Water Industry Process Automation & Control (WIPAC) Monthly - June 2024.pdf

WIPAC MONTHLY
The Monthly Update from Water Industry Process Automation & Control
www.wipac.org.uk Issue 6/2024- June 2024

In this Issue
WIPAC Monthly is a publication of the Water Industry Process Automation & Control Group. It is produced by the group
manager and WIPAC Monthly Editor, Oliver Grievson. This is a free publication for the benefit of the Water Industry and please feel
free to distribute to any who you may feel benefit. However due to the ongoing costs of WIPAC Monthly a donation website has
been set up to allow readers to contribute to the running of WIPAC & WIPAC Monthly, For those wishing to donate then please visit
https://www.patreon.com/Wipac all donations will be used solely for the benefit and development of WIPAC.
All enquires about WIPAC Monthly, including those who want to publish news or articles within these pages, should be directed
to the publications editor, Oliver Grievson at olivergrievson@hotmail.com
From the editor............................................................................................................. 3
Industry news..............................................................................................................
Highlights of the news of the month from the global water industry centred around the successes of a few of the companies
in the global market.
4 - 12
Are EDMs an accurate reflection of wastewater spills..................................................
This month Professor Peter Hammond published a paper that looked at the accuracy of Event Duration Monitoring data in one of
England's water companies. The article that was produced is reproduced here questioning the accuracy of Event Duration Monitoring
and whether it is a true reflection of the number of spills to the environment
13-14
How accurate is EDM data...........................................................................................
In the feature article this month we look into alot more detail into the history of the monitoring of EDM data, why it was ever
installed in the first place and some of the technologies looking at some of the uncertainties that exist within the data and how we
are probably over-estimating the number of spills.
15-18
Workshops, conferences & seminars............................................................................
The highlights of the conferences and workshops in the coming months.
19 - 20

From the Editor

The key to applying Digital Transformation in the Water Industry is to share our collective experiences and understand
what we can apply and where. In this spirit this month I travelled to Shanghai at the invitation of the IWA Digital Water
Programme sub-group in China. To say that I was blown away by what I saw would be an under-estimate. The development
of the Digital Water concept had been taken "up to 11" to paraphrase the idiom from "This is Spinal Tap," and in fact this
was the case all the way across the city of Shanghai and seemed to be in everything from the proliferation of electric
vehicles across the town, to the spongefication of the city as well as in the water industry too.
An example of this is in the mandate that water leakage from 2025 is going to be given a maximum national allowance of
9% from 2025 onwards. The figure of 9% is familiar as this is the same as in Denmark and like the Danish the Chinese are
obviously adopting Digital Transformation in the water industry to help meet this target. There were also conversations
which through somebody whispering translations in my ear I could understand about the commercialisation of data and
the fact that it is going to be a taxable resource sitting on the bottom line of a company. The debate was fascinating even
for me getting the highlights and it really brought out the value of data for me. The thought was that the data would have
a positive commercial value but when we actually look at the data in the water industry alot of it is collected for regulatory
purposes and of course the value of data, rather than being positive, is actually more than likely to have a negative value and so putting it on the bottom line of
a company as an asset rather than being a taxable benefit is going to be a source of income through tax relief.
My huge thanks has to go to the Chinese Digital Water Sub-Group for their gracious invitation to join them for such a fantastic even and such wonderful
hospitality.
Also this month through the IWA there has been the release of two papers/books which are fundamental to a discussion that has been had around the accuracy
of instrumentation and the queries over the accuracy of event duration monitoring data across the UK. First of these releases is the Metaco task force that has
been working on the accuracy of data and the use of metadata within the water industry, the project and its output has been a few years in development but is
there to help utilities to ensure that data is right. The second paper was released by the IWA Digital Water Programme and was written by Dr Carl Wordsworth
of NEL. Measurement uncertainty and the Guide to the expression of Uncertainty Method (GUM) is something that we don't think about much but in fact think
about alot. My favourite lines to start of the white paper is:
It is a popular misconception that measurement is an exact science. In fact, all measurements are merely estimates
of the true value being measured which implies some degree of doubt about the accuracy of that measurement itself.
When you bring this into the context of the Digital Transformation in the Water Industry (or any industry) and the ever present phrase of "Garbage in Garbage
Out" the importance of understanding the uncertainty of measurement comes into very sharp focus. That focus has been sharpened even more this month with
the open discussion about the accuracy of event duration monitoring. Of course in this case the uncertainty of measurement has been brought into very sharp
focus and this is includes looking at the unforeseen anomalies of measurement which are caused by external factors, a copasac triggering a sensor every time
it fills, or a bird landing on the sensor triggering a spill, or someone leaving a calibration plate under the sensor by accident making it look like an installation is
spilling when in reality its not. These are all the uncertainties that we have to consider when looking at the data that we see.
Have a good month,
Oliver

IWA Digital Water Programme brings out next White Paper on
Measurement Uncertainty
The IWA Digital Water Programme has published its next white paper this month entitled Measurement Uncertainty in Digital Transformation. The White paper
was written by Dr Carl Wordsworth of TUV:NEL. Accurate measurement is a corner-stone of Digital Transformation but Dr Wordsworth highlights the popular
misconception that measurement is an exact science. In fact, all measurements are merely estimates of the true value being measured which implies some
degree of doubt about the accuracy of that measurement itself. For example, the repeated measurement of a fixed quantity will never yield the same result
every time. The degree of doubt about the measurement becomes increasingly important with the requirement for increased accuracy. For example, with
regards to fluids, the relative cost of the measured fluid would need to be considered: i.e. the measurement of the flow of petroleum has historically been much
more accurate than the measurement of water flow for either industrial or domestic supply. Uncertainty of measurement gives an indication of the quality or
reliability of a measurement result.
The purpose of the white paper is to give the reader an understanding of the factors affecting the accuracy of a measurement, and of the methods used to assess
the way in which the various factors contribute to the overall accuracy. This document is by no means a comprehensive review of measurement uncertainty. If
more information is required, the reader is asked to consult the ISO/IEC “Guide to the expression of uncertainty in measurement (GUM)”.
The White Paper on Measurement Uncertainty is available to download from the IWA Digital Water Programme website by clicking here.
IWA Metaco Report released on the use of Metadata in the water
industry
The International Water Association Metaco Taskforce has this month published the results of the last several years of work in its book "Metadata Collection and
Organization in Wastewater Treatment and Wastewater Resource Recovery Systems.
In recent years, the wastewater treatment field has undergone an instrumentation revolution. Thanks to increased efficiency of communication networks and
extreme reductions in data storage costs, wastewater plants have entered the era of big data. Meanwhile, artificial intelligence and machine learning tools have
enabled the extraction of valuable information from large-scale datasets.
The book provides recommendations to handle the challenges presented by this revolution, and aims to clarify metadata concepts and provide advice on their
practical implementation in water resource recovery facilities. This includes guidance on the best practices to collect, organize, and assess data and metadata,
based on existing standards and state-of-the-art algorithmic tools.
The book was edited by Kris Villez, Daniel Aguado, Janelcy Alferes, Queralt Plana, Maria Victoria Ruano & Oscar Samuelsson and a large number of international
experts contributed to its compilation. It is Open Source and is available for free to read on the IWA website by clicking here.
SWAN Forum releases ground-breaking Data as a Service Playbook
In response to the ever-growing thirst for more innovative business models in the global water sector, SWAN recently launched its DaaS Playbook, providing a
unique, step-by-step guide to enhance water and wastewater utility data management. Despite the widespread use of big data technology in various industries,
its implementation in the water sector has lagged. Using this Playbook, more water stakeholders will now be able to take advantage of the strategic opportunity
known as “Data-as-a-Service” (DaaS): a performance-based approach to accessing high quality data on-demand. The Playbook makes accessible much needed
know-how for implementing a DaaS model and adopting new solutions, including understanding the associated risks and necessary utility maturity factors.
A collaborative effort by utilities and industry experts, the Playbook highlights common business drivers and project barriers with implementation advice on
how to craft a DaaS contract, differentiate service level standards, and assess critical success factors. It further features 14 global DaaS water, stormwater, and
wastewater utility case studies, serving as a blueprint to improve utility operations and decision-making processes
According to Dr. Peter Prevos, Manager Data Science at Coliban Water in Australia, “If we had the DaaS Playbook before we started our digital metering project,
we could have reduced a lot of complexity in our current deployment.” Likewise, Reeza Palm, Solutions Lead at Ontec Systems in South Africa stated, “The
Playbook offers an extensive implementation guide for a smooth integration and maximizes insights for consumers, businesses and utilities.”
Within the water sector, DaaS can be defined as: “A partnership model in which a technology supplier operates and maintains specific hardware equipment for
collecting, transmitting, and processing data, and the utility pays only for the delivered results.”
The SWAN Forum DaaS Playbook is available on the SWAN Forum website and is accessible by clicking here.
Page 4
Industry News

Northumbrian Water's project to reduce storm overflow spills is first
of its kind in the UK
Northumbrian Water has started a ground-breaking £20m project which is set to significantly reduce spills from storm overflows across Tyneside.
The project, which is set to be the first of its kind in the UK, will see a combination of new technology, sensors and AI analytics used to lower the risk of
overflows happening and is based upon research and proven techniques used in the United States.
In South Bend, Indiana, the smart sewer technology – sensors, AI analytics, control measures – were installed in a section of wastewater network with the aim
of reducing the number of spills from storm overflows. Over a 10 year period, they saw an 80% reduction in the amount of spills with a combination of smart
controls and targeted investment.
Here in the UK, storm overflows are used by water companies and in countries across the world during times of heavy rainfall in order to prevent sewer flooding
from taking place in customers’ homes. They act as a relief valve on the wastewater network, and they are used with Environment Agency consent to protect
homes from the devastation that can be caused by internal flooding.
The ‘smart sewer’ project is revolutionary in that it will allow Northumbrian Water to make changes to the flow and direction of wastewater (which contains a
dilute mix of sewage, rainwater, run-off from roads and fields, and water from sinks, showers and appliances) moving it around the sewer network, and making
spills less likely to happen.
Using a mix of AI technology and hundreds of smart sensors placed along sewer pipes, it will predict when and where rain is about to hit in the region and when
and where the sewer networks are more likely to reach capacity and spill.
It will then automatically balance the flows of the network, diverting this wastewater to the emptier parts of the network, managing capacity and reducing the
likelihood of spills taking place. The technology will also identify areas where additional capacity is needed, allowing further targeted investments to be made
to build alternative storage for rainwater where it is needed most.
This real-time decision support system will be powered by a digital twin – which is a digital version of the physical sewer network which runs ahead of time and
gives Northumbrian Water more control over the system and the chance to make changes before spills happen.
The “smart sewer” will be carried out in partnership with HydroDigital, and will help to reduce the impact of storm overflows on the region’s rivers and keep
the high standards of the region’s bathing waters – with 32 of the region’s 34 bathing water currently meeting Defra’s top two standards of Excellent and Good.
NigelWatson,InformationServicesDirectoratNorthumbrianWater,said:“Thisisanexcitingandreallyinnovativeprojectwhichissettocompletelyrevolutionise
the way that our network operates, and maybe even how our industry works as a whole.
“We are determined to be at the forefront when it comes to using clever new technology to protect our rivers and coasts as much as possible. This could be a
massive step for us towards reducing how we use storm overflows.
“We know that we, like all water companies, need to do better when it comes to managing how storm overflows operate – and this, along with other
innovations and projects we are working on, is set to be a huge step forward in protecting our environment, whilst continuing to protect homes and businesses
from flooding.”
Luis Montestruque, Principal at HydroDigital, added: “With two decades of exclusive experience building smart sewer systems, we're proud to partner with
Northumbrian Water on this ground-breaking project.
“This initiative is pioneering in its use of AI for design, advanced hybrid digital twin technology, innovative stress avoidance routing control, and use of
probabilistic weather forecasting.
“It stands out for its large number of sensors and globally coordinated control points and one of the most aggressive implementation timelines in the industry.
“This project will set a global standard in how water companies use smart sewer technology to reduce spills at a fraction of the cost and time needed by
traditional engineering solutions.”
Page 5

Levels of caffeine may help pinpoint polluting wastewater leaks in
storm drain systems
In developed countries such as Japan, wastewater systems designed to keep harmful pollutants out of storm drainage are aging and deteriorating, sending
contaminants into local bodies of water. Finding the source of a leak in wastewater systems that are often buried far underground can be challenging. The
conventional method can miss leaks, and it cannot detect leaks found downstream.
Researchers have proposed using the levels of caffeine, a common household pollutant that isn’t otherwise found in the environment, to find likely sources of
leaks in wastewater systems. The findings were shared in a paper published in Environmental Chemistry Letters on 5 April 2024.
“For a long time, wastewater and storm runoff were combined to form sewer systems. The problem of combined sewer overflows during rainstorms has been
long-standing, so the system was changed to separate the sewer from the storm drain around 50 years ago. However, even in the case of newer, separate sewer
systems, the possibility of sewage leakage due to aging pipelines is becoming a concern because the oldest ones have been in the ground for five decades,” said
Noriatsu Ozaki, an associate professor at Hiroshima University's Graduate School of Advanced Science and Engineering in Higashihiroshima, Japan.
From June 2022 to May 2023, researchers collected water from storm drains during dry periods from six urban drainage areas once or twice a month. At each
collection point, they collected samples five to 11 times. They also collected rainwater, puddle water, and domestic sewage samples. They tested multiple
common household chemicals, including fragrance compounds frequently found in soaps, detergents, and cosmetics including OTNE, HHCB, AHTN, DPMI, and
musk ketone; caffeine; and benzophenone, a common sunscreen ingredient.
“These compounds are consistently detected in domestic wastewater in Japan,” said Ozaki. “In addition, three polycyclic aromatic hydrocarbons (PAHs), which
are commonly used as indicators of air and urban surface pollution, were also measured.”
To get a baseline reference, researchers measured how frequently these chemicals are found in rainwater and puddle water. PAHs were detected 80% of the
time, most of the fragrances were found 60% to 82% of the time, and benzophenone was found 100% of the time in rainwater and 90% of the time in puddle
water. Caffeine and the fragrance compounds DPMI and musk ketone, however, were much lower. They were detected less than half the time in rainwater and
puddle water.
PAHs and benzophenones were so abundant in rainwater and puddle water that it is difficult to distinguish the source of elevated levels of these chemical
compounds in the storm drains to identify leaks. The level of contamination between the rainwater, the domestic sewage, and the storm drains in the districts
measured was only different by one order of magnitude. For the three fragrances, there was a more significant difference, with two or more orders of magnitude
between the tested storm drains and the domestic sewage.
However, the level of contamination of caffeine was distinctly different for rainwater and puddle water, storm drainages, and domestic sewage. There is little to
no recirculation of caffeine into the drainage system via rainfall and the source of any caffeine in runoff could be attributed to domestic sewage. Caffeine is also
the most stable in water phase among the tested chemicals and it could be, in theory, easy to use as a tracer for future research.
• Looking ahead, researchers want to understand more about the pollution caused by these leaks. “We want to clarify the extent of the possible pollution of
the receiving public water bodies, such as rivers, lakes, or coastal areas, by the leaks,” said Ozaki. “And finally, we want to develop the diagnostic technology
to indicate the leakage at the site using the trace organic chemicals as an indicator.”
Other contributors include Tomonori Kindaichi and Akiyoshi Ohashi at the Graduate School of Advanced Science and Engineering at Hiroshima University in
Higashihiroshima, Japan.
Page 6

Cybersecurity, a must for European water utilities
Concern about cyberattacks has been on the rise in the last 20 years. The first attack was on a utility in Queensland (Australia) in 2000, whilst more recent
attacks hit Israel’s water supply in 2020 and a water treatment plant in Florida in 2021. We only have to input the term “cybersecurity” in Google to see the
importance of this phenomenon.
New technological trends in the water cycle, such as automation, early warning systems and smart metering, bring significant advantages and innovations to
the water sector, but also open up new attack vectors for cybercriminals. Therefore, as Idrica's Water Technology Trends 2024 report pointed out, utilities are
spending more time and effort on strengthening and increasing their cybersecurity initiatives.
Measures to improve cybersecurity in Europe
There were 107,777 registered cyberattacks in Spain in 2023, up 94% on the previous year. This data comes from the Annual National Security Report 2023,
drawn up by the Department of National Security.
According to the report, the fact that attackers possess “greater technical and operational capabilities” has led to cyberattacks increasing in frequency,
sophistication and severity. This situation is getting worse due to society's “high dependence on information and communications technologies”, as the report
points out. Indeed, Spain’s second biggest threat today is the vulnerability of cyberspace, second only to disinformation campaigns, though it has a potentially
greater impact. For this reason, according to Begoña González, head of Information Security at Idrica, "water operators must establish a series of strategies
aimed at strengthening their cybersecurity". The expert identifies six:
• Risk assessments: regular risk assessments must be carried out to identify vulnerabilities and potential threats.
• Continuous monitoring: continuous monitoring systems must be implemented to detect suspicious activity in real time.
• Training and awareness: employees must receive training on cybersecurity best practices to create a culture of security.
• Redundancy and resilience: redundant systems and disaster recovery plans need to be established to ensure operational continuity.
• Upgrades and patching: systems must be kept up to date with the latest security patches.
• Encryption and authentication: data encryption and strong authentication must be rolled out to protect sensitive information.
In this scenario, “governments and other stakeholders are strengthening legislation to mitigate the situation” Gonzalez stresses.. Regulations such as ACN in
Italy, on cloud services; ENS in Spain, on information security; ANSSI in France, focused on product certification; and BIO in the Netherlands, on information
system management, are just a few examples.
In this regard, Idrica's expert says: European countries must implement the NIS2 directive which provides legal measures to promote cybersecurity in the
European Union, ensuring:
• Member States are well equipped to respond to any incidents that may occur.
• The creation of a Cooperation Group to safeguard cooperation between Member States, as well as the exchange of information between
them.
• The promotion of a culture of security in all essential sectors (European Union).
Idrica, a company founded by Fomento Urbano de Castellón, S.A., is aware of the importance of implementing appropriate organizational, technical and
operational measures to manage security risks. Therefore, it has certified the information system that runs its design, development, implementation, support
and maintenance services for the GoAigua platform according to ISO 27001 and the Spanish National Security Scheme.
Page 7

Water industry rejects BBC claims over dry day spills as based on
“flawed methodology and inaccurate interpretation of data”
Citing “flawed methodology and inaccurate interpretation of data”, the water industry has strongly rejected claims in a recent article by the BBC which highlighted
data as ’potentially indicating’ dry day storm overflow spills from all water companies in England.
Anglian Water’s Head of spill reduction, Gail Pickles clarifies the discrepancy and explains why a dry day spill, isn’t always a dry day spill.
Gail Pickles: We know our customers expect action to stop all spills – no number other than zero will do. We have a huge plan to address this, but we also want
to be as transparent as we can to explain our data and the action we are taking.
Storm overflows (CSOs) have been around for decades and were initially introduced to our network as a means of protecting homes and businesses from
flooding during periods of heavy or prolonged rainfall or snow melt. Acting as pressure release valves, storm overflows allow excess water into rivers or the sea
to prevent sewers from overflowing and backing-up through toilets, drains and manholes. The clue is in the name - storm overflows. The job they do means
they should not operate when it’s dry.
We are the only country in Europe to have installed monitors on all our storm overflows. Event duration monitors (EDMs) indicate the start and stop times of
when a storm overflow may have been active – and I choose that word deliberately, for a good reason.
Getting accurate information about storm spills is not straightforward. In fact, the technology and EDM monitors we’re using are still relatively new – less than
five years old. They are placed in sewer pipes – which are fairly inhospitable environments and it’s not uncommon for them to be ‘activated’ without a spill
occurring.
Nearby activity such as high-speed trains, interruptions in network signal or even a very active spider web can trigger an activation. If we see a sensor has been
activated when we wouldn’t normally expect it, like in dry weather, we send our teams to check the site and use other telemetry, catchment and weather data
to decide whether a spill is in fact genuine. It takes a great deal of time, data and expertise to make sure we’re reporting the most accurate information we can,
all of which is shared with our regulator, the Environment Agency in an annual return. And we take a very cautious approach to what we include, if we can’t find
enough robust evidence to suggest a spill didn’t happen, it goes in the return.
The BBC ‘dry-day spill’ methodology
Dry day spills are not a standard measure. Should an EDM activation occur on a dry day, its verification depends on three further elements: the recent rainfall;
the size, shape & geology of the catchment, and on-site data from a variety of sensors, aside from EDMs. While there is no finalised methodology laid out from
the EA on how dry spills should be calculated, we’ve been heavily involved in suggesting how that could be ascertained, taking all of these factors into account.
The geography of that catchment is hugely important in determining whether a spill occurs on a dry day. Water flows downhill so the less hilly an area, the
longer it takes to drain through the catchment. This means that in a large catchment area that is relatively flat, rain takes time to drain, so in periods following
heavy rainfall, a storm overflow could still operate some days after it has stopped raining. This doesn’t mean the spill has happened on a dry day.
The BBC has applied a 9KM2 area around an EDM monitor to calculate the amount of rain (or lack of rain) which may lead to an activation on a given day.
However, geology and the time it takes for water to flow through the system varies considerably from catchment to catchment. For example, for the monitor in
Great Billing, Northamptonshire the actual catchment area is 127 KM2, more than 14 times larger than assumed by the BBC, so therefore water would still be
flowing through the catchment for a considerable time after the rainfall has stopped.
How accurate is water company data?
We have enough sewer pipe to go around the world twice. As we’ve said, this monitoring technology is still new, and it takes time and a team of operational
and data experts to verify the thousands of lines of data we get from EDMs on this network.
We cross reference all this information with the best, localised weather data, as well as other monitors, neither of which the BBC has access to. And our
understanding is getting better all the time. Because of the precautionary approach we take, we now know that some of the spills we declared in 2022 were
actually not spills at all, but we would always rather over report.
Taking action
Ultimately we want to stop all spills and consign storm overflows to history. Every single one of the 1,471 storm overflows across our network now has a detailed
improvement plan that will see discharges significantly reduced. Our shareholders have just fast tracked an addition £100m, to begin this work now.
Earlier this year, we launched our near real time storm overflow map, updated hourly, that shows the most recent activations. From next year, if our business
plan is approved by Ofwat, we will be able to move forward with a £1bn package of investment to tackle storm spill over the next five years.
We want our customers to know that we are taking action and investing in the right solutions which will have the most benefit for the environment now and in
the future.
Page 8

Southern Water projects awarded share of £40 million Innovation
Fund
Southern Water’s work to innovate as part of its wider goal of driving down use of storm overflows Southern has been recognised with two projects being
awarded a share of Ofwat’s Innovation Fund. The schemes were awarded funding from Ofwat in its fourth Water Breakthrough Challenge, that looks for
solutions with the potential to deliver wide-scale transformational change benefiting customers, society, and the environment.
The first project to benefit will receive £1.58m and will help us develop a platform for water quality monitoring that uses machine learning and artificial
intelligence to analyse and calibrate data from monitors. If proven, the platform will support our efforts in expanding water quality monitoring of waterbodies
across our region. These will help us to improve our ability to learn more about water quality in our region, to help us in our work creating healthier rivers and
seas. The project will address the challenges that water quality monitors have, as due to the environment they are in, maintenance and calibration is challenging
and expensive. Using AI and machine-learning could be a game-changer, that if successful, will make it much easier to deploy more monitors, whilst improving
the accuracy of information that they provide.
The second project will benefit from £1m and will help us develop a unique platform to help us make informed decisions about where to put sustainable urban
drainage solutions (SuDs). SuDS are a holistic approach to managing rainfall that mimics natural drainage processes - helping to reduce flooding, watercourse
erosion and pollution risks caused by development. They can also make our urban areas more climate resilient
What will the tool do?
The tool, which our modelling team and partners at HR Wallingford, are developing will help us to understand the benefits of placing SuDs in more areas of our
network. SuDS-iQ will enable users to understand what SuDS are, how they work, and the benefits they provide within a visual, online environment. SuDS-IQ
will provide a platform for collaboration in the wider water industry, through collaboration with partners at Yorkshire Water, Thames Water and Anglian Water.
The tool will also be co-developed with SuDS users in other sectors, including local authorities and developers.
Southern Water Innovation Programme Manager, Rory Miles, said: “Innovation is key for activities across Southern Water, from developing new solutions to
help us tackle big challenges: from water efficiency to protecting our environment. We need to think creatively and collaborate in and out of the water sector to
address these very complex challenges.”
“Both of these projects will help us in our work creating healthier rivers and seas, and will enable us to implement more solutions across our region – through
finding the best places to place SUDS, and to support an expansion of our water quality monitoring.”
Helen Campbell, Senior Director, Ofwat said: “There are big challenges in the water industry that must be solved, some are well known and others are less so.
In our fourth Water Breakthrough Challenge we called for solutions with potential to deliver wide-scale, transformational change for customers, society and the
environment – and that’s exactly what today’s winners have done.
“From rain gardens to prevent flooding to green energy from treated sewage, innovations to cut the water sector’s carbon footprint to robots that patrol the
pipe network, the winners are all helping shape a more sustainable and efficient water sector.”
Radiflow, Garland Technology Join Forces To Strengthen Real-Time
Anomaly Detection In OT Environments
In response to rising threats against critical infrastructure, Radiflow, a leader in Operations Technology (OT) cybersecurity and risk management solutions, has
partnered with Garland Technology, a pioneer in scalable network test access points (TAPs) and Data Diodes, to deliver an exceptional OT security solution. This
collaboration combines Radiflow’s expertise in OT cybersecurity with Garland’s packet visibility technology to deliver a cost-effective, enhanced, end-to-end
security solution for critical infrastructure and industrial plants.
Nation-statethreatactorsareincreasinglyfocusingtheirattentionondisruptingindustrialprocessesandcriticalinfrastructure.RadiflowandGarland’spartnership
helps operators detect anomalies in network behavior and communications that might be indicators of compromise. Garland’s network TAPs capture every
communication packet and send a copy to Radiflow’s OT Security Platform for prompt analysis. As anomalies are detected, Radiflow’s platform automatically
alerts stakeholders and security personnel of a potential cyber attack, so that they can respond effectively.
“Garland Technology has been involved in critical infrastructure projects since 2011 when we designed our first Data Diode TAP for a customer,” said Chris
Bihary, CEO & Co-Founder. “Since then, we’ve been building network visibility products to help provide technologies like Radiflow’s OT Security Platform the
packet-level visibility needed to protect the world’s most critical assets. This exciting solution takes replicated data from our network TAPs and Data Diodes and
turns it into actionable insights that facilitate precise threat detection. Together, we’ve simplified network management and security operations in closed and
segregated environments that still use old and legacy network equipment while enhancing overall control and visibility.”
The collaboration between Radiflow and Garland Technology ensures complete data capture of all network transactions, enabling effective anomaly detection.
This facilitates precise threat detection and reduces false positives through uninterrupted data analysis. Additionally, it maintains network performance and
uptime with secured data streaming.
The joint solution is highly flexible. It adapts to a variety of network configurations and can scale seamlessly with infrastructure changes. Security teams can
monitor multiple environments from a single centralized dashboard.
This technology partnership underscores Radiflow and Garland’s commitment to OT security, as they empower operators of cyber physical systems (CPS) with
the tools and insights necessary to defend against today and tomorrow’s cyber threats. This partnership delivers a cost-effective approach to enhanced security,
while creating a clear path toward compliance with industry standards, such as NIS 2 and IEC 62443. Customers can operate their OT environments with full
confidence that they are protected from current and future threats.
Page 9

Mayor Andre Dickens announced that the City of Atlanta plans to leverage artificial intelligence (AI) to manage its ageing water infrastructure, reports Statescoop.
This decision follows two major water main breaks earlier this month.
The two pipes affected measured 36 inches and 48 inches in diameter, and were about a century old: one was installed in 1910, and the other dates back to
1930. The city declared a state of emergency as a result of the water line breaks and the disruption to water services. The breaks and repairs left parts of the
city under a boil water advisory, affecting businesses, medical facilities, residents, etc. The city designated points where residents could pick up water and
announced a financial relief programme to help small businesses affected by the water crisis.
Mayor Dickens said "We are currently coordinating with the U.S. Army Corps of Engineers. We have sought their assistance because they have the most
experience in handling a crisis like this," on June 3, when the Atlanta Department of Watershed Management lifted the boil-water advisory in parts of the city.
And he added that the U.S. Army Corps of Engineers would help the city “develop a plan to assess and evaluate our ageing infrastructure.”
The city plans to install AI-enhanced devices on water line valves to detect and prevent breaks, Dickens revealed at a press conference. The new AI devices will
be deployed at the locations of the recent breaks; they will provide early warnings and help maintain the water infrastructure more effectively.
Dickens also indicated that the city might seek federal funds to support improvements to its water infrastructure, a project that could cost billions. This federal
assistance would be crucial in addressing the extensive needs of the city’s water systems. He also announced the establishment of a “blue ribbon” panel of
water infrastructure experts, including former Mayor Shirley Franklin and Metro Atlanta Chamber of Commerce CEO Katie Kirkpatrick. This panel will guide and
advise on the city's efforts to enhance its water systems.
Implementing AI technology in Atlanta's water management represents a significant advancement. By partnering with the U.S. Army Corps of Engineers and
assembling an expert panel, the city aims to develop a robust strategy for maintaining and upgrading its water infrastructure, ultimately ensuring reliable access
to clean water for all residents.
Atlanta will use artificial intelligence tools to detect water main
breaks
New algorithm tracks Texas daily reservoir evaporation rates
Summer can be an extra challenging time for Texas’ 189 major water supply reservoirs. With temperatures consistently reaching 100 degrees or higher,
reservoir evaporation rates see high increases. Accurate evaporation rate estimates are crucial for water resource managers, as reservoirs play an essential
role in our social and economic systems by supplying water for agricultural, municipal, and industrial consumption. Reservoirs are also critical for mitigating
impacts from droughts and floods.
A recent study published in “Water Resources Research” highlights the efforts of Texas A&M University researchers Dr. Huilin Gao and Dr. Bingjie Zhao, with
co-authors from multiple institutions, state, and federal agencies. The research team developed a more accurate method for estimating daily evaporation
rates.
“This method will enhance decision-making processes related to reservoir operations, water rights allocation, and long-term water planning in Texas and
beyond,” said Dr. Nelun Fernando, manager of Texas Water Development Board’s (TWDB) water availability department.
Zhao, Gao, and their team developed a new computer algorithm to estimate daily reservoir evaporation that accounts for factors not considered by current
methods.
“If you look at our daily evaporation algorithm, it uses regular meteorological data like wind, temperature, and relative humidity, so it's a lot easier to calculate
for each reservoir,” said Gao, a professor in the Zachry Department of Civil and Environmental Engineering.
According to the article, “Long-term and consistent reservoir evaporation information is typically reported on a monthly scale. Accurate daily evaporation
information is lacking, but it is crucial for hydrological scientific research and regional water resource management.”
The most common methods for estimating evaporation rely on data from Class A Evaporation Pans. These pans sit outside of the reservoir and estimate
evaporation by measuring changes in the pan’s water level. The pan evaporation data is then converted to reservoir evaporation data using an adjustment
factor known as pan coefficients. Since evaporation pans are typically located away from the reservoir, they do not account for the effects of wind, water depth,
or air and water temperature differences across the reservoir. This can lead to inaccurate measurements, creating uncertainty for water resource managers.
“The lakes are much deeper than the evaporation pans, causing the water temperatures to be very different,” said Zhao. “This means the evaporation rate
predicted by the evaporation pan cannot represent the real lake accurately.”
At this time, the daily evaporation algorithm has only been applied to Texas reservoirs. The results reveal a clear geographic distribution and strong seasonality
of evaporation throughout Texas, with the highest average losses occurring in July. Additionally, the data reveals a significant upward trend in evaporation
rate, with an increase of about 1.1 inch per decade. Gao and Zhao collaborated with Desert Research Institute (DRI) to develop an online portal that allows
stakeholders to visualize and download data in near-real time.
Due to the success of the algorithm’s estimation on Texas reservoirs, the research team is currently working on evaporation data for all major reservoirs in the
western United States.
The paper was coauthored by researchers from DRI, TWDB, Lower Colorado River Authority (LCRA), U.S. Army Corps of Engineers (USACE) – Dallas-Fort Worth
District, and U.S. Bureau of Reclamation.
Page 10

Gaps in stream monitoring may hinder water management in
California, study finds
California relies on its rivers and streams for a plethora of services—water supply, flood control, biodiversity conservation, and hydropower generation, to name
a few. As a result, understanding the flow of water through the state's stream network is critical for supporting California's economy and ecosystems. A new
study published by UC Berkeley researchers in Nature Sustainability finds, however, that California's rivers and streams are critically under-monitored, making it
difficult to properly manage water supply and control floods, monitor changes in freshwater biodiversity, and understand how climate change is affecting water
supplies. According to the authors' analysis, only 8% of all rivers and streams in California are monitored by stream gauges, the technology used to measure the
flow of water upstream or downstream from their installation site.
"As climate change progresses and the demands on California's water resources and water infrastructure grow, it is critical to have reliable, timely, and
comprehensive information about water in rivers and streams," said lead author Lucy Andrews, a Ph.D. candidate in the Department of Environmental Science,
Policy, and Management.
"Our work highlights concerning gaps in California's water monitoring capabilities and proposes tools for addressing those gaps."
After evaluating stream gauge coverage, Andrews and co-author Ted Grantham, an Associate Professor of Cooperative Extension, assessed the degree to which
stream gauges support important water management objectives such as dam operations, biodiversity conservation, and monitoring for scientific research.
"Measuring streamflow near dams is critical for handling water supply and controlling floods, but our research determined that only 9% of California's large
dams are covered by a gauge upstream and/or downstream," said Grantham.
The researchers also found that only 30% of watersheds supporting the highest diversity of freshwater species were monitored. "California is a biodiversity
hotspot, but its freshwater species are also among the most imperiled in the world," said Andrews. "More monitoring of these critical streams is needed to
protect these vulnerable species."
Finally, Andrews and Grantham evaluated the monitoring of streams that are minimally impaired by human activities, which provides insights for researchers
into how climate change is affecting hydrology. They found that less than 1% of the unimpaired streams in the state are gauged. To illustrate possibilities for
improving stream monitoring, Andrews and Grantham modelled scenarios in which current gauges are relocated and in which additional gauges are installed
across the state, especially in regions where gauge density is low. They used an optimization algorithm to identify potential gauge sites and then ranked them
by their relevance to management objectives.
The authors found that some sites can support more than one management objective at a time, making a reconfigured or expanded monitoring network more
efficient, cost-effective, and relevant.
"We hope that this study paints a hopeful picture—that even though streamflow monitoring in California is currently inadequate, with appropriate investment,
it's possible to design and build better networks using the simple computational tools we propose," said Grantham.
"Having more information about how much water is in our rivers and streams will help us to better manage rivers and streams in the future."
Page 11

Advanced algae sensor proves valuable tool in protecting drinking
water
Advanced technology tested nearly two years ago in the water treatment
system that serves Toledo could prove valuable in efforts to protect the water
that pours out of taps well beyond northwest Ohio, according to research
published by The University of Toledo.
UToledo scientists installed a real-time algae sensor at the Toledo low service
pump station in eastern Lucas County in 2022 as part of a wider-reaching
initiative aimed at the early detection and management of harmful algal
blooms sponsored by the U.S. Army Corps of Engineers. The installation put
the facility on the map as the first in the nation to test out the fluorescence-
basedtechnologythatdetectsapigmentthatscientistsbelievedcouldflagthe
release of toxins from blue-green algal cells. In research published recently in
the peer-reviewed journal Science of the Total Environment, their analysis of
the resulting data confirms that the technology worked as intended.
“The instrument is able to detect blue-green algal cell lysis in real time,
providing an early warning of potentially elevated levels of microcystin toxin
in the raw water supply,” said Dr. Kuo-Pei Tsai, lead author on the article and
a post-doctoral associate at the UToledo Lake Erie Centre. “That means the
water treatment plant staff could immediately begin to take precautions if another catastrophic occurred like the one in 2014.”
Scientists now have ample tools to detect and monitor harmful algal blooms, which in Lake Erie are caused by cyanobacteria, also called blue-green algae.
Harmful algal blooms have been a focus of particularly intense research since the Toledo water crisis that left half a million residents without safe tap water
for three days in 2014. But one complicating factor water plant managers face is that harmful algal blooms are not uniformly harmful. Most of the time, intact
cyanobacterial cells can be easily filtered from incoming water along with their toxins. When the cells start to break down, however, their toxins are released
into the water, requiring managers to apply chemical treatments to absorb or destroy the toxins.
The breakdown process is called lysis. It can result from outbreaks of naturally occurring viruses in the environment, called cyanophages, as scientists hypothesize
happened during the 2014 water crisis, or through the application of algaecides or water treatment chemicals. When cyanophages attack a bloom, large pulses
of toxin can be released in a matter of hours. Traditionally, water treatment plant operators have relied on relatively slow and costly assays to directly monitor
both cell-bound and free toxin levels in the water. The PhycoSens, the device produced by German company bbe Moldaenke and installed at the pump station
by the UToledo Lake Erie Centre, complements but does not replace these assays by detecting in real time a by-product of cyanobacterial lysis: a pigment called
unbound phycocyanin.
Scientists hypothesized that the detection of the pigment would serve as an indicator that cyanobacterial cell membranes are breaking down and potentially
releasing microcystin, and that the instrument’s reports on water samples taken every quarter-hour during the harmful algal bloom season would alert operators
to jump into action.
“The instrument will allow water treatment plant operators to see when the condition of a harmful algal bloom in their source water is changing rapidly and
to respond appropriately,” said Dr. Thomas Bridgeman, professor of ecology and director of the UToledo Lake Erie Centre and senior author of the research
article. “Without real-time data of this kind, the conservative approach may be to over-treat water with chemicals to ensure safety, which adds expense and can
detract from water’s taste. This technology will allow treatment plant operators to better match their responses to the severity of the situation, saving money
and improving taste while still providing a high level of safety.”
The Phyco-Sens took samples between mid-July and mid-October in 2022, offering researchers a vast cache of data to analyze. Additional laboratory studies
with cyanobacteria, treatment chemicals and cyanophages helped them to reach the conclusion is that the presence of unbound phycocyanin is indeed a useful
indicator of the onset of cyanobacterial cell lysis and in turn the potential release of microcystin. The device’s purchase, installation and related research are
funded through a $1.4 million grant to develop enhanced technology for early detection and management of harmful algal blooms through U.S. Army Corps
of Engineers.
Dr. Youngwoo Seo, professor in the Department of Civil and Environmental Engineering and Chemical Engineering, leads the three-year project that began
in 2021. Dr. Dae-Wook Kang, assistant professor in the same department, joins Bridgeman as a co-investigator. The researchers and their collaborators are
working with municipal drinking water treatment plants in Bowling Green, Celina and Oregon in addition to Toledo, where the Phyco-Sens is deployed again
this year and already taking samples ahead of the harmful algal bloom season.
Page 12

Article
Are EDMs an accurate
reflection of wastewater spills
Every year a new set of statistics attempts to establish exactly how many million hours water companies have spent spilling raw sewage into Britain’s rivers and
coastal waters. These figures are met with horror, but the truth is worse still: we do not actually know how much sewage is being spilled. New research shared
exclusively with the New Statesman suggests that most of the monitors used by the water industry’s leading water company to track spills have generated
inconsistent results. This implies that significant sewage spills into rivers such as the Derwent in Derbyshire and the River Severn in Shropshire have been missed,
and thousands more have been misreported.
This data is used by the government to regulate the companies that provide water and sewage services, which are at the core of our critical national infrastructure.
It is used to ensure that bathing water is safe to swim in, and to direct billions of pounds’ worth of investment. If the findings are correct then it is not fit for
purpose.
Spills happen because each sewage treatment works has a limited capacity for the amount of untreated sewage (in litres per second) it can handle. During a
period of heavy rain the flow can exceed this level and the extra rainwater, mixed with raw sewage from homes and businesses, will overflow into a storm tank.
Once the tank is full (which can take a few hours) the sewage begins spilling from the tank into the environment.
The sewage that flows into treatment works (and the treated water that leaves them) are monitored by “flow meters”. These monitors receive Environment
Agency-approved certification and have been relied upon for decades. In recent years, however, the government has sought to address the growing problem of
sewage pollution by requiring the installation of a different kind of monitor – “event duration monitors”, or EDMs – on storm overflows. In December last year
the Environment Secretary, Steve Barclay, announced that all of the UK’s nearly 15,000 outflows are now fitted with EDMs, which he said would collect a “wealth
of data” to “ensure that we know the full extent to the problem – increasing transparency, revealing the worst-offending overflows, and enabling regulators to
hold polluters to account”.
But independent analysis of the EDM data has found it to be highly questionable. Peter Hammond, a computational biologist who works with the campaign
group Windrush Against Sewage Pollution, has analysed data from 200 sewage treatment works over a two-year period, and found that EDMs at more than half
of these sites generated results that were inconsistent with the flow of sewage and local rainfall.
Hammond focused his analysis on data collected by Severn Trent, which is the water industry leader in Environmental Performance Assessments, having been
awarded the highest four-star status every year for the past four years, and was the first water company in the UK to ensure all of its storm outflows were
monitored by EDMs. Hammond believes that if there are questions to be asked about Severn Trent’s data, these questions are likely to apply to all the UK’s
water and sewage companies.
A sewage spill at a wastewater plant has a clear pattern, Hammond explains: the untreated sewage flowing into the works rises to a certain rate (the “storm
overflow rate”) and then typically levels off, as it overflows into the storm tank (which, when full, overflows into a watercourse such as a river). At this point the
EDM – which measures the depth of fluid in the storm tank, usually with an ultrasonic sensor – should begin reporting a spill. However, Hammond found many
examples in which the flow pattern clearly illustrates a spill, but the EDM has not recorded one.
These inconsistencies suggest that sewage is regularly being spilled into rivers, but not being recorded. “EDMs are the way that spills of untreated sewage are
going to be monitored in the future,” Hammond told me, “so it’s worrying that there’s already signs of huge unreliability.”
Hammond’ ‘s findings include evidence that untreated sewage spilled into the River Derwent for hundreds of hours with no spills being recorded by the EDM.
These spills occurred from a sewage treatment works at Matlock in Derbyshire, in November 2022, a month in which heavy rain caused flooding across the UK.
As the rainfall increased in Matlock, flow meter recorded sewage flowing into the works rising to around 100 per cent of the storm overflow rate, then flattening
off – the clear signature of sewage overflowing into the storm tank. At one point this continued for around two weeks, but the EDM did not record a single spill.
At other times, spills were recorded by monitoring equipment when it was highly unlikely that they could be taking place, suggesting the monitors also routinely
generate false positives.
In April 2021, for example, there was almost no rain for four weeks, and the flow of sewage into the Rainworth sewage works in Nottinghamshire never reached
more than 70 per cent of the rate at which the storm overflow begins to be used – but the EDM recorded spills on 16 different days.
Water companies must tell the Environment Agency if their EDMs are not operational, and the industry has been criticised in the past for failing to ensure all
EDMs are working. However, the data Severn Trent submitted to the regulator for these periods states that the EDMs at Matlock and Rainworth were operational
for more than 99 per cent of the reporting period. There is no suggestion Severn Trent has acted improperly or broken the law in the way it has handled its data
– the question is whether EDMs in general are sufficiently reliable.
Page 13

Hammond has compiled a detailed report of his findings, which also shows that EDMs which appear reliable can also miss spills if they stop working. At Itchen
Bank sewage works, on a stretch of the River Severn that Severn Trent has marked for improvement as a “bathing river”, an EDM appears to have missed at least
eight spills while not operational. At Fleckney sewage works, which discharges into the Grand Union Canal, more than 200 hours of spills appear to have missed.
In all, Hammond’s analysis of 400 annual data series found that 55 per cent of EDMs generated results that appear inconsistent with the data on sewage flow
and rainfall.
When the New Statesman shared the data and analysis from Rainworth and Matlock with Severn Trent, the company responded that it would not be able to
comment without further investigation that included accounting for the complexities of each site, but that it does conduct retrospective reviews of EDM data.
Rainfall and sewer catchment patterns, it noted, are complex and should be factored into the data from each individual monitor.
On 10 November 2021, Boris Johnson's government announced that its “world-leading” Environment Act had become law. Thanks to 22 Conservative MPs who
voted against the government to include an amendment on sewage, the Act imposed a duty on water companies to reduce sewage discharges. However, it also
enshrined the event duration monitor in UK law. The Act specifies that it is the “frequency and duration” of sewage spills that is important; the volume of sewage
spilled is accounted for “where the information is available”.
Despite their legal status, almost none of the EDMs used on the almost 15,000 sewage outflows in England and Wales have been certified by the Environment
Agency. The certification process was only introduced in March 2023, after the majority of EDMs had been installed. A guide compiled by the water industry
in 2021 acknowledges that for some EDM sensors, “additional information is required to determine whether the sensor is reading correctly”. Some types of
sensors “can be left in the incorrect position after high levels and provide unreliable data”, the guide warns, while even the more advanced sensors can suffer
faults including a build-up of dirt or condensation that can cause them to “struggle to read properly” or to generate “noisy data”.
The Environment Agency describes EDM data as “key” to its regulation of water companies and says that the “robust and consistent” monitoring they provide
helps it to direct around £1bn per year of investment in infrastructure. Environmental performance forms a key part of Ofwat’s (the water services regulation
authority) considerations on the extent to which water companies are allowed to raise their bills.
There are signs that water companies themselves are aware that EDMs can be unreliable. At least 2,500 remote cameras have been installed at storm overflows
around the UK to allow companies to check if spills are really happening, but the companies are not compelled to share the camera data with the Environment
Agency.
This confusion appears convenient for water companies. Because EDMs only measure the duration of a sewage spill – and not the amount spilled – it is much
harder for the government to impose fines or charges. The Liberal Democrat manifesto promises a “sewage tax”, while the Labour manifesto commits to
“automatic and severe fines” and “independent monitoring of every outlet”. Such measures will be impossible without reliable data.
If flow meters were used to measure spills, said Hammond, “you might be charged per litre of what you’ve spilled. And if it turns out it was illegal as well, then
maybe you could then add a fine on top. You wouldn't need to go to court, you would just introduce it as a charge. Most companies definitely don't want that.”
Dodgy data also helps to shape the public's perception of sewage spills. A small run-off of mostly rainwater and a billion-litre spill of raw sewage become the same
data point, if they last for the same amount of time, and headlines can only report the dispassionate statistics of hours of spillage. Thanks to the government's
failure to establish reliable facts about sewage spills, the true extent of water companies’ failure to protect the environment remains obscure.
This article was originally published by the New Statesmen magazine.
Figure 1:Data from Matlock STW 2022 (Courtesy of New Statesmen Article based on Peter Hammond's WASP Paper
Page 14

Feature Article
How accurate is Event
Duration Monitoring?
The Water Industry has installed Event Duration Monitoring across England & Wales over the past approximately 15 years and all of this data is now available
on-line for all to see in near real-time. However, a recent article has called into question the accuracy of this monitoring saying that the data cannot be relied
upon. This a worrying assertion as in reality this data has been widely used in the British Parliament and the House of Lords and is widely published each year.
In fact, this data is directly responsible for the £56 billion programme of investment scheduled over the next decade or so to generally bring storm overflows
down to less than ten spills per year on average.
So, have we got it all wrong and can we rely on Event Duration Monitoring? What is the history of the monitoring
A brief history of EDM monitoring
Despite what everyone thinks with EDM monitoring starting in 2013 as a result of the ministerial direction it in fact started much earlier with a handful of event
duration monitors in the water company business plans for 2009. This would have meant that the concept of event duration monitors were first though of in
and around 2007 or 2008. These monitors were mainly for Shellfish Water and Bathing Waters to allow both these stakeholder groups to understand when
storm overflows affected people swimming in the sea and of course to help protect Shell-fisheries which are an important commercial stakeholder.
It wasn’t until 2013 and the release of the Ministerial Direction by Richard Benyon that the widespread deployment of Event Duration Monitors was thought
of. At this point the Water Industry delivered a programme under the Water Industry National Environment Programme between 2015 and 2020 to deliver the
ministerial direction of the vast majority of combined storm overflows monitored. Public opinion drove this further and in the PR19 business plan for delivery
between 2020 and 2023 the remaining combined storm overflows were monitored. The exact number of EDMs installed is shown in figure 1.
When the data started getting published publicly was when the scale of combined storm overflow spills were revealed in a very public manner and the issue
became a very public scandal.
A lack of governance
The original EDM monitors were there to inform shellfisheries and bathing waters giving an indication of when it was safe to harvest shellfish or bathe in coastal
waters. The following monitoring programme was only meant to improve the awareness of how much sewage was going to the environment. Before the mass
EDM programme storm overflows were monitored with an idea of what volume was actually discharged to the environment. The widespread installation of
EDM monitoring into the wastewater network was meant to work hand in hand with modelling to provide a better estimation of the impact that combined
storm overflows were having on the environment.
Although good practice guides were released the EDMs which were installed under the U_MON1 and U_MON2 programmes are essentially ungoverned as
the Environment Agency did not apply their own Monitoring Certification Scheme (MCERTS). The original published Good Practice Guide applied a +/-5mm
accuracy to the physical structure but not to the actual measurement device.
On wastewater treatment works the use of EDMs are now being installed under the U_MON3 driver and these will be under the Environment Agency MCERTS
programme by 2026 and so this data can be relied upon.
But lets look in a bit more detail:
Driver Code Description
BW_MON
(previously S8 or
RB5)
Provision of event and duration monitoring on CSO and
storm tank - all discharges impacting bathing waters
U_MON1 Schemes requiring edm from storm discharges identified
as high risk other than bathing and shellfish waters
U_MON2 EDM of storm discharges identified under the risk-based
approach and not identified under U_MON1, RB5 or S8
U_MON3 Install EDM on WwTW overflows to storm tanks at those
WwTW we can't use existing monitors to be confident
that the permitted FFT settings are being complied with
U_MON6 Install EDM on Emergency Overflows and flow monitors
where necessary to protect the environment from the
effects of urban wastewater collection and discharges.
Page 15

Event Duration Monitoring Technologies and Accuracies
When installing any instrument, the right technology has to be installed for the application. These technologies all have their strengths and weaknesses. This
has to be borne in mind at installation and with the ongoing maintenance. This will have an impact on the accuracy of the measurement and in the data that
is produced. This is why, for regulatory purposes the MCERTS scheme exists as it applies a rigour to the monitoring and subjects the measurement installation
to 5-yearly inspections by an independent inspector and in-between inspections an auditable management system. Part of the MCERTS Inspection applies a
measurement uncertainty.
This ensures that the accuracy of the measurement is maintained and the measurement uncertainty is known. This measurement uncertainty is taken into
account within environmental permits, this is why FFT compliance assessment has an allowance of 92% of FFT (which is the maximum allowable measurement
error of the measurement system). Without this rigour within the water industry any measurement that is taken should be utilised with caution.
For Event Duration Monitoring within the wastewater collection network there is no actual standard of maximum uncertainty, although in the EDM Good
Practice Guide V2.2 an allowance of +/-5mm was applied to the weir this was not applied to the actual instrument itself. In the EDM guidance for wastewater
treatment sites and pumping stations which applied from 31st March 2023 a minimum accuracy of +/-5mm was applied which is very tight but achievable
accuracy depending on the measurement technology used.
Measurement Technologies
In the Good Practice Guide for Event Duration Monitoring V3.0 a number of different measurement technologies are suggested for EDM monitoring including:
• Ultrasonic sensor
• Radar sensor
• Multiple sensor options
• Pressure transducer
• Conductivity probes
• Float or Tilt switches
• Storm pump events
Of these technologies there are various reasons why some are more applicable than others and we briefly go through the options.
Inferred measurement
Using storm pump events is an inferred measurement and relies on storm pumps actually being present. The method works on the recording of the start and
stop times of the storm pumps. This type of measurement works well where the storm flow is directly pumped from the wet-well of the pumping station. It does
always indicate when a storm event happens as there can be a mechanical failure of the pump (due to a warn impellor) which makes the pump appear that its
pumping when it isn’t, this is a maintenance issue and should be a rare occasion.
Where storm pumps are utilised rather than a gravity overflow then it is a good method that is utilised.
Contact (direct measurement) technologies
Pressure transducers, probes (both conductivity and capacitance) and switches (float and tilt) are types of direct measurement with contact between the
measurement technology and the wastewater being monitored. This is less than ideal in a wastewater network solution as it does require a greater maintenance,
in terms of fouling and cleaning of the sensor. In storm conditions the power of the actual overflow can also dislodge and effect the accuracy of the measurement.
This makes all of these technologies impractical to use.
Equally both probe technology which could be either conductivity or capacitance and float technology is arguably not accurate over time. Both probes and floats
are good indicators but are not particularly accurate as the mechanical nature means they become loose and the accuracy of measurement is not maintained.
Pressure transducers can be very accurate but again are subject to fouling. Like indirect measurement technologies they tend to be off-set above the base of
the measurement area. As per floats and probes the fact that they are in the wastewater means that they will be subject to a greater risk of mechanical failure
in high storm conditions.
Level-based (indirect measurement) technologies
Both the ultrasonic and radar technologies are examples of indirect measurement technologies. They are remote from the flow sitting above the wastewater
level and as such are not susceptible to fouling from the flow. These are pre-dominant technologies that have been used in the wastewater industry for many
years. Radar technology has only recently (within the past 5 years.) being employed within the water industry for any measurement outside of digester levels
due to the development of the technology and its application to the water industry. This has mainly been driven by one company, Vega, and the adoption of
radar technology is becoming more commonplace. This is since the installation of network EDMs which were mainly using ultrasonic measurement technologies.
The main difference between ultrasonic and radar technologies is that ultrasonic uses the speed of sound to measure the level by creating an ultrasonic wave
utilsing a piezo-electric crystal and radar technology measure uses the speed of light.
In conclusion non-contact level measurement has pre-dominantly been used within the water industry and is utilised as is more accurate and less-subject to
fouling. Water companies that have installed contact measurement technologies are tending to replace them with non-contact measurement as they find the
contact measurement technologies are not reliable enough.
Page 16

Principles of measurement for non-contact level measurement
In order to understand the limitations of non-contact level measurement it is necessary to understand how all non-contact level measurement works and why it
is indirect. Both ultrasonic and radar measurement technologies are air-firing technologies that instead of measuring the water level directly they measure the
distance of the air to the water. Neither technology can directly measure the water level.
This is done by inputting the total distance from the bottom of the chamber or channel to that is being measured. This is called the Empty Distance (i.e. the total
distance without water in the channel or chamber) and is measured to the face of the sensor. The level of the water is then calculated from the empty distance
minus the depth of air that is measured usually up to a maximum level which is termed as Hmax or the maximum height. The span of measurement is from the
bottom of the chamber Hmin to Hmax. Either device does also have to have a space above Hmax to work accurately. This is called the blanking distance which
is minimised in radar technology but is normally around 300mm in ultrasonic technology.
The blanking distance is there, especially technology working
at the speed of sound, as the sensor itself acts as both a
transmitter and a receiver of the ultrasonic signal. The 300mm
represents the time that it takes for the device to switch
between transmitting and receiving. This isn’t the case for
radar technology that can measure up to the face of the device
although there is a zone where the measurement uncertainty
increases. This is shown in figure 2.
It has to be borne in mind that non-contact level measurement
is a calculation, and the setting of the empty distance is
absolutely vital when measuring. Theoretically the empty
distance should never change, as long as the sensor position
never changes as the physical dimensions of the chamber
or channel never changes but the empty distance is used to
calibrate the distance measured to ensure the level of water
that is being measured is accurate.
Technological (fixed) accuracies
Sensor accuracies
Any measurement device has a technological limitation. When we use a ruler, it is calibrated to measure in centimetres and millimetres. If we want to measure
more finely or conversely more coarsely, we use a different measurement technology with a different resolution.
The same can be said of all of the measurement technologies and this can be checked via either the manufacturers specifications and/or the MCERTS scheme
where the measurement technologies have gone under rigorous testing to measure their accuracies. The CSA website has reports on all of the accuracies of
all of the technologies for water flow meters , for the ultrasonic and radar-based devices this equally applies for the accuracy of the level measurement. When
looking at the measurement technologies ultrasonic technologies have a minimum uncertainty of measurement of +/-6mm and or 0.25% of the measured range
whichever is greater. For radar technology this is +/-2mm. Figure 2 lists the current technologies that are available and their measurement uncertainty
Manufacturer and model Technology type % Measurement uncertainty Measurement uncertainty
over full range (mm)
Pulsar Flow Cert Lite
(internal temp sensor)
Ultrasonic 0.193 5.79 (at 3m)
Pulsar Ultra 4 Ultrasonic 0.193 6 (up to 3m)
Siemens Hydroranger 200 Ultrasonic 0.47 9.4 (up to 3m)
Siemens LUT430 Ultrasonic 0.25 7.5 (up to 3m)
Siemens LT500 with LR110 Radar 0.08 2 (up to 5m)
Vega C21 Radar 0.044-0.173 3 (up to 5m)
Figure 3: Accuracy of various certified measurement technologies
There are some measurement technologies that are commonly used that are not certified including the Technolog Cello which has a minimum measurement
uncertainty of 10mm and the non-certified Pulsar technologies which as a group of technologies using the same measurement sensor have a minimum
uncertainty of 6mm
.
For the ultrasonic technologies there is a balance between how-close to the wastewater a sensor is installed and its accuracy. For the radar technologies, as they
operate at the speed of light the distance and accuracy balance is not important.
This is why, within the level measurement market, the use of radar technology is becoming more prevalent as the accuracy of measurement has improved and
become more cost-effective in the past five years. Ultrasonic was the best available technology but had its limitations especially over large distances. Where an
EDM has been installed and is measuring at greater than 3m the accuracy of measurement will not be acceptable considering that the standard has been set to
+/-5mm. In these circumstances radar measurement technology is the only viable option.
Figure 2: Simplified diagram of the basis of level-based non-contact measurement
Page 17

Structural accuracies
As acknowledged in the CIWEM Good Practice Guide V2.21 there will be uncertainties associated with the overflows themselves. Weirs are not level and nor are
overflow points. The allowance in the Good Practice Guide was for +/-5mm. This all has to be taken into account together with the measurement uncertainty
of the sensor.
When the fixed measurement uncertainty of a new sensor is looked at together with the measurement uncertainty due to variation of the physical structure it
can be seen that there can easily be an error of up to 10mm (i.e. up to 5mm from the sensor and 5mm from the actual structure). This is the sort of error that is
quantified by an MCERTS Inspector and where the knowledge of the uncertainty is critical it would prudent to have it fully quantified by an independent MCERTS
inspector although this is still not the case for network EDMs and indeed on wastewater treatment works is only set to a standard from 2026.
Maintenance related (dynamic) accuracies
Measurement uncertainties will vary with time and will depend upon both the physical state of the sensor and its installation as well as electronic drift from the
instrument itself. This will very dependent upon each and every installation.
Referenced in the CIWEM Good Practice Guide is a note about maintenance, in this there is vague statement:
Equipment should be appropriately inspected and maintained to ensure reliability and repeatable operation. Latest inspection information
should be accessible to analysts to support understanding of data quality and consistency. Periodic physical and calibration checks should
be undertaken to ensure reliability and repeatable data measurements.
This gives no detail on what maintenance regime is expected to maintain reliable and repeatable data. This could take the form of the most common maintenance
strategy within the water industry in terms of “fix on fail,” where a monitoring system is only replaced when it falls out of service and is unrepairable. There is
more detail later on in the document that states procedures should include:
• Testing of equipment and settings
• Visual inspection of equipment for any damage or misalignment.
• Whether devices used for regulatory reporting will be physically tagged.
• Clarity over use of information where sites supply information for more than one purpose.
• Confirmation that issue does not persists after a maintenance visit.
All of this again is not detailed enough to test the calibration of the instrument and its accuracy. The majority of what is stated in the document could be satisfied
via a visual check of the instrument itself and checking that it scaled correctly, and the settings of the transmitter are as originally programmed.
A better statement which should have been used would have be:
A physical verification of the accuracy of the instrument, this is normally accomplished using a calibrated verification plate and comparison to standard
reference points.
This is in fact referenced in the document where it states:
Periodic physical and calibration checks should be undertaken to ensure reliability and repeatable data measurements.
Unfortunately, the word “should” has been used rather than “shall” indicating that it is desirable not essential. It is arguable that the authors of the document
meant for this to be essential but that is not what has been written.
Sensors will drift in time, and this is down to normal operation and will be individual to each site. This is why the MCERTS scheme exists so that there is a distinct
and rigorous methodology applied and independent expert makes an assessment of the degree of measurement uncertainty as well as an audited management
system to ensure that the correct happens in a scientifically robust manner according to industry best practice and company standard operating procedures.
Summary
From this article we can see that EDMs were not installed for the purpose that they are now being used for. The lack of governance around the measurement
shows that EDMs can’t be relied upon to be 100% accurate as they were never designed to be in the first place. If this had been the original intention, then
the installation of monitoring would have followed a different slower and more expensive path to make sure that the data that the EDMs produced were 100%
reliable in the data that they produced.
Of course, over time and with the right investment levels agreed by the regulator this can be changed and the data become more certain and EDM’s installed to
a more accurate standard but this is not the current state of play. What future installations will show is that in general the current level of monitoring is actually
over-estimating the situation and we are seeing a worst-case scenario currently.
In the meantime, though the industry will react, technologies will develop and the benefits of the monitoring that has been installed is at least we have an
indication of the current situation.
Page 18

Water, Wastewater & Environmental Monitoring Conference & Exhibition
Birmingham, UK
9th - 10th October 2024
WWEM is moving to the Birmingham NEC in 2024. Planning is still underway but the firm favourites like the Flow Forum, Instrumentation
Apprentice Competition and the Learning Zone will be returning as well as some surprises. Watch this space for updates but what is sure that
in its new home in Birmingham the WWEM Conference and Exhibition will be bigger than ever.
Sensor for Water Interest Group Workshops
The Sensors for Water Interest Group has moved their workshops for the foreseeable future to an online webinar format. The next workshops
are:
10th July - Skills Workshop
9th-10th October - WWEM
International Water Association - Digital Water Summit
Bilbao, Spain
12th - 14th November 2024
The Digital Water Summit from the IWA returns to Bilbao for another year to disseminate the latest in Digital Trends and Innovations
International Water Association -World Water Congress & Exhibition
Toronto, Canada
11th - 15th August 2024
The show-stopper in the IWA Calendar is the World Water Congress & Exhibition which is in Toronto this year with hundreds of hours of
conferences and thousands of visitors to hear about the best in the water industry
Siemens Transform
Manchester, UK
17th - 18th July 2024
Join thousands of participants for a spectacular technology exhibition and conference exploring how to accelerate your digital and sustainability
transformation by combining the real and digital worlds.
Hear from and collaborate with experts, experience transformative technology, and work with a vibrant community to solve real-world
challenges. Covering topics from decarbonisation to the industrial metaverse, co-create tangible solutions to make your organisation more
competitive, resilient and sustainable.
Page 19
Conferences, Events,
Seminars & Studies
Conferences, Seminars & Events
2023/4 Conference Calendar

Water Industry Process Automation & Control (WIPAC) Monthly - June 2024.pdf

Water Industry Process Automation & Control (WIPAC) Monthly - June 2024.pdf

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