Port Hills’ loess is known to have highly dispersive tendencies and be very hard to control once in suspension.
Sediment controls were going to be insufficient for the slope, size and soil type on this project coupled with the lack of room for appropriate water retention ponds.
The climatic variation over all four seasons was also going to cause significant dust issues for the site with residential properties as close as 15m from exposed cuts.
Canterbury is renowned for experiencing long, hot dry summer days and in the middle of an El Nino event these days were going to become more prominent.
A progressive point-source stabilisation program utilising Vital Bon Matt Stonewall was implemented throughout the life of the project.
The program was designed on future weather patterns and site reworking. Vital Chemical products provided robust stabilisation which was easily applied as required, by site contractors with full onsite support and training.
The employment of a point-source stabilisation program utilising Vital Bon Matt Stonewall was very successful in reducing erosion and fugitive dust emissions throughout the life-cycle of the works, including autumn and winter seasons which have the highest rainfall.
In addition, progressive point-source stabilisation afforded cost savings by reducing sediment controls required onsite along with associated maintenance and decommissioning of those controls.
The project was fully compliant, completed on time and on budget.
