contamination

Industrial Management Facilities represent a hazard to the down gradient surface water and groundwater environment. The assessment of the risks such facilities pose to the water environment is an important issue and certain compliance standards are set by regulators, particularly when the potential for an impact on the water environment has been identified. This paper will aim to describe how the contamination was conceptualized, estimated, limitations and how it is technically not feasible to establish one limit or compliance value of known contamination in different aquifers.

The improvement in hydraulic fracturing techniques resulted in the exploitation of natural gas associated with low-permeability organic-rich shale formations in the United States. South Africa has prospective shale gas resources linked with the marine black shales of the Whitehill Formation found in the Karoo Basin. Plans exist to develop the Karoo shale gas resources to diversify the primary energy mix. However, concerns among stakeholders about groundwater contamination and source of water for hydraulic fracturing remain unresolved.

To control the impact of nitrate and its sustainable mitigation in groundwater systems used for drinking water production, it is crucial to understand and quantify sources as well as biochemical processes which (permanently) remove nitrate.

In an alluvial aquifer in Germany (Hessian Ried) that serves as major drinking water recourse for the Frankfurt metropolitan area, water quality is challenged by nitrate contamination from intensive agricultural land use locally by far exceeding the drinking water limits of 50 mg/L.

Households in many rural areas worldwide rely on septic tanks, simple pit latrines or other means of wastewater disposal. Many such households are not served by a piped mains water supply, but rather obtain their water supplies from local wells. Sampling studies of private wells in Ireland and elsewhere have shown many wells to be contaminated, with sources of microbial contamination known to include domestic wastewater treatment systems, as well as practices associated with intensive agricultural production.

Anticipated Shale Gas Development could intensify possible natural hydraulic connectivity between deep groundwater reservoirs and shallow aquifers in the Karoo. This project attempts to test geochemical evidence of natural mixing between old groundwater from deep aquifers and young groundwater from shallow aquifers using selected isotopic signatures in conjunction with borehole yields. Borehole yields were determined using slug tests. All isotopes (δ18O, δ2H, δ13C, 3H and 14C) were analysed in the laboratory of Environmental Isotope Group of iThemba Laboratories in Gauteng.

The proximity of aquifer systems to sources of contamination exposes them to severe environmental threats. Pollutants that leak from petrol stations, industrial areas and landfills eventually seep through the vadose zone to reach shallow groundwater, leading to groundwater contamination. One of these pollutants is Methyl Tertiary-Butyl Ether (MTBE), which is a polar organic compound that is volatile at room temperature.

The most used methods for the capturing of shallow groundwater contamination are the use of abstraction wells and infiltration trenches. The use of trenches for the interception of shallow groundwater contamination has become a popular choice of remediation method due to the lower cost than a comparable pump-and-treat system. Trenches have large surface areas which limits the tendency of filter media clogging with suspended media as well as only a single pump and lower maintenance requirements.

South Africa utilizes coal for energy and chemical feedstock thereby generating millions of tons of ash every year. The ash is stockpiled in surface waste facilities where it poses a risk of leaching and contaminating groundwater. This study utilizes standard leaching tests, TLCP and SPLP, to evaluate and predict the mobility of different elements that leach from fly ash. Two different fly ash samples (Ash M and Ash T) were used in the study. A QEMSCAN analysis was also performed on the samples as well as the coal to determine the elementary and mineralogical compositions.

Burning of coal for electricity production has resulted in vast amounts of ash being deposited in ash dumps. Rain water and ash water conditioning results in the wetting of ash dumps and if the water retention capacity is exceeded there is a possibility of leaching to soil and underlying aquifers. In this study two different coal ash are used to determine the water retention as excess amount of process water at power stations ash dumps can lead to impeding the desired water balance, which can be critical for maintain various plant processes.

Unconventional gas development in South Africa consists of but not limited to shale gas extraction commonly known as “fracking”, Underground Coal Gasification (UCG), Coalbed Methane (CBM), to extract natural gas from geological formations is a new, rapidly expanding industry in the world and in South Africa. However, there are general concerns that these operations could have large negative impacts such as groundwater contamination.