Client:

Area Size:
150 ha

Timeline:
10 days

Product:
HydroBond

Port Augusta Ash Dam

Dust Suppression & Revegetation

Find out how we did it

Background

Port Augusta Ash Dam

In early 2017 the Flinders Power Station ash dams measuring a total of 275ha had been coved with topsoil from an adjacent borrow pit to the depth of 150-250mm. In July-August of 2017 earthworks were carried out across the property with a mixture of native chenopods, grasses, and other species – this was conducted with a drill and either dropped or spun onto the soil surface and lightly incorporated by following harrows. After the application of seed, there was approximately 100mm of water over a period of two months, which contributed to poor germination and establishment of vegetation, with close to failure over most of the dam’s surface.

Issue: The Port Augusta area was experiencing damaging southerly winds, which were picking up the dust from the ash dam and causing abrasive dust storms, as a result of minimal vegetation cover. This issue became a serious potential health and environmental problem for the local community, therefore, required addressing as quickly as possible.

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Project Overview

Port Augusta Ash Dam

In May 2018, Erizon’s team of environmental experts met with Flinders Power key personnel upon their
request, to discuss a working solution for their dust suppression and revegetation concerns associated
with their ash dam.

During the site visit, the team thoroughly examined both the ash dam and nearby burrow pits, via drone mapping and site surveying. During this time, a substantial number of soil samples were also taken and sent off for comprehensive analysis. The results indicated that the substrate profile was not suitable to support productive plant life, with high to very high salinity levels detected in the soil. In conjunction with the host environment, this became a critical factor in the failure to germinate and establish vegetation.

Erizon stated that a dust control solution could be achieved using a non-toxic environmentally friendly dust suppressant in the short-term; however, vegetation cover would be the only long-term sustainable solution for the ash dam and borrow pit.

Based on the test results found from the various soil samples, in conjunction with previous efforts to revegetate the property, Erizon explored many potential options as the project deemed challenging. A sustainable based recommendation involving a dust suppression solution for the high-risk topsoil dust and an amendment to the high level of salinity found in the soil, would need to be tailored specifically to the site requirements.

After an extensive analysis backed by science, the team put forward a recommendation program with confidence:

• HydroBond – Dust Suppression for Revegetation
• AgCalcium Boost – Displaces salt and sodium from the seed zone

In September 2017, upon consideration of the proposed recommendation, Erizon provided a trial for the HydroBond and AgCalcium Boost solution to be tested on an area of the dam, measuring 2,500m². The trial depicted various conditions that were displaced throughout the 180-hectare ash dam and was monitored 24/7 to gain an understanding of the environmental variables.

After a successful trial period of nine months, Flinders Power confirmed that Erizon would be given the task to continue using the tailored HydroBond solution on the remainder of the high-risk areas, covering 180 hectares of the property.

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Solution

Port Augusta Ash Dam

The foundation of the recommended product solution consisted of HydroBond, designed to effectively suppress dust while simultaneously promoting faster germination and added seed protection. Formulated using a specialist blend of polymers, water and propriety additives, to ensure superior technical performance and the development of bio-degradable crusting once applied to the soil. HydroBond is both permeable to air and water, allowing for germination and seeding to take place.

In conjunction with the HydroBond, AgCalcium Boost was incorporated into the tailored solution to compensate for the high levels of salinity detected in the substrate. The use of the calcium ameliorates counterbalanced the adverse effects that the sodium salts were placing on the seeds, by naturally displacing the salts away from the seed zone, therefore providing a greater chance for vegetation growth.

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Scope

Port Augusta Ash Dam

After the successful results of the nine-month trial, Erizon mobilised to the Flinders Power site on Wednesday the 26th of September to commence the application of the HydroBond and AgCalcium Boost solution to 150 hectares of the Port Augusta ash dam. Works commenced the following day on the 27th of September, 2018 and were completed on the 6th of October – spanning ten days from start to finish.

Upon site mobilisation, Erizons purpose-built HydroTrucks were checked off and prepared with the HydroBond and AgCalcium Boost solution. The HydroTrucks contain agitators within the holding tank designed to maintain homogenous mixing; this allowed for an effective hydraulic application of the solution onto the ash dam substrate. Following the initial site evaluation and changing ground conditions, a higher concentration of the tailored HydroBond solution was applied to access roads and cultivated areas. The solution was dispersed at a rate of 1.5 litres per m² and consisted of 350 litres per hectare.

Guarantee
As per the client’s request, an eight-month guarantee on the HydroBond and AgCalcium Boost solution was provided and commenced from the 4th of October 2018.

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Challenges

Port Augusta Ash Dam

• Over the duration of the project cycle, high winds and gusts posed difficulties during the application of the solution; therefore a strategic approach was undertaken to minimise the loss of HydroBond through wind drift and to ensure that the project deadline remained on schedule.

• Dues to the small scale access roads, there were some constraints placed on the team concerning safely and effectively manoeuvring equipment into logistical application positions.The team took this challenge extremely seriously by ensuring that the correct hazard assessments were measured and workplace safety procedures were in place.

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Results

Port Augusta Ash Dam

The objective of this project was to suppress topsoil dust while providing an amendment to the highly saline soil by underpinning plant germination.

Over the eight-month guarantee period, monthly monitoring and inspections were conducted onsite, involving: dust resistance, surface crust integrity, and weather conditions. Erizon was able to provide a solution that met the client’s goals by providing a dust control solution and vegetation growth that was significantly greater than anticipated – the client was pleased with the overall outcome.

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