Welcome to Bekkelaget Wastewater Treatment Plant

Gas holder and Rock caverns Upgrading plant Admin building The plant was built in the period 1998 to 2001, replacing the old plant from 1963 in the neighborhood. The plant is located in rock caverns with a total area of 45.000 square meters. In the back ground you can see the city hall and Holmekollen ski jump The Municipality of Oslo, signed in 2001 a 15 years operation contract for Bekkelaget WWTP with Bekkelaget Water inc. Bekkelaget water inc. have 15 employees, and is owned by Anglian Water Group (AWG) (UK) Admin building

FACTS: 35-40% of all wastewater from Oslo, treated at Bekkelaget WWTP Plant put in operation in 2000 Owned by the City of Oslo, operated by the private company Bekkelaget Water inc. (BEVAS) Approximate 280.000 pe Average daily flow ~100.000 m3/d Outlet demands: P-removal > 90% N-removal > 70% (including overflow) Sludge production ~5.500 tons DS/year Gas production: 3.700.000 Nm3

Concession New demands from 01.01.2009: Nitrogen 70% of all nitrogen must be removed Phosphorus: 90% of all phosphorus must be removed Organic matters: 70% of organic matters as BOD5,must be removed And the total amount of overflow must be less than 2% of the total loads of nitrogen, phosphorus and organic matters These new demands together we increasing load to the plant will cause some challenges in the future

Phosphorus and Nitrogen loads to Inner Oslofjord 1910-2004

Water capacities Dry weather flow 1450 l/s -125.000 m3/d biologically treated (max capacity 1900 l/s) Water flow rates between 1900-4000 l/s is treated chemically Water flow rates between 4000 - 6000 l/s is treated through 3 mm screens

Water and sludge treatment process Primary sludge Buffertank Buffer Silo Bio sludge Dewatering Thickener Digester Biogas Overflow Magasin~35.000m3 4000 l/s < Q < 6000 l/s Sand, grit and screenings FeSO4 PAX-18 Activated sludge Clarifier Primary Filter PAX-18 Precipitation Primary 1900 l/s<Q< 4000 l/s Q<1900 l/s Q=1900 l/s Biogas- upgrading

Overview Water treatment Inlet tunnel Screens, sand and grit removal Primary settling/ direct precipitation Bio step, activated sludge Clarifiers Extra space(not in use) Sand filters Sludge treatment Digesters Ventilated air treatment – odor control Biogas, upgrading (out) 212 m 12

Sludge – heating system - existing Primary sludge Sludge buffertank RSL 2 Silo Biosludge De watering Thickener Digesters Biogas RSL 1 Boiler (gas/oil) Heating – buildings and plan Ventilation + adm in building

Sludge – heatingsystem Primary sludge Sludge buffertank RSL 2 Silo Biosludge De watering Thickener Biogas to upgrading RSL 1 Excess heat from upgrading plant Boiler (Gas/oil) Upgrading biogas Heating – buildings and plan Ventilation + adm in building Pellets Cooling of sludge Heat pump Without heatpump in operation Digesters

Use of biogas The plant produces large amounts of biogas It is similar to f.ex Propan and has a high heating value Until 2006 – gas used for sludge drying and heating of sludge and buildings From 2006-2010, only 50% of produced energy from gas used Different solutions discussed Electricity production Fuel production, two different options – gas production similar to 2,2 million liters of diesel pr year Heat to district heating system

Bærekraftig drift Optimalisering energibruk - BRA BRA nå og fremtiden: Til nå Anlegget satt i drift 2000, relativt moderne anlegg Lys og ventilasjonsstyring Frekvensomformere Stort overskudd biogass Fremover Varmepumper Oppgradere/frigjøre biogass til drivstoff Pellets som støttevarme Fokus på O2 regulering, godt nok Bruk av lavverdig energi I forbindelse med vurdering av alternativ fremtidig bruk av biogassen på BRA ble det utarbeidet et miljøregnskap -  Emisjonstall El 0,1 tonn CO2/Mwh Fjernvarme 0,051 Diesel 0,26 Muliggjøres fordi: Ambisiøse planer Klar politisk målsetning Ny teknologi Voksende marked

Upgraded biogas (biomethane) Upgraded biogas (biomethane) as fuel is almost CO2 neutral and is the most environmental friendly of fuels commercially available In 2009 the biogas production was 3.600.000 m3 (60% methane), equivalent of 24 million kWh/year or 2.2 mil liter diesel. The production can keep 80 busses running on biomethane, every day The plant for upgrading of biogas to biomethane was put in operation early in 2010 The investment costs for this plant was 32 mill NOK. Including necessary investments rebuilding the heating system and the sludge treatment process the total cost was 55 mil NOK

COOAB ® process – CO2 absorption gassholder Gas drier High pressure compressor Activated coal - filter 200 bar CO2 0,5 bar 2 bar Odorizer CO2 removal/ COOAB recovery

Water quality 2010 *Concession numbers are incl. overflow. **Results from 2010 incl. overflow

Sludge Sludge production: 17.700 tons sludge, or 5.400 ton TS / year 90% of sludge are being used as a fertilizer for grain production Limit (mg/kg TS) 2002 2009 Pb (mg/kg TS) 80 36,8 18,8 Cd (mg/kg TS) 2 1,48 0,68 Hg (mg/kg TS) 3 1,04 0,65 Cr (mg/kg TS) 100 34,3 19,8 Ni (mg/kg TS) 50 26,3 17,1 Cu (mg/kg TS) 650 703 277 Zn (mg/kg TS) 800 398 410

Bekkelaget Water inc.(BEVAS) The Municipality of Oslo has signed an operation contract for Bekkelaget WWTP (BRA) with BEVAS for 15 years Operation contract stared in October 2001 BEVAS is owned by Läckeby Water Group (Sweden) Läckeby also have interests in Purac AB, and offer services within, construction, design, building, equipment and operation. The company has 180 employees, has a turnover on 600 mil. SEK, and runs businesses in 10 countries