Our certified open-air composting facility at Parkgate Farm near Purton processes thousands of tonnes of green waste each year

By transforming this material into high-quality compost, we help improve soil health, support agriculture, and contribute to the circular economy across the South West, including Berkshire, Bristol, Gloucestershire, Somerset, and Wiltshire.

Commercial Composting

What is compost?

Compost is a nutrient-rich soil improver made from biodegradable green waste. Through a controlled natural process, materials like grass cuttings, leaves and hedge trimmings break down into a stable organic product that enhances soil structure and fertility.

How the composting process works

We only accept green waste at Parkgate Farm. We do not accept food waste, treated wood, or invasive plant species, such as Japanese Knotweed. This strict input control ensures the final product is free from harmful contaminants and unwanted seeds.

What's our composting process?

Hills Waste (Isometric compost illustration - FINAL) Large

Composting in action

Turning green waste into compost

Contamination Removal

Inspection and contamination removal

Incoming loads are visually inspected, and any plastics, metals or non-compostable materials are removed. Waste that fails to meet quality standards is rejected. 

Compost Shredding

Shredding and batching

The material is shredded to a consistent size and arranged into long rows called piles (known as "windrows"). Each can hold up to 800 tonnes. 

Composting

Composting (sanitisation and stabilisation)

Over approximately 10 weeks, the compost is actively managed:

 

    • Turned regularly to maintain oxygen levels
    • Monitored for temperature (up to 65°C) and moisture
    • Maintained in compliance with PAS 100:2018 and REAL certification standards
      These high temperatures help kill pathogens such as E. coli and prevent weed growth.
Compost Maturation

Maturation

The material is left to cool and stabilise during a final two-week phase, ensuring it is fully mature. 

Compost Screening

Screening and quality testing

The compost is screened into two grades:
    • 0–16mm: for agriculture, horticulture, landscaping, and land restoration
    • 0–40mm: typically used in land restoration and agriculture
      Regular lab tests are conducted to verify nutrient levels, absence of pathogens, and product performance (e.g. tomato germination tests).
Compost Application

Use and application

The finished compost is used by local farmers, land managers and landscapers to enrich soil, support plant growth, and reduce dependence on synthetic fertilisers.  

Certified composting quality you can trust

Our composting process adheres to:


 

These certifications cover input material quality, processing standards, testing, and full traceability.

 

Compost is produced under our Quality Management System (ISO 9001:2015) and overseen by trained operatives and a dedicated compliance manager.

 

Our HACCP procedures ensure consistency and safety at every stage.

PAS 100 Certificate

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phone  0808 145 4533

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Hills Waste Solutions Ltd

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Shrivenham Road

Swindon

SN1 2NR

 

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