Future water management of cities Research based decision support for urban water system development Martin Rygaard ([email protected])

With help from Sarah, Brudler, Berit Godskesen, Karsten ArnbjergNielsen, Erik Arvin, Linda L. Fang, Borja V. Perez, Benedek Plosz, Anders Damgaard

Decision support – Technology Development

EXAMPLE 1

2

DTU Environment, Technical University of Denmark

DTU Environment in Singapore 2015

1 Objectives Scenarios for implementation of a novel ressource recovery technology

3 3

Use Life Cycle Assessment as a support tool for the TRENS developers

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Assess the environmental impact of the scenarios

2 DTU Environment in Singapore 2015

The scenarios: Implementing TRENS

A Conventional watewater treatment

10%

90%

B Agricultural reuse: 4 DTU Environment, Technical University of Denmark Irrigation & Fertilization

DTU Environment in Singapore 2015

The scenarios: Implementing TRENS

A Conventional watewater treatment

B Agricultural reuse: 5 DTU Environment, Technical University of Denmark Irrigation & Fertilization

10 km DTU Environment in Singapore 2015

LCA – Method in brief • Functional unit: 1m3 of influent wastewater • Life cycle inventory: operating reports for existing processes, databases for infrastructure and modeling of sludge and algal processes (ASM-2d and ASM-A) • Impact assessment: International Reference Life Cycle Data System (ILCD 2011)

• Uncertainty analysis

Contribution analysis Pertubation analysis (sensitivity ratios)

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DTU Environment, Technical University of Denmark

DTU Environmentassessment in Singapore 2015 Uncertainty

LCA – Method in brief • Functional unit: 1m3 of influent wastewater • Life cycle inventory: operating reports for existing processes, databases for infrastructure and modeling of sludge and algal processes (ASM-2d and ASM-A) • Impact assessment: International Reference Life Cycle Data System (ILCD 2011)

• Uncertainty analysis

J Clavreul et al., 2014 Env. Mod. Software

EASETECH

Contribution analysis Pertubation analysis (sensitivity ratios)

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DTU Environment, Technical University of Denmark

DTU Environmentassessment in Singapore 2015 Uncertainty

Included processes Processes A, B WWTP Construction A, B WWTP Operation A, B Discharge to sea A, B Waste incineration A, B Emissions to air A, B Biogas combustion

B Agricultural reuse: Irrigation & Fertilization

A, B Combustion in flare B TRENS B Pipeline B Fertilizer substitution

B Use-on-land

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Results

1 PE



x kg coal/p/y

Marine Eutrophication

Human/Eco Toxicity

L. L. Fang et al. in revision for Water Research

Scenario A: Without TRENS Scenario B: With TRENS sidestream  irrigation & fertigation

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Process contributions scenario B

B Agricultural reuse: Irrigation & Fertilization 10

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Decision support – Climate adaptation

EXAMPLE 2

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“Green“ stormwater management: • Decouple rain water from sewer • Discharge of water via new flow routes – on the surface • Represent asset in themselves  Transformation of roads, parks and public areas

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Source: Konkretisering af Skybrudsplan Nørrebro (HOFOR, Københavns Kommune & Rambøll 2013)

Cloudburst Management Plan for Nørrebro

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Slide: Sarah Brudler

Results for the “green“ and “grey“ scenario 14000

PE / 2.6km2

12000 10000 8000

"Green" scenario

"Grey" scenario

6000 4000

2000 0

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Drinking water softening will save households approx 80 SGD/person/yr

Decision support – Softening in Copenhagen

EXAMPLE 3 14

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Assessing impacts of softening

-60%

Change in hardness levels -30%

(Godskesen et al. J.Env.Man. 2012)

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DTU Environment in Singapore 2015

Advice for the Danish Health Inspectors 1.4

Unit: DMF-S 1.5

Fluoride (mg/l)

E

2.0

1.2

2.0

A: Typical Danish groundwater B: Softened groundwater C: Typical desalinated and remineralized water D: Rainwater E: Danish groundwater (high fluoride content)

2.5

Relation based on Danish water quality data: (Ca: 31.4-162.3 mg/l; F: 0.06-1.61 mg/l)

1.0

1.5

2.5 0.8 0.6

3.0

2.0

3.5

0.4

A

Softening

B

0.2 D 0

4.5 20

2.5

3.0

4.0

0.0

16

1.0

C 40

DMF S  0.18F  0.33 0.11Ca  83.53   exp1.05    0.25 25.63  

3.5 60 80 100 Calcium (mg/l)

DTU Environment, Technical University of Denmark

120

140

(Based on Bruvo et al., J. Dental Res., 2008)

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Decision support – Alternative water ressources

EXAMPLE 4

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Environmental evaluation of scenarios for future water systems

Environmental impact (mPET/m3)

2

A shift towards treatment intensive water supply

1.5 (Rygaard et al., Sci.Tot.Env., 2014)

1

0.5 DK Energy mix 2012 DK Energy mix target 2020

0 Groundwater based supply

19

Desalination

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Manufacturing

Transport

Construction

Maintenance

Decommissioning

Disposal

Pipes

Concrete / PE pipe production

Truck

Excavation & disposal of soil

Cleaning

Excavation

Treatment/ recycling

Channels

Concrete production

Truck

Excavation & disposal of soil

Cleaning

Excavation

Treatment

Planted areas

Grass seed / tree seedling production

Truck

Sowing / planting

Mowing & disposal of grass / cuttings

Excavation

Composting

Drainage

Clay / gravel production

Truck

Excavation

Excavation

Landfilling

Paved areas

Gravel / cobblestone production

Truck

Excavation & disposal of soil

Cleaning

Excavation

Landfilling

Decommissioni ng of park areas

Excavation

Landfilling / composting / treatment

Lowering of park areas

Excavation

Landfilling

Health risk

Environmental impact

Economy

(Brudler, 2015)

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Future sustainable water systems

DTU Environment, Technical University of Denmark

Freshwater impacts

DTU Environment in Singapore 2015