Designing a hands-on environmental sampling training course for students that meets the requirements of industry

A large percentage of new geology graduates will find employment within the environmental sector and will likely be engaged with clients and regulatory agencies on permitting, environmental baseline studies, contaminated site assessment, the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) and on supporting engineering projects. Compared to the traditional mining and oil & gas sectors, demand for environmental professionals is generally less volatile, is often based in major population centres and offers a greater degree of career stability. The environmental profession encompasses a wide range of degrees, including chemistry, engineering, geology, hydrology, environmental law, and biology. This can make for a varied and stimulating career choice

Arsenic speciation in surface water draining the golden zone Breccia deposit in central Alaska

The Golden Zone (-149.6397222,63.2188889) is a 9,900 hectare Au–Cu-Ag mining claim located in the Chulitna mineral belt of the Valdez Creek mining district in south-central Alaska, approximately 240km north of Anchorage. It is bordered on the north and west by the mountainous Denali Wilderness Area, which is off limits to mining and an environmentally sensitive area. The Golden Zone property lies at the northern end of the Chulitna-Yentna mineral belt, a fault-bounded block of Devonian to Triassic sediments and volcanoclastic sediments (Hedderly-Smith,2011

Characterization and remediation of sites contaminated by historical fuel spills in Arctic Alaska

The Naval Arctic Research Laboratory (NARL) was operational from 1947 until 1980 occupying a 350 acre site north of the city of Barrow. At a latitude of 71 degrees north Barrow is the most northerly city in North America and is located at the strategic junction of the Chukchi and Beaufort Seas. Most of the original structures at NARL are still intact and have been put to other uses. However, complete utilization of the facility is limited by soil contamination dating back to its former use. Most of the contamination relates to fuel spills but metals, PCBs and chlorinated solvents are also present at some locations above action levels. Characterization and remediation efforts have been ongoing since the Navy left NARL and are expected to continue for another decade or more. Sub-surface movement of contaminants is complicated by the presence of permafrost which limits vertical migration of contaminants and restricts lateral migration to the unfrozen zone, which is active during the summer months. As extreme low temperatures in Barrow during the Arctic winter greatly reduce the effectiveness of natural degradation contaminant concentrations can remain elevated for an extended period. Other remediation options are limited by the high cost of transporting contaminated soil by barge during the short window when ocean transportation is possible; there are no road connections to Barrow. This poster provides an overview of efforts to characterize sub-surface contamination at the former NARL site and the effectiveness of previous attempts to remediate specific sites. Observations on the future direction of clean-up activities will be presented in light of the growing importance of the Arctic as an economic and strategic resource and the environmental concerns of local inhabitants

Geochemical aspects to reusing dredged canal sediment

Britain's canal network was instrumental in the rapid explosion of the industrial revolution in the late 18th century, allowing efficient transportation of coal and iron to industrial centres and of products to market. The canal network began to diminish in importance with the advent of rail transportation in the mid-1800s, but still served commerce until the 1960s; the larger ship canals are still used. By the late 20th century many canals were abandoned, derelict (Figure 1), impacted by pollution, and were contributors to urban blight. However, thanks to the efforts of enthusiasts and conservationists, canals have since enjoyed a renaissance for leisure boating and, more recently, as a catalyst for urban regeneration via projects such as the Millennium Link in Scotland (Fleming 2000). This £78 million engineering project required the removal of thirty canal obstructions via new road bridges, locks, and the iconic Falkirk Wheel canal lift (Figure 2)

Remediation challenges in the Arctic – lessons from Alaska’s North Slope

Alaska’s North Slope comprises a 250,000 km2 broad plain extending from the Brooks mountain range in the south to the Arctic Ocean in the north, at a latitude that is well above the Arctic Circle. Despite a resident population of less than 10,000, the region has around 450 identified contaminated sites. The majority of these sites are associated with military installations, including DEW and former White Alice radar stations, oil exploration and production at Prudhoe Bay, and diesel releases from the storage and handling of fuel in remote villages. Historically, proper disposal of used oil and hazardous waste has been exacerbated by high transportation costs within a region that is largely road less and wholly dependent on air and ocean transport. Characterisation of sites and the prediction of contaminant migration is complicated by the presence of continuous permafrost in the region. The active layer, which is the upper soil horizon that thaws, reaches a peak depth in August of around five feet, with suprapermafrost water flow restricted to this narrow zone. Within gravel pads placed to support infrastructure, groundwater flow is generally predictable, but within native tundra soil fracture flow dominates. Further, pockets of contaminated media can become isolated through differential ground melting if the thermal regime is disturbed. Some case studies from Prudhoe Bay and Utqiagvik are presented to illustrate uncertainties in characterising Arctic sites. The remoteness and extreme climate of these sites places limitations on site remediation options. In-situ methods, including bioremediation and mycoremediation have some potential to reduce costs and limit the environmental impact of remediation

The impact of artisanal gold mining, ore processing and mineralization on water quality in Marmato, Colombia

Marmato, Colombia, has been an important centre of gold mining since before the first Spanish colonizers arrived in 1536. The Marmato deposit is hosted in a dacite and andesite porphyry stock as sheeted sulphide-rich veinlet systems. The district is currently experiencing a surge in both major mining projects and artisanal mining, driven by sustained high gold prices. Ore from small-scale and artisanal gold mining is processed in numerous small mills (entables) around Marmato, which impact surface water quality through the discharge of milled waste rock slurry, highly alkaline cyanide-treated effluent, and high dissolved metal loads. To investigate the impact of artisanal mining and ore processing, water samples were collected in January 2012 from streams around Marmato. The average dissolved metal concentrations in impacted streams were Zn, 78 mg L −1; Pb, 0.43 mg L −1; Cu, 403 µg L −1 Cd, 255 µg L −1; As, 235 µg L −1; Ni, 67 µg L −1; Co, 55 µg L −1; Sb, 7 µg L −1; and Hg, 42 ng L −1, exceeding World Health Organization drinking water guidelines. In addition, arsenic speciation was conducted in-situ and indicated that 91–95% of inorganic arsenic species is in the form of As(V). Spatial analysis of the data suggests that entables processing ore for artisanal miners are the main contributor to water pollution, with high sediment loads, alkalinity and elevated concentrations of dissolved arsenic, cadmium, mercury and lead, caused by the processing of gold-bearing sulphides in the entables. Geochemical data from surface water were compared to a comprehensive data set of whole rock analyses from drill core and channel samples from the deposit, indicating that the deposit is significantly enriched in gold, silver, lead, zinc, arsenic, antimony, and cadmium compared to crustal averages, which is reflected in the surface water geochemistry. However, elevated mercury levels in surface water cannot be explained by enrichment of mercury in the deposit and strongly suggest that mercury is being added to concentrates during ore processing to amalgamate fine gold

A pilot study for the nature-based conditioning of dredged urban canal sediments and their beneficial reuse

Introduction: Only a small fraction of the estimated 200 million cubic metres of sediments that are dredged each year from ports, canals and waterways are repurposed. As part of the SURICATES [1] Interreg NWE462 project, a pilot study was conducted in 2019 to address the technical and economic challenges to adaptive sediment reuse, using passive dewatering and revegetation to accelerate sediment conditioning. Figure 1 Falkirk South site with the Union Canal in the background Methods: A 800 m2 treatment area was constructed on a former open cast coal mine site adjacent to the modern section of the Union Canal near Falkirk, Scotland constructed in 2001 as part of the Millenium Link. Six cells were designed that received approximately 1,018 m3 of wet sediment dredged from the Union Canal by a pontoon mounted excavator, which was emplaced over three weeks during July and August 2019. The project aim was to condition sediment for reuse in engineering projects along the canal.Canal sediments sampled in-situ prior to dredging consisted of silty sand and fine sands (10µm – 120 µm), with up to 23% loss on ignition at 550 ºC (equivalent to c.13% total organic carbon). This is consistent with leaf litter and other natural inputs from the canal system. Conditioning of wet canal sediment into a material that can be beneficially reused requires both dewatering from its initial dry weight of around 20% to around 65%. De-watering progress was monitored over a period of 6 months using pre-installed monitoring wells and fiberglass sleeves for use with a Delta-T PR2/6 [2] time-domain reflectometry moisture probe. This probe allowed moisture content to be measured at six depths within the sediment. Soil texture, surface features, and re-vegetation were also documented over the course of the pilot trial.Results: Progressive evidence of sediment de-watering was measured and observed over the course of the trial. This was evidenced by a reduction in the measured moisture content, falling water levels in the wells, and the formation of a crust on the sediment with polygonal desiccation cracks. Our observations also suggest that crustal formation is a largely irreversible process as sediment dewatering rebounds rapidly after heavy rainfall events. Some surface oxidation of organic matter was suggested by colour changes. Figure 2. Monitoring well levels in Cell F1.Discussion: The pilot study reinforced the importance of establishing effective drainage pathways, ideally at both the base of the cells and on the sediment surface to manage runoff and dewatering. Despite an exceptionally wet summer, the material was suitable for excavation and reuse as soil by February 2020. Due to the short residence period, weather events, flooding, and germination issues with the batch of seed used, the effects of plant growth were not observable, other than for voluntary revegetation. Lessons from this pilot study have been applied to two full-scale studies at Bowling and another site on the Forth & Clyde Canal that began in 2020.References: [1] SURICATES - Sediment Uses as Resources In Circular And Territorial EconomieS. Interreg, North-West Europe. https://www.nweurope.eu/projects/project-search/suricates-sediment-uses-as-resources-in-circular-and-territorial-economies/[2] Delta-T Devices, Burwell, Cambridge https://www.delta-t.co.uk/

Repurposing dredged canal sediment for topsoil at Bowling, Scotland

The aim of the SURICATES (Sediment Uses as Resources in Circular And Territorial EconomieS) Project is to increase sediment reuse for erosion and flood protection. To investigate potential opportunities to reuse dredged sediments as topsoil following phyto-conditioning, a pilot scale operation was undertaken at Bowling, Scotland. As part of normal maintenance, 550 m3 of wet sediment was removed from the Forth and Clyde Canal at Old Kilpatrick by Scottish Canals using a hydraulic excavator during September 2020, transported by barge, then transferred to a dewatering cell constructed in an old canal basin by lining with a geotextile break-layer and installing engineered drainage. Following initial dewatering, the sediment was sown with three varieties of grass, which each germinated and survived the winter. By March 2021 composite soil samples already met the BS 3882:2015 criteria for topsoil, other than for Zn levels, which reflected the locally elevated baseline values. This allowed the conditioned sediment to be used immediately as topsoil as part of the nearby construction of a long-distance cycle track following an old railway embankment. Following reuse, replicated validations of six grass or wildflower seed mixtures were sown in April 2021 and monitored to verify longer-term suitability as a landscaping soil

Spatial variation of mercury in surface water impacted by artisanal gold mining in Marmato, Colombia

Marmato, Colombia has been an important centre of gold mining since before the first Spanish colonisers arrived in 1536. The district is currently experiencing a surge in both major mining projects and artisanal mining, driven by the high price of gold. Ore from small scale and artisanal mines is processed in numerous small mills or ‘entables’, which impact surface water quality through the discharge of milled waste rock slurry and highly alkaline cyanide-treated effluent. A pressing environmental concern is the use of mercury to amalgamate gold in concentrates from the small mills, which is widespread in other gold producing regions of Colombia. To investigate the spatial distribution of mercury and other potentially toxic elements, surface water samples were collected around Marmato and analysed for dissolved Hg using atomic fluorescence spectroscopy (AFS), and for other trace metals using ICP-MS. The total dissolved Hg in stream water ranged from below detection limits to 142 ng L-1, despite the deposit having a low Hg signature. Other potentially toxic metals, including Pb, Sb, Cd and As were also elevated, but were attributed to the sulphide mineralogy in the deposit. The spatial relationship between dissolved Hg and possible point sources of pollution was analysed using ArcGIS software. The highest values of dissolved Hg are around the Marmato gold deposit where there is a concentration of small mines and mills. Since this is a low Hg deposit, a natural source for Hg can be eliminated, confirming that dissolved mercury reflects sporadic use by artisanal miners

Survey of the needs of patients with spinal cord injury: impact and priority for improvement in hand function in tetraplegics\ud

Objective: To investigate the impact of upper extremity deficit in subjects with tetraplegia.\ud \ud Setting: The United Kingdom and The Netherlands.\ud \ud Study design: Survey among the members of the Dutch and UK Spinal Cord Injury (SCI) Associations.\ud \ud Main outcome parameter: Indication of expected improvement in quality of life (QOL) on a 5-point scale in relation to improvement in hand function and seven other SCI-related impairments.\ud \ud Results: In all, 565 subjects with tetraplegia returned the questionnaire (overall response of 42%). Results in the Dutch and the UK group were comparable. A total of 77% of the tetraplegics expected an important or very important improvement in QOL if their hand function improved. This is comparable to their expectations with regard to improvement in bladder and bowel function. All other items were scored lower.\ud \ud Conclusion: This is the first study in which the impact of upper extremity impairment has been assessed in a large sample of tetraplegic subjects and compared to other SCI-related impairments that have a major impact on the life of subjects with SCI. The present study indicates a high impact as well as a high priority for improvement in hand function in tetraplegics.\ud \u