Firstly, it should be very difficult to deliberately discharge Raw Sewage, in order for a Treatment Works to do so would need substantial interference from Site Personnel, or an abject failure in the operation of the site. Treatment Works are usually designed to retain and recirculate any possible contaminated spillage on site, with only treated effluent being able to leave the works. Without knowing the logistics of the sites in question ist is difficult to comment further.
Secondly, whilst I dont disagree with the abhorrent amount of money paid to Shareholders and Senior Management, (whilst those on the Front Line are denied pay rises as the company claim they cant afford it....), what is the option? Re Nationalisation is a Non Starter, the cost would cripple the country for years to come just to buy the companies back into State Ownership, then add the sheer amount of investment required to upgrade the network, if you really want zero discharges, then that cost is going to be billions.
Many of the complaints about discharges now are simply due to the sewer network being unable to cope in wet weather, there is no miracle cure for this! Population increases have put more demand on sewers and sewage treatment, Investment is going in across the country, and despite media claims, rivers and bathing waters are cleaner now than they have been for many years.
We need an effective opposition to hold the incumbent Government to task, and the British political system relies on such. Sadly, we haven't got anyone up to the task, effectively guaranteeing the Tories power for the foreseeable future.