Case Study: Tough Sewer Clearance for Thames Water in London SE1

A Lateral Approach from IWJS Achieved a Solution for Thames Water


Thames Water was presented with what seemed to be an insurmountable and potentially extremely expensive sewer clearance problem. However a solution was found to be at hand, courtesy of IWJS, when they took over this new challenge for major client Thames.

The serviceability of the sewer located at Waterloo in London had become severely affected by 8 cubic metres of C40 high strength, heavy construction grade cement. This challenging situation seemed a thorny problem that could have presented enormous civil engineering costs potentially for the client and caused major disruption. Especially as the sewer was located within a highly busy central London urban area, therefore it was difficult to rectify the problem without affecting traffic flows adversely for prolonged periods.

IWJS was therefore tasked by Thames to come up with a more creative, cost effective solution, without resorting to a radical and hugely expensive civil engineering intervention. Following a comprehensive survey of the sewer initially by IWJS, to ascertain the full extent of the problem, a full sewer clean was then scheduled. This would follow after the careful removal of the concrete and silt from the 1.2 metres elliptical profile sewer approximately 160 metres in total length.

The Challenge Ahead

Presented with the task, IWJS examined the problem thoroughly from an open perspective that required lateral thought and ingenuity to arrive at a workable solution. A uniquely creative approach was proposed by IWJS, working collaboratively with civil engineering partners, as this was found to be the best way forward, to achieve a cost effective solution. Thames Water therefore commissioned IWJS to head up and carry out the project.

IWJS acted as the principal contractor working alongside First Intervention Team (F.I.T) and major civil engineering partners Amey and McAllister.

Early planning meetings took place to orchestrate the smooth delivery of the project and minimalise any disruption to the area.  With essential traffic management being arranged to provide a temporary bus stop suspension and pavement closure within 2 metres of the curbside. Due to the busy central urban area, much night working had to be employed to deliver the project with as little impact as possible.

The adopted plan was for the McAllister crews to enter in the upstream manhole outside a public house. There inserting bungs to stop the flow, enabling the Amey mining crew to enter at the downstream manhole to drill out the offending concrete from the line. IWJS positioned a tanker adjacent to the upstream manhole strategically, to control the flows safely around the clock, enabling the work to continue unimpeded for the teams working below in the sewer.

Obstacles to Overcome

However, upon closer inspection the McAllister teams were unable to insert the bungs, due to excessive silt constricting the line.  IWJS then carried out a line clean of approximately 130 metres downstream to remove the silt effectively, thus allowing this essential operation to proceed smoothly as planned.

The McAllister team was then able to enter the manhole to insert the bungs and inflate them. Once these were in position and inflated, the Amey mining team was then able to enter the manhole downstream to commence drilling and secure removal of the concrete. With the rescue team (F.I.T.) on hand for all entries into the manholes to ensure maximum safety at all times.

A Positive Outcome

The safe removal of the highly tough concrete proved to be a laboriously slow process. However, once all of the concrete had been removed from the sewer successfully, IWJS was then able to carry out a full clean and provided a further monitoring survey to ensure the line was completely free. The end result of this challenging project, to restore the compromised sewer back to a free flowing line, was achieved effectively. Thames Water was highly delighted with the outstanding results attained, with minimal cost and disruption to their services and the area.

With the mission being fully accomplished, Thames gratefully acknowledged IWJS for their professionalism and skill in managing such a challenging and difficult project.



IWJS retains key Anglian Water contract



Industrial Water Jetting Systems (IWJS) Ltd has retained key business with one of the Group’s major water utility clients, Anglian Water, with the re-awarding of a major annual £4M national contract.

This major contract for IWJS covers 3 of the 4 regional areas of Anglian Water and will roll out over the next 6 years. This further maintains IWJS’s close links with Anglian Water stretching back over 25 years and was gained following tough contract re-negotiation and intense national competition. While price and value for money is of major importance to Anglian Water, it was not the only factor in influencing their decision. With quality of service and IWJS’s impressive record on safety, also playing a significant part in the decision by Anglian Water to remain with the Company. Commenting on the award of the contract with Anglian Water, Christopher Stewart the Managing Director of IWJS said:

“We approached the renegotiation of this key contract with Anglian Water with little room for complacency. Knowing we faced tough competition on price, as all the major water utilities face intense Government pressure to keep costs down and improve the quality of service they provide to their customers.”

Christopher continued… “IWJS has worked hard with Anglian Water to ensure that the service levels we provide in both scheduled and non-scheduled waste water works are kept at the highest levels and we will continue to do so. Our approach being one of constant improvement and innovation, not just in our service levels, but equally in maintaining our unparalleled safety record. We are delighted to retain this significant business with them.”

ANGLIAN-WATER-CLIFF-QUAYAs one of the major national clients of IWJS, Anglian Water requires round the clock 24/7 response over a significant geographic spread, coordinated from the IWJS Woolpit, Colchester and Lincoln depots. Director and Anglian Water’s Major Account Manager at IWJS, David Eade, further added:

“Logistically, this requires both extensive resource and planning of works with Anglian to ensure we provide the right level of cover where needed on scheduled work. With the necessary flexibility to also react to severe weather events and emergencies so that we provide seamless, round the clock cover.”

Geographically, Anglian Water is the largest water and water recycling company in England and Wales. Therefore ensuring IWJS service level agreements are met with Anglian Water is vital in helping this major client service its 6 million plus commercial and domestic customers, over 27,500 square kilometres regionally and supporting a network of 112,833 kilometres of water and sewer pipes. Along with the 1,257 water and water recycling works across its region, which is around a quarter of all those in England and Wales, impressive statistics indeed.


IWJS keeps ahead of the field…


Newmarket Racecourse has re-awarded the annual waste tankering contract to leading waste water management company IWJS, for the fourth successive year.

NewmarketRacecourselogoIWJS has been successfully servicing the contract at Newmarket Racecourse for the last three years and helps keep essential services running at the course during the busy flat racing season. The operation requires sufficient fleet capacity and carefully scheduled timing to keep pace with the high demand during Newmarket’s racing season. The UK’s premier flat racing course, Newmarket has a capacity of up to 45,000 race-goers at each of it’s 39 events scheduled to be held during the coming 2016 racing season.

Speaking about the work being re-awarded the work, Shaun Leeder, the contract manager at IWJS said:

 “We are delighted to be working with Newmarket Racecourse again. Especially as they’re such a high profile client, which obviously requires us to be available around the clock to meet their needs during the busy race season and events calendar.”

Additionally, IWJS provides the waste water management services to support the many major music events that are staged at Newmarket Racecourse too. Amongst the many international acts lined up to play at Newmarket this year are included artists such as the Corrs, Jess Glynne and the UK’s biggest girl band Little Mix. With capacity audiences anticipated, meaning that IWJS will have a busy time keeping services at the Newmarket race meetings and events in full flow throughout the year.



Industrial Water Jetting Systems Ltd 

Dickens House, Old Stowmarket Road, Woolpit, Bury St. Edmunds IP30 9QS

Tel: 01359 242606   Fax: 01359 242621   Email:






Sewer surveys to the highest standard


Adam Wharton and John Bishop are the latest DSS Environmental CCTV team leaders to pass their OS19X  Pipe Condition Classification Course.

The 5 day course is designed to give an understanding of the key features and technology involved in pipe sewer classification work to the WRc Manual of Sewer Condition Classification – 4th edition.

The course covers the need for and role of sewer condition classification, the key features of the various categories of pipe sewer and how to recognise and code the conditions and features.

With these qualifications DSSE CCTV crews are able to provide a great enhanced service to our clients when surveying and reporting on their sewer infrastructure.

The reports enable the right action to be taken to ensure optimum performance of the sewer asset.

Training is a vital part of the business not only for the technical aspect, as in this case, but also to ensure the highest safety standards.

The environment in which our crews work can be hazardous and best practice, through training, reassures our clients that the asset, their staff and the public are well cared for.

DSSE is part of the IWJS group of companies and offers the full range of services for the waste water sector including CCTV surveys, sewer clearing, re-lining, small civils works and waste tankering.

More information on DSSE is available at or by phoning 0800 58 58 76.

Relining expertise at IWJS

The Task
What to do when you are faced with having to reline a 38m section of 750mm storm drain in a very demanding environment?

The site conditions meant that access to one end of the drain was on rough ground that suited 4×4 vehicles, the other end in tight residential roads a further 30 m on from the end of the relining section. In between, the drain running under houses and other structures.

When a major Water Utility company was faced with this particular set of problems, DSS Environmental Ltd demonstrated they had the capabilities and won the contract to undertake the works.

What we did

The three day project started by digging down to reveal the storm drain, cut through the top to gain access and build a tower to take the relining equipment.

Following a CCTV survey to finely assess and measure the problem section, a combination jet/vac unit was used to clean the drain followed by remote guided cutting equipment to remove tree roots.

A further CCTV survey confirmed the section was clean, clear and ready to take the liner.

The 2 ½ tonne pre-wetted (resin impregnated) liner that arrived in refrigerated transport on day two was winched through the access point and carefully positioned using the CCTV crawler as the underground eyes.

The next part of the process involved inserting a calibration liner inside the resin liner and using water to fill the ‘cali’ to press the resin liner to the sides of the drain ready for the curing process.

Using 3m BTU of heating capacity, the water in the calibration liner was heated to 80oC and kept at temperature for 8 hours to ensure the resin liner was properly cured.

Day three saw the safe removal of the equipment, a final CCTV survey to ensure the liner was fully functional and the making good of the site.

Safety is always paramount on this type of operation and the weather was constantly monitored. ‘Packers’ were used to temporarily stop the water flow throughout the three days and a Flexline tanker was on site 24/7 to over pump any rainwater if the weather turned. After all, that is the purpose of storm drains.

 The outcome

With a written report (including a CCTV survey DVD) sent to the client confirming a successful operation, IWJS have again demonstrated their expertise in the sewer relining and sewer repair sector.