When Northumbrian Water identified the need to design two towable trailers equipped with analytical equipment for continuous measurement, they approached Pollution & Process Monitoring (PPM) to complete the bespoke build.
The trailer monitoring project is referred to as SWAT (Site Wastewater Analysis Trailer) by Northumbrian Water. The project was managed by Loren Jennings, project sponsor was Laura Evans and Technical Support was provided by Mark Gibson (Operational Technology Engineer). Mark was responsible for the instrument selection and liaised with PPM to define the overall design, from the initial concept to the final outcome.
It’s no easy task to complete a bespoke monitoring station and even more challenging to pre-mount the instrumentation within a towable trailer environment. The usual considerations of sample delivery, sample pre-treatment, sample distribution, automatic compressed air cleaning, reagent bunding are also coupled with making the trailer a suitable environment, to house the analytical instrumentation.
The roof of the trailer had to be insulated, the walls adapted to take the weight of the instrumentation and bench top space integrated to allow scientists to perform analytical measurements. Base units were also installed to provide ample storage during transit. Lighting and heating were integrated to make the environment suitable for the specialist instrumentation.
Both trailers were equipped with instrumentation to analytically measure ammonia, iron, total phosphate and alkalinity. Probe measurement of pH, COD and temperature were also integrated into both trailers. Additionally, the inlet trailer was configured for redox and conductivity measurement, whilst the outlet trailer was configured for turbidity. The signals from all the instruments were wired back during the initial fabrication of the analytical trailers to a common signals box so that they could be simply connected into an NWG-approved telemetry outstation for remote data capture.
Sample acquisition was a critical aspect of the design. None of the instruments can perform reliably without receiving a continuous supply of sample. The sample has a propensity to foul and rag, so is often a challenge. The sample pump requirement may be slightly different on each and every site, so a common approach would be required. PPM worked with NWL to test and approve a suitable funnel/strainer arrangement which would facilitate reliable availability of process sample to the pumping arrangement. The design included regular compressed air back purging to automatically clean transfer lines.
The ability to deploy the trailers quickly and obtain real time data will prove to be of great assistance for site profiling. It will save time and provide a more detailed picture of process events to optimise treated water quality and augment environmental improvement.
“PPM have proven to be an excellent collaborative partner. PPM have been considerate and flexible, incorporating specific NWL design and instrument specification requirements. PPM have produced a high-quality product one which leaves us best placed to make on-line measurements on very demanding applications.”
– Mark Gibson, Operational Technology Engineer