The cost of repair is quite varied. Sometimes systems are fully compliant and they may well just need some small remedial works doing – maybe some new access chamber covers repairing or replacing if they’re not secure. The worse-case scenario would be a complete replacement. typically speaking this could be anywhere between £8,000 – £15,000 – that would be  a reasonable range of costing. But every site is different – there is no such thing as a standard quotation cost: it is very site specific.