
Ugarelli R.M. 1 , I. Selseth 1 , Y. Le Gat 2 , J. Rostum 1 and A. H. Krogh 3<br />
1 SINTEF Building and infrastructure, contact detail: Dr. Rita Maria Ugarelli, SINTEF Building<br />
and Infrastructure, Pb. 124 Blindern, NO-0314 Oslo, Norway, rita.ugarelli@sintef.no<br />
2 Irstea Bordeaux – REBX, 50 avenue de Verdun, 33 612 Cestas<br />
3 Vann- og avløpsetaten, Oslo kommune<br />
Abstract Strategic use of condition monitoring to support rehabilitation planning of the Oslo<br />
wastewater network is the topic presented. The full paper will describe the process followed<br />
from investigating the quality of the data, overcoming limitations of the Nordic standard for<br />
condition assessment, selecting the final dataset for models calibration and finally modelling<br />
the prediction of the deterioration process under selected rehabilitation strategies. The model<br />
applied for the analysis is termed GompitZ and it based on the probabilistic theory of Markov<br />
chains; it defines the relationship between the current state and the expected service time of<br />
sewer pipes using Close Circuit TV inspections (CCTV) as classification input.<br />
The GompitZ deterioration modeling tool has been delivered by IRSTEA (Le Gat, 2008) within<br />
the framework of the CARE-S FP5 project (Sægrov, 2005). The model has been further<br />
developed in the last years also thanks to the testing and validation done in Oslo.<br />
Besides a model parameter calibration module, the GompitZ tool contains a module devoted<br />
to long term simulation of rehabilitation programmes. Four rehabilitation strategies can be<br />
performed and therefore compared: i) a "do-nothing" option that simulates the "natural"<br />
evolution of the pipes in the absence of rehabilitation, ii-iii) a "length-driven" and a "budgetdriven"<br />
option that simulates the annual rehabilitation of the most deteriorated pipes up to a<br />
total length/budget fixed by the user for each year belonging to the simulation period, and iv)<br />
an "optimization" option that estimates the optimal mean annual rehabilitation length of most<br />
deteriorated pipes to be implemented in order to bring the network just below a given global<br />
deterioration condition at a user-given time horizon.<br />
By comparing different strategies is possible to see (and calculate) the benefit in terms of<br />
improvement of the network conditions obtained by applying a given rehabilitation strategy,<br />
instead of “doing nothing”. Costs versus benefits can therefore be balanced in order to choose<br />
the winning and more feasible solution.<br />
The research also highlighted a major issue: the need to review the Norwegian standard<br />
(NorskVann, 2007) used to classify pipes from visual inspection. The problem consists on the<br />
standard being too pessimistic in the pipe classification leading to a much more negative<br />
figure of the overall network need for rehabilitation that it is in reality. By classifying the pipes<br />
as much more close to collapse than thy actually are, brings also to a too high estimation of<br />
the investment needs for rehabilitation plans.<br />
1
The research is currently focused on further developing the GompitZ tool by introducing the<br />
concept of “risk” in the ranking of segments for prioritizing rehabilitations in long term<br />
simulations. The choice of the strategy to undertake would be then based on a trade-off<br />
between costs, conditions and risk.<br />
Reference<br />
Le Gat, Y. 2008. Modelling the deterioration process of drainage pipelines. Urban Water<br />
Journal, 5, 10.<br />
NORSKVANN 150/2007: Dataflyt - Klassifisering av avløpsledninger (Dataflow. Classification of<br />
sewer pipes.<br />
Sægrov S, 2005. CARE-S Computer Aided Rehabilitation of Sewer and storm water networks,<br />
IWA publication 2005, ISBN 1843391155.<br />
Information<br />
The abstract is meant as a platform presentation and the language of the platform<br />
presentation is English.<br />
2
Prioritering av flomforebyggende tiltak i norske avløpssystemer<br />
G. Torgersen*, J. Bjerkholt**<br />
*geir.torgersen@hiof.no Høgskolen i Østfold / Universitetet for miljø og biovitenskap, Norge<br />
** Universitetet for miljø og biovitenskap, Norge<br />
Abstract<br />
I denne artikkelen presenteres det en studie av 22 store norske byers forhold til metoder for<br />
bærekraftig overvannshåndtering og flomforebyggende tiltak. Studien omfatter også noen<br />
svenske og danske byer. Målet med studien har vært å finne ut hvordan kommunene<br />
prioriterer dette i praksis ved utbedring av eksisterende avløpssystem.<br />
Klimaendringer fører til mer intens nedbør i mange deler av verden, også i Norge. Det gir<br />
blant annet store utfordringer i forhold til å håndtere vannet i byer. Ledningene i byene er<br />
dimensjonert for lavere nedbørsintensiteter enn det som forventes i framtiden, og allerede i<br />
dag merkes endringene i klima. Disse utfordringer kommer i tillegg til lav utskiftingstakt på<br />
avløpssystemet og økt urbanisering.<br />
I Norge har det ennå ikke vært oversvømmelser i den størrelsesorden som man har sett i<br />
København de siste årene. Fra 1992-2007 ble det utbetalt 5 milliarder kroner fra<br />
forsikringsselskapene knyttet til vannskader i kjellere, naturskader ikke medregnet. I det<br />
nasjonale vannskaderegisteret har det vært en økning i antall kjelleroversvømmelser fra ca.<br />
2000 i 2008 til ca. 3000 i 2012. Forsikringsbransjen regner med at utbetalingene for skader vil<br />
øke med 40 % de neste 10 årene. Det har de siste årene vært flere rettsaker som følge av at<br />
forsikringsselskaper har krevd at kommunene holdes ansvarlige for skader på grunn av<br />
manglende kapasitet på det offentlige avløpsnettet.<br />
Internasjonal forskning konkluderer med at lokal overvannshåndtering med minst mulig bruk<br />
av ledningsnett, er den beste og mest fleksible måten å møte framtidens overvannsutfordringer<br />
på. Et skifte fra tradisjonell metode der overvannet føres i ledninger, til en mer bærekraftig<br />
metode, er som prinsipp en så fundamental endring at det betegnes som et «regimeskifte». En<br />
slik overgang forventes å tvinge seg fram som følge av bl.a. klimaendringer.<br />
I spørreundersøkelsen til Norges største kommuner framkom det at byene i dag har store<br />
utfordringer i forhold til personellsituasjonen, og aktiviteten ikke uten videre kan økes fra<br />
dagens nivå. Undersøkelsen viste at større satsing på flomforebyggende tiltak må skje<br />
gjennom strengere prioritering innenfor dagens økonomiske rammer. For å undersøke<br />
satsingen på bærekraftige løsninger og flomforebyggende tiltak, var det derfor relevant å finne<br />
ut hva som i praksis prioriteres når avløpssystemet skal utbedres. Undersøkelse ble gjort i 2<br />
steg:<br />
Steg 1 var en undersøkelse av hva som var utløsende årsaker og hvilke metoder som ble<br />
benyttet ved utbedring av avløpssystemene. Det for å gi et bilde på hvor kommunen står i dag<br />
på overgangen mot et nytt «regime».
Steg 2 var en gruppering og vurdering av drivere som ble antatt å påvirke utviklingen. Det er<br />
bl.a.: dagens tilstand, virkemidler, hendelser, myndighetskrav, press fra opinionen. Ved<br />
intervjuer / litteratursøk ble kvantitative data vurdert i forhold til hvor mye/lite de betyr for<br />
overgangen til et mer bærekraftig regime.<br />
Resultatene fra undersøkelsen viste at i Norge står tradisjonelle metoder som åpen grøft og<br />
separering veldig sterkt i de undersøkte byene. I 2010 ble 75 % av eksisterende<br />
avløpssystemet utbedret ved åpen grøft og separering. Utløsende årsak oppgis å være<br />
flomreduksjon i 23 % av tilfellene. De forespurte kommunene i Sverige og Danmark syntes å<br />
ha kommet lenger i bruk av bærekraftige løsninger for overvannshåndtering. Sentrale<br />
myndighetskrav etterfulgt av økonomiske incentiver i forhold til rapporterte resultater, kan<br />
være viktig for svenske og danske kommuners prioriteringer. Norge har i praksis ingen slike<br />
økonomiske incentivordninger. Dagens innrapporteringssystem oppfordrer kommunene til å<br />
være aktivitetsorienterte, bl.a. gjennom fokus på investeringsbeløp og antall meter utskiftet<br />
ledning. Et rapporteringssystem bør heller sette krav til å måle effekten av et tiltak, f.eks.<br />
redusert vannføring. Det kan føre til mer innovasjon, bærekraftige løsninger og gi større fokus<br />
på flomforebyggende tiltak.
Abstract - presentation January 31, 2013<br />
WANDER Nordic Water and Materials Institute 1<br />
Sinkokatu 11, FI-26100 Rauma, Finland<br />
Title: Developing the renovation of the sewerage and the drainage standards, quality and<br />
harmonization process chains in Finland<br />
Authors: Pelto-Huikko, A.* and Kaunisto, T.*<br />
* WANDER Nordic Water and Materials Institute / Prizztech Ltd., Sinkokatu 11, FI-26100 Rauma,<br />
Finland.<br />
Contact person: Aino Pelto-Huikko, email: aino.pelto-huikko@wander.fi<br />
Presentation in English.<br />
In Finland, the rehabilitation of sewerage and drainage can be done with many techniques. These include<br />
total repair, replacement and renovation. The renovation techniques have been used for several years in<br />
sewerage (>DN 150) but drainage have had a minor role until recent years. However, there are still many<br />
questions concerning for example selection of the right technique.<br />
The renovation techniques include many technical solutions including linings with different materials and<br />
slip linings. The technique can crack the old pipe or not. The structure of the new pipe can be a part of the<br />
old pipe or it can be self-supporting.<br />
The standardization of the methods is done mostly in European level or in some cases in international<br />
level. The content of the standards have to be evaluated. Because the European product acceptance<br />
system for these products is still under preparation, national regulation is needed to set the requirements.<br />
Besides the composition of the material, also the work performance affects the quality of renovation<br />
significantly. Corporate or personal certificates, internal and external quality control and documentation<br />
of work performance are all factors to be examined. These issues need to be decided and implemented<br />
nationally. For sewerage, there is no authority which would be responsible for what material is placed,<br />
and how the renovations are done. For the drainage, the local authority evaluates whether the building<br />
license is needed.<br />
The aim of the project is to evaluate the renovation situation, the standardization, quality, harmonization<br />
schemes, assistance to the workmanship and the evaluation of the work quality.<br />
The report will be published in December 2013 (in Finnish).<br />
WANDER<br />
www.wander.fi<br />
first.last@wander.fi
Title: Demand Driven Distribution<br />
Author Jim Rise<br />
Company Grundfos AS<br />
Email jimrise@grundfos.com<br />
Type Platform presentation<br />
Language Can do it in English as well as Scandinavian<br />
Reduce water loss with flow-dependant pressure management<br />
Leakages can cost water companies much more than the water lost from the distribution<br />
system. Demand-driven distribution solutions can help reduce and control leakage by<br />
compensating for surplus pressure in the pipes system and by reducing water hammer which<br />
causes new holes.<br />
The solution in both these cases is the control system, and in particular proportional pressure control<br />
– a unique solution that automatically optimises energy consumption and minimises water loss by<br />
15%.<br />
Reduce leakage<br />
Water companies continue to dedicate significant resources to resolve issues related to non-revenue<br />
water (NRW). NRW is water that has been produced and is “lost” before it reaches the customer,<br />
thereby costing water companies’ money.<br />
Reducing leakage and water loss requires initiatives such as increasing the speed of leakage<br />
detection, optimising asset management and not least by designing a pressure management strategy.<br />
Pressure management is now well recognised as being essential to effective leakage management.<br />
The benefits of reducing and controlling NRW and leakage reduction in particular include financial<br />
gains from the increased amount of water reaching the customer, effectively meaning a reduction in<br />
water production. This includes the possible delay of costly capacity expansion, the increased<br />
knowledge about the distribution system gained in the process, and the reduced risk of damage and<br />
contamination.<br />
Water hammer a major issue<br />
An important contributing factor behind new leaks is water hammer. Caused by sudden momentum<br />
changes in a pipe system, this phenomenon can be reduced or eliminated by lowering fluid<br />
velocities, gradual pump ramp-up/ramp-down or reducing pump size, for example. Software<br />
analysis packages exist today; these vary in complexity, dependent on the processes modelled.<br />
For example, a big pump has a big water hammer effect; this is a factor of the pump’s inertia.<br />
Smaller pumps reduce the risk of water hammer and involve cost savings from lower operating<br />
costs, reduced energy consumption and less leakage loss.<br />
Compensating for friction loss
The central challenges for any water distribution system are to secure a stable water supply, manage<br />
what may be scarce water resources, locate and remedy pipe breaks, reduce leakages, and keep<br />
operating costs as low as possible.<br />
Traditionally, a water distribution system would consist of one duty pump supplying demand at<br />
constant pressure maintained by valves or variable frequency drives (VFD). In addition, an identical<br />
pump and VFD would be installed as a backup, in case of failure.<br />
With a demand-driven distribution solution.. The system is designed to supply precisely the flow<br />
needed at the pressure required, with a number of parallel-coupled pumps running at best efficiency<br />
point, instead of one big pump. Surplus pressure in the pipes system is considerably reduced, and<br />
the risk of water hammer causing new leakages is substantially lessened. For the consumer there is<br />
no change in tap pressure, but leakage is reduced significantly.<br />
Reduce leaks with a pressure management strategy<br />
Proportional pressure control automatically optimises energy consumption and minimises water by<br />
automatically adapting the set point to the actual flow.<br />
If the pressure loss in the pipe system is 2 bar during high flow periods, the pump discharge<br />
pressure must be set to 6 bar in order to deliver a tap pressure of 4 bar.<br />
However, in a low-flow situation, the pressure loss in the pipe system may only be 1 bar. If the set<br />
point remains fixed at 6 bar, this would increase tap pressure to 5 bar. The surplus 1 bar in the<br />
system increases leakage loss and represents excess energy consumption, hitting your cost level in<br />
two ways.
c:\users\icnmsm\desktop\pres_clementson_inlackage_atgardsforslag_helhetssyn.doc<br />
Abstract<br />
Beställare NORDIWA 2013<br />
Från Ingemar Clementson/ Viveka Lidström<br />
Till nordiwa2013@svensktvatten.se<br />
Tillskottsvatten i ledningsnät - en ansvarsfråga<br />
Att ha ett klart definierat verksamhetsområde för VA är viktigt. Detta ger en<br />
tydlighet i ansvarsfördelningen för de olika vattenslag som hanteras både vad gäller<br />
skyldigheter och rättigheter. Ett fall då oklarheter i ansvarsfrågan och<br />
åtgärdshanteringen råder är t.ex. då flödet ökar i spillvattennätet vid nederbörd i ett<br />
område där det inte är samma huvudman för spillvattenhantering och<br />
dagvattenhantering. För att ta reda på vem som har juridiskt och tekniskt ansvar<br />
behöver kommunen ha en god översikt över vilka ledningar som finns i marken<br />
och vilka flöden och avrinningsområden som gäller.<br />
Ramböll Sverige har för Staffanstorps kommun genomfört en större utredning<br />
kring problematiken med ökat flöde i spillvattennätet i samband med nederbörd.<br />
Det ökade flödet i spillvattennätet har lett till flera översvämningar inne på<br />
fastigheter, ökat slitage på pumpstationer, oönskad breddning samt svårigheter i att<br />
optimera reningsprocessen i reningsverk.<br />
Inom uppdraget har olika källor till inläckage lokaliserats för att ge ledningsägare<br />
möjlighet att göra kostnadseffektiva åtgärder. I fält har ca 650 fastigheter, ett flertal<br />
ledningssträckor samt andra möjliga källor till inläckage undersökts med röktest,<br />
färgning av vatten samt flödesmätningar. Källorna till inläckage har varierat<br />
beroende på vilket område som undersökts. I tätorter har felkopplingar varit den<br />
största enskilda källan, i rurala områden är det främst dräneringsledningar och i<br />
vissa områden har läckande ledningar stått för en stor del av inläckaget.<br />
Genom att känna till de felkällor för tillskottsvatten som finns kan konstruktiva<br />
åtgärder genomföras i samarbete med fastighetsägare inom ett område där<br />
dagvatten ej ingår i kommunens verksamhetsområde.<br />
Datum 2013-01-30<br />
Ramböll Sverige AB<br />
Skeppsgatan 5<br />
211 11 Malmö<br />
T: +46-10-615 60 00<br />
www.ramboll.se<br />
Ramböll Sverige AB<br />
Org nr 556133-0506<br />
1(2)
c:\users\icnmsm\desktop\pres_clementson_inlackage_atgardsforslag_helhetssyn.doc<br />
Resultatet av projektet har givit en helhetsbild av flödessituationen i aktuellt<br />
område. Denna har redovisats i en GIS-modell där anteckningar, beräkningar,<br />
fotodokumentation samt klassificeringsstatus visas på ett sätt som är kompatibelt<br />
med kommunens nuvarande och framtida digitala VA-system. Modellen är också<br />
gjord för att kunna anpassas till VA-banken samt ligga till underlag för<br />
översvämnings/ledningsmodeller såsom Mike Urban/ Mike She.<br />
Helhetsgreppet som tagits har bidragit till att skapa ett underlag för kommunen att<br />
på ett systematiskt sätt räta ut frågetecken om ansvarsfördelningen i<br />
dagvattenhanteringen.<br />
Vidare har hanteringen av information gjorts på ett sätt som förbereder kommunen<br />
för en möjlig utvidgning av verksamhetsområdet som inkluderar även<br />
dagvattenhantering.<br />
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Title: Focusing of sewer network renovations<br />
Authors: Laakso, Tuija; Vahala, Riku, Aalto University<br />
E-mail addresses: tuija.laakso@aalto.fi, riku.vahal@aalto.fi<br />
Abstract for a platform presentation to be held in English.<br />
Abstract<br />
Getting accurate and up-to-date information on the renovation need of sewer assets is difficult; on<br />
the other hand, the sewer network needs to be renovated periodically. Traditionally, in Finland, the<br />
sewer network inspections and renovations have been made based on few sources of data (e.g., pipe<br />
age and material) and not necessarily using a systematic planning approach. In such a context, the<br />
EfeSus project aims at developing a systematic, comprehensive and a partly automated procedure<br />
for deciding which assets to renovate in the network and when. The main aim of this paper is to<br />
present the project and its objectives as an example on how the improvement of sewer network can<br />
be challenged in practice.<br />
Efesus, financed largely by the Finnish Funding Agency for Technology and Innovation (Tekes),<br />
focuses on the separate sewer network of the Finnish city Espoo (population of around 250 000) and<br />
analyzes in detail 20 representative network areas. The data utilized in the assessment include:<br />
GIS data from the utility’s network information system:<br />
o pipe locations and depths, pipe diameters, slopes, materials, installation years;<br />
o closed circuit television (CCTV) inspections;<br />
o occurred operational disturbances;<br />
o water consumption in different network areas (on annual level).<br />
Flow data from the utility’s telemetry system.<br />
Rainfall data.<br />
Environmental data concerning:<br />
o ecological status of groundwater areas;<br />
o ecological status of surface water areas;<br />
o road type classifications.<br />
In order to achieve efficient prioritization of the sewer renovations these data need to be collected,<br />
evaluated and analyzed. Efesus starts by gathering and combining from different sources data that<br />
are considered useful for renovation planning. Similar to the projects CARE-S (Saegrov 2005) and<br />
COST-S (Savic et al 2005), the approach in EfeSus is includes: 1) decision-making based on<br />
available data, and 2) automated data analysis and decision support by means of a software<br />
(prototype) created in the project. The software, using as inputs all the different data collected,<br />
assesses each pipe with respect to its estimated structural and operational condition, as well as to its<br />
importance in the network structure and the vulnerability of the surrounding environment.<br />
As a result of the analysis, an index will be assigned to each pipe indicating how often the pipe<br />
should be inspected and what its renovation need is. After this, so-called renovation entities are<br />
built up from a number of pipes that can be considered similar enough to be renovated at the same<br />
time. Based on this assessment, further on-site investigations such as CCTV inspections, smoke<br />
tests and manhole inspections as well as actual renovations can be targeted and scheduled much
more accurately than currently. As a result, both financial and human resources are expected to be<br />
allocated more efficiently than currently.<br />
References:<br />
Saegrov, S. (ed.) 2005. CARE-S. Computer-Aided Rehabilitation of Sewer Networks. International<br />
Water Association.<br />
Savic, D.A., Djordjevic, S., Dorini, G. 2005 COST-S: a new methodology and tools for sewerage<br />
asset management based on whole life costs. Water Asset Management International December<br />
2005, Vol. 20.
Title: A GIS based environmental risk assessment of wastewater pumping station overflows<br />
Name of author: Leena Sänkiaho, M.Sc(Eng.)<br />
Name of the institution: Pöyry Finland Oy, Jaakonkatu 3, 01621 Vantaa, Finland<br />
E-‐mail address to the author: leena.sankiaho@poyry.com<br />
Platform presentation<br />
Language of the platform presentation: English<br />
The Helsinki Region Environmental Services Authority (HSY) operates nearly 500 wastewater<br />
pumping stations around the Helsinki metropolitan area. As HSY is currently renewing its<br />
environmental permit, they are obliged by the environmental authority to conduct an environmental<br />
risk assessment, which reviews the wastewater pumping station overflows. Similar studies have not<br />
been conducted before, hence there are no common guidelines or previous examples of how the study<br />
should be carried out.<br />
To go through all 500 pumping stations individually would have been time consuming and inefficient.<br />
This led to the development of a new geographic information system (GIS) based method. The<br />
presentation will include a description of the method used and how the results can be utilized.<br />
In Finland the Finnish Environment Institute and The National Land Survey of Finland publish free GIS<br />
data. For instance all groundwater areas, lakes, rivers, sea shore and nature reserves are available in<br />
GIS formats. In addition the metropolitan area cities have conducted surveys that map the ecologically<br />
valuable small streams. Beaches can be mapped according to the address details available. HSY<br />
supplied the coordinates of the fresh water intakes. All these data was used as separate risk layers in<br />
the GIS analysis. The layers were rated according to the severity and consequence a sewer overflow<br />
may pose. The rating method has been modified from the rating method used in Water Safety Plans<br />
(WSP) (Bartramet al. 2009).<br />
HSY provided the pumping station coordinates and capacities. The GIS analysis is based on an overlay<br />
operation. If a pumping station overlaps a risk layer, the pumping station will be awarded with the risk<br />
rating.<br />
There are three ways to utilize the results: risk layers, risk sums or risk scores.<br />
Risk layers:<br />
This method detects the pumping stations which are located on certain risk layer. For instance<br />
pumping stations which are located less than 500 m from a beach can be listed and certain risk<br />
prevention methods can be applied to these stations or beaches.<br />
Risk sums:<br />
A risk sum is the aggregated risk rate for each pumping station. It is assumed that a pumping station<br />
will have a higher environmental risk if it is located on more than one risk layer. The values range<br />
from 0 to 6. For instance, the highest risk sum was allocated to a pumping station that is located on a<br />
groundwater area, it is also on the buffer zone of a groundwater well (< 500 m) and less than 100 m<br />
radius from an ecologically valuable small stream.<br />
Risk scores:<br />
It is assumed that the overall risk is also related to the pumping station capacity as the pumping<br />
station capacities vary from 3 l/s up to 2000 l/s. Therefore the risk sums were weighted by the
pumping capacities. Based on HSY’s experience several assumptions were made: For instance, it was<br />
assumed that the risk score of a mega sized (> 200 l/s) pumping station with a risk sum value 3 equals<br />
a small pumping station (< 10 l/s) with a risk sum value of 6.<br />
This analysis will help HSY to prioritize the pumping stations on which risk prevention actions should<br />
be taken. It will also give valuable information about which actions should be taken if an overflow<br />
occurs.<br />
References:<br />
Bartram, J. Corrales, L.; Davison, A.; Deere, D.; Drury, D.; Gordon, B.; Howard, G.; Rinehold, A.; Stevens,<br />
M. (2009) Water safety plan manual: step-‐by-‐step risk management for drinking-‐water suppliers.<br />
World Health Organization (WHO), Geneva
Methane formation in sewer systems<br />
Malin Isgren I *, Patrick Mårtensson I , Jes la Cour Jansen I , David J. I. Gustavsson II , Oriol Gutierrez III<br />
I<br />
Water and Environmental Engineering, Department of Chemical Engineering, Lund University, Box 124,<br />
SE-221 00 Lund, Sweden<br />
(E-mail:kt08mi2@student.lth.se, kt08pm4@student.lth.se, jes.la_cour_jansen@vateknik.lth.se)<br />
II<br />
VA SYD, Box 191, SE-201 21 Malmö, Sweden (E-mail: david.gustavsson@vasyd.se)<br />
III<br />
Catalan Institute for Water Research, ICRA. Scientific and Technological park of the UdG. Emili Grahit, 101<br />
17003 Girona, Spain (E-mail: ogutierrez@icra.cat)<br />
* Speaker We would like to present this paper as an oral presentation in English.<br />
INTRODUCTION<br />
Hydrogen sulphide in sewer systems is a well-known problem. However, formation of the potent<br />
greenhouse gas methane has not received as much attention. A few studies have been executed on<br />
rising mains (i.e. Guisasola et al., 2009) since these are theoretically the ones with the highest<br />
potential for methane formation. Gravity mains are the most common kinds of pipes but are still<br />
poorly investigated. Investigations of these are necessary if methane formation in sewer systems<br />
shall be fairly evaluated. Factors that affect methane formation are among other things the presence<br />
of organic carbon together with anaerobic conditions. The amount of methane formed per volume<br />
wastewater depends on the ratio between the inner surface wall area covered with biofilm and the<br />
volume of the pipe. This theory has been proved, not only in studies on rising mains but correlate<br />
also well with formation of hydrogen sulphide. The main aim of this work was to develop a<br />
sampling method for determination of dissolved methane in wastewater samples and to detect any<br />
methane content in gravity mains with the highest potential for methane production in Malmö,<br />
Sweden.<br />
METHOD<br />
Field samples were collected at the inlet, downstream a pressurized system at Sjölunda Wastewater<br />
Treatment Plant (WWTP) and in scattered selected manholes in the sewer system of Malmö,<br />
Sweden. The sampling technique enables sampling and at the same time avoids getting air into the<br />
sampling bottles. This was accomplished by keeping the collection vials under water, while putting<br />
the cap on (Alberto et al., 2000). Wastewater sampling at the WWTP was executed by lowering a<br />
sampling bottle close to the incoming pipe, the device is shown in Figure 1. The rubber stopper was<br />
released when the bottle reached the selected level.<br />
Figure 1. Device for wastewater collection at WWTP.<br />
Sampling in manholes was executed by climbing down and filling sampling bottles. From the<br />
sampling occasions all laboratory analysis were performed within 24 hours. The sampling analyses<br />
were done by filling half of a vacuum tube with wastewater and then allow equilibrium. The<br />
methane content was determined with a gas chromatograph and the amount of methane was
calculated with Henry´s law.<br />
RESULTS AND DISCUSSION<br />
The methane analysis of the samples taken from the manholes located in Malmö showed that<br />
methane exists. The concentration varied in every manhole and the highest and lowest encountered<br />
was 0.58 and 0.11 mg CH4/L respectively. Since none of the examined sewers were pressurised and<br />
only the wastewater was analysed, the emitted amount was probably higher than the encountered as<br />
most of the methane formed will be released to the air. The methane from the incoming pipe at<br />
Sjölunda WWTP was examined twice and the result is shown in Figure 2.<br />
Figure 2. Variation in amount of methane in the influent to Sjölunda WWTP.<br />
The methane amount varies during the day and the amount released is about 2 kg/h. The samples<br />
were taken in the middle of the winter (water temperature around 14°C) and as methane is favoured<br />
by increased temperature this value can be taken as minimum that enters the WWTP.<br />
The full paper will present all the measurements and evaluate research needs in order to be able to<br />
estimate the potential contribution of methane formation in the sewer system in Malmö to global<br />
warming.<br />
REFERENCES<br />
Alberto M.C.R., Arah J.R.M., Neue H.U., Wassmann R., Lantin R.S., Aduna J.B., Bronson K.F.,<br />
2000. A sampling technique for the determination of dissolved methane in soil solution. Soil and<br />
Water Science Division, International Rice Research institute P.O Box 3127, MCPO 1271, Makati<br />
City, Philippines. Global Change Science 2 (2000) pp. 57-63.<br />
Guisasola A., de Haas D., Keller J., Yuan Z., 2008. Methane formation in sewer system, Advanced<br />
Water Management Center, The University of Queensland, St Lucia, 4067 Queensland, Australia.<br />
Water Research, 42 (6–7) (2008), pp. 1421–1430.
Abstract for:<br />
13 th Nordic Wastewater Conference<br />
To be considered in all categories<br />
Title:<br />
Laboratory and field investigation of Chemical disinfection of sewer overflow in<br />
Copenhagen Area<br />
Authors:<br />
Henrik R. Andersen, DTU Miljø, hran@env.dtu.dk<br />
Anitha K. Sharma , DTU Miljø<br />
Ravi K. Chhetri , DTU Miljø<br />
Jesper Berner, KEMIRA<br />
Robin Gramstad KEMIRA<br />
Öjstedt Ulrik KEMIRA<br />
Dines Thornberg, Udviklingssamarbejdet.<br />
Kasper Juel-Berg , HOFOR<br />
Annette Kolte-Olsen , Nordvand<br />
Jean De Dieu Otoa , Greve-Solrød forsyning<br />
Abstract<br />
Combined Sewer Overflow (CSO) has been a problem in every large city with old sewers resulting in<br />
deterioration of water quality of receiving waters around the city. . With the anticipated increased rain<br />
intensity due to climate change and increased loads on sewer system due to urbanisation the problem is<br />
expected to be magnified in the future. Copenhagen has many beaches and several public baths in the old<br />
harbour and to maintain the high water quality for bathing it is necessary to reduce the microbial pollution<br />
from the CSOs.<br />
Disinfection of CSOs reduces the load of microorganisms and the most common methods are UV-light or<br />
addition of different forms of chlorine. However, UV-disinfection of CSOs is not attractive due to high<br />
capital cost and non-predictive occurrence of CSOs. Disinfection with chlorine forms toxic by-products. In<br />
recent years, laboratory and full scale investigation of novel organoperoxide disinfectants, peracetic<br />
acid(PAA) and performic acid(PFA) have shown that these chemicals can be attractive disinfectants. We<br />
presents results from laboratory and field investigations on disinfection of CSOs using PFA and PAA.<br />
The laboratory part of the study aims to produce the relevant information in order to find the most suitable<br />
chemical disinfections agents for CSOs in different contexts: Concentration profiles, disinfection efficiency,<br />
byproducts and residual toxicity is investigated. Additionally a literature study is performed to describe the<br />
costs and handling of each chemical. The project, “DesiCSO”, partly funded by Vand-i-Byer and will be<br />
finished in March 2013.<br />
The field investigations will be performed at 3 different sites with the aim to investigate whether it is<br />
possible to obtain bathing water shortly after heavy rainstorms in full-scale. The project named FRODO,
which is partly funded by the Danish VTU-fond. The full-scale test will mainly take place in the spring and<br />
summer of 2013.<br />
The first field test is at a large pumping station north of Copenhagen (Skovshoved), where frequent CSOs<br />
occur and the CSOs are discharged 1,6 km out to the sea through a pipe. Performic Acid will be tested due<br />
to a short retention time in the pipes.<br />
Example of full scale dosing equipment from <strong>Kemira</strong><br />
The second field test will investigate the combination of filtration and chemical disinfection with PFA and<br />
will be performed at an existing test site in Copenhagen, Scherfigsvej facility. This facility consists of two<br />
filtration units (100µ and 20µ) and in 2003-2006 investigations were performed in a LIFE project, where<br />
filtration in combination with UV-disinfection was tested for disinfection of CSOs with no success.<br />
The new beach at the effluent from Scherfigsvej is very popular in the summer
The third site is a series of overflow retention basins in Tune south of Copenhagen, where CSOs occur from<br />
the final basin to a small stream which merges in to the sea near the beach. PAA will be tested at this site<br />
since the CSOs occur very rarely like once a year with a long reaction time of 6 hours for the chemical<br />
disinfection in the basins.
Flood Risk Assessment Implementing GIS hydrological Computation and 1-D<br />
Hydraulic Model to Determine Service Level Capacity in Drainage Systems – A<br />
Case Study from Brøndby – Denmark<br />
Sabah Al-Shididi 1 & Joshkun Yolju 2<br />
1 MSc Environmental Eng., MSc Environmental Policy, BSc Building and Construction Eng.,<br />
Project Manager/Modeller at Avedøre Wastewater Services (Spildevandscenter Avedøre),<br />
sas@spvand.dk, +45 3634 3854.<br />
2 BSc Environmental Eng., BSc Civil Eng., Drainage Engineer at Avedøre Wastewater Services<br />
(www.spildevandscenter.dk) for Brøndby Utility, jy@spvand.dk, +45 3634 3819.<br />
(Platform Presentation, English) Open for Poster.<br />
Abstract<br />
Climate change is already a challenge for water companies to optimize drainage systems capacity<br />
and it will continuously intensify. A need occurred to determine service level capacity and flood<br />
risk assessment in Brøndby – Denmark,<br />
which was exposed to the challenge of<br />
extensive flood in recent years and<br />
particularly during the monster rain event of<br />
July the 2 nd 5-year event<br />
2011.<br />
Potential flood<br />
This paper reviews a new method to<br />
combine GIS hydrological computation and<br />
1-D hydraulic model to determine flood and<br />
hydraulic capacity of the drainage system in<br />
Horsedammen in Brøndby, a catchment of<br />
78 ha. This new method has the ability to<br />
overcome the present hardware limitations<br />
regardless of size of the catchment and the<br />
resolution of the flood grid implemented in<br />
the model and still reaching accurate results.<br />
The results have saved a great deal of<br />
modelling and simulation time. Simulations<br />
of status scenario, solution scenario, future<br />
climate change solution scenario and<br />
monster rain event scenario have been<br />
carried out producing a flood map for each<br />
scenario including regulated terrain for<br />
solution purposes and an optimised drainage<br />
system capacity for the determined service<br />
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level capacity. The method is an effective tool for analysis, assessment, planning and design of<br />
drainage systems and can be used for river systems and other 1-D modelled systems applied to rain<br />
events.<br />
A supplementary presentation of the results in 3-D images and video records presenting the<br />
simulation results on time step basis has been possible to produce. Results can be presented on<br />
Google Earth and similar online GIS programmes.<br />
Key word: Flood, GIS hydrological Computation, Climate Change, 1-D hydraulic model, Brøndby.<br />
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