Inspection camera being lowered into sewer manhole for 3d digital examination

Five techs accelerating CCTV inspection turnaround

Five techs accelerating CCTV inspection turnaround

Inspection camera being lowered into sewer manhole for 3D digital examination

As the old adage goes, time is money. A significant amount of the cost for CCTV inspections can be attributed to the equipment, site set-up, back office processing of deliverables and associated labour. The good news is there are new technologies available to CCTV contractors and asset owners alike that can be used to drive down the overall cost of the CCTV inspection process.

5G for cloud streaming and streamlined access to online tools

The pipe inspection process is a field-based task and has to happen wherever the pipe is located. Prior to the roll out of 5G, the transmission of large amounts of data (such as video data, network mapping data) to and from the inspection location was often time prohibitive. In Australia, with Telstra’s rollout of 5G many major city locations and some rural locations now have access to fast wireless data streaming services. We can expect to see many IoT (Internet of Things) and cloud streaming services being deployed in wastewater networks as the 5G coverage and adoption increases.

AI for advanced analytics

Artificial Intelligence (AI) comes in many shapes and sizes and can be utilised in multiple areas to aid the pipe inspection process. Not only are there applications like VAPAR’s that can automatically detect defects in pipes based on the inspection footage, but there are also statistical models that can predict pipe degradation, making the scoping of the next CCTV inspection package more targeted. AI has the potential to streamline both on-site activities as well as back-office activities, by taking out the manual parts of the inspection workflow.

APIs and integrations for data centralisation

Application Programming Interfaces or APIs are used to streamline data between different software tools (in particular, online software tools) without needing a person to manually export data from one system and format it or manually enter it into another system. 

When it comes to the pipe inspection and asset renewal process, there are many software tools involved. The process will typically start within an Asset Management System (or AMS) where pipes are selected for inspection. These pipes then need to be matched using a GIS system (Geographic Information System) so that operators know where underground the pipes are positioned, and how to gain access. Once the inspection data is captured, the results then require review before being entered back into GIS and AMS platforms. The whole process can take several days, if not weeks, with different formats and spreadsheets and manual data entry required. Through the use of APIs, data being passed back and forth can be repeated and automated without the resource load and delay of having to manually match data in different systems each time.

There are a number of other uses for APIs in asset management given the number of different software tools that are involved in maintaining an asset throughout its lifecycle. 

Autonomous hardware control for finer movement

Many existing crawler systems have telemetry (movement) data available that is being under-utilised in the current method of capture. Building systems that use this data and either recommend or automate crawler movement can prevent the camera tipping and traction issues. Currently operators need to be very careful in their operation of crawler hardware and can risk losing the expensive camera gear in the pipe. Crawler manufacturers are looking for ways to utilise this telemetry data in a way that assists operators and speed up the capture process. The future of such technology, if paired with AI, could lead to fully autonomous inspections being carried out at a faster rate with lower risk to the hardware.

Computer vision

The concept of computer vision (CV) is to use the pixels in a digital image to better understand what is happening in the picture. Some common computer vision applications include edge detection and filtering “noise” from images. Computer vision can also be used to estimate measurements from an image and to track changes over a series of images. The combination of computer vision tools can be used to provide additional insights and estimation measurements within CCTV inspection footage. We may also see applications for CV that stitch images together to create a “street view” like rendering of pipes, creating a software alternative to the similar deliverables that can currently only be obtained using specialised 360 degree cameras.


There is so much innovation that is happening in the CCTV inspection space, and there are many companies that are pushing the boundaries. Talk to your clients and suppliers about how they can include some of the above industry innovations into their delivery process, and you might find some savings and additional value. 

For further information about how you can streamline your CCTV inspection process, you can also visit the VAPAR website here.

CCTV Truck1

How to capture AI-friendly Pipe Inspection Footage

How to capture AI-friendly Pipe Inspection Footage

As VAPAR’s CTO, it’s safe to say I’ve got a good familiarity with which inspection footage works well (and which doesn’t) for automated pipe inspections using artificial intelligence (AI).

Over the last few years, the capability of image recognition AI models have improved significantly, meaning automation is a universally serious time-saver for many organisations looking to optimise or streamline their image based assessments. 

Although accuracy of artificial intelligence has improved over this time, the results which AI models are able to produce can sometimes be limited by the characteristics of the inspection footage which they are fed. If Contractors are looking to maximise the results they can achieve for themselves and their clients using AI, there’s definitely some recommendations I’ve observed which should be followed.

As different AI vendors may have different ways of handling challenges and developing solutions. I’ve tried to cover each point with a generalist approach. Many of these challenges would also be true of a person trying to provide a condition assessment based on the footage alone.

Challenges and Limitations

Firstly, to get some better context around the recommendations, I’ll outline the main challenges and limitations of AI for automated CCTV coding I’ve observed during my time with VAPAR.


Generally, pipe inspection standards will define a number of codes to be used which require granular detail which is not reliably achievable for operators or software without quantitative computer vision and tracking of camera telemetry.

Sizing of Features

Determining the size of features within millimetre accuracy is a challenging task for software and human operators alike. As an alternative criterion for software, categorisation of defect severity could be undertaken using relative categories, such as ‘small’, ‘medium’ and ‘large’, that are aligned with quantitative ranges.

‘Clock’ Positioning

Using 12 segments (named to align with clock references) can be challenging depending on the amount of panning, tilting and zooming that the operator undertakes during the inspection. Quadrants or eighths would likely yield more consistent results from both manual and automated assessment.

Soil Through Defect

Currently, distinguishing the difference between soil visible through a defect, debris sitting inside a pipe, or roots can be a difficult task for AI.

Start & Finish Nodes

Start nodes may not always be present in footage captured by CCTV contractors. Furthermore, the type of maintenance hole used to access pipes can be difficult for AI to ascertain. Inspection footage is typically started from the centreline of the maintenance hole pointed directly down the barrel of the pipe to be inspected. These nodes are typically evident to the CCTV operator as they require entry to perform the inspection. 

Continuous Defects

It can be difficult to determine whether defects are discrete or continuous when a CCTV camera is moving through a pipe. This is due to the capture of the defects jumping in and out of frame during camera operation.

Multiple Assets in a Single Video

Where a CCTV camera travels through more than one asset, AI will need a way of identifying this distinction and handling the condition assessment of the assets separately. Otherwise the defects detected would all be assumed to be part of a single pipe asset which is incorrect.

Multiple inspection time frames captured in a Single Video 

Where a camera operator approaches an issue that needs to be immediately resolved (such as a blockage), they can stop the recording of the footage, clear the issue, and resume recording again. Where the halted inspection footage and completed inspection footage for the same asset are in a single video, AI needs a way of identifying this distinction between previous or ‘abandoned’ footage vs.‘completed’, and then overriding the abandoned condition assessment with that of the completed footage.

Shape or Dimensions Change

Where pipe shape or dimensions change, quantifying the extent of this change can be difficult to determine when using visual inspection footage alone.


Now that I’ve outlined the core problems we’ve encountered with AI for automated CCTV coding, let’s cover some tips to ensure you’re capturing AI-friendly pipe inspection footage:


There are a number of standard procedures that operators can apply to ensure inspection footage is optimised for use with AI pipe assessments. Areas where standardised procedure can be introduced to great effect are:

  • Standardising the asset information block at the start of footage capture
  • Standardising the chainage on-screen display positioning.
  • Standardising a requirement for the CCTV camera head to be centred within the pipe and field of view also centred (to see equally the top and bottom of the pipe).


There are also a number of procedural restrictions which CCTV operators can observe in order to create footage optimised for AI-based pipe assessments. These include:

  • Restriction of cleaning inspection footage (i.e. CCTV capture during jetting, where the jetting head is visible throughout the  footage and obscure the field of view) used for condition assessment.
  • Restriction on reversing significant distances through the pipe – this can cause offsets in the chainage measurement and also cause problems for the AI, which will duplicate the detection of defects and features.
  • Restriction on zooming whilst moving (either driving forward or panning), as this can make this camera movement difficult to track.
  • Restriction on stopping and starting the capture of footage within a single video, i.e. where cleaning is performed or the camera is moved without recording, the inspection should be taken in a single pass.

These recommendations are some of the main components we’ve identified that have the ability to impact the post processing of video files – either by AI or by an inspector.


What data says about service defects in sewer pipes (and how to prevent them)

What data says about service defects in sewer pipes (and how to prevent them)

Back in October, we published a blog outlining the most common structural defect types within sewer pipe infrastructure, according to a data set of around 30 km which we’d borrowed from footage in Australia, NZ and the UK.

Now, we’re rounding things out by providing the same information for service defects within sewer pipe infrastructure, using the same data set to provide unique, data-led insights about the most common service defects in sewer pipes, and how to prevent them.

About Service Defects

By way of background, service defects are those that have an impact on the operational capacity of a pipe, impairing the pipes effectiveness to convey wastewater through the pipe network. 

Compared to structural defects, service defects will not involve the structure of the pipe itself. Commonly observed service defects include displaced joints, debris or root intrusions.

A Quick Summary of Our Data Set

If you’re after a more comprehensive overview of the dataset we used, I’d definitely recommend checking out our previous blog on structural defects (that shared the same dataset) to get a complete picture. In this instance, I’ll just cover the key points to avoid bogging things down.

The data set we used consisted of 605 pieces of wastewater pipe inspection footage, representing 26.45 km in combined network length from Australia, NZ and the UK.

Concrete and vitrified clay were the most commonly observed pipe construction materials, representing 45.25% and 42.02% of the dataset respectively, flexible plastics represented 11.79%, and a miscellaneous ‘other’ covered a tiny 0.95% of materials.

A variety of pipe diameters were also identified; 150mm (6 inch) diameter was the most commonly found within the footage, followed by 225mm (9 inch) and 300mm (12 inch).

Shorter pipe chainages were more frequently observed than longer ones; the ‘0-20m’ chainage category forming just under a third of total results – combined with the ‘20-40m’ category, these two represented around 54% of our total data set. Chainages of over 100m were infrequently observed in the data set; with any chainage over 100m forming just 5% of the total observed chainages.

Defects – An Overview

Immediately, there’s a few clear key trends observable in the data set; occurrences of displaced joints and root intrusions are by far the two most common defect categories, with instances of lesser severity significantly more common than those of greater severity. In fact, instances of displaced joints were so common that they formed three of the top four most common service defects we observed.

A full breakdown of the defects we discovered can be seen in the treemap diagram below:

With the overarching trends spelt out, let’s dive a little deeper into the two most common classifications of defects that we’ve just discussed.

Displaced Joints

Firstly, it’s important to note that since WSA 05 2020 (Australia’s version of a conduit assessment code) was released, displaced joints are now classified as both structural and service defects. If you’re keen to learn about the changes that WSA 05 2020 brought, I’d highly recommend reading another blog we released in September which outlines the most important considerations on this topic.

Looking into the data we collected, it’s clear that among service defects within sewer pipes, instances of displaced joints are king (perhaps instead, they should be labelled a royal pain!). Diving in a little deeper, instances of joint offset (sometimes referred to as ‘radial’ displacement) occur around 2.5 times as frequently as their joint separation (can also be referred to as ‘open’ joint) counterparts.

The prevalence of displaced joints within pipe infrastructure is most common in vitrified clay pipes, particularly older designs without rubber rings in joints. With our dataset including a high proportion of vitrified clay (42.02%, to be precise), there is a pretty clear correlation found in the defects we observed compared to the materials used in their pipes.


The other main service defect culprit which we identified within the data set was that of fine root intrusion, which was the second-most observed defect category.

Similar to displaced joints, the prevalence of root intrusions won’t be any great surprise to anyone who deals with sewer pipes day-to-day; they’re a constant thorn in our side!

From our data set, we observed that the majority of fine roots intruding into sewer pipes entered the pipe through the joints. This suggests that implementing better pipe sealing could act as a remedy to regular incursions of fine roots.

A study undertaken by University of Melbourne outlined the most common factors causing greater frequency of root invasions, those being tree proximity, tree maturity, tree type, soil type, and temperature/evaporation rates. The study found that “blockages occurred most frequently when temperatures and evaporation were at their lowest, i.e., August to October.”

The study also investigates the efficacy of both chemical and physical treatments to prevent root intrusion. The physical treatments included compaction and cement slurry, both of which showed quite promising results in inhibiting root growth compared to their chemical counterparts – which I found particularly interesting. The study attributes the effectiveness of the cement treatment to “increasing soil strength above the force that the roots were able to exert”.

What can be done to prevent these defects?

Joint Displacement

Although there’s no silver bullet solution to prevent joint displacement, there are a few ways that asset owners can limit the prevalence of displaced joints in their sewer pipe infrastructure.

The best time to take action to prevent displaced joints is prior to, or during the installation process. Adding spigot and socket (or similar) pipe joints and a flexible joint material into engineering specifications will help to maintain the water-tightness of the pipe even with some degree of inevitable joint articulation.

Additionally, during installation, ensuring that pipe bedding material has undergone a thorough level of compaction will help to prevent settlement or movements in these pipes over time.

Finally, when installing sewer pipes that have spigot and socket joints, drainlayers should ensure that pipes are pushed precisely to the witness mark. By implementing a careful approach during installation, asset owners will notice fewer cases of damaged pipe ends and rubber seals.

In instances where joint displacement has already been identified, more extensive works will generally be needed to address the issue. Depending on the severity of the defect, pipe relining may be required. In particularly severe instances, excavation and replacement of offending pipe sections may be the only solution.


Firstly, I’d like to point out that one of the most effective ways to minimise root intrusion into pipes is by minimising joint displacement in pipe networks. So, if you’ve implemented the advice directly above – you’re already halfway there!

The application of herbicidal foam in sewers is one of the leading solutions for reducing regrowth of roots that enter sewer pipes. I’d highly recommend checking out this video if you’ve never experienced how this process works.

There’s a trend which is seeing asset owners move away from root cutting as a solution to root-related defects, and with good reason. A great article from Newman Plumbing explains it brilliantly; “each time roots are cut they respond by regrowing thicker and faster, similar to pruning a hedge. The aggressive nature of the cutting process will also damage the condition of the pipe and will inevitably result in costly rehabilitation or replacement.” Many asset owners seem to be in agreement, and are moving towards other means such as herbicides so as to minimize the impact of repairs on their pipe infrastructure. 

For particularly problematic sections of sewer pipe, relining the complete asset may be necessary so as to remove the opportunity for the roots to reach water via the joints.


That’s all, folks! If you haven’t already seen them, check out our other blogs on structural defects in sewer pipes, and defects in stormwater pipes.

Sewer Blog Image V2

Why do sewer pipes break? Here’s what the data actually says.

Why do sewer pipes break? Here’s what the data actually says.

In May, VAPAR completed a data-dive to check out the most common defects found in stormwater pipe infrastructure. More importantly, we provided recommendations based on this data to help asset owners to reduce the risk of defects developing.

Last time, we noted that our stormwater CCTV footage inspections unearthed patterns of defects according to the material used to construct the pipe. This was a great development, since an element of predictability gives asset owners the chance to take informed action during their design and construction process to mitigate the risk of defects occurring down the line.

At the time of publication, I’d promised to deliver a similar piece relating to sewer pipe infrastructure. This time around, I’ll be breaking my analysis down into two parts – one with data and recommendations around structural defects (you’re reading it now!) and one around service defects (which will be released soon).

Defects in Sewer Pipes vs Stormwater Pipes

Before we get stuck in, I’ll just clarify a few points for any non-engineers who might be reading – there’s some differences between wastewater and stormwater pipes.

Sewer pipes and stormwater pipes mainly differ due to:


In urban areas, all properties need wastewater connections, which will generally (on average) start at 150 mm (6 inch) in diameter. 

Conversely, stormwater pipes are only used when overland flow depths in kerb profiles exceed the allowable, in which case a pipe should be installed. These pipes need to carry a larger capacity from the upstream point, generally (on average) starting at 300 mm (12 inch) in diameter.

Pipe Material

Because sewer pipes are ubiquitous, reasonably priced and readily-accessible pipe materials are most commonly sought for installation. This means that wastewater pipes will more frequently be made of materials such as PVC or vitrified clay than stormwater pipes.

On the other hand, since stormwater pipes are typically of larger diameter (and therefore demand greater reinforcement), more expensive materials such as concrete will be used for installation more frequently.


It’s also commonly noted that sewer pipes will generally contain less debris (street litter, leaves, branches) than their stormwater counterparts. However, because wastewater pipes are typically smaller in diameter, always flowing, and have more lateral connection/junction points, there’s a greater comparative risk of blockage.

In most cases, wastewater network odours are managed through controlled venting of the system. This can reduce the rate of pipe degradation, however the chemical and biological composition of wastewater still means that design lives of between stormwater and wastewater can still greatly differ.

Snapshot – Our Dataset

We used 605 pieces of sewer pipe inspection footage, representing 26.45 km in combined network length as our dataset for our investigation. 

The footage had been uploaded to VAPAR’s cloud platform by VAPAR clients over the last few months for automated analysis, and was sourced from clients located in Australia, New Zealand and the UK.

A Breakdown of our Dataset

Material Types

From the footage which we used, concrete and vitrified clay were by far the most commonly identified construction materials, representing 45.25% and 42.02% of the dataset, respectively.

The third most common material present was flexible plastic (11.79%), whilst a miscellaneous the ‘other’ category encompassed just 0.95% of materials.

Vitrified clay is a very common material type for pipes of smaller diameters. As mentioned earlier, the ubiquitous nature of sewer pipes make it an ideal material for installation – vitrified clay is a natural material, and is readily available in many countries. 

Moving into the larger wastewater pipe diameters, concrete will more commonly be used as a construction material due to the increased reinforcement demands larger diameters impose. For the purpose of this blog, I have defined concrete construction to encompass steel reinforced (SR), fibre reinforced (FR) and asbestos cement – although strictly speaking these don’t have the same structural attributes as each other.

Plastic pipe construction is the ‘up and comer’ amongst wastewater materials. Plastic construction is becoming more and more prevalent as the material behaviour is becoming better understood by asset owners.

Pipe Diameters

A variety of pipe diameters were also identified; 150mm (6 inch) diameter was the most commonly found within the footage, followed by 225mm (9 inch) and 300mm (12 inch).

From a logical perspective, the spread of pipe diameters in our dataset makes a lot of sense, and absolutely aligns with my expectations of a typical wastewater network. Pipe of smaller diameters connect to properties everywhere, and are the most common diameter; these in turn feed into increasingly larger pipe diameters deeper into the network. As we move deeper and deeper into a wastewater network, we can expect the pipe diameters to increase, with their frequency to decrease accordingly.


Within the dataset, shorter pipe chainages were more frequently observed than longer ones; the ‘0-20m’ chainage category forming just under a third of total results – combined with the ‘20-40m’ category, these two formed around 54% of our total data set.

Chainages of over 100m were infrequently observed in the data set; with any chainage over 100m forming just 5% of the total observed chainages.

Again, the distribution of this data makes perfect sense given the context of a sewer network. Because sewer pipes are so ubiquitous, there are large numbers of pipes connecting properties to mains, meaning that networks of mains pipes change direction frequently to facilitate connectivity.

Structural vs Service Defects – What’s the Difference?

Before we dive in, I’ll quickly clear up the difference between structural defects compared to service defects.

A structural defect is one which has an impact on the structural integrity of the pipe itself. Over time, structural defects may worsen significantly to the point that the pipe requires significant repair work, or even replacement. Common structural defects could include cracking, breaking, or surface damage.

Service defects are those that have an impact on the operational capacity of a pipe, impairing the pipes effectiveness to convey wastewater through the pipe network. Common service defects include displaced joints, debris or root intrusions.

In this edition, we’ll be covering structural defects encountered in wastewater pipe infrastructure. We’ll release the results for service defects in the next edition of our blog.

Structural Defects

Combined Results

Overall, minor instances of longitudinal cracking was the most commonly observed defect from the dataset, representing one of the three most common defect classifications across all material types. 

Similarly, minor instances of circumferential cracking was also highly represented, also present in the top three defect categories across all pipe materials.

Surface damage (aggregate exposed) and minor instances of multiple cracks were the other main defect culprits our platform recognized.

A full breakdown of combined structural defects across all pipe types is below:

Small cracks and exposed aggregate formed the most common defect types within our data set, which makes logical sense. Both of these defect classifications are most common amongst concrete pipes, which were the most prevalent in our data set, making up 45.25% of the total material observed. 

Over time, and with changes in the pipe environment, these types of defects would continue to degrade, eventually progressing to more severe defects which could have meaningful interruptions on wastewater service to the areas they service.

Since it’s difficult to make informed recommendations from this data without specific contextual parameters, we decided to separate our defect analysis by pipe material type to identify clearer patterns and trends.

Defects by Pipe Material


Surface damage (aggregate exposed) was the most frequently discovered defect found within pipes of concrete construction. Minor instances of circumferential cracking and longitudinal cracking were also present in concrete pipes, whilst surface damage caused by corrosion was also prevalent in the dataset.

A full breakdown of defects found in concrete pipe is below:

The results gleaned from our concrete pipes are extremely interesting, and supports the typical engineering hypothesis of failure modes from surface related defects. 

Once concrete aggregate has been exposed from initial surface damage, corrosion becomes more prevalent – with concrete cover reducing, steel reinforcements become exposed to air and moisture, causing them to corrode. Corrosion products will then leach out of any cracks or fissures in the concrete cover, resulting in spalling of the concrete cover.

Although cracking is prevalent in the dataset, it is on aggregate less prevalent than what we would see in other rigid pipe materials (i.e. vitrified clay) due to the structural reinforcement. 

Circumferential cracking may suggest angular movement of the pipe (relative to the pipe central axis), potentially caused by ground movement over time or poor bedding compaction. 

Longitudinal cracking (especially at the 12, 3, 6 and 9 o’clock positions) can suggest that design loads have been exceeded. 

I will note that this data includes other types of concrete/cement materials, which may impact the results.

Vitrified Clay

It’s not an exaggeration to say that if you’ve got a defect within a vitrified clay pipe, far more often than not, there’s going to be cracking involved.

Minor longitudinal cracks, minor circumferential cracks, and minor multiple cracks were the most common defect that the VAPAR platform picked up in pipes of this material. More severe longitudinal cracking, multiple cracking and circumferential cracking were the next most common defects observed.

Again, a full breakdown of defects within vitrified clay pipes is below:

Unlike concrete, vitrified clay pipes are not reinforced, so longitudinal, circumferential and multiple cracking are perfectly normal (and expected) defects for this material type.

Some progression in the severity of cracks is evident; whilst smaller cracks are the most evident defects for vitrified clay pipes, there is still a sizable (albeit smaller) representation of large cracks too.

In case you were interested in finding out a little more about the vitrified clay vs earthenware, I would definitely recommend this excellent piece provided by Jonathan Morris of Opus International Consultants (Wellington).

Flexible Plastics

Cracks again dominated the most frequently observed defects within pipes made with flexible plastics, taking out five of the six most frequent defect causes.

However, they didn’t take out the top spot, which went to minor instances of deformation (severity less than 5%) – no great surprise given the flexible nature of plastic construction.

Below are the defect results for flexible plastic pipes:

There’s a growing sentiment that using plastics for pipe construction is the way forward for asset owners. 

A study conducted on 4 different pipe materials (concrete, polyvinyl chloride (PVC), vitrified clay, and ductile iron) suggested that “that PVC pipe is the most sustainable option from both environmental and economic viewpoints”. I’m personally interested to see how this unfolds across the industry.

How can good planning and design help avoid impactful structural defects?

A common theme that we’ve observed is that the majority of more impactful defects (i.e., those that are more severe) generally stem from degradation of initially minor issues.

Asset owners should log instances of minor defects, and assess other factors that could potentially affect the degradation of the asset. This will allow for an informed, effective reinspection plan to be established in order to monitor the progression of defects, and prevent major, impactful structural issues to infrastructure.

Asset owners should also make an effort to observe the technical specification of their pipe construction materials. By doing this, they will be able to make informed, data-driven decisions when evaluating the contents of their asset management plans, ensuring that pipe infrastructure is allocated an appropriate amount of resources and attention.


That’s all, folks! We’ll be releasing similar information relating to service defects soon in an upcoming blog, so stay tuned.

Innovate4Water Virtual Conference

Innovate 4 Water Conference

Our CEO and co-founder, Amanda Siqueira, has had an excellent opportunity to present at the Innovate 4 Water conference in Brisbane, organised by the International Water Centre (IWC).

The presentation was hosted on an innovative conferencing platform that combined both physical and virtual participation, meaning ideas sharing and networking opportunities were still flowing, despite the physical separation.

It was a great initiative and implementation to keep people innovating for water.

Presenting at the SWAN 2020 conference

Co-founder and CTO Michelle Aguilar had an excellent opportunity to share the latest developments we are working on with United Utilities last night at the 2020 annual SWAN conference. Presenting with James Devereux in the Wastewater panel, we saw plenty of incredible developments in this space and are excited to see innovative tech being adopted around the world to deal with the challenges. It is promising to see some of the giants of the water industry are busting through barriers for adoption. The insights that have come from working with UU over the past nine months have been invaluable!

We are now a SWAN member!

We are proud to announce that we are now officially a member for SWAN – The Smart Water Networks Forum.

SWAN is a UK-based global hub for the smart water sector. It brings together leading international water utilities, solution providers, academics, investors, regulators, and other industry experts to accelerate the awareness and adoption of “smart,” data-driven solutions in water and wastewater networks worldwide. 

We are excited to be joining great water innovators.


New opportunities open for NSW Councils to valuate their drainage assets

With EOFY fast approaching, we are seeing more Councils get in touch to complete their pipe condition assessments to fulfil asset valuation requirements.

There’s good news for NSW LGA’s who now have a bit more time to get their reporting done in recognition of the impact of COVID-19, as well as sharing in the $500M funding boost announced by the Commonwealth government last week.

If your organisation needs a fast, accurate and cost-effective way to meet EOFY asset valuation requirements for piped infrastructure, get in touch!

Read more about the recent Office of Local Government (NSW) asset valuation media release here.
Read more about the recent Office of Local Government (NSW) funding boost media release here.

How to increase the lifetime of your stormwater pipe assets: analytics on commonly observed defects

At VAPAR, we’ve been doing more and more work with a number of councils and municipalities over the last couple of months and are finding some interesting insights from the CCTV inspection data that are relevant to more than just the pipes in our clients drainage network.

Most of the stormwater CCTV inspection footage that we are processing is producing the same types of defects, and in some cases, there are things that can be done during the design and construction phase that can prevent the occurrence and frequency of common defects. After all, prevention is better than cure.

There are also a handful of ways that these common defects can be addressed if the timing of any intervention is being undertaken a long period after the pipe has been installed.

Sample dataset

Based on 1,421 stormwater inspection CCTV videos, representing 35.53 kilometres (or approximately 22 miles) that have been analysed by VAPAR’s web platform in the last couple of months, we dug into the data to look at the most common defects that were present, based on what was identified from the inspection footage.

But first, by way of context, below is a breakdown of the factors that characterise the sample dataset:

By material type

The majority of the sample dataset was from steel reinforced concrete pipe. The next most common material type was polyvinyl chloride (PVC). Other pipe materials were excluded from the sample dataset as there were not enough of them to be representative of ‘common’ defects.

Note that this analysis is focused on Stormwater pipes only; the majority of sewer pipes processed through our system are excluded from this dataset and will be covered in another post.

By diameter

The below is a tree diagram displaying that the greatest number of CCTV videos in the sample dataset came from 375 mm (15 inch) diameter pipes, followed by 450 mm (18 inch) and 300 mm (12 inch).

By chainage

The graph below shows the spread of chainages inspected in each of the CCTV videos from the sample dataset. As you will notice, the majority of the CCTV videos are less than 50 linear metres (or 164 liner feet) in length.

Structural defects

Steel reinforced concrete pipes

When explaining the defects observed in these types of pipes to our non-engineering team members, I found this particular explainer video of ‘how concrete pipes are made’, including showing the wrapping of reo-bar and casting of concrete pipes, to be particularly helpful and engaging.

Below is a treemap diagram of the most common defects identified in the most common defects that were observed in the sample dataset. From this you will see that longitudinal cracking, damaged lifting holes and circumferential cracking are the most common defects for this pipe material.

There are a number of reasons steel reinforced pipes can crack, many of which are described here. Longitudinal cracking is more notable than circumferential cracking, as circumferential cracking does not have as much of an impact on the load bearing capacity of the pipe.

Due to the weight of the steel reinforcement in each pipe, most steel reinforced concrete pipes have a manufactured lifting hole (also referred to as a lifting eye) on the top of the pipe to aid handling and installation. However, if the wrong concrete pipe lifting device is used during handling, lifting holes can become damaged, whereby there is excessive spalling of surrounding concrete etc. Over time damaged lifting holes can cause other issues such as circumferential cracking and infiltration, which may or may not cause further deterioration to the overall pipe condition, and are therefore defects worth noting during CCTV inspections.

Surface damage showing corrosion products or exposed reinforcement was also a common defect observation. This defect is typically weighted quite severely in condition assessment standards because of the theoretical importance of concrete cover in maintaining the integral strength of the steel reinforcement. However I found this blog post to provide an interesting perspective based on in-ground results of steel reinforced concrete pipes over a 30 year life span. Check it out.

Polyvinyl chloride pipes

The treemap diagram of defects for polyvinyl chloride (PVC) pipe from the sample dataset shows that deformation to varying extents are the top three most common defects identified. Anecdotally, I have experienced deformation to be a commonly observed defect during inspection of PVC pipes, and I was really interested to see this bear out in the data analysis of the sample dataset.

Some degree of deformation in PVC pipes is expected. After all, they are ‘flexible’ pipes. In fact, most PVC pipes will deform over their design life. The degree of deformation, and the time span over which this deformation is observed are the important factors for asset owners to understand when inspecting the pipes. For example, high degrees of deformation at any age of PVC pipe is a cause for concern. However, for small to moderate degrees of deformation, knowledge of the age of the pipe can help asset owners understand whether the structural integrity of the pipe is impacted or not.

What should I do about these structural defects?

Without a doubt, and as a chorus of literature will attest to, the bedding material, thickness and compaction can go a long way to overcome a number of the structural defects listed above that relate to the load bearing capacity of the pipe. This holds true for both rigid and flexible pipe materials. In fact, for flexible pipes in particular, I would go so far as to say that bedding and bedding compaction is the major factor to the structural performance of pipes. Using experienced drain layers and a well-planned inspection and testing plan during installation can reduce the risk of these common structural defects developing later on.

Additionally, pipes need to be designed for both design loads, as well as the construction loads that are imposed before the allowable depth of cover is achieved. This is quite a common cause of structural defects in newly laid pipes, alongside improper handling. In my opinion, the designer should ensure this is accounted for, as once the construction starts, site engineers are challenged with too many moving parts on site to constantly check weight restrictions for their heavy equipment as and when the pipes are getting laid. Accounting for live construction loading may add to the project’s capital cost (from purchasing higher strength pipes), but can save overall costs in quicker acceptance for adoption by the asset owner, and the asset owners operation and maintenance activities down the track.

Pre-adoption CCTV surveys should be a ‘hold point’ in the inspection and test plans before taking on the asset, and are an opportunity for asset owners to request that drain layer contractors remediate any defects identified before adding the asset to their network.

Service (or O&M) defects

Minor levels of debris and deposits were the most commonly observed defects in the stormwater CCTV sample dataset. This comes as no surprise to those of us that are familiar with the operation of stormwater pipes; at times it feels as though they pass just as much leaf litter and street litter as they do surface water. Apart from the reduction in cross sectional area, small amounts of debris and deposits start to become an issue when the presence of that debris/deposit increases the risk of additional debris accumulation over time.

Infiltration/inflow in underground pipes is another common observation in the stormwater CCTV sample dataset, and in stormwater CCTV inspection footage in general. Groundwater ingress and other water source interactions with stormwater pipes are responsible for this defect. Infiltration/inflow is not as consequential in stormwater pipes as it is in sewer pipes, though something to note during CCTV inspections as they may indicate poor joint tightness.

On a side note, the current (2013) version of the Australian conduit inspection reporting code has displaced joints as a service defect for stormwater pipes which is why ‘displaced joints’ appear here in the service defects. This ‘service’ categorisation is expected to be updated in the upcoming (2019) version where displaced joints will be classed as ‘structural’ defects.

What should I do about these service defects?

Source control is definitely the name of the game to reduce the instances of debris and deposit build up in pipes. Gross pollutant traps, or litter traps, at key points in the network can reduce the introduction of debris into the system. Designing pipes with enough fall can also aid the pipes ‘self-cleaning’ ability. The other common defects that are joint related can be addressed during the design, construction and commissioning phase. Where possible, installed pipes should be installed with a rubber ring joint to facilitate allowable joint articulation whilst keeping the joint as watertight as possible. However, even with rubber ring joints in design drawings, if the drain layer contractor has not pushed the pipes to the witness mark, or even over-inserted, this can cause issues with the joint. A commissioning CCTV survey should pick this defect up for remediation.