WIPAC Monthly - December 2016

WIPAC MONTHLYThe Monthly Update from Water Industry Process Automation & Control
www.wipac.org.uk Issue 12/2016 - December 2016

In this Issue
From the Editor.................................................................................................................... 3
Industry News..................................................................................................................... 4 - 9
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.
ORP Sensors - Are they really the best thing since sliced bread......................................... 10-11
ORP sensors are one of those instruments that have been talked about for years. I’ve certainly heard then used as a
replacement for DO amongst other things. In this article by instrument manufacturer, Hach. A balanced view is presented
explaining their use and where it can and can’t be used and gives a sense check to the technique

The use of online monitoring to detect THM’s in wastewater............................................ 12-15
In this case study from Paso Robles in California the use of online THM monitoring is examined in the context of it being
used to decide upon the operational strategy to limit THM formation as a disinfectant by-product. The case study from
AMS shows that the use online monitoring can prove to be invaluable in plant operational strategy and optimisation
The importance of flow and its measurement to the Water Industry.................................... 16-17
The measurement of flow in wastewater and its importance is often overlooked. In this short article by WIPAC Group
Manager we look at the fundamentals of flow and its measurement and why the old adage about measuring to manage
is so important to the Wastewater Industry
Workshops, Conferences & Seminars................................................................................... 18-19
The highlights of the conferences and workshops in the coming months

The photograph of the front cover is the Paso Robles Wastewater Treatment works from the AMS case study this month about
using online THM Monitoring to optimise operational strategy
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.
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

It is at this time of year that everyone starts to relax, look forward to the festive season and also start to look back at
what a year it has been. Others are sharpening their pencils to start on the articles that are going to invariably produced
in January to explain what we found out last year and what we are going to find out next. When I look back at last year
what am I going to say?
Well it was an interesting year and I think that the industry is starting to wake up to the use of data and its conversion
to information and that the industry is not all about collecting data for the sake of collecting it but it is also about using
that data to give some sort of operational benefit. So what’s changed have we suddenly had a light bulb moment or is it
something that we have always thought that we ought to do but the instruments aren’t good enough, the data isn’t right
or its just too difficult. Maybe its a bit of all three and maybe we are starting to overcome the “resistance to the effective
use of instrumentation,” a concept that was one of the first subjects that we floated on the Water Industry Process
Automation & Control Group over five years ago.
Certainly I can say that the industry is starting to wake up, I see it in my “day job” that the resistance certainly existed, a common phrase has always been “we
can’t rely on that data,” and it has been through the application of rigour and the application of the basics and working with some incredibly intelligent and
also diligent people and turning the handle a few times that the quality raises and the information becomes useful as people start to rely on it, treat as correct
and the barriers to the resistance fall down.
Perhaps also it is a case of technology developing as well. It is evident that we, as a world are starting to connect ourselves together. It has happened with
mobile phones which now become our portable office. This year we have been treated to Virtual Reality headsets, 3600 video cameras and all in the world of
entertainment. However we have also seen the continuation of the connected home and it is one step from being able to see the inside of your fridge from
your phone and the same fridge act as personal organiser for you and your family to the next where your in home personal electronic assistant being unable to
read your water meter and allow you to pay the bill by the push of a button or the swipe of your finger over your mobile phone fingerprint scanner. What I’m
saying is that the connected home is becoming a reality very very fast and it is something that people will start to get used to. The Water Industry, as with any
service industry is centred around the technical parts of the job but also around customer service. If the customer wants to interact with the water company
by the refrigerator electronic panel (cyber security aside) or via their mobile phone there this is a direction that we must head towards if we are to work with
our customers. It is something, in short, that they will demand. It is more than likely that it will be the customer demanding that the Water Industry take the
leap into the great “Smart” unknown if we are not careful and if we are not prepared to take this leap then we may well stumble.
So as an industry what do we have to do?
First is to go back to basics, ensure that we apply the rigour in the instrumentation that we install. In the article in this edition that I have written I talk about
the fundamentals of flow (in fact it applies to all instrumentation). Its a concept that many readers will be familiar with, asking the question what an instru-
ment is for, selecting the right technology, installing it in the right way and looking after it. In short treating it with respect and valuing it. If we don’t do this
then the “Smart Water Industry” will fail. From this step its working out what we want, the stakeholder engagement, what information do we need. Lastly
its bringing it all together and managing what we do. As I have said in the past its putting enough information in front of the right people (or controllers) to
influence the decision making. Knowing when something is going to happen, in advance and in sufficient time to manage the process in an informed way. It’s
what is already happening, or starting to happen in our homes and that expectation that it happens in our workplaces is only going to grow.
Have a good month and a wonderful New Year
Oliver

New EU interactive mapping tool shows changes in the Earth’s
surface water
SW Water plans field-scale drone trials for leak detection in 2017
South West Water is working with the University of Exeter to test the use of drone technology and thermal imaging for leak detection. Laboratory tests of the
thermal cameras have proved positive and field-scale trials are planned for 2017.
The technology works by attaching a thermal sensor to a drone which would then be flown along pipeline routes particularly in rural locations. The thermal
sensor can detect differences in soil temperature which could be caused by an escape of water.
With 18,000kms of pipe, much of it in rural and remote areas, and more than a million service connections to customers the technology could help reduce the
cost of leak detection and repair by pinpointing more exactly the location of a leak, particularly in rural locations where traditional methods are less effective.
South West Water is one of the leading companies for tackling leakage, with performance twice as good as the UK water industry average for water lost per
kilometre of main. Leakage has reduced by 40% since the early 1990s and nowadays most visible leaks are repaired with 72 hours.
Bob Taylor, Director of Drinking Water Services, commented:
“Water is part of our region’s natural capital. It is a precious resource and, especially once it’s been treated, we all need to use it wisely and not waste it. Finding
a cost-effective method of finding large escapes of treated water has the potential to help save water and make our service more efficient, which is why we’re
continuing this trial with the university to test the technology on a landscape scale.”
WRc Assess & Address® Awarded Dŵr Cymru Framework
Contract
WRc’s Assess and Address have announced they have been awarded the framework for Dŵr Cymru Welsh Water’s Water Main Inspection & Survey Services.
A dedicated team at Welsh Water established more than 400 trunk discreet metered areas (TDMA’s) covering over 5000 km of network. Detailed analysis
of both balance results and asset performance resulted in a need for a program of further field work to determine the origin of the unaccounted for loss;
leakage, unallocated demand, illegal use etc. WRc has supported Welsh Water since January 2016 by assessing Unaccounted For Water (UFW) on this upstream
network by creating water balances for each TDMA and SR operated by Welsh Water. This included detailed analysis of network meter uncertainties using
WRc’s databank of meter testing research and expert knowledge. Their team of technical specialists also produced detailed recommendations for
immediate interventions to help Welsh Water reduce leakage.
To aid this investigation Welsh Water had a requirement to undertake water main inspection and survey activities and, after a rigorous procurement process,
a Supply of Services Agreement has been awarded to WRc Assess and Address® which will be supported by supply partner API.
Keith Walker, Head of Commercial Enterprise at WRc comments
“Our first survey carried out under this framework located 2 Ml/d on a trunk main which was highlighted by our earlier desktop analysis of UFW as a good
candidate for leak location - a great success for both analysis and field teams! We look forward to continuing to assist Welsh Water with prioritising and
completing their Water Main Inspection and Survey activities.”
The European Commission has co-produced a new interactive mapping tool consisting of 3 million satellite images collected over the past 32 years which
highlight changes in the Earth’s surface water. Developed by the Commission’s Joint Research Centre and Google Earth Engine, the Global Surface Water
Explorer is a new online interactive mapping tool that will be accessible to everyone and serve to improve European and global policies for example on
climate change and water management. The maps show that, although the overall amount of surface water has increased globally, important losses have
occurred in specific regions of Asia. The maps reveal that many of the changes are linked to human activities such as the construction of dams, river
diversion and unregulated water use. Other changes can be attributed to climate change impacts, including droughts and accelerated snow and glacier melt
caused by higher temperatures and increased rainfall.
Tibor Navracsics, Commissioner for Education, Culture, Youth and Sport, responsible for the Joint Research Centre, said:
“This new tool is a goldmine. Large amounts of data is generated every second by satellites. However, turning data into knowledge has long been a challenge.
This initiative of the Joint Research Centre and Google Earth Engine has enabled satellite data to be translated into a user-friendly tool that is both accessible
to citizens and will help policy makers across the EU and the world take informed decisions.”
The information contained in the maps will help policy makers better design and monitor measures to prevent and mitigate the amount of flooding,
water scarcity and droughts that has been increasing in some parts of the EU. The data can also be used as part of the EU’s contribution to multilateral
environmental agreements, such as the United Nations Framework Convention on Climate Change, or help reach the Sustainable Development Goals.
Click here to access the Global Surface Water Explorer
Page 4
Industry News

New DNA based method set to revolutionise monitoring fish in
lakes
A new DNA method that could revolutionise the way fish are monitored in lakes has been shown to detect 14 of 16 key fish species known to be present in
Lake Windermere, compared to just four species found by conventional surveys.
Fish are sensitive indicators of water quality and their assessment is an important part of water management. In England, Wales and Scotland regular lake fish
monitoring is not feasible with existing tools and resources. Netting can capture all the fish in an area, but it is costly and can injure or kill fish.
The research project tested a new approach to assess both the type and numbers of fish present in three large lakes in Cumbria (Windermere, Bassenthwaite
and Derwent Water)
The approach uses environmental DNA (eDNA) - the DNA that fish leave behind in the water from their skin, urine or faeces. The eDNA can be used to provide
information on fish living in the lake. New technology allows all the DNA in a water sample to be sequenced and identified. According to the Environment
Agency, the multi species identification method is rapid and sensitive and has real potential to change the way it carries out ecological assessments.
The work is part of a wider programme of research by UK agencies to develop DNA based methods for environmental monitoring and decision making.
Using eDNA is relatively new, and so far much of the research has focused on developing methods to assess the presence or absence of single species.
The next step will be to demonstrate that the findings can be repeated at different times of the year and that the method has wider applicability to a greater
range of water bodies, such as those with varied chemical and physical properties.
The next step will be lead by the Scottish Environment Protection Agency (SEPA) and will include the assessment of Scottish lochs which are more nutrient
poor and where fish (and eDNA) are likely to be found in much lower numbers as well as repeated assessment of Lake Windermere.
Bespoke pH adjustment system used at Midlands reservoir
A bespoke pH adjustment system has been used to treat 46 megalitres of alkaline water created by a large-scale upgrade project at a Midlands reservoir.
Severn Trent Water’s Ambergate Reservoir serves customers throughout the East Midlands, but with much of its infrastructure dating back over 100 years it
is approaching the end of its design life. As a result, a major four-year upgrade is currently underway.
Part of the upgrade work entailed filling chambers in the newly constructed reservoir with highly alkaline (pH11) lime water to induce crystal formation within
the fine cracks that occurred during the curing of the concrete structure.
The Laing O’Rourke/ NMC joint venture team working on the project approached process solutions experts Siltbuster to create a system capable of treating
the extremely large volume of water used.
The bespoke containerised pH adjustment system created by the company was used to treat 46 mega litres (46,000 m3) of alkaline water at rates of up to
750m3 per hour and cleaned to the highest standards, enabling it to be discharged into a nearby surface watercourse.
With limited space on site and tankering of the water off-site not an option, Siltbuster created a bespoke system designed to take a side stream of the 400m3
per hour water and saturate it with CO2 to neutralise the pH. Under pressure, the fully saturated water was injected back into the mainstream of water
allowing the full 400m3
per hour to be neutralised before being discharged. The system was recorded as treating circa 740m3 per hour of the high pH waters,
which significantly reduced overall dewatering time.
Tristan Hughes, Siltbuster’s Regional Sales Engineer, said: “Creating bespoke systems to address specific issues is a core part of what we deliver for our
customers. This project involved the treatment of extreme flow rates so we had to build a system able to cope efficiently and effectively with a very high
volume of water. We successfully achieved that while also delivering environmental and commercial benefits.”
Page 5

Southern Water adopts cloud-based IT system for sewer
monitoring data
Southern Water has adopted a new system for storing its pipeline condition survey data on the cloud, where it can be easily accessed by engineers and
contractors. The utility is now using the WinCan Web system recently launched by CCTV reporting software provider WinCan.
Southern Water has for some years utilised an alternative document management system for the compilation and storage of its pipeline survey data. With
survey data being provided largely on DVD, the method of electronic storage meant that should engineers wish to view a survey, first the data file had to be
retrieved and then the whole video had to be watched to find the location of interest as the system could not utilise effectively location selection.
In order to make the evaluation and use of the recorded data more effective Southern Water looked for a new system that could offer the accessibility needed
by its engineering team from one central storage source. It chose the WinCan Web system, which is compatible with the WinCan VX survey reporting software
which is currently being used by all of Southern Water’s survey contractors.
Southern Water’s pipeline inspection works are undertaken by the company’s Tier 1 contractor, Cappagh Browne, which will engage with approved contractors
on their behalf.
Once a survey is completed, using WinCan VX and WinCan Web the report can be uploaded to the central storage facility immediately. This facility means that
if a survey is of particular importance or urgency it can be viewed by the engineering team within minutes of the survey being completed or if the survey is part
of an ongoing routine programme the report can be uploaded at a later time. The system also allows the updating and continuation of survey reports that may
be being either revisited or simply extended from a survey started at an earlier date.
The process has been designed to be easy so as to minimise the time required for the transfer of the data. This not only means that more time on site can be
dedicated to the survey itself but also reduces the ‘off-survey’ time required to handle the data process. The data is securely held and backed up, while the
absence of any need for physical delivery of the project information means that the turnaround of the survey results from site to report delivery is much quicker.
Leigh-Ann Butler, Sewer Rehabilitation Engineer with Southern Water, said: “The implementation of the WinCan Web system within Southern Water has made
accessing and analysing survey data far more user-friendly. Any of our 50+ engineering team can now access reports as and when required and search the data
for the information they need from videos or pictures as part of their ongoing operations.”
Paul Purton, Surveying & Technical Manager for Cappagh Brown, added: “Working with our approved external contractors, the utilisation of the WinCan VX
reporting software alongside the new WinCan Web remote storage facility means that all CCTV reporting is achieved to the same recognised standard whilst
being made available to our client as and when they need it, whether that is immediately or not. This minimises the off-site time that needs to be allowed for
when planning surveys making the job much more efficient and cost effective for both us as the contractor and for Southern Water.”
WinCan’s Paul Woodhouse concluded: “We are very pleased to have been able to work with the Southern Water team to develop a system that will enable
them to manage, plan and implement their pipeline network operations based on current and easily accessible data. This type of situation is precisely the sort
of operation that WinCan Web has been designed to handle quickly and effectively. We will of course continue to be available to offer any support that is
necessary to Southern Water’s engineering team as the new WinCan system develops further.”
Google And University Of Michigan Team Up To Help Flint With
New App
Residents of Flint, MI, continue to have concerns about their water system. Even when officials have stated the water is somewhat safe to drink with use of
filtration systems, residents remain sceptical. In an effort to help, the University of Michigan and Google have partnered to create an app that will assist Flint
residents with the water crisis.
The Associated Press reported, in a story published by ABC News, that the app, known as “Mywater-Flint,” was developed by computer science researchers at
the university’s Flint and Ann Arbor campuses with Google’s technical and financial support. The app tools are designed “to provide information about lead-
testing results, water testing, where pipes have been replaced and the location of distribution centres for water and filters.” Developers of the app have said that
they can also “predict” which homes are more likely to have higher lead levels based on their age, location, value, and size.
According to Tech Times, computer scientists at UM’s Flint and Ann Arbor campuses worked with Google in order to provide people in affected areas with
information on how the Flint water crisis is being dealt with. Google gave the researchers a $150,000 grant to assist in funding the project.
“We’ve developed an essential resource,” UM computer science assistant professor Jake Abernethy told UM-Flint News. “It’s an independent platform that gives
people information they need and want to know as they navigate this complex situation.”
Those who use Mywater-Flint will be able to log in to find out about testing of newly placed water pipes, in addition to where water distribution centres and
filters are located in their community.
The research team also hopes “that the new app can help promote transparency and trust among the people of Flint devastated by the crisis.”
Recently, lawmakers on Capitol Hill passed a bill that seeks to provide emergency aid for Flint.
The Water Resources Development Act (WRDA) and a continuing resolution will “provide $100 million for lead removal projects in Flint through the Drinking
Water State Revolving Fund and another $20 million to EPA to begin issuing loans under the Water Infrastructure Finance and Innovation Act (WIFIA) program,”
according to the Association of Metropolitan Water Agencies.
Page 6

Ofwat concerned about Yorkshire and Southern’s data quality
Nomenca retains and expands MEICA framework with EA
Nomenca, part of NM Group, has retained its MEICA framework with the Environment Agency (EA) in the South-west region and expanded its current
operational area.
The two-year programme forms part of Nomenca’s service and maintenance portfolio, and will see it deliver planned preventative maintenance, project works
and a 24-hour, 365-day reactive maintenance service to EA assets. These include: pump stations; flood gates; sluice gates; buildings and penstocks.
For the past decade, Nomenca has provided MEICA services to the EA in the north Wessex region, which is a combined area of Somerset, Avon and the
northern section of west Wiltshire. Not only has it retained this area but has also been successful in being awarded the south Wessex region for the first time,
which covers Dorset and south Wiltshire.
Ben Wilson, Nomenca’s framework manager, said: “The EA is a key client for us having worked together for such a long period. Our operational teams have been
involved in both emergency, non-MEICA related incidents, particularly in flood situations. We are obviously delighted to have retained this framework and are
relishing the prospect of delivering across the south Wessex area.”
Ofwat has raised concerns about the quality of data provided by Yorkshire Water and Southern Water in monitoring performance.
In its annual assessment of water companies’ information quality, Ofwat said the two companies “did not provide sufficient confidence and assurance” about
their ability to deliver, monitor and report performance. This led to a “reduction in trust and confidence”, it said.
The regulator has demoted the two companies to the ‘prescribed’ category of its company monitoring framework. Meanwhile, South East Water, Severn Trent
Water and United Utilities all moved up to the ‘self-assurance’ category. These companies met expectations in most, if not all, of Ofwat’s assessments.
South West Water and Affinity Water moved down to the ‘targeted’ category. They did not consistently meet the high standards expected for companies in the
‘self-assurance’ category, which led to a reduction in the trust and confidence stakeholders can have in their information.
Ofwat senior director Keith Mason said: “We expect companies to be transparent and have processes in place to ensure their information can be trusted. The
ratings we have published today enable customers to compare their water company with others, which is important to help drive improvement.
“We assess large water companies each year on the quality of their information. The top performers will have less involvement from us. Where we’re
concerned by the quality of this information, we will intervene to make sure they improve.”
A spokeswoman for Southern Water said although the company was “disappointed” with Ofwat’s decision, it will use the ratings assessment to “drive further
improvements” and ensure it is providing information in an “open and transparent manner which benefits our customers and stakeholders”. “We look forward
to working with Ofwat in making these improvements,” she said.
Ofwat said it would take account of the quality of companies’ information in its next regulatory review – PR19 – which concludes in 2019. PR19 will review
monopoly companies’ revenues and pricing policies beyond 2020. Companies that wish to secure ‘enhanced’ status, and benefit from a streamlined process,
must “demonstrate high quality information and assurance”.
All ‘targeted’ and ‘prescribed’ companies now have the opportunity to improve their status before this process begins.
Driving Your Digital Roadmap To The Future
It’s the same old story: Water and wastewater utility leaders are presented with incredible challenges. Aged and crumbling infrastructures, along with
heightened regulations, are creating capital needs that far exceed available revenues, and mounting utility rates are generating fatigue and frustration in
ratepayers. Leaders are caught in a constant balance between the need to address existing issues and the responsibility for planning for the future. Terms such
as “smart infrastructure” and “data management” are floating around like solids in a clarifier.
The mortgage and the dream vacation aside, how does a modern utility manager resist the urge to walk — no, run — away from it all? The answer may be
simpler than you realize.
“I am in the business of legacy building,” states KC Water’s chief engineering officer, Andy Shively. “We are the stewards of the people and gatekeepers for
tomorrow’s generation. People are our most precious resource.”
Leaders are caught in a constant balance between the need to address existing issues and the responsibility for planning for the future.
Shively’s approach has been referred to as the “people paradigm shift” — and it’s the catalyst that drives the application of massive amounts of data in Kansas
City, MO. KC Water has collected more than 30 terabytes of data, and the department is adding over 200 additional gigabytes each month.
Data Management
With this quantity of records, it is not a surprise that many utility directors across the nation are now including the management of data as part of the capital
improvements planning process. Technology companies, such as Microsoft and Esri, are rising to meet this need by providing suites of application products or
“apps” specifically designed to help water and wastewater utilities collect, analyse, and share data. Industry organizations such as the National Association of
Clean Water Agencies (NACWA) and the National Association of Sewer Services (NASSCO) have also responded to this trend by releasing standards by which
that data should be collected, formatted, and coded.
continued overleaf
Page 7

“The water and wastewater industry is experiencing an incredible shift in the use of information and maps,” states Mark Robbins of Esri’s Global Water Practice.
“Four years ago, utilities were primarily focused on mapping their assets and tracking some information on leaks and breaks. Now, utilities are collecting and
analysing even more information as they respond to ratepayer pressure for greater transparency in proving the value of their work.”
Data management may be a hot, new topic, but Shively believes that data management is not a new practice. “Simply put, data is information. Our forefathers
used information, or what we now call data, to make important decisions about our nation’s infrastructure.”
Shively further states that the smart use of data has a multigenerational effect. Like a time capsule, our nation’s aging water and sewer lines contain a deep history
of information laid by the stewards who managed the infrastructure generations before. This data is the key to unlocking answers to today’s increasing number
of challenges.
The People Principle
This brings us back to what Shively says is our most important resource: people.
“Data alone is a useless collection of zeros and ones. Our infrastructure is literally a digital road map to the future, but we need drivers to find solutions,” states
Shively. ”To function, data requires the element of people — those who are willing to apply critical thinking to our collective history of infrastructure and connect
data with real solutions that impact future generations.”
Kansas City is on a mission to become the most connected Smart City in the world, and Shively serves as part of the city’s Smart City Advisory Board, representing
the caretakers who are helping to build the smartest city on the planet — from the ground up.
Working The Numbers
In Kansas City, Shively and his team examine all possible impacts to determine the reasons for systems failures and to make smart decisions about future
investments. The first step for the team is to collect information, or data, about all aspects of the city’s water, wastewater, and stormwater system. This data
includes the pipes’ dates of installation, diameters, and break histories. Shively’s team then adds people to the equation by rating the consequences of failure
each pipe segment will have for the residents of the city. Through this approach, Shively has helped find multiple solutions that have proven to increase service
reliability, reduce expenditures, and create smart plans to address the city’s specific infrastructure needs.
By analysing more than a century of data, Shively discovered that certain water main segments carried higher likelihoods of failure — those segments included
pipe 6” and smaller, pipe installed from the 1940s through the 1960s, and segments with histories of multiple failures. This data was used to strategically and
proactively replace the city’s most critical and break-prone water mains. This 100-year plan has already reduced water main breaks from 1,839 in 2011 to only
746 in 2015.
The city’s private inflow and infiltration program, considered to be among the largest in the nation, also makes smart use of system data and feedback from
residents. The program, called Keep Out the Rain, was developed using a combination of data collected through smoke testing, dyed-water testing, and closed-
circuit television (CCTV) work. The data pointed Shively’s team to the areas of the city most impacted by inflow and infiltration issues. Keep Out the Rain teams are
now targeting those areas to perform free sewer connection evaluations and provide free plumbing repairs that will reduce the amount of stormwater entering
the system. Data helps customers find out if they are within the work areas simply by entering their addresses online. On-site evaluation teams are able to access
data in real time to immediately calculate whether or not repairs are cost-effective for the city; and outreach teams use real-time data entry from the evaluators
to catalogue customer feedback and adjust communication efforts, which encourage participation in the program.
In 2012, Shively worked closely with the city’s information technology team and with Esri developers to create a solution to the city’s annual hydrant
inspection process. The team customized an “off-the-shelf” Esri application to eliminate a paper process that was resulting in delayed repairs to hydrants.
Inspection teams can now locate hydrants using a GIS and instantly upload inspection reports and pictures of hydrant defects. Work orders to repair damaged
hydrants are automatically generated. This process has dropped the percentage of out-of-service hydrants from 4 percent in 2011 to a consistent less than 1
percent out-of-service number since 2013.
In 2016 Shively and his team completed a 100-year plan for strategic sewer main rehabilitation based on information provided through CCTV video data, NASSCO
coding, and pipe maintenance history. The team is also launching a data-driven water main repair application which helps inspectors triage break situations in the
field and quickly and accurately locate the correct valves to shut.
In Kansas City, data is a key element in providing responsive and reliable service to customers, and it supports the framework for the city’s 100-year water and
sewer infrastructure investment plans. Still, the equation is not complete without industry leaders, such as Shively, to find and implement solutions that will have
multigenerational effects.
“Everyone has been to the school of hard knocks, but unfortunately there is no alumni association,” remarks Shively. “We each have a responsibility to share
successes and learn from failures so that we can all build a legacy for the next generation.”
Building A Better Future
This year, Shively initiated a national challenge to city leaders and utility contractors encouraging them to be proactive in finding the strategic and data-driven
solutions necessary to relieve future generations of the crisis of infrastructure funding gaps that cities face today. Kansas City’s billion-dollar smart infrastructure
challenge includes the use of data management to find and implement these solutions.
More information about Kansas City’s smart city approach can be found at kcmo.gov.
continued
Page 8

One City, One Plan, One Water: How Los Angeles Is Transforming
Water Management
Carollo Engineers unveils an ambitious plan to turn one of America’s most water-stressed cities into a model of sustainability and resiliency. Los Angeles rambles
across nearly 500 square miles of coastal basin in Southern California, brandishing vast beaches, wooded hills, and some of the largest companies and industries
in the nation. With a population topping 4 million, a reliable water supply is one of the keys to keeping the city growing and vibrant.
Yet California is now in its fifth year of a persistent and unforgiving drought, straining the city’s ability to effectively manage its various water supplies and sources
to meet customer demands. On Oct. 14, 2014, Los Angeles Mayor Eric Garcetti issued Executive Directive Number 5 in response to the lack of rainfall and ongoing
drought. From this directive was born the city’s “One Water LA 2040 Plan,” which is an integrated approach for combining water supply augmentation, wastewater
treatment, and stormwater runoff capture and management into a $10- to $20-billion capital improvement program. The capital improvements will be part of
the city’s ongoing efforts to expand local water supplies by more than 200,000 acre feet per year through recycled water, groundwater recharge, and stormwater
(both dry and wet weather) capture and use.
Ultimately, the city hopes to be able to use the river not only as an ecological asset, but as a way to store water for either groundwater replenishment or an
alternative to potable water for irrigation.
Once complete, this collaborative plan will both chart the course for managing the city’s future water needs for the next 25 years and answer Mayor Garcetti’s call
to make the city’s water supply more resistant to the effects of drought and climate change.
A Model Plan
Carollo Engineers is partnering with the city of Los Angeles in developing and implementing the One Water LA Plan — an effort that is forging new collaborative
relationships across the city and driving the development of new tools and technologies to meet the city’s project goals.
The actual One Water LA Plan began with a comprehensive, integrated water model that linked multiple water types and sources to create a water balance tool.
This involved an innovative adaptation of Carollo’s Blue Plan-it™ model, which was configured to account for all of the city’s key water supply sources, including a
dozen sewer sheds, four wastewater treatment plants, and hundreds of miles of storm drains and channels.
Once the Blue Plan-it modelling framework was in place, Carollo was able to help the city develop and evaluate multiple water supply scenarios against a series
of specific criteria, including resiliency to climate change, distributed versus centralized infrastructure, and cost. In addition, the city was able to explore a number
of sensitive scenarios to determine the overall robustness of potential solutions to various kinds of uncertainty. The results of these efforts will become detailed
facility plans for the production and maximization of recycled water to augment local water supplies, the capture and infiltration of more than 100,000 acre feet
per year of runoff to augment groundwater supplies, and the capture and targeted reuse of 85 percent of the stormwater traditionally lost to the ocean. Each of
these plans will include triggers that establish clear guidelines for when the city proceeds with subsequent phases of facility construction.
“We reached some interesting conclusions during our modelling efforts,” notes Gil Crozes, Carollo’s One Water LA project director. “We determined that while
some of the water management solutions could come from adapting current treatment and monitoring technologies, some of the things the city wants to do in
the future will require new and innovative technologies developed by the water industry itself.”
One example of the need for new technologies is found in the city’s oldest waterway, the Los Angeles River. From the earliest days of Los Angeles, the LA River was
a key water source for the pueblo and early city residents. However, a series of severe floods in the early 20th century resulted in several flood control measures
that transformed the once untamed river into a series of concrete channels.
With growing interest in the LA River as both a water source and recreational area, Carollo is leading the Los Angeles River Flow Study as part of the One Water
LA Plan. The study’s objective is to develop a consistent understanding of existing and future flows into the LA River and the water needs to meet the restoration
objectives being completed by the U.S. Army Corps of Engineers. This will require new methods to monitor and evaluate the river’s hydrological conditions and
sensitive habitats, as well as new ways to maintain existing ecosystems. Ultimately, the city hopes to be able to use the river not only as an ecological asset, but
as a way to store water for either groundwater replenishment or an alternative to potable water for irrigation.
Communication As A Key To Success
Naturally, with any large-scale effort involving multiple departments, regulatory agencies, and a host of stakeholders across the city, communication and outreach
is critical to project success. To effectively manage stakeholder participation, the city used a three-level framework (Inform — Involve — Collaborate) to better
articulate where stakeholder input was going to be most sought. In addition, the city used four different groups to provide input: one-on-one meetings, an
advisory group, special topic groups, and the general stakeholder group. Using this layered approach, the city has been able to more quickly and more
effectively get the input needed. With Carollo’s support, the One Water LA program has held stakeholder outreach meetings and town hall events for more than
80 neighborhood councils, 15 council districts, and more than a dozen local, state, and federal agencies.
The results from the city of Los Angeles’ One Water LA will be some of the most collaborative and forward-thinking water management planning in the country.
One Water LA is demonstrating the ability of a major metropolitan city to come together, cooperate both internally and externally, and make the significant capital
planning decisions needed to secure a reliable and sustainable water supply for both new residents and future generations. For Los Angeles, the overall result will
be greater public and business confidence which, in turn, will help with raising the funding necessary to implement the One Water LA program. While the lessons
learned in Los Angeles will translate to similar cities across the country, until that happens, the One Water LA Plan will set the standard for integrated approaches
to water management across a vast range of residential, commercial, and environmental demands.
Page 9

Article:
ORP Sensors – Are They
Really The Best Thing
“Since Sliced Bread”?
There have been many publications lately that claim universal appeal of the ORP sensors and their applicability across the board. This concerns me, because
the authors sometimes forget to mention some well-known practical limitations of the method, let alone the realities of water treatment applications
potentially influencing the sensor performance. This is why I’d like to set the record straight and provide a balanced account of what the ORP method and
sensors are good for and where may be not be appropriate. I am doing this only because the misunderstanding of this method may cause confusion among
the engineering companies specifying analytical equipment for water utilities and this, in turn, causes potential misapplication of this technology and
failed end-user expectations.
The ORP method that stands for Oxidation-Reduction Potential bears in its name the implication that it is applicable only for monitoring the chemical reactions
with not just exchange of electrons, but accompanied with change in oxidation degree of some ions, molecules, or atoms in such processes (redox reactions).
Therefore, such chemical reactions are accompanied by change in redox potential of the solution and this is what ORP sensors detect – change in the potential,
not concentration of specific molecules, atoms, or ions. Can this change be correlated to the shift in concentration of the species of interest? Of course; however,
we must always be cognizant of the cost of such correlation and the factors affecting its accuracy.
It is a given and well-known fact that accuracy of the ORP method and sensors built upon it is dependent on such common factors as temperature and pH of the
solution to name just a few. If the temperature influence may be compensated relatively easily, the pH provides a noticeable interference and must be either
controlled or its swings must be compensated by multiple sensors and some mathematical algorithm. The algorithm may be as simple or as complex as the
matrix where the measurement takes place, because the pH may influence the oxidants and reducers in a different manner. Let’s add another known
interference to the ORP measurement – activity of the ions in the solution, which is correlated with total dissolved solids (TDS) and may be called the matrix
effect. However, this interference may depend on the nature of such solids and therefore such influence may be quantitatively different based upon the water
sample composition.
Thus, we can conclude that the best use of the ORP technology is in stable water matrices where major interferences are under control. The best example of
such matrix is cooling water that is prepared with corrosion control in mind and therefore has most of the constituents under tight control. Therefore, it makes
sense that in cooling water one can correlate ORP of the water with concentration of the oxidizing disinfectant with acceptable degree of accuracy. There are
other examples of such stable samples and they may be combined under the umbrella of industrial water applications – the applications when the matrix is
tightly controlled to achieve specific goals and the only variable is the redox reaction.
When the water sample is not as tightly controlled, there is another way to efficiently correlate concentrations of added oxidizer or reducer to the matrix – by
applying ORP in a differential manner, before and after addition of the target analyte. However, in some situations there are better alternatives as was imple-
mented in a successful application of differential conductivity measurement for CIP (clean-in-place) processes, when the ORP was evaluated and dismissed.1
The most important lesson here is to understand the difference between the industrial applications where the water matrix can and, sometimes, must be
controlled and municipal applications (DW and WW) where such control is not easily achievable and may be impossible. Therefore, blindly recommending ORP
sensors for the latter applications seems at least irresponsible.
There is another aspect diminishing the value of ORP sensors in all applications across the board that is frequently overlooked – the sensor maintenance
requirements. It is well known that all electrochemical sensors require calibration, because the core technology is based upon consumption of the electrode
material, etc.
However, speaking specifically of the ORP sensors, not everyone knows that
their response to increase and decrease of the oxidant is uneven, especially
when the matrix influence is significant. The figure below shows results of a
test conducted at a WWTP where the response to dechlorinating agent feed
was recorded:
As can be seen from the graphs, there is an advantage in speed of response
to increase of the oxidant (chlorine) vs. a regular colorimetric method (Hach
CL17); however, there is a very sluggish response of the ORP sensor to
decrease of chlorine concentration, while the CL17 responded immediately.
This and other factors may greatly reduce accuracy of the ORP correlation to
the concentration of target analyte and may require a specific instrumentation
setup, additional calibrations, and mathematical algorithms to provide
ongoing verification of the sensor performance, as described in this
publication.2
The advantages potentially provided by the ORP sensors may be easily
offset by the sensor fouling, which is not uncommon in WW and raw water (DW
intake) applications where implementation of this technology is frequently
recommended by some E&C companies and sensor manufacturers. There are
published evidences that fouling of the ORP sensor may completely erase all
advantages in cost and “ease-of-use” and therefore other methods to control
raw water pre-oxidation may be recommended.3
Page 10

To conclude, I would like to reiterate a few main thoughts about implementation of the ORP technology and associated sensors:
• Know your water and avoid ORP technology if the matrix is unstable;
• In order to provide meaningful correlation of ORP with concentration of target analyte, all interfering factors, e.g. pH, temperature, TDS, etc. must be
tightly controlled or truly compensated;
• In order to achieve expected performance, ORP technology may need to be implemented in a differential mode, before and after addition of the oxidant/
reducer;
• Be aware of maintenance requirements to ensure ORP sensor performance;
• Be aware of sluggish response of the ORP to decrease of oxidant concentration in the sample;
• Based on all the above, scrutinize the suggested use of the ORP technology to understand the advantages and deficiencies, especially if the application is
in the municipal water treatment.
1. “Inductive Conductivity for Control of CIP Processes” - Vadim B. Malkov, Jeff Tocio – Proceedings of 53th ISA Analytical Division Symposium (April 20-23, 2008), Calgary,
Canada, AD2008.S12
2. Vadim B. Malkov, David L. Rick “Oxidation/Reduction Measurement” - US Patent, Pub. No.: US 2012/0298529 A1, Nov. 29, 2012
3. Vadim Malkov and Mike Sadar, “Control of Iron and Manganese Ozone Removal by Differential Turbidity Measurements” – Ozone: Science & Engineering, 2010, Vol.32,
Issue 4, p. 286-291
Drones: How They Can Change Your Water Operations
An eye in the sky offers a new dataset for treatment plant and pipeline infrastructure planning
and decision making.
As water and wastewater operations continue to upgrade, expand, and improve maintenance
procedures, the new kid on the technology block can help.
Drones, also known as unmanned aircraft systems, are usually outfitted with camera systems
that can be used for aerial photogrammetry. Photogrammetry is a form of photography that
ties to preset data points on the ground. The visuals taken by a drone then align with the data
points, enabling creation of 3D images and interactive models.
How can this help a waterline system
operator, water or wastewater treatment plant, or pipeline installer?
The information collected from a drone can be used to create a comprehensive set of plans detailing a
facility or underground utility system — if the utilities are in trenches and viewable from above. Over time,
most water operations go through multiple stages of additions, add pipelines, or establish new phases
of operations. Site information is contained in separate documents in multiple places, and perhaps only
one or two of your staff who have worked with you for years know all of the ins and outs of your facility.
A drone can collect thousands of photographs of existing facilities and utilities being installed or updated,
and skilled surveyors and data managers can combine those images into an interactive, visual map for
use in all future planning needs. Your information is then easily accessible, contained in one place, and as
thorough as possible. The map includes precise measurements. The photos and information collected can
also be turned into an Orthoprint or 3D model for engineers to use in helping design upgrades to facilities
or operations.
Drones can also be used for inspections during the
construction process. Rather than budgeting dollars for an
inspector to walk the pipeline every few days, a drone can fly
over regularly, taking photos to inspect construction progress
and integrity. If an issue is found and needs to be reported,
high-definition photos taken by the drone can be included in the
report. In some cases, when there are disagreements between
a project owner and a contractor, a drone can collect real-time
information to review and pinpoint material amounts or other
discrepancies.
If you’re interested in collecting your facility or infrastructure information via drone, look for an experienced surveying
firm to complete the work. RETTEW was granted an exemption by the Federal Aviation Administration to use a drone
for commercial purposes, which is an important factor in selecting a surveying company. The firm is also insured for
drone operations. Surveyors that are well-trained in aerial photogrammetry skills know how to place control points in
the right places and can quantify and qualify the data collected. Expert surveyors also use national mapping standards,
ensuring a final product trusted by water and wastewater operators.
Using a drone for data collection can help you with projects ranging from updating processes to designing additions, as
well as building changes, maintenance, and demolition. The specific plans and measurements detailed with an easy-
to-use visual software can make your life easier as your operations continue to evolve.
Page 11

Case Study:
The use of Online Monitoring
to Detect Low-Level of THMs
in Treated Wastewater
Summary
The City of Paso Robles, California used an online water quality instrument
to characterize and monitor low-levels of bromodichloromethane (BDCM) and
dibromochloromethane (DBCM) in their treated wastewater for ground water recharge
(GWR) use. The high frequency of reliable and accurate trihalomethane (THM) data
provided by the online instrument proved essential to the City’s disinfection by-product
(DBP) strategy to obtain regulatory compliance with NPDES permit levels.
Introduction
The City of Paso Robles operates a 4.9 mgd activated sludge wastewater treatment plant
(WWTP) to meet the needs of 36,000 plus residents and a number of local vineyards
and wineries. Treated wastewater from the facility is used for GWR to replenish the Paso
Robes water basin and Salinas River. The facility faces stringent NPDES permit restrictions
on effluent levels of total nitrogen (TN), microbiology and THMs.
Prior to 2015 the Paso Robles WWTP encountered routine TN and toxicity violations.
The trickling filter plant and use of effluent settling ponds provided minimal nitrogen
removal treatment, while large levels of effluent ammonia reacting with the disinfectant
chlorine (indirect chloramination) assured THM compliance. The State Water Board
instructed the city to remediate TN and toxicity violations with a plant upgrade that
would better address nitrogen removal treatment to meet the TN 10 mg/L maximum
requirement.
BNR Upgrade Leads to Increased THM Formation
As a result of the recommendation from the State Water Board the Paso Robles WWTP underwent a $47 million dollar upgrade to a biological nutrient removal
(BNR) process in 2015 in efforts to achieve compliance. The upgrade helped the facility reduce TN by using bacteria to convert ammonia in the treated effluent
into nitrogen gas, which is lost, and other nitrogen species. However, an unexpected consequence of the upgrade was an increase in THM formation (Figure 1).
By effectively reducing ammonia levels, the chlorine disinfectant injected prior to effluent discharge reacted with the residual organic matter leading to
elevated THM levels. Whereas Total THM (TTHM) levels were below practical quantitation limits (PQL) prior to the installation of the BNR process, following the
upgrade levels averaged approximately 60 ppb. The facility faced quarterly fines up to $12,000 as a result of the THM violations.
Figure 1 City of Paso Robles WWTP Effluent Parameters Before & After BNR Upgrade
Regulated Contaminant NPDES Limit Before BNR Upgrade After BNR Upgrade
Total Nitrogen 10 ppm ~40 ppm2
~10 ppm4
Total Coliforms 23 MPN1
In & Out of Compliance
Routinely at Method
Detection Limit (1.8 MPN)
THMs
0.56 ppb BDCM
0.40 ppb DBCM
Non-Detect3 TTHM ~60 ppb5
BDCM ~15 ppb
1.
MPN - most probable number in 100 mL over a 7 day median
2.
Almost all as ammonia
3.
Very low levels due to large excess of ammonia pre-disinfection with Cl2
4.
Mostly nitrate, ~ 0 ppm ammonia
5.
Before implementing chloramination
Paso Robles Wastewater treatment Works
Page 12

Chloramination Trial to Mitigate THM Formation
In an effort to reduce THM levels without compromising disinfection and TN limits the WWTP facility trialled the use
of chloramination.
The chloramination evaluation began in March 2016 and was operated under the following conditions:
• Cl2
dosing to maintain residual of 9 ppm
• Ammonium sulphate (15-30%) dosing upstream of Cl2
disinfection
• NH3
and Cl2 dosing pump speeds respond to process flow volumes and residual BNR ammonia
• Disinfection contact time ~50 minutes
• Final neutralization of excess Cl2
with NaHSO3
• THM compliance point at discharge into Salinas River after a weir and a polishing channel that further reduces concentrations of THMs by
volatilization and evaporation
The facility relied on standard laboratory methods to quantify TTHM levels at the start of the chloramination trial. However, obtaining a high frequency of grab
samples results needed to facilitate the optimization of the chloramination process became impractical. Using an analytical laboratory, it would take up to two
weeks to obtain results, cost $250/sample, and the facility would receive dated results of water quality that had already been discharged. Looking for more
timely results, the facility decided to pilot a new online low-level THM monitor manufactured by Aqua Metrology Systems (AMS) that would allow them to
accelerate the optimization of the chloramination process by providing high frequency, real time and reliable data on TTHM, DBCM and BDCM levels.
Low-level Online THM Detection Methodology
The standard configuration of the online THM-100™ analyzer uses a “purge-and-trap” method to extract the THMs from a 250 mL sample, followed by their
desorption into a chemical mixture that generates a coloured product when heated. Once heated, a time-resolved spectrophotometric analysis of the reaction
kinetics is performed since the four THM species (chloroform, bromodichloromethane, dibromochloromethane and bromoform) react at different rates. The
reaction absorbances for the sample and calibration parameters derived from the onboard THM standard are then used to calculate the sample’s composition
and concentrations of THM species and their total.
The low-level wastewater application at Paso Robles demanded the development of three new modifications to the THM-100 platform:
1. Pre-concentration: THMs from as many as four online samples can sequentially be transferred by “purge-trapdesorb” into the same chemical mixture
before starting the reaction. This affords an increase in sensitivity up to four-fold.
2. Enhance optical detector sensitivity: The length of the flow-cell was increased three-fold (from 2 to 6 cm) to provide a longer path for light to travel,
resulting in higher absorbances more differentiated from the blanks.
3. DBCM & BDCM reporting: A refined calculation method for quantifying the DBCM & BDCM species was developed, and their concentrations were
outputted to SCADA and the shared THM result files in the cloud.
The low-level detection THM analyzer was installed in June 2016 at the sampling location post-disinfection and predechlorination. Data from the online monitor
was expected to run slightly higher than compliance sample readings due to placement of the instrument upstream of the weir and polishing channel and their
THM-reducing volatilization and evaporation effects.
Chloroform (CHCl3) is the predominant THM species at the Paso Robles WWTP, in the range of 75-95% of the TTHM. As a result, TTHM levels of approximately
2 ppb would need to be accurately quantified to understand if the chloramination successfully reduced the BDCM levels to below 0.56 ppb. If effective, DBCM
compliance below the 0.4 ppb NPDES limit would automatically be guaranteed considering the THM speciation profile in this discharge water, with a typical
BDCM : DBCM ratio of approximately 6 : 1.
Reliable Data from Online THM Monitor Helps Optimize Treatment Plant
The automated online monitor analyzed six samples daily from June through September 2016. The monitor captured fluctuations in TTHM, DBCM, and BDCM
levels at the Paso Robles WWTP resulting from daily cycles, process changes, plant maintenance activities, and unexpected operational failures. The online THM
data proved fundamental for understanding the impact of chloramination ratios and THM speciation and levels. An increase to the ammonia : chlorine ratio
leads to a decrease in TTHM levels and an increase in the percentage of CHCl3; in combination these two effects further suppressed the regulated brominated
THMs (Figure 2).
Figure 2 City of Paso Robles WWTP Online THM Data (June-September 2016)
Page 13

Aside from the prolonged periods of routine plant operation, the online THM monitoring revealed a few abnormal events that would otherwise have gone
unnoticed. Two significant operational failures were identified:
1. Nightly events of extremely high THMs in late-June, early-July and mid-September were caused by under-dosing ammonium with the peristaltic
pump when the flexible tubing was worn out. The severity of the failure increased with a reduction in pump dosing rates, which correlated with the
nightly low-flows of wastewater at the plant.
2. On 26 July 2016 an online monitor of BNR residual ammonia fell out of calibration, falsely reporting elevated levels. In response, an operator
manually turned off the ammonium sulphate dosing pumps. Without any ammonia residual from the BNR or by ammonium dosing the chloramina-
tion effort was undermined, and BDCM levels rose to over 35 ppb as the residual organic matter combined with the more reactive chlorine.
Under routine plant operating conditions, the online monitor revealed daily cyclic THM levels. THM concentrations peaked in the 10:00 am sample, but six
hours later they dropped to the lowest daily levels, a pattern that correlated with plant flow rates and automated treatment operations. The online monitor
reliably captured these diurnal fluctuations for DBCM at extremely low levels, between 0.1 and 0.7 ppb (Figure 3). The online THM monitor also captured the
effect of BNR maintenance on THM levels (Figure 4), which temporarily dropped at the post-dechlorination location to below the NPDES limits enforced at the
site of GWR discharge. When one of the two BNR tanks was brought off-line for maintenance on 9 August, it caused a net reduction in the conversion of influent
ammonia to other nitrogen species (N2 and nitrate). Although the plant was now out of compliance for TN, the increase in ammonia carry-over into the
disinfection system brought about an elevated ammonia : chlorine ratio, leading to a reduction in THM formation by this ‘enhanced’ chloramination.
THM Compliance Samples During Chloramination Study
On 16 June and 8 August 2016, NPDES compliance samples from the GWR discharge location were submitted to the analytical laboratory. Figure 5 shows the
results in which the lab reported that BDCM and DBCM were ‘in compliance’ by being below the lab’s PQL of 0.5 ppb for these two THMs.
Figure 5: City of Paso Robles WWTP Compliance Samples
NDPDES THM Limits (Daily Average) 1
Date Sample Type
& Location
CHCl3
—
BDCM
0.56 ppb
DBCM
0.40 ppb
CHBr3
—
16th
June 2016
Compliance Grab Sample1
10.3 ND ND ND
Online Monitoring2
15.6-12.9 1.64-1.12 0.21-0.10 ND
8th August 2016
Compliance Grab Sample1
Not Reported ND ND 1.2
Online Monitoring2
15.2-11.4 2.91-2.78 0.66-0.59 ND
There are several interesting observations to be made about the reported THM values and the NPDES limits. This commentary is not intended to specifi-
cally criticize this laboratory, but to emphasize the general principal that it is challenging for an analytical technique to accurately quantify species whose
concentrations approach the method’s PQL.
1. There is inherent unreliability in the accuracy of analyte levels close to a laboratory method PQL (or MDL). Whereas the NPDES limits may be derived
from a careful analysis of the available health science and the water discharge environment, assuring compliance is unreliable without the support
of a reliable laboratory analytical methods with detection limits considerably below the regulatory levels.
Specifically in this case, the lab analytical method has a PQL of 0.5 ppb for DBCM, but the regulatory limit is lower at 0.4 ppb. A sample
containing 0.45 ppb would technically be out of compliance, but the lab analysis should be reported as ‘Below PQL’ – and therefore probably in
NPDES compliance – whether accurately detected or not.
Figure 3: City of Paso Robles WWTP Daily Cyclic THM Data Figure 4: City of Paso Robles WWTP BNR Maintenance Effect on THMs
Page 14

2. There are some internal inconsistencies in the THM results reported by the laboratory. The CHCl3
concentration in the sample of 16 June was
reported at 10.3 ppb. If it is accepted that this value is reliable, and that other lab samples and online THM analyses over this period were typically
speciated with 90% CHCl3, it should be expected that the BDCM concentration for this sample would be about 1.0 ppb, double the PQL (and not
‘Non-Detected’ as reported).
In comparison with the online THM monitor, the BDCM results for this date were between 1.6 and 1.1 ppb, at the location upstream of the THM-
volatilization action of the weir and polishing channel, which are expected to reduce the BDCM level to ~1 ppb at the compliance sample location
but unlikely (as other measurements have shown) to drop the concentration below the PQL level of 0.5 ppb.
3. For the 8th
August 2016 compliance sample, it is unexpected that the concentration of bromoform would have been measured as high as 1.2 ppb. This
is inconsistent with the characteristic THM speciation in this discharge water of ~90% chloroform, with a ~10% sum of BDCM, DBCM and bromoform
in progressively smaller amounts.
For example, a water sample with this speciation and a TTHM level of 10 ppb is expected to contain ~9.0 ppb CHCl3, ~0.85 ppb BDCM, ~0.12 ppb
DBCM, and bromoform at ~0.03 ppb or less. Moreover, in more than 20 samples from this site of 10-20 ppb TTHM analysed at the AMS’s laboratory
(by Standard Method 524.4), bromoform was always below their PQL of 0.2 ppb. Furthermore, it is highly improbable that the detected bromoform
originated in the raw water arriving at the WWTP, without being accompanied by a significant quantity of DBCM that was not detected.
In fact, the predominant THM in the Paso Robles drinking water supply is BDCM, and bromoform is the least dominant THM species. As a possible
explanation, it is plausible that the detected bromoform in the 8 August 2016 sample could have as its source method carry-over from the preceding
analytical sample or quality control standard.
Summary: Regulatory Compliance and Ensured Water Quality
Accurate and reliable high frequency water quality data was imperative for Paso Robles WWTP to control the chloramination process and ensure
regulatory compliance. The facility faced stringent limits on DBCM (0.40 ppb) and BDCM(0.56 ppb) and timely analytical results were necessary. Standard
laboratory analysis became impractical and the facility pilot tested the efficacy of a new commercially available online THM monitor capable of low-level
real-time detection of DBCM and BDCM.
The online monitor provided accurate and reliable low-level detection of DBCM and BDCM formation at-or-below NPDES permit limits. The high frequency data
helped The City to evaluate the DBP prevention strategy and ensure the quality of treated wastewater used in the GWR program.
Through the adoption of a BRN treatment system, chloramination and online THM monitoring the Paso Robles WWTP obtained regulatory compliance by being
below NPDES permit limits for TN, microbiology and THMs at the June and August 2016 sampling dates.
Footnote
Although the June and August 2016 compliance samples were below the NPDES THM limits, the Central Coast Regional Water Quality Control Board
(CCRWQCB) and The City of Paso Robles have since entered into a time-schedule order agreement for THM compliance, giving the Paso Robles WWTP the
opportunity to consider alternative plant upgrades and treatment methods, which must bring the plant into compliance by June 2021. The City had been
planning on investing in the infrastructure for recycled water and was open to switching disinfection methods if chloramination was infeasible with the goals
of the recycled water project.
The City sought relief from the current low-level THM limits during design and construction. The CCRWQCB revised and relaxed The City of Paso Robles
NPDES THM limits on 27 July 2016. New interim BDCM and DBCM limits of 10 and 5 ppb respectively are now in effect. Paso Robles WWTP must report on the
preparation and implementation of a pollution prevention plan for THMs, with a strategy to achieve full compliance of the original NPDES regulations by June
2018. While the City is still evaluating options for THM control, the exceptional quality of work performed by AMS and the reliable data from the online monitor
have helped Paso Robles to solve their THM problem.
Page 15
About the Author
Rick has served as CEO of Aqua Metrology Systems since 2012. Prior to joining AMS, Rick held senior management and
board level positions in the energy, industrial, technology, and water sectors. Rick has a keen interest in technology
start-ups and has successfully led several companies in securing seed and development funding. Rick holds a degree in
Land Economy from the University of Cambridge, United Kingdom.
Aqua Metrology Systems Ltd. (AMS) is a leader of online and offline analytical instrumentation for the determination
of water contaminants, specifically disinfection by-products and trace metals, across municipal and industrial markets.
AMS, registered in the United Kingdom, has operations in Silicon Valley, California. The company’s mission is to
develop and commercialize online and offline, real-time analytical solutions for regulated contaminants in drinking
water, process water and wastewater.
AMS was founded in 2007 by an experienced team of Silicon Valley technologists accustomed to building and
commercializing highly sophisticated analytical instrumentation capable of detecting trace metals in silicon wafer
manufacturing process chemical systems.
AMS online THM-100™ monitors and offline THM-100GS™ analysers were developed under the belief that real-time
accurate and reliable data is vital to process control and optimization; and this information should be readily accessible
to those responsible for protecting water resources, water treatment, regulators and the consumers.

Article:
The importance of flow & it’s
measurement to the Water Industry
Without flow the water industry, quite literally, wouldn’t exist. Gigalitres of water & wastewater are abstracted, treated, delivered, consumed, collected,
treated & discharged every day of the week. How we manage this water has a very large impact on the way we live and on the environment that we live in.
To misquote the old adage in order to manage the water that flows through the water industry we have to measure it.
Measuring water and especially wastewater
The majority of this article will talk about measuring wastewater but at its very essence
the principles are the same although the wastewater side of things comes with its own
complications. In the main we, as an industry, measure wastewater flows using two techniques.
The first is in open channels using a primary device such as a flume or a weir and this regulates
the velocity flowing through the device which causes the level to rise. This level change is used
to measure the flow using the universal flow equation where flow is equal to velocity multiplied
by the area. Secondly is using electromagnetic flow meters in closed pipes where the area is
fixed and the part of the equation that you measure is the velocity. These two technologies
typically comprise about 90-95% of all in-line measurement techniques.
However, there are alternatives and although relatively rare outside of flow surveys in the
wastewater network are still in use. The first of these is Time of Flight flow measurement which
like the electromagnetic flow meter measures the velocity of water in a closed pipe and
the second is the area velocity device which measures both elements of the Universal Flow
Equation by measuring both the velocity and the area. Typically, in an open channel but more
recently technological developments have seen this typically submerged method come out of
the water and use non-contact methods.
The problems with flow measurement
The technology exists in the wastewater industry to measure flow in virtually any process
application but there are problems and the skill in measuring flow is picking the right flowmeter
for the right job. It’s rare that a flow meter (or any instrument) is installed in an installation that
is absolutely perfect for the job and compromises normally have to be made and normally this
is where measurement usually starts to go wrong. When installing any instrument the following
should be considered.
Why – What is being measured and why, is there a purpose for the measurement. If the answer is no then stop and don’t install an
instrument where it isn’t needed
What – A flow meter, like any instrument, should be selected for the application. Anyone who says that their meter can be installed
anywhere is wrong. Looking at the application and seeing what type of flow meter fits is key bearing in mind any interferences in
channels or pipes. Mostly the errors that these interferences produce can be mitigated if thought through and incorporated into design
in advance
Where – This is going to depend upon what the use of the flow data is going to be. Is it for compliance, is it for operation of the main
flows of the treatment works or is it for controlling an individual process. This will of course affect the application and type of flow meter.
How – The answer here is listen to your supplier, they will advise the best method of how to install a flow meter. Also, take into account
how a meter is going to be installed, how it is going to operationally maintained and also how it’s going to be replaced.
Thinking of these three points in the installation of any flow meter or instrument means that it will actually work rather than being squeezed into an
application which won’t work in terms of either the application or sometimes the operation. This eventually results in the meter failing to work correctly and
the trust the reliability in the measurement failing.
Typically the top five reasons why something won’t measure correctly are
• Fouling – Be it an open channel or a closed pipe all installations are subject to fouling from plants, trees and other vegetation to
overdosing of chemicals that can narrow the bore on pipes
• Physical damage to the measurement structure – More one for the open channel but with age flumes start to peel away from the
concrete or weir plates start to bend. The only option, replacement.
• Poor Installation – Open channels need to be relatively calm, flat and free discharging. In civil engineering, a tolerance of 10-20mm is
normally considered as flat. In flow measurement this tolerance reduces to 1-2mm. Closed pipe meters usually need to be flooded and
Figure 1 A typical flume and level based measurement device
Page 16

situated away from turbulence or disturbance if not this will affect measurement accuracy
• Telemetry errors – If a meter is being routed back to telemetry with a 4-20mA loop make sure the scales agree at both ends. Normally a
no-brainer but often the biggest source of error
For example, a simple V notch weir system (figure 2) if not accessible for cleaning by operational staff doesn’t get cleaned, this causes plant life to grown on it.
The plant life cause an obstruction in the measurement device causing the level to rise up and for the actual measurement to read high. The operator has a look
at the reading and doesn’t believe it because its reading “too high,” the root cause is of course the plant life in the weir. When its removed the flows return to
“normal,” as long as too much damage hasn’t been caused. This is a downward spiral that the wastewater industry had fallen into for quite some time before
the advent of the MCERTS scheme which brought standards to flow measurement within the wastewater industry. The standards and associated management
systems that need to be in place has brought a standard to wastewater flow that has resulted in an increased reliability in flow measurement.
When it’s right it has lots of uses
When flow measurement is correct, it has many uses, when its wrong it can be counter-productive. The first use of flow measurement under the MCERTS
Scheme is to measure the compliance of the various treatment works with their permit conditions in terms of both the dry weather and flow to full treatment
conditions. The MCERTS scheme was originally setup and still exists to measure dry weather flow compliance but this is extending in scope to cover flow to full
treatment conditions.
There are some technical difficulties with this approach primarily with the fact that most flow installations are on the effluent from treatment works but this is
not insurmountable. However, the uses of flow measurement are significantly more than just to measure compliance.
For example
• Compliance relies on accurate flow measurement. If your flow measurement isn’t accurate then it can appear that a site is non-compliant
when it really isn’t, it could indicate growth or infiltration where it doesn’t exist.
• In Operation & Control – Flow measurement is a fundamental part of the treatment works and on large works is often used to control
storm water management, return & recirculation flows, and settlement tank desludging. As well as in many sub-processes aside from the
main treatment flow on a works
• Designing treatment works relies on correct flow measurement being recorded for many years to get a picture of site performance and to
answer the question as to whether an existing works needs to be upgrade.
There are many more uses for flow measurement and this article can’t go into them all, suffice it to say the measurement of flow is one of the
fundamental bases of both the engineering design and operation of both the water & wastewater industries as long as the fundamentals as long as it is
installed and operated in a way that allows the data that is produced can be relied upon. The consequences of getting it wrong is to put us in a place where
errors in measurement or the fact that they are perceived that they can’t be trusted costs more than installing it correctly in the first place.
Figure 2: Fouling & damage to weir plates and poor installation of electro-magnetic flow meters are quite often the largest source of error
Page 17
About the Author
Oliver Grievson is the Flow & Instrumentation Specialist for the Foundation for Water Research as well as being a
Director of the Sensors for Water Interest Group and also Wastewater Education 501 (c)3 as well as being the group
manager of the Water Industry Process Automation & Control Group (WIPAC). He has had many years experience in
both the operation and engineering sides of the Water Industry and is currently a technical expert and manager in
flow and instrumentation regularly consulting & lecturing on both a national and international basis.
He is a Chartered Scientist, Environmentalist and Water & Environmental Manager as well as a Fellow of both
CIWEM & the Institute of Environmental Sciences and a Member of the Institute of Measurement & Control.

January 2017
Institute of Water - Eastern Section - Dragon’s Den
30th
January 2017
Cranfield University , UK
Hosted by Institute of Water & Cranfield University
February 2017
Market Opening
1st
February 2017
Think Tank Museum, Birmingham
Hosted by the Sensors for Water Interest Group
8th Smart Energy Europe & the Future Utility
2nd
- 3rd
February 2017
London Park Plaza, London UK
Hosted by Oliver Kinross
March/April 2017
Smart Wastewater Networks
8th
March 2017
Merseyside Maritime Museum, Liverpool, UK
Smart Water Networks
21st
March 2017
Hilton Birmingham Metropole, Birmingham, UK
Hosted by the Faversham House Group
Smart Water Systems
24th
-25th
April 2017
London, UK
Hosted by the SMi Group
May/ June 2017
Specification & Installation of Sensors
3rd
May 2017
Principality Stadium, Cardiff, Wales
SWAN 2017
9th
-10th
May 2017
Tower Hotel, London UK
Hosted by the SWAN Forum
12th
Specialized Conference in ICA
11th
-14th
June 2017
Quebec City, Canada
Hosted by the International Water Association
September 2017
Sensing in Water 2017
27th
-28th
September 2017
Nottingham Belfry, Nottingham, UK
Page 18
Conferences, Events,
Seminars & Studies
Conferences, Seminars & Events
Market Opening Workshop
Where: Think Tank Museum, Birmingham, UK
When: 1st
February 2017
Description
From April 2017, over 1.2 million eligible businesses and other non-
household customers in England will be able to choose their supplier of water
and wastewater retail services. There is an expectation that the opening of
the non-household water market will support business customers to become
more water-efficient and will stimulate benefits for customers in the form of
lower bills and better value for money, better customer service, and more
tailored services to suit individual customers’ needs.
In this new open water market, water retailers will seek to offset low
retail margins by delivering innovative and value-adding services to
customers; services that will also differentiate them from their competitors.
Both retailers and wholesale companies will be looking to meet their
obligations to customers, to the market operator and to each other at the
lowest possible operating cost.
This workshop is aimed at water retailers, wholesalers and the industry
supply chain and will focus on the role of sensor technology, data and the
insight it delivers in enabling market reform. Early opportunities are likely to
focus on metering and meter estate management, billing, water efficiency,
surface water management, trade effluent, customer engagement and
private network management.
Smart Wastewater Networks
Where: Merseyside Maritime Museum, Liverpool
When: 8th
March 2017
The use of sensors in the Wastewater Network has been sparse and far
between. The complexity of wastewater collection has meant that this
development within the Wastewater industry has been delayed. However
with the requirement for event duration monitoring, improvements in sensor
technologies and modelling software, the industry is starting to develop
improved methods of managing the Wastewater Network.
In this SWIG Workshop on Smart Wastewater Networks we will discuss the
drivers and developments in the Wastewater Network..

0
Eastern Area Innovation Showcase
- transforming the water industry
Vincent Building
Cranfield University
Cranfield, MK43 0AL
30th January 2017
10:00-16:00
Book your place:
http://tinyurl.com/dragonwater
Page 19

WIPAC Monthly - December 2016

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WIPAC Monthly - December 2016