Using Soil Science to Improve Rehabilitation Outcomes on a Solar Farm Project

Successful rehabilitation begins long before construction is complete. Understanding the physical and chemical properties of the soil allows rehabilitation to be tailored to site conditions, improving vegetation establishment, reducing erosion risk and delivering more sustainable long-term outcomes.


Dynamic Environmental Services was engaged by GRS to undertake a detailed soil investigation and develop a Rehabilitation Plan for the Wandoan South Solar 2 project in Queensland. The project required a comprehensive understanding of soil characteristics across the site to develop practical recommendations for soil amelioration, revegetation and long-term rehabilitation.


Working in conjunction with agronomist David Hall, our team designed and implemented a comprehensive soil sampling program before interpreting the laboratory results to develop a rehabilitation approach tailored to the site's unique constraints. The recommendations considered not only vegetation establishment, but also erosion risk, soil stability, dispersive soils, nutrient deficiencies, construction sequencing and the long-term performance of rehabilitated areas.


Rehabilitation on major infrastructure projects is often approached using generic specifications that assume soil conditions are relatively consistent across a site. However, soil characteristics can vary significantly over relatively short distances, particularly where dispersive, sodic and magnesic soils are present. Understanding these variations allows rehabilitation to be tailored to the specific constraints of a project, improving vegetation establishment while reducing erosion and long-term maintenance requirements.


Our services included:

  • Soil investigation and sampling program design
  • Field soil assessment and landscape observations
  • Laboratory testing program development
  • Soil chemistry interpretation
  • Dispersive and sodic soil assessment
  • Soil fertility assessment
  • Soil amelioration recommendations
  • Fertiliser recommendations
  • Species selection
  • Rehabilitation planning
  • Erosion risk assessment
  • Long-term rehabilitation planning


The investigation included the collection of 135 soil cores across 27 representative sampling areas, targeting both surface and subsoil profiles to understand the characteristics most likely to influence rehabilitation success. Laboratory testing assessed a broad range of physical and chemical soil properties, including aggregate stability, particle size distribution, exchangeable cations, nutrient status, salinity and pH, providing the information required to develop practical, evidence-based rehabilitation recommendations.


The investigation identified widespread sodic and magnesic soils, highly dispersive soil conditions and significant nutrient deficiencies that had the potential to affect vegetation establishment, increase erosion risk and compromise long-term rehabilitation success. Rather than relying on standard rehabilitation specifications, Dynamic Environmental Services developed practical, evidence-based recommendations for soil amelioration, fertiliser application, species selection and rehabilitation methodologies tailored to the site's specific conditions.


The rehabilitation recommendations also considered stockpile management, progressive rehabilitation, erosion protection measures, concentrated runoff from solar panel arrays and long-term monitoring requirements, providing the client with a practical framework to guide rehabilitation throughout construction and into the operational life of the project.


By combining expertise in soil science, erosion and sediment control, rehabilitation and construction, Dynamic Environmental Services developed practical recommendations that could be readily implemented during construction while supporting long-term rehabilitation outcomes. The result was a rehabilitation approach that was scientifically informed, practical to deliver and tailored to the specific conditions of the site.


Outcomes

  • Site-specific rehabilitation recommendations based on detailed soil investigations
  • Practical recommendations for soil amelioration, fertiliser and species selection
  • Rehabilitation approach tailored to the site's soil and construction constraints
  • Improved long-term vegetation establishment and land stability
  • Reduced erosion and rehabilitation risks through evidence-based planning 


Client Feedback

"Thank you for the recent Soil Sampling and Revegetation Plan.  I would just like to mention that it was an absolute pleasure working with you and the whole Dynamic team.


I was particularly impressed with Dynamics seamless interaction into our management systems and the high quality of communications both emails and phone calls which solved dilemmas and made decisions clear, simple and easy.


Additionally, I would like to advise that our client was particularly impressed with the report which resolved several weeks of internal circular discussion upon their overnight review. In short, they were impressed with the quality, depth and thoroughness of the report which gave them the confidence to approve our site management plan."


By Lisel Dingley March 29, 2026
We regularly see sites assume that because they hold approval for an ERA, they can undertake anything that falls within that ERA. That’s not how Environmental Authorities work. An EA does not approve the full scope of what an ERA could include. It approves what you applied for — including the way the activity is undertaken, the infrastructure used, the controls you committed to and the scale and intensity you described. Sometimes, there are some obvious limitations set by your EA per ERA. For example, you may hold ERA 54 Mechanical Waste Processing, Threshold 2 (general waste), therefore, if you want to take regulated waste, you know that you aren't licenced to do so, as it is Threshold 3 & 4. It's the more subtle changes where things can come unstuck, particularly in the waste management ERA space. What Your EA Actually Covers When your EA is granted, it is based on a specific proposal. That proposal includes: The activity itself Where it will occur What materials or wastes are involved How it will be undertaken What controls are in place to manage environmental risk That combination forms the risk profile that was assessed and approved. It is not a blanket approval for all variations of that activity/ERA. Where Sites Get Caught Out Most non-compliances in this space are not deliberate. They come from operational changes that seem minor at the time: Moving an activity to a more convenient location Scaling up volumes Changing inputs slightly Adjusting how something is managed day-to-day Individually, these can seem insignificant. But from a regulatory perspective, they can fundamentally change the risk to environmental values — which means they fall outside what was originally approved. Example 1 – Crushing Concrete under ERA 54 You are approved to undertake crushing concrete under ERA 54. What was approved: Crushing within an enclosed building Dust suppression sprays on the machine Settled dust wet cleaned within bunded area, and vac truck removed offsite to be disposed at facility that is licenced to accept it You now want to undertake crushing outdoors. It’s still crushing — so it feels like it should be fine. But the risk profile is no longer the same: Dust is no longer contained and can travel offsite Fine material can be mobilised into stormwater Noise is no longer attenuated by the building (for offsite sensitive receptors/neighbours) Wind becomes a factor The original approval was based on a controlled system. Moving outdoors changes how emissions behave and where they end up. Example 2 – Wastewater Reprocessing under ERA 55 You are approved to receive and reprocess wastewater in ponds. What was approved: A purpose-built pond with engineering design Construction Quality Assurance (CQA) completed Leak detection system installed Groundwater monitoring bores in place Defined and assessed allowable inputs You now want to construct another pond, or accept a slightly different input. Again, this appears similar. But, because you think you are already approved for this activity, you aren't putting together an EA application which steps through all the requirements, and therefore, some aspects get missed: If the new pond is missing any of those design or verification elements, seepage risk increases Without monitoring or leak detection, early warning systems are lost Different inputs may behave differently in storage or treatment (for example, odour risk) The original assessment of contaminants and volumes may no longer apply Even if the pond looks the same, the certainty of performance and level of risk is not the same. Example 3 – Other Activities under ERA 55 You are the same site as Example 2, already approved under ERA 55 to receive and reprocess wastewater in ponds. You now want to treat contaminated soils using stabilisation (e.g. lime dosing). It’s still ERA 55 — so it feels like you should be covered. But let's think about what was approved: Treatment of liquid waste in lined ponds Risks primarily related to odour, pond failure, seepage and groundwater What changes: Dust generation from handling soils Airborne contaminants and exposure pathway To be undertaken in an unlined, unbunded area Stormwater contamination from open treatment areas Land contamination risks Potential for offsite reuse (if uncontrolled, contamination of other sites) Same ERA — completely different risk. The original EA for wastewater ponds does not consider these impacts, so the new activity has not been approved. Why “Almost the Same” Isn’t the Same A key point that is often missed is this: Environmental risk is driven by more than just the activity itself. It is driven by: How emissions are generated How they are controlled The pathways they can travel The receptors they can reach Small changes to any of these can significantly change the outcome. Two activities that look identical operationally can have very different impacts once you consider odour, dust, surface water, noise, or groundwater pathways. When Do You Need an EA Amendment? As a general rule: Assume an EA Amendment is required. Request a pre-lodgement meeting, be clear about the change you are thinking of, and take guidance from the assessing officers. This is not a space for “we’ll just make the change and see how it goes”. Why It Matters Operating outside the scope of your EA is not just a paperwork issue. It can result in: Non-compliance with conditions Environmental harm or nuisance Regulatory action Be issued a stop works notice, essentially cutting off your source of income Costly and time-consuming remediation or retrospective approvals We often see sites end up in a far more difficult position trying to justify a change after the fact, rather than assessing it properly upfront. In Closing Your EA is not an approval for everything that falls under the ERA listed on your licence. It is approval for what you applied for — a specific activity, undertaken in a specific way, with specific controls. If those things change, your approval may no longer apply. That’s why the detail in your original EA application — and any amendments — matters. What you describe is what gets assessed, and ultimately, is what you are approved to do. If your operations are evolving, don’t assume you’re covered. Stop, assess the risk, and confirm whether an amendment is required. Give us a call to discuss your waste-related activities — whether it’s an original EA application or an amendment. Last updated 29 March 2026. This information is general in nature, may not be current, and may not be applicable to your specific circumstances. It should not be used as a substitute for site-specific professional advice.
By Lisel Dingley March 27, 2026
When is it a resource? When is it a waste? And what do you actually need to do? 
By Lisel Dingley November 19, 2024
Hypothetical Situation: A site’s Environmental Authority lists a number of groundwater bores, and states that they must be monitored for certain parameters 6 monthly. The EA has another condition which states that a groundwater review must be undertaken every 3 years by an appropriately experienced person (hydrogeologist). The site diligently samples the groundwater bores, and collates the field and laboratory results into a spreadsheet. However, those results are not reviewed when they are received… because the EA says that a groundwater review must be undertaken every 3 years, with no other specific review obligations. Given groundwater monitoring is intended as a warning system for contamination, is only reviewing the groundwater results every 3 years adequate to meet the General Environmental Duty of the Environmental Protection Act? Or a general EA condition such as the requirement to take all reasonable and practicable measure to prevent or minimise the likelihood of environmental harm being caused by the activities? When a dam containing hazardous waste is found to be leaking (found upon visual inspection), and subsequently the previous two years of groundwater data are reviewed and found to indicate this has been occurring prior to the visible leak being detected, it is likely this will not be looked upon favourably in a prosecution. “But it wasn’t time for our 3 yearly review!” is unlikely to be acceptable to the Regulator. Perhaps the EA has another condition which states that deterioration of groundwater quality must be reported to the Regulator within 14 days of receipt of the results. If data is only reviewed every 3 years, how is this condition being met? Perhaps the EA has a condition that requires the development and implementation of a Groundwater Monitoring Plan. It is suggested an adequate Groundwater Monitoring Plan should include guidance on interpretation of results, not just what, when and where to monitor. In our opinion, a Groundwater Monitoring Plan without interpretation guidance is defective and non-compliant with the intent of the condition. And if it does have guidance, is this clear enough to be accurately and swiftly executed by site personnel? We see many shortcomings in groundwater monitoring. Some of the most common and most significant include: · Data that clearly demonstrates potential environmental harm, which has not been noticed or investigated. There are some really easy ones in this space – your groundwater should not have PFAS in it! If it does, you either have identified contamination of the aquifer or contamination of your samples by your sampling methodology or the laboratory. Regardless, this should be promptly investigated. · Sites not being aware which of their bores is a leak detection bore and which are aquifer monitoring bores. One should be dry and the second should not be dry, and if this is not the case, this needs investigating. · Sites not having modelled groundwater flow direction to determine what is an upgradient (background) monitoring bore, and what is downgradient (identification) monitoring bore, and therefore not being able to interpret results adequately. · Not monitoring water quality in ponds that have the potential to leak, and therefore being unaware of the potential contaminants that would indicate seepage into the aquifer from the pond. Groundwater monitoring can be a highly effective detection system of potential environmental harm, but only if it is undertaken well, by persons with a comprehensive understanding of monitoring well construction, groundwater and contaminants, and with an adequate system of bores in place. Last updated 19 November 2024. This information is general in nature, may not be current, and may not be applicable to your specific circumstances. It should not be used as a substitute for site-specific professional advice.
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