Wastewater auditing for large UK water company

The Challenge

WRc were commissioned by a UK Water Company to undertake detailed independent audits of 17 waste water treatment works to assess whether the plants, if operated in accordance with good industry practice, were capable of achieving compliance with all permit conditions placed on the owners and operators, and highlighting any areas of deficiency.

The Solution

Operational
After visiting the sites and gathering data from owners and operators, our team constructed a reference design plant to simulate the flows and loads experienced over the previous 5 years. This reference plant, designed using WRc's Plan-It STOAT software package, was then compared with the treatment assets available on-site in terms of capacity and ability to treat the flows and loads. A dynamic model of the current assets was constructed using WRc STOAT, and the team assessed and the ability of the plant to treat the variable receiving loads.

Financial
The audit also assessed the extent of each company’s proposed future capital maintenance plan, together with any specific remedial works that were being implemented, to provide recommendations for cost solutions. This also accounted for additional capital investment or capital maintenance work required to minimise the risk of operational failure or consent exceedance. WRc used a risk based approach to assess each works for their potential for failure. This involved undertaking a Failure Modes and Effects Analysis (FMEA) for each works in accordance with the UKWIR Capital Maintenance Planning Common Framework.