1. Welcome to Bekkelaget Wastewater Treatment Plant

2. 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 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

3. 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 pe
Average daily flow ~ m3/d
Outlet demands: P-removal > 90% N-removal > 70% (including overflow)
Sludge production ~5.500 tons DS/year
Gas production: Nm3

4. 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

5. Phosphorus and Nitrogen loads to Inner Oslofjord 1910-2004

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

7. 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

8. 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

9. 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

10. 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

11. 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 , 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

12. 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

13. 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 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

14. 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

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

16. 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

23. 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