Waternet is a water utility company in Amsterdam that is working towards a more circular water economy through various innovations. They have integrated their wastewater treatment plant with a waste incineration plant to produce biogas, electricity, heat, and recover nutrients. They also recover struvite from wastewater, produce green gas for vehicles, improve a lake's water quality for cooling, and implement projects to make Amsterdam more resilient to heavy rainfall. Other projects recover heat from shower water, produce calcite pellets to soften drinking water, explore new sanitation concepts, and use biomass to create products like benches.

1. Water in the circular economy
Jan Peter van der Hoek & Alice Fermont
July 2017
Innovations @Waternet

2. Content
Introduction Waternet
Integration of Waste, Wastewater treatment and
Energy
Production of green gas for transport
Introduction of struvite recovery
Ouderkerkerplas – a clean source for cooling
Amsterdam Rainproof
Heat exchanger in the shower discharge
The Calcite Factory
New sanitation
Thermal energy recovery – cooling with drinking
water
Biomass is turned into products
Photo: Merlijn Michon

3. Water in the circular economy
Waternet: water
cycle company
Executive organisation of two governmental
boards: City of Amsterdam and Water Authority
Amstel, Gooi en Vecht
Tasks:
• Drinking water production and distribution
• Sewerage and wastewater treatment
• Surface water control (dykes, waterlevel)
• Groundwater control
• Shipping

4. Waternet: some key factors
Customers 1.2 million
Municipalities 20
Employees 1,850
Annual budget € 400 million = $ 450 million
Drinking water 90 million m³/y = 23,775 million gallons/y
Leakage 2-3%
Drinking water connection 100 %
Wastewater 125 million m³/y = 33,000 million gallons/y
Sewage connection 100%, almost no sewage overflow, separate
system
Waste water treatment plants 12
Sewage 4,000 km = 2,500 miles
Dikes 800 km = 500 miles
Nature (resources) 4,200 hectares = 10,400 acres

5. Core values
• Expedient
• Sustainable
• Customer oriented
Non profit customer service
• Satisfied customers 88%
• Brand awareness 91%
Tariff
a 4 person household in 2017 has to pay:
•Water management levy: € 148
•Waste water treatment levy: € 158
•Drinking water charge: € 196
•Sewerage levy: € 128 +
Total water costs: € 631
= total cost recovery
= 2% average annual income

6. Klik om de stijl te bewerken
Combination with Waste Incineration
Plant
WasteWater
TreatmentPlant
Waste
Incineration
Plant
sludge
biogas
electricity
heat
Innovation: Integration of Waste,
Wastewater treatment and Energy

7. Water in the circular economy
Challenge: Combine
Energy, Waste and
Water
• Reallocation of wastewater treatment plants
from Amsterdam to the harbour of Amsterdam
• Limited space available for wastewater
treatment
• Ambition to decrease energy use at the
wastewater treatment plant
• Ambition to cooperate with AEB, the Waste-to-
Energy company of Amsterdam
incineration plant for waste
Waste water treatment plant in Amsterdam
Old wastewater treatment plant in Amsterdam

8. Electricity [20,470 MWh/year]
District heating
[70,000 GJ/year]
Sludge [82,900 ton/year]
Heat [50,700 GJ/year]
Biogas [12.3 mln m3/year]
WWTP
Amsterdam West
AEB, Waste to Energy
Company
Result: Integration of Energy, Waste
and Water
Avoided natural gas usage: 1.8 M m3/year
Avoided greenhouse gas emissions: 3,200 ton CO2-eq/year

9. Klik om de stijl te bewerkenInnovation: Production of green gas for transport,
fuel for 171 company cars of Waternet

10. Challenge: Biogas at
the WWTP is burned as
it exits the flare stacks
• Spill of gas
• Use of fossil gas for transportation
• High CO2 emission due to
transportation and burning of gas
• Turn biogas into green gas

11. Result: Production
green gas at the
Amsterdam WWTP
• 12 million m3 biogas (8.4 million m3 green gas,
enough for 7,000 households = 25,000 people)
• The produced green gas is used for transport fuel
• CO2 is a by product and can be used for green
houses or chillers in lorries
• Additional benefits: cleaner air if green gas is
used in transport
• Cost reduction: extra income is about
7 euro ct/m3

12. Klik om de stijl te bewerkenInnovation: Introduction of struvite recovery
at the WWTP

13. Challenge: Operational
problems at the waste-
water treatment plant
• Clogging of pipes due to uncontrolled
struvite precipitation = magnesium
ammonium phosphate
• High maintenance costs
• Spill of nutrients
• No resource recovery

14. CAS Number: 7785-21-9
Result: Recovery of
struvite at WWTP
• Improving dehydrating sludge
– Lower costs
– Higher energy production Waste to Energy Plant
• Less wear dehydrating sludge
– Lower maintenance costs
• Production of struvite 800 ton (get back
100 ton P for fertilizer)
• Reduction of greenhouse gas emissions
with 1,120 ton CO2-eq/year

15. Innovation: Ouderkerkerplas –
a clean source of cooling

16. Water in the circular economy
Challenge: Clean water
and sustainable energy
• Poor water quality and algae blooms at the lake
Ouderkerkerplas due to high phosphate
concentrations
• Limited recreation function of the lake due to
poor water quality
• Expensive solution to upgrade water quality
• NUON (energy company) needs cooling
capacity for buildings
• Energy savings and transition to sustainable
energy

17. Water in the circular economy
Result: Clean water and
sustainable energy
• Innovation to bind phosphate at the bottom of
the lake is proved
• Improvement of water quality and less algae
blooms at the lake Ouderkerkerplas
• Extended recreation function of the lake due to
better water quality
• Cost effective solution to upgrade water quality
• Production of sustainable energy for cooling
capacity

18. Water in the circular economy
Innovation: Amsterdam
Rainproof
• Network approach
• Dedicated team for task
• Main target: mainstreaming rainproof in urban
networks
• Goal rainproof Amsterdam in 2050
Stichting PlantageLab: working together to rainproof the city, Photo: Merlijn Michon

19. Challenge: Amsterdam
not cloudburst resilient
• Heavy rain due to climate change
• Increase of hard surface (paving
gardens, buildings & roads)
• Densification of the city
• Public and private need to take action
• Lack of awareness

20. Water in the circular economy
Result: Rainproof
movement
• Movement of over 100 partners taking actions
to adapt to cloudburst events
• Shared ownership, raising awareness within
public and private sector
• Incorporated in 15 urban policy documents
• Capacity building: exchange knowledge and
instruments for others to act
• Many physical rainproof projects (public and
private)
• Copied example for other (inter)national cities
and initiatives

21. Water in the circular economy
Innovation: Heat exchanger in the
shower discharge
Heat is lost Heat is reused

22. Water in the circular economy
Challenge: Showering
loss of thermal energy
• 49 l (1/3 of) tap water used for showering
• Average temperature is 35° C
• 60% ( 3.6 GJ) of household energy used for
heating water
• Thermal energy discharged into the drain
• Reuse of thermal energy is necessary for
energy transition

23. Water in the circular economy
Result: Shower heat
exchanger saves
money and energy
Tested in Uilenstede 100 apartments:
• 53% efficiency
• 40% energy reduction
• Average annual saving: € 50/apartment
• 180 kg CO2 reduction/apartment
Whole city of Amsterdam (412,000 households):
• energy saving 4% (gas & electricity)
• CO2 reduction 54 kton

24. Innovation: The Calcite Factory
Pellet softening with ground calcite

25. Challenge: Softening of drinking water with
reuse of calcite CaCO3
Garnet sand from
Australia
Calcite pellets
(CaCO3) with
garnet nucleus

26. Result: Factory to reuse calcite and to improve
products
• Cost savings:
€ 109,250/year (0.4%)
• Environmental savings (LCA): 39,900 Eco-
points/year (5%)
• Pure calcite, no sand in resource

27. Innovation: New sanitation

28. Water in the circular economy
Challenge: Introduction of circular household
concept to save energy and water

29. Water in the circular economy
Result:
New sanitation
• New sanitation contributes to
• energy reduction and production
• reuse of raw materials (phosphate)
• Delay in planning is a financial risk
• Laws and regulations are not ready for new
sanitation
• Awareness is growing on need for energy
transition (no gas, energy labels)
• Show booth for new sanitation (acceptation)
• Pilot for new concepts on sanitation

30. Water in the circular economy
Results: thermal
energy recovery
from drinking water
Energy use
(kWh/year)
GHG emission
(ton CO2-eq/year
Traditional
cooling
machines
2,000,000 1,220
Cooling with
drinking water
200,000 120
Total Costs of Ownership
(million €)
Traditional cooling machines 8.0
Cooling with drinking water 5.4
Innovation: Thermal energy recovery–
cooling with drinking water

31. Water in the circular economy
Challenge: Cooling with sustainable energy at
the bloodbank Sanquin

32. Water in the circular economy
Result: thermal energy
recovery from drinking
water
The system:
The elements:Traditional
cooling
machines
Cooling with
drinking
water
Energy use
(kWh/year)
2,000,000 200,000
GHG emission
(ton CO2-
eq/year)
1,220 120
Total Costs of
Ownership
(million €)
8.0 5.4

33. Innovation: Biomass is turned into products
like a bench from biocomposite

34. Water in the circular economy
Challenge: Reuse of
grass an CO2
reduction
• We harvest 6,000 tonnes of dried aquatic
plants, reed and grass
• The harvest is turned to green waste or left
to rot away
• Possibility to achieve CO2 reductions
of 7 ktons
• Looking for options to make new products
from the pants, reeds and grass

35. Biocomposite
Result: Aquatic plants, grass, reeds are turned
into products

36. Water in the circular economy
Editor and texts
Jan Peter van der Hoek
Alice Fermont
@Waternet 2017
Contact:
Waternet
Korte Ouderkerkerdijk 7
PO Box 94370,
1090 GJ Amsterdam
www.waternet.nl