Biowaste Collection and Treatment ISWA Beacon Conference The Global Challenge: Optimising the C Cycle 23rd May 2008

Presented by: Dr Dominic Hogg

Outline – How Much Food Waste? – Biowaste Collection Issues – System Modelling – UK Experience with Food Waste Collections – Conclusions

How Much Food Waste?

UK Household Food Waste Generation 1. 6.7 million tonnes generated – worth €19 billion – –

ONE THIRD of what we buy! Approx 30 mn tonnes CO2 equ (estimate)

2. Truly unavoidable food waste is 19% of total 3. 61% of food waste is avoidable – worth €12 billion –

359,000 tonnes of potatoes –

–

190,000 tonnes of apples –

– –

177,000 tonnes whole or untouched 179,000 whole or untouched

45% of all salads are thrown away 8% of avoidable is ‘in ‘in date’ date’ when disposed

4. 20% ‘possibly ‘possibly avoidable’ avoidable’ 5. 1.2 million tonnes still untouched and in packaging Source: Exodus Market Research (2008) The Food We Waste, Report for WRAP, April 2008

Composition of ‘Bin Waste’ (UK, 2002) Fines

Newspapers & Magazines Other recyclable paper

Kitchen waste

Board packaging Card and paper packaging

Garden waste

Wood Furniture Disposable nappies

Source: Parfitt 2002

Other Miscellaneous combustibles

Composition of ‘Residual Waste’ (England, 2006) WEEE Fines

Hazardous Paper

Unidentified

Card

Food Waste Plastics

Fibres / shoes

Misc Organic

Garden Waste Metals

Source: Defra 2007

Glass

Misc Inorganic

Composition of Unrecycled ‘Bin Waste’ (English County Recycling / Composting 40% of Waste)

Paper Card Dense Plastic Plastic Film Textiles Glass Miscellaneous Miscellaneous Non-combustibles Ferrous Metal Non-ferrous metal WEEE Hazardous Organic non-catering Organic catering Fines

Biowaste Collection Issues

Garden Waste 1. UK Context – Can apply a charge for garden waste collections, but not for refuse collection – Most offer garden waste collections without charge

2. Free Garden Waste Collections – Affect home composting – Lead to ‘latent’ uncollected garden waste being collected… – And waste growth

Effect of Stopping Home Composting 200

180

Effe ct (k g pe r h o use h o l d p e r y e a r )

160

140

120

100

80

60

40

20

0 Areas w ith Gardens 200m2

Type of Area

Increase in Quantity Delivered to HWRCs

Increase in Quantity Set Out for Collection

Growth in Waste 4,000

Seasonal Hump 3,500

2,500

All Waste Excl Kerbside Garden All Waste Incl Kerbside Garden

2,000

Before GW Collection

After GW Collection

1,500

1,000

500

Ap r-0 M 2 ay -0 Ju 2 n02 Ju l -0 Au 2 g0 Se 2 p0 O 2 ct -0 N 2 ov -0 D 2 ec -0 Ja 2 n0 Fe 3 b0 M 3 ar -0 Ap 3 r-0 M 3 ay -0 Ju 3 n03 Ju l -0 Au 3 g0 Se 3 p0 O 3 ct -0 N 3 ov -0 D 3 ec -0 Ja 3 n04

Tonnes Collected

3,000

Month

Food Waste 1. Add to Garden Waste? – – – –

Frequency of collection? Frequency of residual waste collection? Odours? Capture of food waste?

2. Collecting Separately – Allows less frequent refuse collection – Increases capture – Allows for charging / constraints on garden waste

System Modelling

Hypothesis 1. Most Studies Suggest Environmental Benefits from AD Over Aerobic Composting 2. Most UK Assessments Stated ‘AD too expensive’ 3. UK Context PostPost-Animal ByBy-products Regulation – –

Composting of garden waste allowed in openopen-air Composting of food waste must be inin-vessel

4. Hypotheses: If We Keep Garden Waste and Kitchen Waste Collection Separate – –

Treatment costs can be kept down If collection costs are not excessive, AD can be incorporated in a cost effective manner

Key Methodological Issues 1. Quantity of Waste Collected from Households is Affected by the Collection Service –

Focus NOT on a tonne of waste, but on the household

2. Cost Modelling Takes Account of: – – –

Costs of doorstep collection service; Changes in cost of operating containerparks (reduced tonnages where garden waste is collected free) Costs of treatment of collected biowaste and residual

3. Biological Treatment Systems Lead to Emissions Over Extended Period of Time –

Model emissions as they occur over time and: 1. Apply unit damage costs; and 2. Apply discounting to future emissions (declining over time)

Key Methodological Issues 4. Greenhouse Gases – All emissions accounted for – Biogenic emissions accounted for (no mistakes)

5. Source of Energy Avoided – Average UK Generation – Note – now, Defra says CCGT

Scenarios Modelled Dry recycling

Biowaste

Refuse

Biowaste Treatment

Base case BC

Fortnightly 240l bin, capture norm, 5% reject

None

Weekly 240l

garden only G OC

Fortnightly 240l bin, capture high, 5% reject

Fortnightly (alternating) 240l

Fortnightly (alternating) 240l

open air windrow (with HWRCcollected garden waste) (OC)

all biowaste G+K IV

Fortnightly 240l bin, capture high, 5% reject

Fortnightly garden and kitchen (alternating) 240l for those with gardens, kerbside bucket for those without.

Fortnightly (alternating) 240l

all doorstep collected to in vessel composting (IV), HWRC collected garden waste to OC

kitchen only K AD/OC

Fortnightly 240l bin, capture high, 5% reject

Weekly, kitchen caddy & kerbside bucket

Fortnightly (alternating) 240l

food waste to anaerobic digestion (AD) , HWRC garden waste to OC

>200 kitchen only (IVC) K IV

Fortnightly 240l bin, capture high, 5% reject

Weekly, kitchen caddy & kerbside bucket

Fortnightly (alternating) 240l

all (incl HWRC-collected garden waste) to IV

>200 kitchen only (AD) K AD

Fortnightly 240l bin, capture high, 5% reject

Weekly, kitchen caddy & kerbside bucket

Fortnightly (alternating) 240l

all (incl HWRC collected garden waste) to AD

>200 kitchen plus K+ AD/OC

Fortnightly 240l bin, capture high, 5% reject

Weekly, kitchen caddy & kerbside bucket. Intensive home composting promotion.

Fortnightly (alternating) 240l

food to AD HWRC garden to OC

Fortnightly 240l bin, capture high, 5% reject

Weekly, kitchen caddy & kerbside bucket. Intensive home composting promotion.

Fortnightly (alternating) 240l

all (incl HWRC-collected garden waste) to in vessel composting (IV)

Fortnightly 240l bin, capture high, 5% reject

Weekly, kitchen caddy & kerbside bucket. Intensive home composting promotion.

Fortnightly (alternating) 240l

all (incl HWRC collected garden waste) to AD

>200 kitchen plus (IV) K+ IV

>200 kitchen plus (AD) K+AD

Notes: OC = open air windrow; AD = anaerobic digestion; IVC = in-vessel composting, HWRC = household waste recycling centre (containerpark)

Results – Private Costs (£/hhld)

Notes: OAW = open air windrow; AD = anaerobic digestion; IVC = in-vessel composting, HWRC = household waste recycling centre (containerpark) Residual Waste = £75 per tonne

Results – Environmental Costs and Benefits (high unit damage costs) (£/hhld w.r.t. base case) External Cost per Household (relative to intermediate base case)

£2.00

£1.00

£0.00

-£1.00

-£2.00

-£3.00 Residual to Incinerator excl Disamenity

-£4.00

-£5.00

-£6.00

-£7.00

-£8.00 G OC

G&K IV

K AD/OC

K IV

K AD

Scenario

K+ AD/OC

K+ IV

K+ AD

Results – Net Social Costs (£ per hhld) External Cost per Household (relative to intermediate base case)

£14.00

£12.00

£10.00

£8.00

£6.00

£4.00

Residual to Incinerator excl Disamenity

£2.00

£0.00

-£2.00

-£4.00 G OC

G&K IV

K AD/OC

K IV

K AD

Scenario

K+ AD/OC

K+ IV

K+ AD

UK Experience with Food Waste Collections: With and Without Garden Waste

Low Captures Food Waste Collected Fortnightly with Garden Council 1 2 3 4 5 6 7

Food % of combined bin 10.2 24.9 8.4 16.3 35.7 30.0 1.0

Garden % of combined bin 89.8 75.1 91.6 83.7 64.3 70.0 99.0

Winter Composition Analysis

Low Captures Food Waste Collected Fortnightly with Garden

8.63%

0.41

Annual Quantity (kg/hhld/yr) 21.3

Paper and Card

13.68%

0.65

33.8

Garden Waste

76.63%

3.64

189.3

Contaminants

1.05%

0.05

2.6

100.00%

4.75

247.0

% Material Composted Food

Total

Weekly Quantity (kg /hhld/wk)

Source:- Three Rivers System Co-collecting Food and Garden waste

Low Captures Food Waste Collected Fortnightly With Garden Kesgrave

(wheeled bin) Composition of Material (%) Organic Garden Organic Kitchen Degradable PE Sacks Paper / card Other Plastics Minerals Non-compostable wood Total Quantity of Material (kg/ (kg/hhld kg/hhld/fortnight) hhld/fortnight) Organic Garden Organic Kitchen Degradable PE Sacks Paper / card Other Plastics Minerals Non-compostable wood

Grange Farm

(wheeled bin)

Leiston 1

Leiston 2

(PE sack)

(PE sack)

98 1.5 0 0.4 0.1 0 0 100

91.1 8.3 0 0.4 0.1 0.2 0.1 100

75.8 20.4 0.9 1.5 1 0 0.4 100

74.8 23.9 0.9 0 0 0.4 0 100

11.28 0.17 0.00 0.05 0.01 0.00 0.00

7.76 0.71 0.00 0.03 0.01 0.02 0.01

4.28 1.15 0.05 0.08 0.06 0.00 0.02

4.40 1.41 0.05 0.00 0.00 0.02 0.00

Source:- These are our own figures calculated from data presented in the paper by G. Davis, H. Bulson, N. Sharpe, D. Harrison and E. Billett (2004) A Comparative Study of Wheeled Bins Versus Degradable Polymenr Sacks for the Kerbside Collection of Organic Wastes, CIWM Scientific and Technical Review, 5(1), May 2004, pp. 18-30.

captures per annum

4.5

18.5

30

36.5

Higher Captures from Weekly Food Waste Residual collected weekly from black sacks 2,0 1,8 1,6

Kg/hh/wk

1,4 1,2 1,0 0,8 0,6 0,4 0,2 0,0

Source:- Provisional review of WRAP 17 carried out by Eric Bridgewater, Resource Futures

Higher Captures from Weekly Food Waste Participation (food waste)

Capture rate

Capture kg/hh/yr

Food waste weekly, caddies, Residual fortnightly

60%

50%

100

Food waste weekly, caddies, Residual weekly

30%

20%

40

Garden & food fortnightly, residual fortnightly (no caddies)

?*

10%

20

System

* although participation in garden and food waste together can be obtained, participation in the food waste element alone is generally problematic as material is presented in a single container.

Source:- Eunomia analysis of trial performance in OWL, Barnet, Ealing, Ealing trials, Richmond, Somerset, Bexley, Bristol, North Dorset, Hertsmere, Hackney, Harringey, Isle of Wight, BANES, Preston, Islington

Weekly vs Fortnightly Food

Kg / household / annum RANGE Kg / household / annum Approx AVERAGE

Fortnightly collection of food

Weekly collection of food

10 – 60

60 - 120

20

80

What Drives Performance – Food waste should be collected frequently and more frequently than residual – – – –

Odour Convenience Practical incentive to participation Establishing habits

What Drives Performance – Fortnightly Refuse Capture Rates from Eunomia analysis

Residual Frequency

kg/hh/wk

kg/hh/yr

Fortnightly

1.83

95.18

Weekly

0.74

38.41

Participation Rates from Eunomia analysis Weekly Refuse Collection Participation Scheme Rate OWL Trial 19% BANES Trial 28% Ealing 27% Richmond 44% Average 30%

AWC Refuse Collection Participation Scheme Rate Somerset 50% N Dorset 56% Preston Trial 80% Average

62%

What drives performance - Containers

Impact of Liners – Resident Perceptions “On a scale of 1-5, where 1 is worst and 5 is best, how would you rate your …”

…Kerbside Container”

…Counter-top container”

…Liners”

Average across all container types

Vented with liners

3.9

4.6

4.6

4.4

Solid with liners

4.5

4.7

4.6

4.6

Solid without liners

4.2

3.3

No containment

3.7

3.9 3.6

Impact of Containers – Ealing Trial Capture rates for all households 40%

35%

30%

kg/hh/wk

25% May

20%

Oct

15%

10%

5%

0% Vented

Source:- Eunomia original research

Bags

Solid

Impact of Containers – Ealing trial

Average food waste per 1000hh (kg)

Tonnes per annum (92,000 hh)

Difference between bag and non bag systems (tonnes)

Vented with liners

1,083.93

5,185.54

1,346.48

Solid with liners

1,068.32

5,110.85

1,271.80

Solid without liners

802.48

3,839.05

-

Treatment Cost Issues

CoCo-collecting Food and Garden – Have to treat all material ‘in‘in-vessel’ – Approx €30 more to treat each tonne of garden waste – Higher disposal costs due to lower impact on residual waste – Transport costs? – Bulking – Location of facilities?

Treatment Costs for Food Waste When Adding Food to Garden Waste Garden waste collected (kg/hhld) Food waste collected (kg/hhld) Costs of treating garden waste (£/hhld) Costs of treating food waste (£/hhld) Total costs of treating biowaste (£/hhld)

Before food waste collection (windrow) €27/t

After food waste addition (in(in-vessel) €60/t

200

200

0

30

€5.33

€12.00

£-

€1.80

€5.33

€13.80

Change in cost (£/hhld)

€8.47

Tonnage of food waste to be treated (tonnes / hhld)

0.03

Implied treatment cost of food waste added (£/tonne)

€282.33

Effects on Food Waste Generation?

Food Waste and Home Composting

NB Age Correlation with Home Composting Source: Exodus Market Research (2008) The Food We Waste, Report for WRAP, April 2008

Food Waste and Efforts to Recycle

Source: Exodus Market Research (2008) The Food We Waste, Report for WRAP, April 2008

Food Waste and Commitment to Recycling

Source: Exodus Market Research (2008) The Food We Waste, Report for WRAP, April 2008

Concluding Comments

Conclusions

– Co Collecting Garden and Kitchen Waste – May be a False Economy – Implies Poor Targeting of Capital Spend

– It IS Possible to Integrate AD into Management Systems in a CostCost-effective Manner – This is Most Likely Where: – Kitchen Waste is Targeted for Separate Collection – Home Composting is Promoted

– Net Benefits Will – Be Greatest Where All Material is Digested But Subject to Cost Constraints – Increase as Residual Waste Treatment / Disposal Costs Increase

– Higest Food Captures Require – Liners – Lower Frequency of Residual Collection Relative to Food

– Added Benefit That Total Food Wasted Probably Declines

– C-benefits All Round – PREVENTION, LOGISTICS, TREATMENT

Further Information – Launched alongside Waste Strategy for England 2007 – Managing Biowastes from Households in the UK: Applying LifeLife-cycle Thinking in the Framework of CostCost-benefit Analysis (WRAP) http://www.wrap.org.uk/downloads/Biowaste_CBA _Final_Report_May_2007.567d597c.pdf . – Dealing with Food Waste in the UK (WRAP) http://www.wrap.org.uk/downloads/Dealing_with_ Food_Waste_Food_Waste_-_Final__Final_-_2_March_07.6bd22b7e.pdf

Why Is There Food Waste?

Main Reasons

Source: Exodus Market Research (2008) The Food We Waste, Report for WRAP, April 2008

Vehicle Options Caged vehicles and purpose built − 7.5 tonne GVW with optional bin lift − Limited payload circa 3 tonne depending on chassis & build − Can fill quickly with bulky garden waste − Vehicles relatively easy to acquire − Cheap with low running costs and flexible for other uses − Don’t require HGV driver − Not suitable for loose material

Vehicle Options Dedicated food waste vehicles − E.g. as used in Italy − Specialised body, standard chassis, − No compaction − Payload – approx 1.6t to 3 tonne − Can be operated with single operative

Vehicle Options Stillage vehicles − Food (only) waste co-collected with dry recyclables − Modified cage for food waste collection − Tend to be weekly collections − Rigid containers emptied manually into stillage − E.g. Mendip & S Somerset; Ealing; Organics West London (OWL) trials

Vehicle Options Kerbsider concept