1.The supplied spreadsheet contains historic data recording the temperature of combined effluent discharged by a fictional tannery, Waterside Leather Limited (WLL) over the past four months.

The tannery's discharges are normally controlled within the range 25^oC to 35^oC. The maximum permitted temperature is 40^oC. Regular maintenance is performed on the balancing system (which neutralises the pH of the effluent at the expense of heating the discharge in the process) on a monthly basis.

Use the data to visualise the performance of the effluent control process, describing your analytical approach in detail. Include any graphs generated.

In your view, how well has the plant performed?

In your judgement, what priorities for quality improvements should the plant management set?