House of Commons - Environment, Food and Rural Affairs - Appendices to the Minutes of Evidence

Select Committee on Environment, Food and Rural Affairs Appendices to the Minutes of Evidence

Memorandum submitted by Alpheco Composting Ltd

BIOCOLL AND SATCOMP PROPOSAL

EXECUTIVE SUMMARY

1. A novel biowaste collection and innovative network of in-vessel composting facilities is proposed that, when integrated with recycling, is forecast to divert over 60% municipal waste from landfill and for small or no increase in costs overall.

(a) BioColl would use 25-litre household biowaste buckets for weekly kerbside collection by compact, efficient vehicles carrying 120-litre bins in to which the households' catering wastes, possibly in biodegradable bags, are placed. Through-running those 120-l bins to the proximate composting facility offers two to threefold reduction in biowaste haulage so offsetting the cost of BioColl. Commercial and institutional catering wastes go directly into 120-l bins for co-collection. Soft (non-wood) "green" wastes would be co-collected, while wood wastes should be chipped at the kerbside periodically. Computerised weighing and billing can be included for easy allocation of differential charges or rebates.

(b) SatComp. The composting systems proposed would:

(i) comply fully with the new EU Animal By-Products (ABP) regulations, the proposed UK ABP Order requirements and the rules anticipated for the 2004 EU Biowaste Directive. Since all types of raw and cooked food including meat can and may be processed, the simple rule "Compostables = anything that lived" applies. This will minimise hassle in the home and so win high capture rates for putrescibles with a knock-on increase in the recovery of recyclables;

(ii) be modular with vessels out-doors so the mandatory building is minimal making sites of only 10,000 tonnes/year competitive and amenable;

(iii) be electronically linked to a site management PC that would in turn network to head office and integrate with the BioColl software.

These characteristics permit a network of proximate, satellite sites with economies of scale normally associated with large, centralised plants.

2. Recycling and Residuals. By removing the putrescibles conveniently and weekly, the dry-recyclables and residuals can be virtually free of obnoxious matter and so may be collected fortnightly. Dry-recyclables may be set out for sorting at the kerbside in to a compartmented vehicle or mingled in a bin (120 to 240 litres) for collection by a conventional refuse vehicle (RCV) and sorting in a clean MRF. Residuals may be collected in the alternate week to the dry-recyclables to make efficient use of crews and RCVs, and by scheduling on the same day as BioColl, householders should remember to put out the appropriate receptacles. Thus there would be about 104 waste collection vehicle passes per property per year which, although more expensive than the 52 passes required for mixed waste collections, will be offset by using the more efficient BioColl vehicles, the reduced distances and the major savings on landfilling.

3. Biowaste types, permissible sanitization regimes and alternative collection methods lead to about 14 options. This particular proposal as, illustrated by the flow chart below, is for catering wastes that include household meat and fish wastes but not the other EU Category three animal by-products. Therefore the plant must reduce particles to 60 mm, provide the two barriers proposed for the UK ABP Order and have unclean/clean separation. The flowchart also illustrates the BioColl through-running method.

4. Operating costs including equipment leasing, infrastructure amortization, labour and maintenance are forecast in the range £27-£34 per tonne of biowaste intake at SatComp facilities of 10,000 to 25,000 tones per year. The costs of the separate collections of compostables, recyclables and residuals will depend on location and circumstances, but are not expected to total much more than current practices due to SatComp efficiency and BioColl distance savings that will offset provision of the extra rounds.

5. The scheme also offers benefits by way of scope for co-composting sewage sludge, for automated differential charging of households, for remediating contaminated land and for heat recovery from the biowastes. The impediments that have so far prevented such a scheme being piloted in the UK are identified as the moratorium on composting due to the ABPO, risk aversion, lack of funding such as exclusion from the DEFRA £140 million "Challenge fund" and the low priority to date given to biowastes and composting by WRAP.

Integrated collection, composting and recycling scheme

6. Outline. An innovative scheme is proposed that would integrate the kerbside collections of biowastes, dry-recyclables and residuals with their composting, recovery for recycling and disposal respectively. Holistic integration of these activities is forecast to offer diversion rates of over 60% at very little or no extra cost per council taxpayer compared to current arrangements. The addition of bio-stabilization or bio-drying of the residuals could increase that diversion to about 80%.

7. End markets for compost. Although sustainable waste management is the subject, the paramount objective is to recycle resources, which demands product quality-cum-value. WRAP is developing markets for dry-recyclables and the new PAS 100 standard should stimulate demand for proper quality compost. Some people fear that compost derived from municipal biowastes could swamp potential markets but that is wrong[8]. Bulk compost to improve agricultural or horticultural land will probably earn a market value of £2-£6 per tonne delivered on or close to the designated field.

8. The obtainable price of compost will depend on nutrient and organic matter levels as well the freedom from contamination required by the PAS100 standard. That will almost definitely require catering, "green" and other biowastes to be kept separate from source. Enterprises must focus as much on compost production as on waste disposal. A sustainable composting scheme therefore needs to balance the demands of farmers, growers, and gardeners with, on the other hand, householders and waste collection authorities.

Biowaste collection methods

9. High diversion rates coupled with good quality recyclates (including compost) clearly need high levels of participation and of compliance with the separation rules. Those are essentially voluntary activities so minimal "hassle" in the home is essential. The simple rule that "compostables = anything that lived," with weekly kerbside collection from a small bin that is easily accommodated and washed by the householder (a biodegradable liner may be used) should be almost as easy as current habits. Woody wastes should however, be set out for periodic kerbside chipping because they are bulky and very slow to decompose, [9]but as they only arise in gardens there is obviously holding space. A self-funded kerbside chipping service would not discourage home composting in the way that big (120-litres) bio-bins do and many gardeners will keep the wood-chips as mulch thus reducing "waste" haulage.

10. The convenient and regular weekly removal of all putrescibles should leave the recyclables and residuals virtually free of obnoxious matter[10] and hence lead to higher recovery rates than if some (EG cooked food wastes) were still to go in the "black" bag or bin. Consequently the recyclables and residuals may be collected fortnightly; uncooperative householders will find their carefully sized recycling and residuals receptacles beginning to smell and perhaps overfilling. Since the average household only generates about 10 litres of catering wastes per week it is uneconomic to provide a big bio-bin that attracts more "green" waste and also necessitates an inefficient refuse collection/compactor vehicle[11]. BioColl proposes that households have 25-litre bins with anti-pet/vermin lids and handles for easy emptying in to 120-litre bins; both bins are specifically chosen to comply with lifting and handling regulations. Dense housing areas can be served by bio-collectors with six to eight 120-litre bins on a pedestrian controlled vehicle (PCV)[12]; full bins are transferred on to an inexpensive, flatbed truck for through-running to the composting facility. That truck[13] can also collect directly from more dispersed housing and swap full for empty 120-litre bins at commercial and institutional premises. It can also deploy and recover the PCV(s) from base.

Composting facilities

11. Composting of catering wastes that include meat and fish residues and cooked food is permitted by the extant European and proposed UK regulations[14] provided they:

(a) have a reception, preparation and loading building. BioColl's through running allows a smaller building than would conventional big bio-bin schemes where the RCV must discharge on to the ground inside the building.

(b) separate the "unclean" and "clean" areas to prevent cross-contamination. Clothing and equipment changes or disinfection are required and the collection containers or vehicles must be cleaned while inside the unclean area. BioColl would simplify this by the automatic washing of the 120-litre bins that are "through-run."

(e) monitor and record temperatures to prove compliance and keeping with other records to provide an audit trail of the biowastes, their treatment and distribution of the compost.

Based on R&D testing over the past six years, Alpheco Ltd is entirely confident that its systems will comply with all those requirements. Some but not all other in-vessel systems can probably do likewise. Therefore we refute a footnote in the recent SU report[17] that anyway seemed a variance to the preferment expressed therein for composting. That preferment is also clear in certain EC documents[18]. Furthermore the risk assessment that informed the DEFRA proposals noted that composting is potentially less risky than continuing to landfill untreated animal by-products. [19]

12. SatComp is proposed as a concept for a network of in-vessel composting facilities linked electronically to give economies of scale while complying well with the proximity principle.

(b) Management, marketing, compost sales financial control, invoicing, technical advice and maintenance support can all be centralised and make full use of the computerised records required for every batch. IntMan software will link the system control computers and site management PCs with head office. Furthermore automatic weighing on the BioColl vehicles can also feed in data to simplify the invoicing of commercial customers and to permit waste authorities to reward householders, whether by differential charging or rebates.

13. Recycling

(b) Since all household putrescibles will be collected weekly, the dry-recyclables may be collected fortnightly provided the households have reasonable storage space both inside the receptacle—cardboard boxes can be collapsed—and for the receptacle itself. Many terraced houses are short on space for one 240-litre bin, but the 25-litre bio-bin can easily be hung inside or outside of the bigger bin.

14. Residuals

(b) Similarly to the recyclables, the residuals may be collected fortnightly. Householders might be required to continue with black bags or use a 35 to 50-litre residuals' bin, which could also hang from the recyclables bin.

15. Costs:

(a) Collection As mentioned at footnote 12, the populations of each parish or ward in the whole of Cambridgeshire with Peterborough unitary authority and, separately, in Colchester Borough and Tendring District were tabulated so that probable tonnages of their catering and "green" wastes could be calculated from national average figures. Distances from those parishes or wards to potential SatComp and to existing landfill sites were measured. By assuming five tonnes of biowastes per BioColl type truck, the total annual biowaste-kilometres were calculated. For Cambridgeshire the reduction was two-fold while for Colchester and Tendring taken together the reduction was three-fold. Further study would be needed to fully estimate the cost differences but given that:

(i) the BioColl trucks cost only about £40K compared to a typical RCV at £125K,

(ii) the former does not need an HGV1 qualified driver and the singular efficiency of using PCVs in dense housing areas, significant savings per household are expected compared to merely doubling or tripling RCV rounds to cope with the different streams.

(b) Composting. As mentioned in paragraph three and the lower side-bar to the flowchart, there are 14 feasible combinations of biowaste type, treatment regime and collection method. For convenient comparison of costs, just five have been selected and designated according to the following legend key:

MECW for meat excluded catering wastes,

ACW for catering wastes that may include meat and fish residues

Cat-3 for ACW plus the other category three animal by-products.

UK1 for the particles 400 mm, 600C for two days regime proposed by DEFRA

UK2 for the particles 60 mm, 700C for one hour regime proposed by DEFRA

EC for the particles 12 mm, 700C for one hour regime established by the EU.

RCV for conventional collection by RCVs from big bio-bins,

TRB for the through running of BioColl bins.

The charts below show forecast CAPEX and OPEX in £ per tonne vs. facility throughput in tonnes per annum. The OPEX figures included capital costs by inclusion of a typical rate for leasing the demountable composting and the mobile ancillary equipment over a five-year term. The buildings and site infrastructure were amortized over a 15-year term and the site rent was included at a rate of £3.6 per square metre per year, which is considered typical for bare, industrial land.

MECW/UK1/RCV is cheapest as it does not require the "barrier two" additional treatment whereas seven days in each of the Barrier one and two closed reactors is allowed for in the other forecasts. EC treatment is more expensive than UK1 regimes because of the equipment needed for size reduction; sadly DEFRA's two year moratorium on composting has precluded testing which of the treatment regimes is most cost-effective. The conventional RCV collection makes the composting plant more expensive than with TRB (BioColl) because of the stronger shredder/macerator needed and the screening machine that it also necessitates.

The operating costs included—besides leasing, amortization and rent-labour, fuel, electricity and equipment maintenance. Figures were based on Alpheco's six years' practical experience of in-vessel composting food wastes we collected from Sainsbury's, McDonalds, Plantsman, the Ipswich Hospital and Suffolk Coastal District Council[23].

The steep reduction from 5,000 to 10,000 tonnes per year is mainly due to defraying the cost of the reception building proposed by DEFRA. The slight increase for some regimes going from 15,000 to 20,000 tonnes per year is due to adding a second macerator/loader and might well be smoothed out in practice.

Besides noting that the modularity of the Alpheco composting system allows relatively cost-efficient and thereby proximate facilities, probable diversion rates may also be borne in mind.

In a separate study (available on request), we estimated the maximum probable diversion rates of an integrated recycling and composting scheme using four scenarios shown in the columns below. Cells in the table below show participation per cent multiplied by compliance per cent to calculate the recovery rates. We assumed that an effective publicity and education campaign would build on the promising public interest reported by some recent studies. Convenience (ie hassle of separating meat and cooked foods from other bio-wastes) and "smells-cum-flies & maggots" if putrescibles are only collected fortnightly were also estimated effects.

Collections

Streams & composition Meat excluded Catering Wastes Conventional RCV; Weekly All types of Catering Wastes Conventional RCV; Fortnightly All types of Catering Wastes Conventional RCV; Weekly All types of Catering Wastes BioColl-Weekly

Recyclables 43% 95% x 90% = 86% 95% x 90% = 86% 95% x 90% = 86% 95% x 90% = 86%

Compostables 48% 75% x 67% = 50% due to hassle 75% x 67% = 50% due to smells 95% x 85% = 81% 95% x 85% = 81%

Residuals 9% + unrecovered recyclables and compostables 0% + Meat + 14% of 43% + 50% of 48% =53% 0% + 14% of 43% + 50% of 48% = 49% 0% + 14% of 43% + 19% of 48%—screenings = 35% 0% + 14% of 43% + 19% of 48% = 33%

Overall diversion without MBT 47% 51% No "meat" to landfill 65% Weekly bio- collect encourage 67% as no wood screenings

Overall diversion with MBT 65% * 69% 77% 79%

If the residuals with the un-recovered recyclables and compostables (Row four) were put through an MBT plant with energy recovery or bio-stabilization so that only the residues from that MBT plant had to be landfilled, the overall diversion rates would be increased from Row five to Row six levels. Please note * however, that bio-stabilized residuals, while possibly contributing to diversion rates, may not be counted in recycling and composting rates as they are of little or no value.

16. Potential extra benefits of the proposed scheme are several as follows:

(c) Land remediation. Modular composting facilities that are largely demountable can be set up on brown-field sites for a limited period during which the compost they produce may be used to bio-remediate the contaminated soil on that site. Reports, primarily from North America, show how successfully and cost-effectively old hydrocarbon and explosives contaminated sites have been cleaned up this way.

(d) Heat recovery. The Alpheco and perhaps a few other in-vessel composting systems enable the excess heat from composting to be used for greenhouse or similar heating. This heat is too low-grade for electricity production but even in biogas production (ie anaerobic digestion) plants only about 1/3 of the energy recovered can be electrical; 2/3 are inevitably in the form of heat. In composting plants the heat is a by-product while in biogas plants the digestate is a by-product that most probably needs composting before it can be sold.

(e) Research. As mentioned in footnote 16, DEFRA's proposals for the ABPO amendments are based on a risk assessment that was almost entirely theoretical. They are probably justified under the precautionary principle but may be more stringent than necessary and also than the laws of other EU member states. That could be to the UK's economic disadvantage, so validation of the risk assessment in commercially sized plants seems sensible. The stability at which composted biowastes stop being a significant pollution risk should also be investigated in time to inform the EU Biowaste Directive that is scheduled for 2004. Unnecessary prolongation of controlled waste status would inevitably add to the cost of composting biowastes.

17. Impediments. It may be asked why such a scheme has not yet been tried.

(b) Within the UK several factors seem have prevented such schemes:

(i) Legislation. The moratorium on spreading compost derived from catering wastes that was imposed in early 2001 and may only be lifted when the ABPO is amended in April 2003. While research projects are said to be permissible, funding for them has proved utterly elusive.

(ii) Risk aversion and lack of funding. The split between waste collection and disposal authorities and their aversion to the risk of trying innovative schemes. "Too good to be true' therefore it cannot be" was one response that should be overcome by one or more reference-cum-pilot schemes, for which funding has not been forthcoming so far:

1. Our four, landfill tax-credits applications were rejected apparently for financing policy rather than technical reasons.

(iii) Prospects. The SU "Waste not, want not" recommended:

1. setting up an operational task force to help bridge the gap between central policy-making and action at a local level.

2. a WRAP-led programme of advice to local authorities on the expansion of kerbside collection

3. that there should be particular emphasis on supporting the roll-out of organic waste collections where current provision is low.

4. the waste industry should provide an appropriate range of waste-handling facilities and pursue opportunities for developing new technologies.

It remains to be seen if WRAP any more than the Environmental Audit Committee or the Audit Commission when promoting Best Value, be willing and able to accommodate such innovative schemes as that proposed here. Meanwhile my contacts in the waste management companies opine that they will not fund R&D ahead of profitable contracts.

(c) Hopes that home composting may suffice. While laudable for minimising biowaste collection and making the public more aware of composting, there will be those without space, physical ability or motivation to compost at home. In any case all are advised not to home compost animal by-products (including faces and litter) and indeed small holders and others with pet ruminants and pigs may be prohibited from home composting their catering wastes under the ABPO proposals. It seems that over-emphasis on "green" waste firstly from CA sites and latterly by kerbside collection has diverted attention from the key role of animal by-products and led to misleading hopes for home composting.

Alpheco Composting Ltd.

3 January 2003

8 If 15.5 million tonnes per annum (mpta) of biowaste, being 55% the annual total for England of 28.2 mtpa municipal waste, were co-composted with the 4.8 mtpa of sewage sludge cake, the resulting 15 mpta approx. of compost spread at the permitted rate in Nitrate Vulnerable Zones (NVZ) would take up only 9% of England's agricultural land or 30% of the land on which cereals are grown. Considering that compost would probably applied at 2 to 3 times that rate in the half of the country not designated NVZ and that horticulture and gardening have taken most of the compost available in the more advanced European countries, the chances of saturation are insignificant. Back

9 The lignin of the wood cell walls takes many months of fungal activity compared to the few weeks needed to decompose the putrescibles and soft matter. If woody and soft matters are mixed ab initio, the collection truck must be much bigger, the whole mixture must be shredded, the compost must be screened and the screenings recycled all of which are wasteful and cost extra compared to kerbside chipping. Back

10 Lombardy schemes using this approach report just 10% biodegradables in the residual stream compared to 40% in many Dutch and German schemes where big bio-bins attract more garden wastes and are often collected in alternate weeks. Many householders will put putrescibles in whichever bin is next to go. Back

11 Such RCVs typically of 26 tonne gross vehicle weight cost about £125K CAPEX and £125K per annum OPEX. Their fuel consumption for halt-to-halt is bound to be high and leaves the driver only part employed. The rest of the crew is unproductive during "commuter" journeys from "round" to landfill, incinerator or composting facility. Back

12 Belfast, Haringey and Islington all use pedestrian controlled vehicles (c £10K) for recycling collections. One operator can typically collect from 1,000 properties in one day compared to 850 by an RCV, which also holds up more traffic and requires a part-redundant driver/crew. Back

13 Typically a 7.5 tonner costing £40K when complete with tail lift and flatbed with means to hold the 44-50 x 120-litre bins in place. 7.5 tonne trucks are seldom excluded by Borough Bye-laws whereas conventional RCVs often require special exemption to enter towns by day. Back

14 EC 1774/2002 of 3 Oct 2002 and due to be transposed into UK law by end April 2003 by further amendment to the Animal By-Products Order 1999 (as amended May 2001). Back

15 EC 1774/2002 and the UK proposals are still ambiguous on retention time. Most composting experts foresee the EU Biowaste Directive scheduled for 2004 specifying a respiration rate at which the compost will be sufficiently stable to cease being classified as a controlled waste. Attainment of that threshold will probably require 14-21 days closed reactor composting or at least seven days in-vessel followed by 21-28 days actively managed windrowing. Back

16 These in effect require a repetition of one of the mandatory sanitization regimes to ensure that 99.8% of the biowastes have been satisfactorily treated to reduce pathogens to an acceptable level. EC1774/2002 Article 6(2)(g) permits national laws for composting catering wastes pending rules from the EC Standing Committee on the Food Chain and Animal Health. Annex VI, Chapter II, paragraph 14 however requires that national regulations must "... guarantee an equivalent effect regarding the reduction of pathogens." Equivalent in that context refers to the immediately preceding paragraph which stipulates (a) maximum particle size of 12 mm before entering the composting reactor; (b) minimum temperature 70C of in all material in the reactor; and (c) minimum time of 60 minutes in the reactor at 70C (all material). Since the 100% implied by "all material" is unobtainable in any real system, other European member states may have to adopt similar additional measures to the UK's proposals. Research could however show that the UK proposals, which are based on a mainly theoretical risk assessment, are more stringent than they need be. Back

17 Footnote 91 to SU "Waste not, want not" states, "In the absence of domestic legislation on this issue, the terms of the EU Animal By-Products Regulation will become UK law. These requirements are much more stringent and probably rule out composting operations using catering waste as the feed material." Back