Restoring composting performance on an island with no margin for error

Operator-led composting consultancy for Guernsey's only green waste facility.

weeks on - island

Deliverables produced

biological factors optimised

Year Comissioned

The Brief

When there's no contingency, operational failure isn't an option

The States of Guernsey commissioned external technical support in 2024 to review, stabilise and improve green waste composting operations at the Mont Cuet facility — the island’s principal processing point for biodegradable municipal and landscaping arisings.

Mont Cuet handles garden waste, parks and highways maintenance residues, tree surgery material and periodic clearances. As an island system with no convenient export route, operational resilience is not a preference — it is a requirement. On the mainland, underperforming material can be diverted. On Guernsey, there is no such option. When the system falls behind, accumulation follows rapidly.

Over time, the facility had drifted from active management into a mode of operational firefighting. A familiar feedback loop had taken hold: as space reduced, layout efficiency declined; as layout declined, processing slowed; as processing slowed, space reduced further. Wet weather compounded the problem, limiting trafficability and pushing composting masses close to their limits.

Breaking that cycle was the central objective of the engagement.

"The brief extended well beyond a conventional advisory commission. It called for practical, implementable solutions and, where necessary, direct operational intervention to restore stability."

James Cooper

Envar Consulting

The Approach

Assessment first, then back to first principles. Not a wholesale redesign

Envar began by spending time on site — walking the facility with operators, observing how plant moved through the space and understanding how decisions were made in practice. A desktop study ran in parallel, reviewing historical records, infrastructure and risk data, and engaging island stakeholders in person.

The approach was grounded in a simple question asked repeatedly throughout: what does the biology require, and how can the site be arranged to deliver it consistently?

01 Ground-level site assessment

Time was spent observing and talking with operators before conclusions were drawn. Drawings and procedures tell only part of the story; the true behaviour of a site is best understood at ground level.

02 Desktop and stakeholder review

Historical records, infrastructure data and environmental risk were reviewed alongside in-person meetings with island stakeholders, including a public survey on recycling perception that shaped the subsequent communications approach.

03 Direct operational intervention

Envar mobilised plant and personnel to undertake bulk shredding and stockpile reduction works on-island — including ferry logistics, staffing rotations, accommodation and safety systems.

04 Biology-first thinking

The question asked repeatedly was simple: what does the biology require, and how can the site be arranged to deliver it consistently? Oxygen, moisture control, carbon-to-nitrogen balance, structural porosity and manageable pile geometry.

The Mont Cuet project illustrates the value of combining consultancy with genuine operational capability. Advice divorced from delivery rarely achieves lasting change. Conversely, practical intervention without structured analysis often addresses symptoms rather than causes.

Results in Detail

Stability restored across composting, layout and team confidence

Through structured assessment, direct operational support and pragmatic redesign, the project delivered measurable change across every aspect of the Mont Cuet operation.

Stockpile accumulation resolved

Legacy material was processed and the site returned to manageable capacity, restoring the operational headroom needed to break the cycle of accumulation.

Site layout redesigned around clear functional zones

Reception, processing, active composting and maturation were separated, making it easier for operators to see immediately where material should move next.

Drainage and trafficability restored

Simple surface improvements and minor regrading eliminated persistent waterlogging, keeping the site usable through wet weather without complex civil works.

Consistent process controls introduced

Operators reported greater predictability and the ability to plan rather than react — a cultural shift that, in practice, determines long-term success more than any individual technical measure.

Environmental risk reduced across the site

Improved aeration, better drainage and reduced stockpile sizes brought down odour, run-off and fire risk as a natural consequence of better operational control.

Staff confidence and capability strengthened

Operators reported greater predictability and the ability to plan rather than react — the most meaningful indicator of a composting system that will hold its performance over time.

Strategic Thinking

Composting and organic waste consultancy

If your organisation is facing challenges with composting performance or organic waste operations, we'd welcome a conversation.
Enquiries@envar.co.uk or James: +44 7523 513152

Envar Consulting

In the end, successful composting is rarely complicated. It is simply a matter of doing the basics well, every day.