Environmental Techniques

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Environmental Techniques deliver complete CCTV survey packages of underground assets, highlighting problems such as cracks, fractures, deformation, open joints, roots and intruding connections.  By using the latest technology in image capture and reporting software, we can survey and report in detail to suit clients’ individual needs.  For larger structures such as culverts, tanks and tunnels, Confined Space Trained and experienced Man Entry teams are available to deliver full surveys and condition assessment.

CCTV Operation Photos

Bullet point Trained Operatives to OS19X, OS20X and OS21X

Bullet point Standard Colour CCTV Surveying

Bullet point Pipe and Brick Sewer Defect Classification

Bullet point Pan & Tilt – Survey lengths up to 1200m from one point

Bullet point Size Range 75mm to 1500mm and above

Bullet point On and Off-Road Facility

Bullet point Pushrod, Tractor and Float mounted assemblies

 

REPORTING

CCTV footage recorded from the pipelines is coded to the WRC Sewer Rehabilitation Manual 4th Edition (3rd Edition available if required.) Footage is coded using WinCan V8 software to provide the Client with quality reports which references the associated video file. This allows the Client to access and interpret the information in a consistent manner

For partially, or fully, submerged sewers and culverts, CCTV may not provide a suitable means of determining the pipes condition. If temporary stopping or diversion of the flow is not achievable, Sonar technology can be used to survey critical information for the section of pipeline underwater. In partially submerged pipes, this sonar technology can be used in conjunction with CCTV footage above the water level to offer a complete condition assessment of the pipe. Click here to find out more

Overview: Scheme undertaken in Dublin City Centre including CCTV and Sonar Surveying of pipes, manhole surveys, pumping station surveys and jetting of sewers.

 Location: Various locations around Dublin City Centre

Operations:  CCTV Survey, Sonar Surveys, Manhole Survey, CSO Survey, Pumping Station Survey
Clients: Atkins Ltd, Irish Water, Dublin City Council

 

The scope of the contract was to carry out a comprehensive survey to assess the structural condition of the ageing and complex drainage system at various locations within the south-side of the Dublin City Centre catchment and also to assist the build and verification of the hydraulic model.

Some of the constraints faced during this project

 Large diameter, irregular shaped pipes

 Semi-surcharged and surcharge pipelines

 Heavily silted sewers which had never been cleaned or surveyed before

 Working in busy city centre environment

 Requirement to avoid disruption to vehicular traffic and LUAS flows

 

CCTV SURVEYS

Assessment and recording of condition of approximately 26km of foul/combined/storm sewers varying in size from 100mm to 2700mm and varying in shape (circular, egg, arch and rectangular)

 

SONAR SURVEYS

Initial inspections found that major sewers adjacent to the River Liffey were in a constant surcharged / semi-surcharged state. In order to obtain a survey of adequate use to the client, Sonar surveys were carried out on these sewers using a sonar profiling system mounted on a float. In conjunction with CCTV footage, the sonar data provided much needed information on the condition of the pipe and amount of debris below the water level.

 

Initially, a total of 1km of sonar surveys were completed in this location ranging from 900mm diameter to1350mm. The use of sonar and CCTV on a float system allowed sewers to be surveyed for which no information had been previously collected. Due to heavy infiltration from the River Liffey, overpumping the line was virtually impossible and setting up traffic management to get the overpumping equipment, in addition to the jetting equipment, would have caused major traffic disruptions in an extremely busy location at the centre of Dublin City Centre.

 

A further 4km of sonar surveys were completed along Dublin’s South Quays and Ringsend area as data provided by the initial survey contractor was insufficient for assisting in the build of the hydraulic model due to the pipes being in a surcharged/semi surcharged state. Environmental Techniques were tasked by Dublin City Council and Atkins to survey these sewers with sonar following the success of the initial sonar surveys. To improve productivity, guide ropes for the sonar survey were installed at each location by a man entry team working ahead of the sonar survey squad.

 

The sonar survey proved invaluable for collecting information in the surcharge/semi-surcharged sewers and its utilisation in this situation led to the project being awarded “Innovative Scheme” at the 2015 UKSTT Annual Dinner and Awards Ceremony.

 

MAN ENTRY TUNNEL SURVEYS

Many of the sewers identified for survey were brick, egg shaped culverts, with narrow inverts. Due to the size of the sewers, the narrow inverts and the irregularity of the bricks, it was not possible to undertake the survey of these sewers with a CCTV camera. Instead, man entry surveys were carried out for 1.8km of sewers ranging in diameters 1600x700mm to 2600x800mm (egg shaped). Each survey team consisted of 7 personnel all of whom were confined space trained. Video footage of the tunnels were recorded by the operative who noted defects and inspected them using the camera system.

 

MANHOLE AND CSO SURVEYS

An internal condition and dimensional survey along with a GPS/Total Station survey was undertaken for 179No. critical manholes. The position, diameter, material and invert level of every pipe entering and leaving each manhole was recorded along with the manhole construction details, condition and internal dimensions. Detailed plan and cross sections were completed for the critical manhole and CSOs.

 

PUMPING STATION SURVEYS

Surveys were completed for 8No. pumping stations throughout the catchment. The surveys involved recording dimensions and levels of the pipework and assets within the pumping station chamber and a topographical survey of the pumping station site.

 

SEWER CLEANING

Through abandonment of initial CCTV Surveys, approximately 4.5km of sewers were identified for jetting to facilitate completion of the CCTV inspections. Sewer diameters varied in diameter from 150mm to 1200mm diameter. All jetting/desilting carried out on the instructions of the Client’s representative and CCTV inspections were undertaken immediately upon completion of the cleaning operations.

 

Environmental Techniques undertook a large majority of the works at night to minimise disruption to the vehicular traffic and the LUAS line. Through the use of sonar profiling systems and man entry tunnel surveys, the majority of the lines presented in the scope of this project were able to be surveyed providing network engineers with critical information for their models. These models were further enhanced with the detailed surveys undertaken on pumping stations and combined sewer overflow chambers, allowing critical network scenarios to be modelled.

Overview: CCTV survey of the 400mm ductile iron fuel pipes within Dublin Airport to check for defects/debris before the fuel is pumped into the lines for refuelling commercial aircraft.

 

Location: Pier 4, Dublin Airport
Operations:  CCTV Survey
Client: Dublin Airport Authority
Consultant: RPS Group

 

The survey carried out by Environmental Techniques on behalf of Dublin Airport Authority at Dublin airport was of a dormant fuel pipe designed for the future refuelling of aircraft at their stands via fuel hydrant connections (instead of using fuel tankers.) The fuel pipe runs in a continuous loop around Pier 4 at Terminal 2. 

The survey was undertaken to determine the current condition of the hydrant, to assess any construction debris defects, and determine the presence, if any, of water in the pipe. The fuel pipe is a 400mm internally and externally coated carbon steel pipe, approximately 1000m in length and approximately 2m below ground level. 

Access was limited to two hydrant chambers on either sides of the pier, each access chamber was approximately 4mx2m and 3m deep with the fuel pipe sitting 1m off the floor of the chamber. 

The fuel pipe, has been maintained under a nitrogen gas atmosphere to prevent any build-up of moisture in the pipe. The nitrogen gas was vented off by a specialist contractor prior to the removal of the in-line spool piece of the fuel pipe at each access chamber. With the spool pieces removed this allowed Environmental Techniques to insert the CUES CPR camera system into the fuel pipe. The survey was carried out by stopping and scanning at each pipe joint and hydrant connection. Where the bends were too tight for the CPR to negotiate the 10x optical and 4x digital zoom cameras were used to get a visual overlap survey.

With the works being carried out airside, there was huge importance attached to working within the allotted time window to avoid any impact on the airport’s operations. This included the requirement for each spool piece to be refitted, torqued and the access chamber lids reinstated at the end of each shift before the arrival of aircrafts to the stands at 04.00.

Environmental Techniques were able to survey 700+ meters over the 2 night shifts. The restricted working hours included the need for personnel / vehicle checks to be undertaken by airside security and also the removal and replacement of spool pieces. The crews worked quickly and efficiently, and the project finished well within the allotted timeframe. The execution of the works was complimented by Cormac Bradley from RPS Group.

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