Luggage Point Sewage Treatment Plant (STP) Refurbishment

Luggage Point Sewage Treatment Plant (STP) is located near the northern bank of the mouth of the Brisbane River, to be precise Myrtletown. An article printed in The Courier Mail on the 18th August 1928 describes Myrtletown previously known as “Boggy Creek” as a progressive settlement, and was known for its vineyards and market gardens.

Today, it contains one of the largest Sewage Treatment Plant and Advanced Water Treatment Plant servicing the Brisbane and Western Corridor areas. Our client has been awarded the $4.8M contract to replace the aeration diffusers in the bioreactor tanks at Luggage Point STP. The requirements of this works meant isolation of the inlet channel to dewater the six bioreactor tanks to be cleaned and disinfected before replacement of approximately 24,000 diffusers. It is envisage that this project will take up to three years to complete.

Our innovation

Our client approached us for the purpose of detailing a survey monitoring methodology during the bioreactor refurbishment of Luggage Point Sewage Treatment Plant (STP). Land Solution Australia’s monitoring survey services was to provide a critical risk prevention and mitigation function to confirm the Bioreactor wall structure are in a good condition and at or near full strength before, during and after the dewatering process. To meet the requirements of our client, Land Solution Australia were required to install a number of survey points on each supporting reinforced concrete structure adjacent to the stainless steel inlet penstocks, the drop board gates on the bioreactor outlet ports and the permanently closed penstocks on the mixed liquor inlet channels. Therefore, Land Solution Australia ensured that the survey points were surveyed prior to dewatering the bioreactors and then immediately after dewatering to measure the deflections in the reinforced concrete structures caused by the hydrostatic loads resisted by the structure, which would indicate that a component of the reinforced concrete structure has deteriorated and the structure is not working according to the original design. The structure must be constantly monitored for deflection throughout the entire isolation of each tank as a means to provide early warning to entrants of any possible problem with the reinforced concrete structures.

Recommendation of a smart solution

Land Solution Australia implemented a Real Time Monitoring System to meet the client’s requirements for the Luggage Point Sewage Treatment Plant (STP) Project. This entailed undertaking a pre-install inspection on the bioreactor tank 4.

The requirement identified during the pre-install inspection was to establish a stable structure base needed to fix a Total Station mount bracket with clear line of site to all monitoring locations during the refurbishment process. The installation of the automated monitoring system and monitoring prisms were fixed to the top or face of the outer tank walls, penstocks, gates and channel areas clear of the water line and other obstructions. The team of the Principal Surveyor and Technology partner UPG devised a custom bracket and safety cover to ensure that the Total Station remained stabled and protected during the life time of the project.

The use of an automated S8 Total Station to monitor the monitoring prisms required the Total Station to contain on board atmospheric pressure sensors with additional temperature sensors installed at the Total Station communications box to correct for temperature variation during the project.

To establish an effective Real Time Monitoring System also required Land Solution Australia to work closely with their supporting external team to ensure consistent and stable monitoring of data was being received. Stable communications are essential to the operation as unlike the sensors these instruments rely on communications from the monitoring software to perform the observations.

Land Solution Australia proposed frequency observations at one hour intervals as it was estimated that 10-15minutes to perform a single round of observations for all monitoring components. A single round may include multiple observations of a single prism to improve the relative precision of the results. Based on a maximum sighting distance of approximately 60 metres, adjustment for temperature and pressure, multiple observations to each prism, we anticipate a relative accuracy of the observation rounds to be 1-2mm.

Land Solution Australia also devised that if for some reason the Total Station could not observe a target, the system will record an alarm or flag, and if the same prism cannot be recorded over 4 subsequent rounds, Land Solution Australia will receive an email to investigate the cause of the problem and resolve as soon as possible to restore the system to its optimal performance.

The server and software that Land Solution Australia have invested will perform three key operations; instigate essential communications to the robotic Total Stations to perform the survey observations, provide a central data hub for Total Station measurement data and communication hub for alarms and reporting outlined in the specification.

Premium service delivery

Luggage Point Sewage Treatment Plant (STP) Project for the next 3 years will mean that Land Solution Australia and all concerned stakeholders will have a stable platform to remotely operate, modify and report on the monitoring system. To maintain this efficient service delivery Land Solution Australia have invested in a monitoring software that will; receive data from an optical Total Station, measure, analyse, visualise and report on all monitoring components attached to structures, manage the Total Station monitoring system and view the results from a based web interface to a host of relevant stakeholders and manage access permissions and alarm reporting via email or SMS. The Luggage Point Sewage Treatment Plant Monitoring system is another example of a cutting edge Geospatial solution that has added efficiently to what was traditionally a difficult or high risk task to perform.