Wastewater Monitoring Analysis

Why it’s smart to increase your sewer network monitoring

Effectively managing hundreds of thousands of miles of sewer network is an unenviable task. And with ever-changing industry regulation, stricter statutory targets, additional compliance and a growing abundance of technology, that task could easily be regarded as insurmountable. How can you ever know exactly what’s going on throughout your entire network? It’s impossible. Or is it? Dave Walker, co-founder of Detectronic, investigates.

Expert supplier support and solutions are now widely available to enable every water company to achieve and exceed this challenging task and it all starts with the decision to increase existing sewer network monitoring. The aim is to always be one step ahead and, ultimately, be in a position where you actually understand the entire DNA of your sewer network.

Prevention is better than cure

As defined by the Water Industry Act, 1991, the duties of a water and sewage company (WASC) in relation to wastewater services are:

to provide, improve and extend a system of public sewers, and to cleanse and maintain them to ensure its area is effectively drained; and

to make provision for emptying its sewers and the treatment of sewage. Having had three decades to get to grips with these duties, several WASCs have forged ahead after realising they can effectively meet their duties AND comply with stringent regulatory measures and targets by implementing smart network monitoring. Having strategic monitoring and predictive analytics in place is enabling them to identify any issues before they arise. The old adage – “prevention is better than cure” – is now broadly accepted by the UK water industry. But there is, as always, room for improvement! And, when we take into account the constantly evolving regulatory and compliance landscape, continual improvement is ‘de rigeur’. It is one of the reasons, alongside the constant need to achieve cost-savings, that we have been encouraging water companies to increase their sewer network monitoring for many years.

Meeting regulatory and industry compliance

Established in 1989 following the privatisation of the water and sewage industry in the UK, Ofwat is the non-ministerial organisation tasked with regulating the water sector. One focus of Ofwat is the long-term stewardship of the environment, assets and relationships with customers. As such, along with Government statutes and mandates, Ofwat sets specific regulations, measures and targets that water companies must adhere to and meet in order to avoid financial penalties and, as a consequence, commercial and reputational damage. As you would expect, these are all under constant scrutiny and subject to regular review. For example, back in March, the Government introduced legal measures to reduce sewage discharges from storm overflows in a bid to reduce the harm to the environment.

Storm overflows play a key role in preventing the sewer network from becoming overburdened with sewage and rainfall in the event of wet weather. They provide a release for diluted wastewater in rivers. Unfortunately, the reliance on storm overflows has increased in the last few years as a result of an increased number of annual rainfall events and a wastewater infrastructure that is being overwhelmed by an escalating population. Forming part of a wider agenda to build a greener environment following the pandemic, these measures demand that water companies reduce their dependence on storm overflows. As such, the Government hopes this will translate in a dramatic reduction in the levels of sewage in UK waterways over the longterm.

Part of the measures place a clear duty on WASCs to publish data on their annual storm overflow operations. They must also work closely with the Storm Overflows Taskforce which was established in September 2020 to bring key stakeholders together to ensure progress. As part of this Taskforce, they have had to commit to increasing the number of overflows they will improve on in the next five years. An additional 800 overflows will be investigated and almost 800 improved between 2020 and 2025. And it’s not just statutory bodies that are holding WASCs to account. Surfers Against Sewage are just one of a number of environmental organisations that are gaining increasing public support for their demands for stricter targets and increased transparency in relation to rivers and bathing water. Sympathy for this cause only increases when we read headlines like those back in July outlining that a UK water company had received a record fine of £90 million from the Environment Agency after pleading guilty to 6,971 unpermitted sewage discharges. The shortcomings of the UK water industry are still many and varied but there is at least one clear and proven way to prevent pollutions for good and improve performance at the same time and that is by increasing sewer network monitoring.

Understanding the very DNA of your sewer network

Helping water companies to prevent spills and pollutions, wherever they may occur, has been our day job since 1985. Almost all of the regulatory measures demanded can be satisfied by implementing smart network monitoring and ensuring it covers the entire network. Why? Because only then can you understand the entire DNA of your sewer network and manage it rather that it managing you. You can remain ahead, you can second guess, you will intuitively know what is happening, where and why. Take external flooding in trunk sewers. This is a very common issue. The sewer network has to stand up to so many challenges from natural weather events to manmade problems. It’s inevitable that at certain times it will simply no longer be able to cope and flooding will occur. Being able to actually predict a problem well in advance of it occurring is the result of increased network monitoring. Consistent, robust and highly accurate data facilitated by a combination of AI, machine-learning (ML) and predictive analysis is the key to establishing a truly smart sewer network.

Who’s smart?

Take United Utilities. The company has embraced artificial intelligence (AI) and widely implemented it to proactively monitor and maintain its 78,000km wastewater network to great effect. UU are investing billions to upgrade services and the use of real-time data, AI and machine learning to process data and give advance warning of blockages or level increases. Currently installing 19,000 sensors1 in manholes across its network in the northwest of England, UU wants to get ahead of any issue and tackle it before it causes problems for either the environment or a customer is imperative. The ultimate aim is the creation of a real time performance and condition monitoring platform that will enable efficient wastewater asset management across its wastewater catchments for decades to come.

By interfacing with existing datasets from their current systems such as SCADA / Telemetry, network data sets (sensors & monitors), predictive analytics, forecasting (demand/load/weather), UU are harnessing the many benefits offered by AI and ML technologies to benefit the operating and maintenance of assets.

The solution will enable them to:

observe and understand in ‘real-time’ the network’s performance react to new issues before they become a problem increase resilience

enable an automated control system optimise network performance via increased visibility of accurate and quality data

By enabling this, they will be able to: be more efficient with spending reduce carbon footprint progress effectively to intelligent optimisation With 19,000 data points, UU will be in the enviable position of understanding the very DNA of its wastewater network. It will know how rainfall events affect the asset. It will measure water levels to millimetric accuracy. It will know how exactly how each drainage area impacts on another. As such it will be able to predict performance and identify any problems before they even occur. Now that’s smart.

Alongside UU, Southern Water have plans to deploy 30,000 sensors2 across their network and Severn Trent are currently in the process of installing 10,000 alarm monitors3. Back in February, Thames Water announced they were trialling 300 sewer level monitors4 in a bid to prevent pollutions created by cooking fat and wet wipes (the company has had to tackle several ‘fat bergs’ over the last few years). And, with a focus on solving the problems caused by CSOs, Anglian Water have installed 700 Event Duration Monitors5 on CSOs in their catchment and plan to have a monitor on all of their CSOs by 2023. So, it would appear that WASCs are taking a proactive approach to increasing their sewer network monitoring and we look forward to continuing to play a key role in this essential area of wastewater management.

Sources

1 https://utilityweek.co.uk/ai-putting-eyes-and-ears-in-thewastewater-network/#.YVWZ_RytxKU.facebook 2 https://www.southernwater.co.uk/our-performance/ innovative-sewer-technology-to-tackle-blockages 3 https://smartwatermagazine.com/news/severn-trent/severntrent-begins-phase-two-smart-sewer-monitor-roll-out 4 https://www.thameswater.co.uk/about-us/newsroom/latestnews/2021/feb/sewer-monitors-help-detect-blockages 5 https://www.waterbriefing.org/home/water-issues/ item/18290-anglian-water-how-do-you-solve-a-problem-likecsos?

“It’s one minute to midnight”: why adaption is now as vital as mitigation in climate emergency

Opening up COP26, Prime Minister Boris Johnson declared “it’s one minute to midnight on that doomsday clock” in his attempt to illustrate the seriousness of the climate threat we all face.

While world leaders gathered at COP26, the Environment Agency warned that becoming resilient to the effects of climate change is now just as vital as mitigation. In the EA’s hard-hitting Third Adaption Report, its Chair, Emma Howard Boyd, suggests that we must “make the places where we live, work and travel resilient to the effects of the more violent weather the climate emergency is bringing. It is adapt or die”. The report warns that climate change will cause more floods and droughts, rising sea levels and a greater demand for water supplies. In fact, it is suggested that if no further action is taken between 2025 and 2050 then an extra 3.4 billion litres of clean water per day will be needed due to population growth and climate change. Almost universally accepted as the biggest challenge we face as a population, the effects of a changing climate are already being experienced and are projected to get worse. For example, the 2018 UK State of the Climate report, completed by the Royal Meteorological Society, evidenced that the UK’s climate is becoming wetter. According to the report, the most recent decade (2009-2018) has been on average 1% wetter than 1981-2010 and 5% wetter than 1691-1990 for the UK overall. Furthermore, the amount of rain from extremely wet days has increased by 17% when comparing the same time period. In February 2020, Storms Ciara and Dennis laid bare the dangers of extremely wet days. Flooding in Yorkshire, Lancashire, Cumbria, Shropshire, Herefordshire, Worcestershire and South Wales delivered untold damage and a clean-up bill estimated at well over £400 million.

So, with greater demand and more climatebased challenges, how are water companies adapting their waste water networks? In the UK, a significant hurdle is the age and condition of the Victorian-era sewer system. The capacity of the network will be challenged by larger quantities of rainfall and greater demands through population growth, and so it is imperative that the network remains clear and operational. Ensuring blockages are identified quickly and cleared efficiently is critical. It is estimated that UK water companies spend £100 million every year clearing 300,000 blockages in the network. This is vital work, because blockages in the network can have devastating effects in the form of flooding and pollution events. Huge investments have been made into a wide range of solutions to blockages, both technical and awareness-led, and this has had a positive impact. In fact, Water UK suggests that customers are 8 times less likely to suffer sewer flooding than they were in the early 1990’s, so measurable progress has definitely been made.

However, adapting the network to recognise blockages before they develop significantly is a highly effective way of ensuring the sewers continue to flow. This is something that Thames Water has been proactive with, through investment in a variety of waste water sewer monitoring projects including sewer depth monitoring (SDM) deployments and the installation of HWM’s new early-warning SpillSens level monitoring and blockage alert system. SpillSens is a low-cost, multi-alarm digital float sensor that acts as an early warning system for blockages and sewer overflows. On average, Thames Water spends £18 million every year clearing 75,000 blockages from its complex 68,000-mile sewer network, and as such, is at the forefront of embracing digital technology to prevent flooding and pollution events.

Discussing the installation of SpillSens, Thames Water Operations Manager Anna Boyles explains that “these new sewer level monitors are the very latest bit of kit – they’ve only just come onto the market”. “These monitors are an important tool in our armoury in the fight against sewer blockages. The data they provide gives us a picture of what’s happening in our sewers and helps us to nip blockages in the bud before they cause problems.” Going forward, already stretched sewer networks will be expected to cope with greater intensities of rainfall more frequently. Digital technologies such as SpillSens will play a crucial role in ensuring sewers have the capacity to handle these future challenges. www.hwmglobalc.om