In Southern Water, approximately 120,000 tDS/annum of sludge is treated at 16 Sludge Treatment Centres (STCs). All the STCs employ conventional mesophilic anaerobic digestion with treated biosolids recycled to agriculture. Peacehaven STC treats 9 tDS/annum and produces significantly high biogas production per tDS treated compared to other conventional mesophilic sludge digestion plants. This is measured up to 550 m3 biogas produce per tDS treated. This paper will review the operational data of Peacehaven STC and provide assessment on number of parameters (for example sludge make-up, influence of primary treatment, organic content of the feed stock, mixing, volatile solids reduction) and their relationship with high biogas / energy production.