Image of a CCTV pipe inspection camera on a race track

Let’s race, CCTV pipe inspection cameras!

Let’s race, CCTV pipe inspection cameras!

And why not. As human beings, we desire to race everything else in our lives; cars, motorbikes, lorries, boats and even tractors! So why not race pipe inspection cameras? 

What’s the current speed limit?

Anyone working in this area will know that the specification for inspections of sewerage and drainage networks will limit the camera speed to 0.1 or 0.2 m/sec (0.33 or 0.66 ft/sec) depending on the pipe size. Some of you think even achieving something close to this speed can be challenging given the need to negotiate roots, intruding laterals, debris and Weird Things in Pipes ( #weirdthingsinpipes). Additionally, there’s lots of time spent travelling to an inspection site, finding the asset, setting up traffic management, entering the asset data on the title screen, etc. For that reason, pipe inspection productivity is nowhere near the 2,880 m (9449 ft) per day that could be achieved by a camera travelling down a pipe at 0.1 m/sec (0.33 ft/sec) pipe for 8 hours.

What does that data say about actual camera speeds?

We were keen to understand the average speed of a pipe inspection camera and the data captured in the VAPAR.Solutions platform provides the ability to do this. The platform holds a vast array of data that offers the opportunity to generate insights, including the ability to estimate the average time for a camera to travel through a pipe and complete an inspection. A random sample of surveys from the UK, Australian and New Zealand markets indicates the average speed is 0.13 metres per second (0.43 ft per second), with an 80-second mobilisation/demobilisation time for each survey. The analysis uses inspection footage durations and has removed the supersonic and snail-paced outliers.

Why increase camera speeds?

This analysis demonstrates that the markets generally comply with the specification, so why would you want to increase camera speeds? In addition, we have shown that the time inspecting the pipe accounts for only part of the working day, with time spent on other supporting activities. As with all outstanding racing achievements, not one change leads to success, but a combination of small-time savings creates a race-winning performance. This is generally known as Marginal Gains: small incremental improvements in any process, which, when added together, make a significant improvement (see https://jamesclear.com/marginal-gains). Remember, you only need to be 0.001 seconds ahead of second-place to be the winner, and the same goes for any commercial analysis of a tender.

How can we increase pipe inspection camera speeds? 

It is not about running the camera through the pipe as fast as possible. The purpose of the inspection needs to be maintained; identify defects or characteristics that will prevent the pipe from providing the required service levels. The current specification speeds allow the camera operator sufficient time to identify defects. However, the advent of VAPAR’s AI-assisted defect coding means you don’t have to rely on the camera operator to identify the defects. The AI technology can support the analysis of inspection footage captured at speeds higher than the current standards while providing high-quality output. Additionally, the move to off-site coding means the camera operator can focus on the quality and speed of the pipe inspection footage and is not distracted by the need to code the surveys simultaneously. For example, you don’t see a Hollywood film studio trying to produce the final film while on set!

So, who is up for a bit of pipe inspection camera racing?

About the Author description - Nathan Muggeridge BDM UK and EU - VAPAR

Read more about how VAPAR is increasing the efficiency and value of underground pipe inspections here.

bom national report image

BOM National Performance Report 2020-21: A wastewater snapshot

BOM National Performance Report 2020-21:

A wastewater snapshot

Each year the Australian Bureau of Meteorology releases the National Performance Report for urban water utilities, the 2020-21 report is available for public download here: http://www.bom.gov.au/water/npr/

This annual report aims to provide benchmarking of pricing and service quality for urban water utilities. The report is helpful for utilities to monitor annual trends within their own organisations, as well as look at whether their key metrics sit within the typical range in a broader national context. Utilities are grouped within four size categories (small, medium, large, major). This reflects that revenue base and population density can be a factor in both the cost required to provide water and sewer to customers as well as the level of service that is appropriate or sustainable.

Running to 128 pages, this is a comprehensive report that lists metrics across 166 categories from 86 utilities.  Dependent on your area of expertise or interest, there is interesting information for everyone.

Figure 1 – Australian utilities that submitted data for the 2020-21 report.

This article summary focuses on some of the key metrics that relate to gravity sewer mains and wastewater expenditure.

Sewer Main Breaks and Chokes

To enable comparative analysis, many of the metrics are reported as ‘per 100km of asset’, this is the case for ‘sewer mains breaks and chokes’.1 This last year has seen improvements for many locations with 57% of utilities reporting a decrease in breaks and chokes compared to the previous reporting year with Clarence Valley Council, Gippsland Water, and Gladstone Regional Council all seeing reductions of > 75%.

Utilities reporting the lowest instance of breaks and chokes in each utility group size is listed in the table below.

Table 1: Number of sewer mains breaks and chokes per 100 km (Indicator A14)

Utility GroupUtilityValue
Small (10,000 – 20,000 properties)Water Corporation – Geraldton (WA)3.4
Medium (20,000 – 50,000 properties)Tweed Shire Council (NSW)1
Large (50,000 – 100,000 properties)Gippsland Water (VIC)1.5
Major (100,000+ properties)City of Gold Coast (QLD)3.8

Major utilities saw the largest improvement for this metric. However, reductions were not the norm for small-sized utilities with the median increasing from 13.7/year to 15.6/year, and the average increasing from 25.3/year to 35.5/year.

Capital Expenditure per Property (Wastewater)

The report notes that the national median per property capital expenditure on wastewater services decreased by 11% from 2019-20 to 2020-21.

Utilities reporting the lowest wastewater expenditure per property in each utility group size is listed in the table below.

Table 2: Capital expenditure per property – wastewater (Indicator F29)

Utility GroupUtilityValue
Small (10,000 – 20,000 properties)Gympie Regional Council (QLD)$88.90
Medium (20,000 – 50,000 properties)Dubbo Regional Council (NSW)$3.65
Large (50,000 – 100,000 properties)Power and Water Corporation – Darwin (NT)$146.72
Major (100,000+ properties)City West Water Corporation (VIC)$143.57

Looking more closely at the data split by utility size, the average annual capital expenditure on wastewater is surprisingly similar across all utility sizes; in the region of $275 to $300 per property. The reported figures over the last decade do indicate that small and medium sized utilities may be investing less, on average, on wastewater infrastructure.

While there may be a variety of reasons for this, it will be of some concern if a trend of reduced investment is reflected in a similar reduction in wastewater service level KPIs (including sewer main breaks and chokes).

Figure 2 – Capital Wastewater Expenditure per Property

Despite the significant reported drop in per property wastewater expenditure over the last year (11%); the overall reported capital expenditure on wastewater has remained reasonably stable since 2017 at around $2.7 billion dollars per year – with a drop of 2.9% from 2019-20 to 2020-21 based on reported figures.

Figure 3 – Capital Wastewater Expenditure

Wastewater Operating Cost per Property

The report saw 66 of 86 utilities submit data on operating cost per property to supply wastewater services. The following utilities in each category reported operating their networks at the lowest cost:

Table 3: Wastewater operating cost per property (Indicator F14)

Utility GroupUtilityValue
Small (10,000 – 20,000 properties)City of Kalgoorlie-Boulder (NT)$168.96
Medium (20,000 – 50,000 properties)Rockhampton Regional Council (QLD)$294.59
Large (50,000 – 100,000 properties)Toowoomba Regional Council (QLD)$243.35
Major (100,000+ properties)South Australian Water Corporation (SA)$231.92

Residential Wastewater Bill

The cost to provide services is impacted by a wide range of factors, including but not limited to: age of assets, condition of assets, density of population, climate and topography. The table below lists the lowest residential wastewater bill in each category for the 20/21 period.

Table 4: Typical residential wastewater bill (Indicator P14)

Utility GroupUtilityValue
Small (10,000 – 20,000 properties)Armidale Regional Council (NSW)$465
Medium (20,000 – 50,000 properties)Lower Murray Water (VIC)$491.84
Large (50,000 – 100,000 properties)North East Region Water Corporation (VIC)$239.16
Major (100,000+ properties)City West Water Corporation (VIC)$347.92

The report indicates 57% of utilities had a reduction in the typical residential wastewater bill with Central Coast Council seeing the largest change (-24%). However nationally, the overall trend was only marginal (<1% decrease).

1 Wastewater mains breaks and chokes is intended to include:

  • Gravity sewer mains
  • Rising (pumped) mains
  • Low pressure mains
  • Vacuum system mains

It excludes:

  • Property connections
  • Treated effluent mains
  • Recycled water mains

It can be questioned whether failures on pumped rising mains and chokes within gravity sewer networks should fall under the same metric. While these asset types are intrinsically connected to form the majority of a sewer network, they operate under very different conditions and the mode and cause of failure are often quite distinct.


The information and data for this snapshot is sourced from Part A and Part B of the National performance report 2020–21: urban water utilities. It has been used under the Creative Commons Attribution 3.0 Australian License.

Found the article interesting? Check out our case studies here VAPAR case studies.

sewer overflow

What causes sewer blockage and how to get it cleared?

What causes sewer blockage and how to get it cleared?

Image of sewer overflow due to blockage


Dry weather sewer overflows caused by blockages can create significant issues for utility providers, the community, and the environment. What are some of the reasons sewer/wastewater pipes become blocked?

Tree roots

The number one cause of sewer blockages in most networks is tree roots.1 In addition to sunlight and carbon dioxide, trees require water and nutrients to grow and survive. The consistent flow through sewer pipes provides a rich and attractive source for trees. While the gravity pipe network would ideally be a closed system, there are numerous pipe joints and cracks where tree roots are able to squeeze through as they seek out nutrients. If enough of a gap exists, the root mass can become so large within the pipe that it can eventually block, causing a back-up of sewage flow and discharge at a point upstream. The point of discharge is commonly a sewer maintenance hole or house overflow relief gully. Dry weather overflows may persist for some time before being observed and reported for fixing.

FOG: fats, oils and grease

Another contributor to sewer blockages is FOG: fats, oils and grease. If you’ve ever wondered why you are asked not to pour these cooking by-products down the sink, this is the reason. Incorrectly managed trade waste from food establishments is also a significant contributor to FOG issues in a sewer network. These products increase the likelihood of a blocked sewer and overflow. Fats, oils, and grease can solidify after they cool and build-up on the inside of pipe walls, they have a tendency to coagulate with similar particles, or exacerbate already existing root intrusion issues, and can result in partial or complete blockage of a pipe. An internet search of ‘sewer fatbergs’ will provide graphical insight into the scale of the problem.

Foreign objects

A third cause of sewer overflows is the flushing of objects down the toilet that belong in the rubbish bin. The most recent offender on this list is wet wipes. While toilet paper is biodegradable and designed to break apart after flushing, wet wipes are not the same. This material interacts with both tree roots, fat deposits and other solid materials dramatically increasing the likelihood of blockages. Other common items that don’t belong in the sewer system and contribute to blockages include paper towels, sanitary items, condoms, hair, kitty litter, and cotton balls.

Other potential triggers for blockages in pipes are the build-up of sediment or broken pieces of pipe which reduce the cross-sectional area of a pipe and can lead to partial chokes and eventual blockage.

How are these defects identified during a CCTV inspection?

VAPAR uses artificial intelligence to automatically identify and categorise pipe defects including root intrusion, debris/deposits (incl. FOG build-up), and other obstructions within a pipe that can identify the potential risk of blockage. The VAPAR.Solutions platform provides defect level reporting that can be matched with historical work orders and blockage events to assist in pipe maintenance programs to reduce the risk of future blockages.

Image of sewer corrosion
  1. Sewer performance reporting: Factors that influence blockages (Marlow et al., 2011)