Chertsey, UK


	Plant sheet:	Printable pdf

Plant capacity and performance:

• 9,600 metric tonnes DS/year	• ~ 3 times increased digester throughput
• 2 x 1,600 m³ digesters	• Class A product
• 1.2 MW_e (planned)	• 99% availability on planned operations
• 2-reactor Cambi THP	• >60% VS destruction

The Cambi THP plant at Chertsey, just west of London, England, was built in 1998 and is
owned by Thames Water. It is designed to treat 8,000 tonnes of dry solids annually, which
is produced at Chertsey, Leatherhead, Esher and other wastewater treatment plants.

By introducing thermal hydrolysis, the existing digesters at Chertsey have nearly trebled capacity.

On 9 November 2004Cambi signed an operations contract with Thames Water to operate the THP

plant for a period of 7 years with an option to extend the operation for an additional 3 years.

After re-engineering it has been in successful operation since September 2005.

The benefits of the Cambi process are:

• Existing digesters are able to treat 3 times as much sludge avoiding capital projects at
2 other similar sized sewage plants
• Digester loading at >6 kg VS/m3/day, digester feed of 10.5%, digester hydraulic reten- tion time
of just over 12 days, and >60% VS destruction
• The product is class A (pathogen free)
• 1.2 MW of electrical generation will be installed
• Since Cambi took over operation the plant plant has >99 % availability on planned operations
• The plant acts as an emergency sludge centre for other plants that have less reliable systems