I observed the postulations made by CSIR, represented by Dr A.K. Mensah, on Joy FM’s News File programme with respect to the time budgets it may take to decontaminate affected soils and water bodies at galamsey sites with grave concern. The CSIR representative followed up with a rejoinder, after I expressed my concerns, to reiterate their position on the subject. However, this time, the focus is only on contaminated soils, which suggests that it may take a minimum of 323 years to remediate contaminated soils for any repurposing.

Once again, I reiterate my concerns emphatically, particularly having dived deep into the rejoinder where more details have been provided. I am not particular about plagiarism, about some of the details I intend to discuss from works already done by others, since this is not a journal manuscript or a manuscript to present for the award of marks or any other reward. Again, because this position paper is not a journal manuscript, in-text citations and references will be reduced to the barest minimum and only provide clues to sources with authors and title of reference study.

I will start my arguments by first explaining the processes of mine site remediation through a rehearsing of the key concepts as done by my colleague, differentiating between the major approaches of contaminated soil and water remediation, and providing research-based, regulatory and industry examples of remediation. I shall marshal my points, emphasizing the methods of remediation, type of commodity, time budgets of remediation, and results obtained. I shall then conclude with local examples of heavy metal contaminated soil and waterbody remediation. Since both surface and underground waterbodies first interact with soils, it is difficult to treat the two separately. Underground water tables are contaminated by leaching of heavy metals from the topsoil. Surface waterbodies are contaminated by surface runoff, transportation, and deposition of heavy metals from the topsoil into streams, rivers, and lakes.

To begin with, The National Academy of Sciences in the United States of America has defined three categories of remedial treatment of contaminated waterbodies and soil as following:

Rehabilitation: where land is returned to a form that ensures its productivity is in conformity with prior land-use. This includes a stable ecological state and is consistent with the surrounding aesthetic values.

Restoration: refers to the situation whereby the condition of the site prior to its disturbance is replicated after mining.

Reclamation: simply refers to the process of returning the mined land, water and surrounding environment back to a natural or usable state and reversing any adverse effects on land or water that has occurred because of mining operations. The site is inhabited by organisms that were originally present or others that approximated the original inhabitants. Reclamation can be applied to both open and closed mines, as well as to orphaned and abandoned sites.

Contaminated site remediation involves two major techniques: biological (bioremediation and phytoremediation, and mechanical (physical removal). Biological remediation involves both bioremediation and phytoremediation. Bioremediation involves using biological agents to remediate environmental contaminants. It involves the use of biological agents such as plants and microbes to remove or reduce the effects of environmental pollutants. Phytoremediation is the use of plants to remediate toxic environmental compounds. It has been used extensively owing to its ‘green’ approach. Mechanical remediation involves the physical removal of earth or soil contaminated by excavation, relocation, cleaning, and replacement.

Biological Remediation techniques (bioremediation and phytoremediation)

Lee A. Newman and Charles M. Reynolds (2004) study on Bacteria and phytoremediation: new uses for endophytic bacteria in plants find that a limitation to phytoremediation of solvents has been toxicity of the compounds to plants, and the uncertainty as to the fate of many of the compounds.Thestudysuggeststhat adivision betweenphytoremediationandrhizodegradation is the use of plants to stimulate the microbial community near the root–soil interface to enhance the degradation of recalcitrant compounds in the soil. Although phytoremediation methods have been adopted for many years, the challenges associated with them have promoted the use of bioremediation as an alternative. Of these, microbes are primarily utilized because of their rapid growth and ability to be easily manipulated, thus enhancing their function as bioremediation agents. Different groups of bacteria, fungi, and algae have been employed to remove various environmental pollutants.

Logically, the critical chronological remediation steps include:

Mappingto delineate areas of direct and indirect environmental degradation usingscaled maps, remote sensing, GIS, aerial photographs, etc.

Geological and geotechnical investigations of the stratum that is likely to influence restoration. This includes the field and laboratory testing of soils and materials to investigate the parameters that are essential for sustainable remediation. For example, the toxicity of soil and the stability of waste dumps must be investigated before remediation processes are carried out.

Meteorological and climatological investigations must be conducted to collect standard data (temperature, amount of rainfall, humidity, wind patterns, etc.) and assess their influence on soil and water contamination and their potential influence on remediation techniques.

Hydrological conditions at a site include the quantity, quality, movement, and storage of water above and below the surface. Hydrology is determined by the upslope and onsite characteristics of climate, geology, topography, soil, and vegetation. Whereas the other parameters determine the movement of water into and across the surface, climate provides water input to the hydrologic system.An aquarium is found in soils and geological structures.

Topographic conditions refer to the landscape configuration of a study area. The topography of the disturbed site influences remediation plans, techniques, outcomes, and practices.

Soilconditions, including the soil’s water retention capacity controlled by the combined factors of texture, aggregation, bulk density, and overall depths, directly influence plant productivity, leaching potential, and groundwater replenishment. Therefore, the protocols employed are specific to the region, site, and intended repurposing.

As a first step in remediation, it is necessary to determine the type of soil on which the plants would grow. To do so, it is important to consider the existing mineral matrix (i.e., particle size distribution of natural soils and waste rock piles, mineralogy, geochemistry, organic content, and toxicity) and the types of plants that grow naturally in the intervention area. For instance, the growth and survival rate of plants under cold climate conditions are short and will have less impact on heavy metal removal from contaminated soils.

Once details of the plant and soil are known, nutrients should be generated and added to the soil. Biochar, which can retain moisture and provide a carbon source, is used. The nutrient mixture is then added to the disturbed soil and waste rock on the site to promote the development of soil for plant growth. Explore the relationship between pioneer plants (plants that perform the initial colonization process on poor soils) and other plants growing in the area of interest (AoI) alongside the microbes (fungi or bacteria) associated with each. Since plants have bacteria that can protect, help, or hurt them, it is necessary to identify the root microbes that help plants grow. Get plants to grow on such materials because they start the process of improving soil quality, looking at the survival rate and growth performance of the plants. This requires extensive fieldwork, data collection, robust sampling, and experimentation in order to get robust results.

For instance, in some studies, soil enzyme activity has been used to test the biochemical status of the soil-plant system. Three experimental fields, each 1 hain area, wereplanted with Populus nigra, Salix americana, and grasses (with Alopecurus pratensis, Phalaris arundinacea, Festuca pratensis as the dominant species). The fields were divided into three parts: non-flood control (A), flood-irrigated 10 times per year with 60-75 mm (B), and flood-irrigated 10 times per year with 120-150 mm (C) wastewater per irrigation. The enzyme activity was measured several times during the first 2 years of wastewater application in soil sampled from control and flooded plots (0-10, 10-30, 30-50, 50-70 cm depth) to draw conclusions. This demonstrates scientific rigour for knowledge.

In the paper, Surface mining and reclamation: Initial changes in soil character, Sam J. Indorante et.al. (1981) defined and characterized five different, newly reconstructed soil units on surface-mined land and three undisturbed (cultivated, but not mined) soil units. Selected properties of the reclaimed soils were compared with those of nearby undisturbed soils to determine the changes that occurred during mining and reclamation operations. Comparisons of each of the eight soil units showed the differences between constructed soils and undisturbed soils, between mining sites, and between topsoil and spoil units within each of the mining sites. The properties of the constructed soils reflect the pre-mining overburden characteristics and methods of soil construction, suggesting that considerable control over post-mine soil characteristics can bemanaged by careful selection of materials and material handlingmethods.

Ned Z. Elkins et.al. (1984) studied the Responses of Soil Biota to Organic Amendments in Strip-mine Spoils in Northwestern New Mexico. The aim of this study was to evaluate the relative efficacy of amendments in restarting soil processes after disturbances.They studied the decomposition of barley straw (Hordeum vulgare) and the populations of soil biota.The spoils were amended with straw mulch, bark, top-soil, or no organic additive. Decomposition rates were highest in the unmined area and the bark, amended spoils (K = 0.64 yr−1) (K = first-order rate constant), and lowest on the topsoil amendment and unamended spoil (K = 0.34 yr−1). Few differences were observed in the microflora populations of soil. Where differences were observed, the bark-amended spoils had the highest population and biomass. Soil microflora activity, as indicated by decomposition rates, was enhanced by the bark amendment. Soil microfaunal populations were the highest in bark-amended and unmined soils. Important soil mites (soil Acari) and oribatids were found only in the bark-amended spoils and unmined soils. The study suggests that the addition of selected organic amendments (bark) to mine spoils may be as effective in developing a soil as the more expensive topsoil/mulch procedures currently used in reclamation procedures.

V.A. Akala, and R. Lal (2000) studied the Potential of mine land reclamation for soil organic carbon (SOC) sequestration in Ohio, USA. A chrono sequence study of 0-, 5-, 10-, 15-, 20-, and 25-year-old reclaimed mine soils in Ohio was conducted to assess the rate of carbon sequestration by pasture and forest establishment. Undisturbed pastures and forests were used as the controls. The SOC pool of reclaimed pasture sites increased from 15-3 Mg ha−1 to 44·4 Mg ha−1 for 0–15 cm depth and from 10·8 Mg ha−1 to 18·3 Mg ha−1 for 15–30 cm depth over the period of 25 years. The SOC pool of reclaimed forest sites increased from 12·7 Mg ha−1 to 45·3 Mg ha−1 for 0–15 cm depth and from 9·1 Mg ha−1 to 13·6 Mg ha−1 for 15–30 cm depth over the same time period.

Sheoran, V. et.al. (2010) conducted a review of Soil Reclamation of Abandoned Mine Land by Revegetation. The study observed that the productivity of soils can be increased by adding various natural amendments such as sawdust, wood residues, sewage sludge, animal manure, as these amendments stimulate microbial activity, which provides nutrients (N, P) and organic carbon to the soil. Metal tolerant plants can be effective for acidic and heavy metals bearing soils. For better results, some ecological variables must be considered when selecting species for heavy metal removal from soils. These include their capacity to stabilize soil, organic matter, available soil nutrients, and understory development. During the initial stages of revegetation, quick-growing grasses with short life cycles, legumes, and forage crops are recommended.This will improvethe nutrient and organic matter contents of the soil. Plantation of mixed species of economic importance should be done after 2-3 years of growing grass on the remedial soil. While selecting suitable species for plantation in mine area, the following considerations have to be taken into account: Planting pollutant tolerant species; Plants of fast growing with thick vegetation foliage; Indigenous/exotic plants species with easy adaptability to the locality.

Drawing on examples from Large Scale mine sites in South Africa and Australia, Phytomining and Agromining, as innovative biological remediation techniques, have also been explored. Thus, South Africa’s closed Glencore coal mine site has long been a source of contention among miners, environmental activists, and affected communities.The bone of contention was whether old coal mine site properties could be remedied to provide agribusiness opportunities for surrounding communities. Hence, several organisations were commissioned to research means and methods for remediating the water and soil for a sustainable, long-term agricultural use.An experiment was set up to run a winter wheat pilot programme at the Mpumalanga mine site to investigate whether remediated mine land and mine water could offer sustainable livelihood opportunities for local communities.

The programme, which ran from April 2023 to January 2024, successfully demonstrated how remediated coal-mine land and mine- affected water could be used directly in agriculture. Winter wheat was specifically targeted because the cereal company Kelloggs believed that the grain could potentially be used to manufacture its cereals. The pilot involved growing different wheat crops irrigated by rainwater, reservoir water, borehole water, and mine-affected water on virgin and remediated land and then comparing the results of each approach. When tissue samples tests of the grain and plant were done, it was found to be perfectly acceptable for human consumption.The highest yield was obtained from remediated land irrigated with mine-affected water. The water contained minerals that proved beneficial not only to the plants but also to the soil, improving the pH.

The question is, can we replicate the success of the winter wheat pilot programme at the CSIR site for the same duration with the same grain of crop or with different crops? Alternatively, can we test it at our rehabilitated Galamsey sites (the Ghana Landscape Restoration project adopted sites) and with the same or different crops? Some of the suggested crops are potato, cotton, and maize. However, it is unclear whether the same methodology is applicable to other rehabilitated mine sites with different soil and water compositions. For this reason, it is inappropriate to draw conclusions or generalize that it may be possible to remediate mine contaminated soils and water with just wheat in less than 12 months.All other conditions must be observed.

Agribusiness incubator and agricultural research entity, Thrive Land Restoration, has taken a slightly different, more long-term approach. Thrive seeks to completely remediate the soil through the systematic planting of carefully chosen crops, called hyperaccumulators, which leach toxic minerals from the soil and rectify its pH levels. This approach seeks to rehabilitate soil and integrate local waste streams to produce living soils that can be productively used to grow nutrient-dense crops every season. Hence, nature is used to perform remediation – the right combinations of plants (Phyto), mushrooms (myco), and bacteria (bio)–to perform heavy metals lifting.

Through a highly scientific process, specific Phytomining plants are selected according to the properties of the soil and waste stream. For instance, a hyperaccumulator such as tea can accumulate aluminum without any danger to humans. Coal contains most of the macro, micro, and trace elements that plants need. However, knowing how to safely liberate them is a major challenge. Some plants can preferentially absorb heavy metals, sulfides, nickel, gold, and a variety of other metals. For example, the Thrive Land Restoration experiment discovered a fungus that absorbs rare-earth elements. US-based Sandia National Laboratories patented a process of using citric acid for this same purpose. Thrive is now researching the best plants to use symbiotically with fungi for natural rare earth element extraction.

Often, fungi, on their own, can help restore contaminated soils with mycoremediation, relying on the extensive symbiotic network of underground mycelia with plant roots. This is also nature’s most effective way to draw and store carbon in the soil. The use of Phyto-, Myco-, and bioremediation techniques has enabled Thrive to successfully grow winter wheat using a 30% mix of coal fines, awaste product,with aspecially formulated compost that has been inoculated with indigenous and effective microorganisms, a technique borrowed from Korean natural farming.

Natural farming in Korea takes advantage of indigenous microorganisms to produce fertile soils that yield a high output without the use of herbicides or pesticides. This has been shown to result in an improvement in soil health and loaminess, as well as better tilth and structure.

Soil is the clearing house of the planet, where waste and death are recycled back into life. As indicated earlier, you have to get the soil right first before planting. In this regard, we prove that there are ways to take waste Galamsey products and beneficiate them for use in agriculture. Nature has no concept of waste, as everything plays a vital role in the cycle, which is achieved in less than two (2) years. Do we need 323 years to test and achieve this in Ghana?

In addition, Thrive’s experiment showed that planting certain trees, such as fast-growing silver birch trees, can help to remove subsurface acid mine drainage (AMD). These trees have aggressive root systems, which absorb large amounts of water. One can even tap trees to obtain clean water as the sap rises in the trunk, while fresh filtered water transpires through the leaves to influence precipitation. Silver birch is also the fastest carbon drawdown tree in the world.

Success in environmental restoration is not solely about relying on a single plant species. Rather, it involves understanding the right combination of plants, trees, and ecosystems that can deliver the best outcomes. Focusing on just one solution, and reacting with alarm when it does not yield the expected results, can lead to unnecessary fear and public panic.As scientists, it is our duty to provide well-informed, balanced guidance, and offer reassurance to society, especially in times of uncertainty or crisis. Our role is to inspire confidence through sound research and practical solutions, not to incite panic when challenges arise.

In John Howieson et.al. (2016) study Bread from Stones: Post-mining land use change from phosphate mining to farmland, selected mine sites on Christmas Island in Australia were converted to agricultural land use. The Australian Government co-funded this research with a mining company (Phosphate Resources Limited) to assess the science required to introduce commercial agriculture to the island. The study assessed land-use change methods and results, including pre-commercial trials of selected broadacre crops, rotational cropping using legumes, high-value crops, and a microbial prospecting program to determine the capability of Indigenous bacteria in removing heavy metals from mine site water and soils. This research demonstrates a range of successful methods that enable new post-mining land use to produce farmland from an apatite (phosphate) mine site.

A variety of crops, such as dryland rice, sorghum, chia, quinoa, peanuts, and guar, have been investigated as potential rotational crops. Three experiments were conducted to measure the response of crops to K, and treatments were applied to sorghum, lablab, and mungbean. To examine how the site history affected soil fertility, Hayman soybean (60 kg/ha) and Highworth lablab (60 kg/ha) were both sown on April 25, 2013, each with the MINTOPE fertilizer basal mix at 90 kg/ha. To assess plant growth on the bay site, which was a waste pinnacle site prior to the dumping of the phosphate dryer dust in 2013, chisel ploughing to allow water infiltration and weed management were undertaken prior to sowing Lablab on January 24, 2013.

The cultivation of a selection of vegetable species enabled the assessment of their response to the fertility of soils, fertilizers, pests, and their yield potential. The trials were sown by hand from February to May at different sites and received daily attention. Plants sown included snake bean, yam bean, sweet potato, pumpkin (five varieties), peanut (three varieties), sweet corn, culinary lablab (10 lines selected from a related project on Cocos Island, and 2 new lines identified from work in Tanzania), chia, quinoa, and chickpea (desi and Kabuli types). As post-mining phosphate soils can contain higher levels of heavy metals, particularly cadmium, due to the inherent characteristics of the extant soil, which may be accumulated in plants, crop samples were analysed, both washed and unwashed, to determine heavy metal levels with and without dust contamination.

The program also attempted to identify well adapted microorganisms that facilitate plant growth, Nitrogen fixation, and phosphate solubilization. In addition, it assessed whether mycorrhizal fungi were naturally present in both mined and undisturbed soils. It also investigated whether any other P solubilizing bacteria were naturally present in the soils to aid in the solubilizing of the apatite. To determine the presence of naturally occurring rhizobia, legume seeds were washed with alcohol to remove any cells of rhizobia adhering to dust. Inoculated and uninoculated seeds were sown across key experimental sites.

The growth of lablab, cowpea, millet, sorghum, and maize was exceptional. Above-ground biomass, 8 weeks after sowing in mid-March, was 16 t/ha (dry weight) for sorghum, 5.2t/ha for cowpea. According to this study, these yields are comparable to the best production areas anywhere in the world. A further 5t/ha of sorghum regrowth was harvested on April 15, 2014, confirming the potential of multiple cuts of forage varieties. Through a physical reconstruction of the soil profile followed by a range of regionally appropriate agronomic trials, soil nutrient experimentation, and microbiological research, these targeted approaches achieved land use change from mined sites to highly productive agricultural soils promptly to achieve socioeconomic objectives.

The unanswered question is, are there examples of similar experiments conducted by the CSIR across a sample of mining Districts in Ghana to conclude that we need up to 323 years to remediate and enjoy the renewed potency of our contaminated soils in Ghana? The answer is obvious….

Shiqian Yin et.al. (2022) systematically assessed the characteristics and classification of Arsenic (As) -remediating microorganisms. These include bacteria (e.g., Stenotrophomonas spp.), archaea (e.g., Halorubrum spp.), and fungi (e.g., Aspergillus spp.). They found that functional microorganisms can interact with As in various forms, including redox, biomethylation, biosorption, and bioaccumulation, thereby playing a crucial role in As bioremediation and ecological balance. Studies on the molecular mechanisms of microorganism-mediated As-bioremediation enhance the understanding of the interaction between microorganisms and As and further guide the alleviation and removal of Arsenic contamination. Bioremediation is recognized as a promising novel method for the prevention and control of As-contaminated environments (Laura Passatore 2014 in the Journal of Hazardous Materials).

Arun Karnwal et.al. (2024) studied bioremediation strategies for heavy metal and POPs pollution, and the role of microbes, plants, and nanotechnology and suggests that bioremediation, utilizing plants and microbes, offers a promising solution for the remediation of heavy metal soil contamination. Certain microorganisms, such as Streptomyces and Aspergillus, and plant species, such as Hibiscus and Helianthus, show high metal adsorption capacities, making them suitable for bioremediation.

Arun Karnwal et.al. (2024) further concluded that plants’slow growth and limited remediation efficiency (phytoremediation) have been a challenge. I would want CSIR to take a particular note of these. Recent advancements involve leveraging plant-associated microbes to enhance heavy metal removal. In addition, nanotechnology, particularly nano-bioremediation, shows promise for efficiently removing contaminants from polluted environments by combining nanoparticles with bioremediation techniques. The study underscores bioremediation methods for heavy metals using plants and microbes, focusing on the role of Plant Growth Promoting Rhizobacteria (PGPR) in promoting phytoremediation. It also explores the implementation of nanotechnologies for eliminating metals from polluted soil, emphasizing the significance of soil microbiomes, nanoparticles, and contaminant interactions in developing effective nano remediation strategies for optimizing agriculture in contaminated fields.

FA Otchere et.al. (2004) study of transforming open mining pits into fish farms: Moving towards sustainability requires a site-specific design approach that must consider issues ranging from metal uptake by fish instead of generalization of approaches. Indeed, this reiterates the minerals and mining industry’s mantra that mining challenges are site-specific and can, therefore, not be treated with holistic approaches or generalizations.

In 2023, an MPhil candidate’s supervisor at the University of Energy and Natural Resources (UENR) conducted efforts to investigate the selectivity of agricultural waste adsorbents Towards various metal ions in water. Their study found that coconut shells have a strong propensity to remove 64%, 99.95%, 99.34%, 98.63%, and 54.99% of arsenic (As), mercury (Hg), zinc (Zn), copper (Cu), and lead, respectively, from contaminated waterbodies. This research is currently constructing affordable biofilters for quick in situ heavy metal water filtration. These findings were presented in the 2nd Annual Transformational Dialogue on Small-Scale Mining organized by the School of Mines and Built Environment of UENR and published in the report.

At the 2nd Annual Transformational Dialogue on Small-Scale Mining in 2023, the Department of Biotechnology and Molecular Biology at the University for Development Studies presented their research work on the activation of rice husk biochar using microwave lemon juice-citrate acid for lead and mercury adsorption from the aqueous phase. Their results showed that the technique was capable of removing 99.26% Hg and 92.67% Pb from contaminated water bodies and soils. This has also been published in dialogue reports.