Not only does it save amazing amounts of money but the accolade - 'leading the way forward towards excellence in waste management' - was recently bestowed on Colchester by no less a body than the Audit Commission. With these kinds of plaudits you really do begin to wonder what's going on here?</

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As one of the many in openmouthed amazement, I went to Colchester and met up with Dave McManus (Waste and Transport Manager Street Services) to get some answers.

New vehicles for Colchester

Colchester claims to be the oldest recorded town in Britain - and the cultural centre of Essex. It has a population of some 156,000 living in roughly 66,000 households, two-thirds of whom live within Colchester itself with the rest living in the surrounding rural towns and villages.

Until recently, nine conventional Dennis Eagle refuse collection vehicles were used to collect general waste and paper for recycling on alternate weeks from these householders.

The recycling effort was also supplemented by glass and can collection using 'Fame' stillage vehicles plus 'bring' and civic amenity sites throughout the Borough.

Today, things are dramatically different. Towards the end of 2003, Colchester placed an order with Dennis for thirteen multi compartment 'One- Pass' vehicles and these entered service in April this year. Colchester was already achieving almost 25% diversion of recyclable materials from landfill under the old system, but this has already reached 40% with the new vehicles - and is anticipated to reach 60% in the next two years.

Like all good success stories this one is the result of careful planning and evaluation. Colchester spent years compiling data to ensure that all contingencies were covered. I asked Dave McManus to explain just how they had gone about this. He told me; �We conducted an extensive trial over four years in a small area called West Mersea as part of an Essex County Council initiative. There were about 4,500 properties within this area.�

Successful trials

The trial was extended to include the collection of garden waste, paper, cardboard, glass, cans and general waste on a weekly basis, and a civic amenity site was also provided in the area.

�Because we were attempting to establish the optimum volumes of nominated materials it was possible to divert from landfill, we called it a high diversion trial rather than just a recycling trial,� says Dave.

�At times we hit 60% but this was expensive to achieve mainly due to the number of vehicle types involved and the frequency of collection. It was a 'five-pass' system with one vehicle for each material category. We were using an open-back RCV for general waste, and one for green waste, a caged vehicle for paper and cardboard, another for plastics, and a 'Fame' stillage vehicle for glass and cans.

�In December 2002, we had our 'best value' inspection carried out by the Audit commission and, as part of this, we had to set out clear plans as to how we intended to improve our service in the future. Now, we were in top quartile for many of the things we did, such as recycling, but the one area where we were in bottom quartile was cost and we knew that we had to address this issue.

�At the same time, we were about to rollout a green waste collection service and this gave us the dilemma of how to achieve this without costs going through the roof. The answer had to lie in using a multi compartment vehicle of some sort,� says Dave.

�We looked at the alternatives including Terberg's 'Kerbsider' and concluded that this was not suitable for collecting green waste in conjunction with other materials - and that we would still have to operate conventional RCVs because we would require compaction to cope with general waste volumes.

�I had a contact at Milton Keynes where they were just starting to operate the Dennis 'One-Pass' via a contractor on recycling. So, we took a party up there to have a closer look which included some crew members because we were also keen to obtain their views on the equipment. Our first impressions were good and we felt that we could obtain excellent utilisation in Colchester.�

The One-Pass RCV

The Dennis 'One-Pass' vehicles supplied to Colchester comprise a 7 cubic metre capacity triple-chamber Terberg non compacting tipping 'pod', with a sideloading pannier-type lifter and powered opening side doors, installed between the vehicle cab and a 15 cubic metre capacity standard 'Twin Pack' dualcompartment compaction body.

The 26-tonne GVW 6 x 4 chassis cabs are Dennis Eagle's superb 'Elite 2', in 'driver plus four' specification. Unladen weight is a touch more than 16.5 tonnes, giving a payload of around 9.5 tonnes, and overall length is slightly over 10-metres.

With such a dramatic change in collection regime, going from standard single compartment compaction vehicles to multi- compartment with mixed compaction and non-compaction chambers, there must have been some serious number crunching involved in establishing just how many vehicles would be needed?

�Yes there was,� Dave continued. �We brought in a consultant, Integrated Skills, to help us out with this. Bear in mind, we also needed to establish an overall operating budget that included the vehicle costs to satisfy the Audit Commission inspection which was ongoing at the time as I have said.

�We provided our consultant with every piece of relevant information regarding percentages of materials in our waste stream gathered from our trial at West Mersea and regular analysis at the landfill site. Other costs such as our wage-bill and other administrative overheads were factored in and, from this, an accurate model was constructed in spreadsheet form.

�This enabled us to calculate the impact that changing some of the variables would have on the budget. By a process of fine-tuning, we were able to establish a final figure that more than satisfied the Audit Commission. It also showed us that thirteen 'One Pass' vehicles would be required to replace the nine open-back 'Elites' currently in service.�

Retaining the SFS connection

The refuse collection fleet in service at the time the decision was made to switch over to 'OnePass' vehicles was relatively new. Did this present any financial difficulties for Colchester?

�Our previous fleet had been supplied to us on a seven-year contract with SFS and we were about halfway through that,� Dave replies. �We had both hoped that it would be possible to renegotiate this agreement but in order to comply with EU procurement laws this could not be the case and, therefore, we had no alternative but to go out to tender for the supply of these vehicles.

�I was delighted when SFS was, once again, successful in its bid because we have developed a very close working relationship with the company. SFS was very supportive of our situation and, although we were inevitably faced with early termination penalties in respect of our previous arrangement, this was compensated to a large extent by the efficient manner in which SFS and Dennis Eagle helped to dispose of the existing fleet.

�Many would argue that we were unwise to have incurred additional costs by changing when we did - but I don't agree. Yes it was expensive, but the fact that we knew we would be saving around £400,000-a-year in operating costs from Day One was sufficient justification to do it then rather than later.

�Our workshops also provide all the repair and maintenance requirements for SFS under a separate service supplier agreement. SFS and Dennis Eagle were extremely helpful in other ways too. They supplied the vehicles a week earlier than expected; they made sure we had sufficient crew training, and provided a team of engineers to support the vehicles during the critical transition phase.�

How well is it working?

Having got the whole fleet up and running, I asked Dave how well they were now being utilised? He replies: �Our modelling showed that we needed to increase the number of collection rounds from six to nine which meant a 50% increase in the number of vehicles we had out there.This was because we knew the capacities were different, they were collecting more materials and it was a slower process.

Also, by the end of last year we had extended our green garden waste collection to the whole Borough and this would have to be included.

�Collections are worked on a twoweek cycle. On week one, glass is loaded into two of the three compartments in the Terberg 'pod', with cans and foil loaded into the third. Also, paper and textiles are collected and loaded into the smaller of the two split compartments of the 'Twin Pack' body.

On week two, plastics are collected and loaded into all three compartments of the Terberg 'pod', and green garden waste into the smaller 'Twin Pack' compartment. General residual refuse is collected on both weeks and loaded into the larger compartment of the 'Twin Pack' body.�

Seasonal adjustments

There must be occasions when volumes of certain recyclable material categories exceed expectation during a round, particularly given seasonal variations. How does Colchester cope with the risk of premature filling of any one compartment?

Dave explains: �Whenever a compartment becomes full, the vehicle returns to the transfer station and discharges all the recycling materials whether the rest of the compartments are full or not. Residual waste is taken straight to the landfill site and the completely empty vehicle then rejoins the round.

�At any one time, two of the vehicles in our thirteen strong fleet are nominated for contingency purposes and are rotated accordingly with the rest to cover off-road service and maintenance or breakdown time. These vehicles are also there to provide additional capacity when needed. In the event that even this is not sufficient to cope in exceptional circumstances, then we will hire in open back refuse vehicles in the short term as needed.

�We anticipated that this may happen with respect to garden waste, particularly as we have now extended this to the whole Borough as I've said. In May this year, for example, we collected in excess of 1,300 tonnes of garden waste which was over a thousand tonnes more than during the previous May,� he comments.

�We have been very surprised by the take up in participation by householders in recycling of certain materials such as plastics. In the case of bottles, these tend to be high volume low weight items and can quickly fill the Terberg 'pod'. To reduce the number of trips back to the transfer station to tip plastic material we have modified one of our 'Fame' vehicles and given it a high-sided caged body.

�This meets up with vehicles on their rounds and takes off the contents of the 'pod'. We are also doing this now with glass and cans. It's early days at the moment and only time will tell if we need to look again at how we use the 'One Pass' vehicles but, at the moment I think we're doing all right.�

Some conclusions

Clearly a lot of research has gone into developing the new regime and the concept of 'one vehicle does all' is a tempting proposition.

The 'One Pass' is heavy with all the extra bits mounted on the chassis such as the non compacting 'pod' and all its associated hydraulics. The trade off is payload and this amounts to a loss of well over three tonnes compared with even the largest Dennis 'Phoenix 2' 23W single compartment body, and two tonnes against the twenty cubic metre 'Twin Pack' body.

Given the extra size of the vehicle in the first place, this could be crucial to some operators. Is there a penalty in fuel consumption? Presumably with a heavier unladen weight to start with, and all those rams, packers and lifters working away at once, there must be more than the average amount of work for the engine.

Finally, if any one material volume exceeds capacity you may be faced with extra trips to the transfer station which is time consuming and costly in fuel terms. The option of supplementing the fleet with extra temporary vehicles surely defeats the object of 'a onevehicle- does-all' policy.

Is this the natural pessimist in me looking to pour cold water on what is a brilliantly thought-out programme? I hope not, but only time will tell if Colchester has got it right. One thing is for sure and that is that the volume of recyclable material being retrieved at Colchester is staggering - and you can't get away from that!

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