application form for the european green capital award 2019...

Application Form for the European Green Capital Award 2019

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9 Wastewater management 9A. Present Situation

Indicator Unit Year of data Percentage (%) of total annual generated wastewater load, connected to wastewater collecting system + urban wastewater treatment plants (UWWTPs)

99,7 %

%

2015

No of WWTP 2 2015 Total Design Capacity (PE) PE 2015 Total Load Received by UWWTP (PE) 790.000 PE 2015 Total annual generated wastewater load of the city (in PE)

792.000 PE 2015

Treatment level which is applied in each UWWTP: secondary or more stringent; in this case, type of treatment: nitrogen and/or phosphorus removal, disinfection

Phosphorus, nitrogen and oxygen demand removal.

2015

The sewage system The sewage system in Oslo was constructed over a period of 150 years. The average age of the sewage system is 53 years. The network consists of 2350 km of sewers, 57 pumping stations, 11 retention basins and two Wastewater Treatment Plants (WWTP), Bekkelaget (BRA) and VEAS. The plants are connected to the sewage system by 45 km of tunnels. Oslo owns 100 percent of BRA, while day-to-day operation has been outsourced to the private operator Bekkelaget Vann AS (BEVAS). The VEAS plant is co-owned by three municipalities. Oslo is the largest owner with 70.5 %. The wastewater treatment plants comply with national regulations.

Figure 9.1: The map shows the sewage system in the city and the 45 km tunnel transporting 70 percent of the load to the VEAS WWTP.


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57 percent of the sewage system in Oslo consists of combined sewers, while 43 percent consists of separated sewers. The oldest parts of the sewage network are combined systems, while constructions post 1965 are mainly separated systems. Overflow discharges from the sewage network and wastewater treatment plants constitute less than 2 percent of the annual wastewater load. In 2014 the City of Oslo established a new sewage, The Midgard Serpent (figure 9.1), after investing EUR 140 million. The Midgard Serpent handles wastewater from both old settlements along the lower part of Aker River and the new settlements in the Fjord City Project (9D8). This has improved the water quality in the Aker River, inner harbor basins (9D21) and the Oslo Fjord significantly. Wastewater load The total wastewater load treated in Oslo is 790,000 p.e. 80% comes from households, while 20% comes from the business sector and public buildings. BRA has a wastewater load of 300,000 p.e., while VEAS’s load is 490,000 p.e. All inhabitants are connected to the sewage system In Oslo, 99.7% of the inhabitants are connected to the public sewage system and WWTPs. Those not connected have their own onsite treatment system. Both BRA and VEAS have mechanical, chemical and biological treatment processes. Approximately 2000 inhabitants are connected to 580 local onsite treatment systems. The majority have sealed blackwater tanks and bio filters for filtration and polishing of greywater, whereas those remaining have mini treatment plants (chemical/biological and chemical/mechanical). Complying with international regulations Through the EEA Agreement, Oslo and Norway are subject to the EU Urban Waste Water Treatment Directive. Requirements are implemented through the Pollution Control Act and corresponding regulations. Through its discharge permits, Oslo meets requirements for removal of phosphorous (90 percent) and nitrogen (70 percent), in addition to BOD (70 percent) and COD (75 percent), from all wastewater in Oslo.


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Key figures from the VEAS and Bekkelaget WWTP’s Table 9.1: Key figures from the VEAS and Bekkelaget WWTPs incl. overflow. 2007 2012 2015

VEAS BRA TOT. VEAS BRA TOT. VEAS BRA TOT.

Incoming BOD5 (t/a) 8,096 5,170 13,266 10,757 6,999 17,756 11,358 7,328 18,686

Discharged loads BOD5 ( including overflows t/a)

692 138 830 561 163 624 1,499 425 1,924

Incoming COD (t/a) 22,905 17,479 40,384 24,023 18,189 42,212 24,412 17,974 42,386

Discharged loads COD ( including overflows t/a)

2,560 1) 2,521 1,433 3,954 4,272 1,985 6,257

Incoming Ntot (t/a) 1,847 1,169 3,016 1,949 1,452 3,401 2,151 1,513 3,664

Discharged loads Ntot ( including overflows t/a)

602.4 387.0 989.40 585 431 1,016 1,003 398 1,401

Incoming Ptot (t/a) 245 152 396.9 242 171 413 252 170 412

Discharged loads Ptot ( including overflows t/a)

22.2 12.8 35.0 20.4 13.7 34.1 24.9 15.75 40.65

Treated Waste water amount (mill m3/år)

69.2 40.7 110 71.1 46.8 118 77.2 50.05 127.25

Treatment level (removal of BOD5 %)

91.45 97.3 94.4 94.8 97.7 84.9 87.5 93.0 180.50

Treatment level (removal of COD %)

88.82 1) 89.5 92.1 90.6 83.2 89.0 172.20

Treatment level Ptot (removal of Phosphorous %)

90.9 91.7 91.3 91.6 92.2 91.9 90.9* 91.0 181.90

Treatment level Ntot (removal of Nitrogen %)

67.4 67.5 67.5 70.1 70.7 70.4 53.7* 74.0 127.70

Design capacity (p.e) 490’ 270’ 760’ 490’ 300’ 790’ 490’ 300’ 790’

1)Key figure not measured at this time. 2)400’ equals to 400,000 etc. *The County Governor has granted an exemption from this requirement while the VEAS WWTP being rebuilt.

Sludge management Oslo actively works to reduce the inflow of wastewater containing micro-pollutants to the municipal sewage network. The two treatment plants process the sludge differently, but common to both is biogas production. Additionally, sludge is reused in agriculture and the demand among farmers is high. Table 9.2: Sludge production at VEAS and Bekkelaget in 2015 and use.

Total sludge production (t/a) Use of sludge in agriculture Bekkelaget WWTP 21,071 77 % VEAS WWTP 26,888 100 % Total 47,959 89 %


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Figure 9.2: Circular economy; sludge from Oslo’s two wastewater treatment plants is spread on cornfields around the city (see Good Practice 4, 9D9). Energy utilisation and recycling of wastewater

Bekkelaget WWTP produces an energy surplus. VEAS aims to achieve the same by the end of 2017.

In 2000, the Klosterenga eco-housing cooperative, consisting of 35 flats situated in downtown

Oslo, constructed an onsite treatment system for greywater. The water is collected and treated in a wetland, before it is emptied into the Hovin stream that runs through the area.

Two heat pumps at the Skøyen District Heating Plant, with a combined effect of 27 MW,

extract heat from sewage and provide energy and hot water equal to the needs of 13,000 households (9D10).

Annual energy consumption for waste water treatment is 0.36 kWh/year/pe. Energy from

biogas is mostly utilized as bio methane for waste trucks and buses in the city.


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Figure 9.3: Biogas bus in front of the Opera House in Oslo with the Midgard Serpent underground. 15 % of the bus fleet in Oslo runs on biogas (see Good Practice 4, 9D9

9B. Past Performance Increased capacity In 2008, a rainwater treatment plant (RTP) was built at VEAS WWTP. The RTP is only in use when the main plant is running at full capacity due to heavy rainfall and/or snowmelt. The RTP reduces overflow discharges from the tunnel system by 80 %. Average overflow between 2005 and 2008 was 5 million m3, and with the RTP the average is now 1.47 million m3. The main processing plant treats 2,000 litres/second, and purification levels for phosphorous and organic matter are high. Table 9.3: Overview of waste water treated at the VEAS plant last decade. All numbers presented as million m3

Year Inlet load VEAS Treated in the main plant

Treated in RTP

Total load treated

Overflow

2005 102.59 - - 100.50 2.09 2006 121.55 - - 115.95 5.61 2007 109.87 - - 104.24 5.63 2008 116.17 108.19 1.43 109.62 6.56 2009 106.83 97.33 8.40 105.73 1.09 2010 99.96 93.87 4.76 98.63 1.33 2011 108.36 100.27 6.42 106.69 1.67 2012 105.56 99.02 5.61 104.63 0.93 2013 104.15 99.90 3.55 99.50 0.70 2014 111.00 101.60 7.70 109.30 1.70 2015 109.52 99.70 7.30 107.00 2.52

From 2009 to 2012, the Bekkelaget WWTP was optimized to accommodate increased wastewater loads, from originally designed capacity of 270,000 p.e. to 300,000 p.e (9D21). This enables the plant to accommodate Oslo’s growing population.


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From 2007 to 2011, the plant did not comply with discharge regulations, as these became stricter and the loads increased. Since 2007, Oslo has implemented optimization measures. Today, the plant complies with discharge regulations and was also the first plant in Norway to produce surplus energy - biogas and heat exchangers. These intensive optimization measures and the immediate effect from the new Midgard Serpent sewage system (9D11) together produced record breaking results at the WWTP in 2015 with 91% phosphorus removal, 74.2% nitrogen removal, and 0.80% phosphorus and 0.70% nitrogen overflow in relation to inlet load. Biogas Since 2010, Bekkelaget WWTP has produced biogas and through this contributed to reducing GHG emissions and local air pollution in Oslo. All the biogas is used to fuel waste trucks and buses in Oslo. In 2015 all the waste trucks and 15 % of the city’s buses ran on bio methane. Systematic measures are continuously implemented to further increase portion of biogas upgraded into biomethane. Maintenance measures In 2015, the Master Plan for Sewage and Water Environment 2014-2030 (9D3) was finalized. The sewage network is, on average, 53 years old. In the past five years, the average renovation rate for the network has been 1.3% and approximately 60% of the sewage network has been inspected, a major part using video inspection. When Oslo renovates the network the city uses no-dig method whenever possible. This is less invasive, results in lower CO2-emissions and is energy efficient compared to traditional digging. Asset replacement and renovation investments for wastewater-pipelines per property in 2015

Figure 9.4: Peer comparison of renovation investments in Europe. Source: European Benchmarking Cooperation Systematic efforts to improve the sewage system have resulted both in cleaner waterways and that the Fjord, in most areas, complies with bathing water standards (see also indicator 8). Since 2012, several new beaches and beach resorts have opened in the city centre by the bay and along the rivers inland the city. A few years ago, swimming would not have been recommended in the inner fjord due to poor bathing water quality. On warm and sunny summer days Oslo’s citizens now can experience good bathing water quality in the inner part of the Oslo-Fjord at beach resorts such as the newly established Sørenga (figure 9.5).


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Figure 9.5: Bathing water quality is good in the inner parts of the Oslo Fjord. The beach resort, Sørenga close to the Opera house, opened in 2015. Photo: Katrine Lunke

Measures are based on politically approved environmental targets The overall objective in the Urban Ecology Programme 2011-2026 (The City of Oslo’s environmental policy, 9D2) is that: «Oslo will be a sustainable urban community where everyone is entitled to clean air, clean water and access to attractive outdoor recreational areas». According to target number five, Oslo will maintain and strengthen its blue-green structure. Four sub-targets for waterways and storm water management have been stipulated:

Protecting and enhancing biodiversity Maintaining and further improving Oslo’s green structures Re-opening culverted waterways and creating blue-green corridors Ensuring that management of drinking water supplies, river systems, ground water and the

fjord are eco-efficient Monitoring water quality in waterways and the fjord Oslo has 10 waterways running through urban areas where water quality is a major priority. For more than 10 years the waterways have been monitored through a program looking at bacteriological, chemical and ecological parameters (figure 9.6). Ecological parameters include thorough examinations and assessments of bottom dwellers and fish, which are time consuming investigations, but important to demonstrate the real condition of the ecosystem in each watercourse. Two main waterways are examined each year. The program provides a solid basis for identifying trends and developing measures. All main waterways have moderate to good ecological status upstream, while the status typically deteriorates downstream due to impacts from the urban areas. Data from the monitoring program are annually reported and published on the City’s statistical webpages (9D23), and trends show improvement or no change in ecological status for all waterways. Oslo aims to overcome challenges in order to reach the WFD target in all the city’s main waterways by the 2021 deadline. The City of Oslo is working closely on urban waterways and storm water management. Over the last decade, a number of waterways have been re-opened (figure 9.10). This is important for storm water management. The past five years have shown significant progress and by the end of 2015 a total of 2810 metres of waterways had been reopened, 1080 meters in the last two years. Local purification of storm water and eco design with rapids, deep pools and recreational areas and purification systems managing runoff from the busiest roads, have been established over the past few years (9D12, 9D13).


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Bathing water quality is now good in the inner parts of the Oslo Fjord (see Indicator 8). All Combined sewer overflows (CSO) in Oslo are monitored through a remote control system, monitoring when, and for how long, the CSOs are in operation. Sewage disposal sites are also in place for cruise ships, boats, and recreational vehicles in the city. One of the major challenges of housing development close to streams is the water quality. Oslo has established several major storm water ponds with creeks passing through. Here the water is purified by nature-based methods such as sedimentation, biodegradation and absorption of nutrients in wetland vegetation, before it flows further into residential areas and into the Oslo fjord.


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Figure 9.6: Classification of ecological status of Oslo’s main waterways (EQR).


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The City cooperates closely with NGOs, particularly the Oslo River Forum. Together, they run a project where schools adopt waterways, and commit to removing waste and collect water samples (9D6). In 2015 more than 150 pupils participated and used the teaching material developed by Oslo River Forum (9D7). The project also involves kindergartens and co-owners. The target is the “adoption” of the entire length of the main waterways in Oslo.

Figure 9.7: Agree! Representatives from Oslo River Forum, Schools in Oslo, Agency for Urban Environment and Mayor Marianne Borgen after signing a river adoption agreement. Photo: Fredrik Eckhoff Involvement and European cooperation The City has participated in two large EU projects, TRUST 2011-2015 and PREPARED 2010-2014. The projects offer support networks for knowledge exchange on climate change and sustainability. The Agency for Water and Wastewater Services is a partner in the European research project DESSIN (Demonstrate Ecosystem Services Enabling Innovation in the water Sector) (9D14) as Hoffselva demo-site owner. It participates in the development and demonstration of the technologies and in the testing of the sustainability assessment framework. The project period is 2014-2018.

Oslo joined the Intereg. project Biogas2020 in 2015 (9D15). The project aims to establish a Scandinavian biogas platform promoting technical developments and biogas usage in Denmark, Sweden and Norway.

Oslo has participated in the WssTP, the European Technology Platform for Water, since the EU Commission initiated it in 2004 (9D16). WssTP promotes coordination and collaboration of research and innovation in the European water sector, and at the same time improving its competitiveness. 9C. Future Plans Financing and political priorities The Agency for Water and Wastewater Services in Oslo is a non-profit agency. The entire budget is financed by the water and sewage charges. Budget priorities come from the City Council (9D4). The opex budget for 2015 is EUR 104 million in total and capex budget EUR 107 million. For wastewater


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management in the period 2017-2020, the budget is EUR 390 million. In 2015, a new Master Plan for Sewage and Water Environment was adopted (9D3). The plan covers the period 2014-2030. It describes how Oslo will reach the targets set in the Urban Ecology Programme (9D2), and how the City will fulfil all legal requirements. Below is how he City will concentrate its efforts and budget priorities in the years leading up to 2030: Managing population growth In 2030 Oslo is expected to house a population of 795,000 inhabitants. This, combined with further urban development, will cause higher loads on the sewage system. Safe waste water management In the future, Oslo will prioritize work on pipes that, if they collapse, will pose a threat to the inhabitants, and damage the city’s infrastructure. The risk of operational interruptions is to be eliminated. In addition, Oslo will also prioritize measures that reduce basement flooding. Climate change adaptation Climate change will lead to more intense and frequent rainfall in Oslo. Combined with an increase in sealed surfaces and clayey subsoil, more rain makes storm water management a large challenge for Oslo. In many areas, the sewage network risks overload, and thus increasing urban flood risk. Two measures stand out in connection with the sewage system and flood risk:

Dimensioning of the sewage system will be based on a climate change factor of 1.5. The climate factor will be continuously evaluated, so that it is based on the latest and best predictions.

In order to limit damage caused by storm water, the requirements for local storm water management will be strengthened, e.g. reopen more streams, and construct safe flood-ways. Cooperation across sectors and agencies is vital for success in this work.


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Figure 9.8: Construction of safe flood ways at Hølaløkka in Oslo. The City has decided to reopen closed rivers and streams whenever this is possible and expedient (9D2). To formalize and streamline the municipal cooperation, the most involved municipal agencies have compiled a management document that points out superior principles for reopening projects with a list prioritized projects.


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Figure 9.9: Map showing open and closed stretches of main rivers and small streams/tributaries within the built-up zone of Oslo. The map also displays the positioning of concluded reopening projects in the past decade, as well as on-going and planned projects (9D13).”Marka” is the forest surrounding the City of Oslo.


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Figure 9.10: Teglverksdammen is a large scale reopening of the stream Hovinbekken. All together 650 meters of the stream has been reopened, with sedimentation basins, water rapids, indigenous plant species, a small lake and shallow waters with dense vegetation. Ensuring ecological and chemical quality of water The EU Water Framework Directive (2000) was included in Norwegian law through the Regulation on a Framework for Water Management in 2007 (The Water Regulations). Oslo’s goal is to develop a comprehensive water management system and that all water sources have good ecological and chemical conditions by 2021 (figure 9.6). Requirements set in the Water Regulations and the approved Fjord City Plan (9D17, 9D8), require that Oslo keeps up its comprehensive efforts to minimize discharges to the environment. All CSOs have been classified according to risk. This will be followed up by measures aimed at where the most serious discharges occur, as well as measures aimed at the most vulnerable recipients. This work is expected to cost approx. EUR 63 mill. in the next 7-12 years. The Agency for Water and Waste Water Services developed its own Energy and Climate strategy 2014-2030 (9D19), which maps the contribution to reduced greenhouse gas emissions from water and sewage management.


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Renovating the sewage network To stop continuous deterioration, the aim in the Master Plan for Sewage and Water Environment is to increase the renovation rate from the current 1.3 to 1.6 % by 2030. In the period 2017-2020, EUR 64 mill. is earmarked in the budget for sewage renovation.

Figure 9.11 Rehabilitation of a 700 millimetre sewage pipe using no-dig method Expanding the wastewater treatment plants The Bekkelaget WWTP is overloaded, in spite of several capacity expansions in the past few years. This is due to population growth, which has been particularly high in the eastern parts of Oslo. Extension of the WWTP started in 2013 and the new WWTP will be commissioned in 2020 at a cost of EUR 300 million. In due time, the VEAS WWTP will also be expanded. The plant handles about 60 percent of all wastewater from Oslo, and is also experiencing capacity challenges. From around 2020, a gradual expansion programme will be implemented, at a cost of EUR 98 million. Both of the new WWTP’s are constructed to optimize utilization of sewage sludge to produce biogas Oslo`s “Climate Budget” aims to cut greenhouse gas emissions in half by 2020 The City Government has launched climate budgets for 2017-2020 as a part of the Financial Budget. It consists of 42 measures distributed across tree sectors; Energy/buildings, Resources and Transport. All City departments will be given responsibility for goal attainment and annual expected progress (table 9.4). Reports will be managed within the existing formal financial and governance system of the City.


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Table 9.4 Mitigation measures in the Climate-budget where the Water and Wastewater Services is responsible, including financing and estimated emission reduction. *) For the complete climate-budget see Good Practice 1 (9D18).

Sector/Area Measure

Responsible

Agency/Organizatio

n

Funding for

2017

Cumulativ

e CO2

reduction

2020

(ktCO2)

Resources/

Sewage Equipment to verify emissions

from sewage

Water and

Wastewater

Services

Existing

budget

27

Transport/

Greener

goods

transport

Establish urban freight facility Urban Environment 2 MNOK OpEx

50

Establish energy stations:

freight (Alnabru)

Real Estate and

Urban Renewal /

Urban Environment

/ Climate 5 MNOK OpEX

Increased biogas production

from water/sewage

(Bekkelaget)

Water and

Wastewater

Services

Existing

budget

Increased biogas production

from water/sewage (VEAS)

Water and

Wastewater

Services

Existing

budget

Cumulative CO2 emission reductions for the

42 measures*) 836

9D. References PLANS AND PROGRAMMES

1. The 2015 Municipal Master Plan: Oslo towards 2030 (Norwegian) Smart, Resilient and Green

2. Urban Ecology Programme 2011–2026 (English) The environmental policy of Oslo passed by the City Council. Section 5.3 and 5.4 outlines priorities, targets, strategies and measures Waste water management

3. Master Plan for Sewage and Water Environment 2014-2030 (Norwegian)

4. The proposed Municipal Budget 2017 and the proposed Economic Plan 2017-2020 (Norwegian)


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ADDITIONAL INFORMATION

5. Gjødselvareforskriften (Norwegian) National requirements to sludge used for agricultural purposes

6. The Oslo River Forum Website (Norwegian)

Works to preserve and rehabilitate the waterways of Oslo.

7. Vivid Waterways Teaching Material (Norwegian)

8. Good Practice 5 in the Application: The Fjord City (English)

9. Good Practice 4 in the Application: Circular Economy in practice (English)

10. Hafslund District Heating (English) Presentation of Skøyen District Heating Plant that extract heat from sewage flowing through the sewer mains.

11. The City of Oslo’s Website Environment and climate (Norwegian) Provides an overview of environmental efforts by the City of Oslo.

12. Description of The Midgard Serpent (Norwegian) – a new, modern sewerage system in Oslo.

13. Teglverksdammen (Norwegian)

14. Good Practice 6 in the Application: Reopening of rivers and streams in Oslo (English)

15. DESSIN (English) Demonstrate Ecosystem Services Enabling Innovation in the water Sector

16. Biogas2020 (Swedish)

17. WssTP (English) The European Technology Platform for Water, initiated by the EU Commission in 2004

18. Fjord City Plan (Norwegian)

19. Good Practice 1 in the Application: Climate budget

20. Energy and Climate Strategy, Agency for Water and Waste water Services (Norwegian)

21. Flow charts for the VEAS and Bekkelaget water treatment process (Norwegian)

22. UBRA (Norwegian)

23. Water quality - main waterways (Norwegian)

The City of Oslo’s statistical webpages

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