Ofwat is tasking water and sewerage companies with reducing pollutions to surface waters by a third over the next five years, and the Environment Agency is expecting them to “sprint” to zero serious pollution incidents. For this to be achieved, full attention must be given to wastewater treatment.
The Environment Agency’s 2018 assessment of the performance of England’s nine water and wastewater companies was that only one – Northumbrian Water – was performing at the level required. The need for improvement is unarguable and the regulatory targets for England and Wales highly desirable, but major changes in treatment plant infrastructure and the refinement of processes are needed if this is to be achieved in the AMP7 investment cycle.
Another Ofwat requirement for 2020-2025 – keeping customer bills down – is also front of mind for water utilities.
There are over 7,000 sewage treatment works in England and Wales and over 10,000 sewage treatment works and community septic tanks in Scotland and Northern Ireland. Collaborative working between utilities and suppliers and making better use of available technology and data are areas where utilities can make significant gains across their assets.
This needs to take place alongside more targeted investment and enhancement of existing assets, but it will not be easy. The industry can be risk averse when it comes to reimagining its approach, but when discussing its 2019 price review, Ofwat has said companies must find new and better ways of delivering services. There are ways and means of doing this, not just investing more money but investing it smartly.
The most serious issue we see on sites is equipment failure. If compressors or blowers go down or the screens fail, there will be a pollution event. Remote monitoring and planned maintenance make a big difference in preventing such occurrences.
Harnessing data
There is a vast amount of data that could be used, for example, to closely study a specific geographical location to identify where the risks of operational failure are to be found. Water companies increasingly want remote access and diagnostic equipment fitted as standard, particularly in remote areas. This technology can ensure assets are being managed effectively and that the risk areas are known.
Additionally, huge benefits are available to water companies prepared to share data with the partners designing their wastewater treatment plants. By having sight of specific data ahead of a project’s design, as well as operational information post-completion, suppliers can ensure the best system is installed and that it is operating optimally.
It also means utilities can have full confidence in the sizing of the plant. To avert the risk of a pollution event, designers add in contingency, sometimes resulting in a much bigger plant than is needed. If the supplier can see the relevant data, a solution can be found that is more efficient and cost effective.
Existing assets
Traditionally, wastewater treatment sites took up a large area and more land was required to increase capacity. Such space is not always available now and, if it is, there will potentially be a lengthy planning process to build new units. What is also known is that utilities have redundant vessels on many sites.
By changing the technology in the tank, being flexible with site layout, and repurposing existing infrastructure, utilities can enhance the treatment process and increase capacity without increasing site footprint, making a significant difference cost-wise.
Clients expect treatment works to be capable of dealing with anything that is thrown at them. Having kit that is robust and capable of dealing with variations in influent, but without too much added complexity, is important, along with an appropriate maintenance regime.
Ofwat says customers expect water and wastewater services to be resilient to both “short-term shocks and long-term challenges” such as population growth and climate change. And those services should be affordable. If companies work closely with suppliers to get their wastewater treatment right and are willing to make bold changes and embrace new practices, there is no reason why they cannot enhance treatment processes and provide greater environmental protection, while keeping customer bills at an acceptable level.