Thesis (Ph.D.) OGI School of Science & Engineering at OHSU, June 2008. / Includes bibliographical references.

No description available.

Contamination from agricultural fertilizers and pesticides has been recognized as a serious threat to underground drinking water sources. Through separate federal acts and amendments, the states have been given various levels of support with which to attack this contamination problem. However, these federal acts have not provided enough protection for groundwater from agricultural chemicals. The states must develop their own management programs for groundwater quality protection. Each state needs to consider what type of policy it will use as the foundation of its program. The policy can provide uniform groundwater quality throughout the state, provide for limited degradation throughout the state, or allow variances in groundwater quality for different locations. The strategies available to be used in the construction of a program consist of regulation, imposition of liability, economic incentives, and education. Finally, the states need to realize the basic mechanics needed for program support. The states of Nebraska, California, New Mexico, and Arizona serve as examples to show methods through which groundwater quality protection can be realized. Some major obstacles still exist in the development of effective state groundwater quality protection. These obstacles must be overcome to provide effective management of agricultural contamination of groundwater. / Master of Science

The existence of comprehensive groundwater protection programs on the federal, state, and local levels was investigated. Because of the unique characteristics of aquifers and contamination sources, local groundwater protection programs were found to be the most comprehensive; however, it was discovered that no universally accepted method existed to measure their effectiveness. An evaluation method was developed to determine local groundwater protection program effectiveness, and the method was applied in two case studies, one urban and one rural. The urban program, developed in Dayton, Ohio, was found to be a comprehensive and effectively implemented program; the rural program, developed in Clarke County, Virginia, was found to be a comprehensive program, but lacked full implementation. The experience gained in the case studies was used to revise the format of the evaluation method, and draw conclusions concerning the usefulness of the method. A description of the evaluation method, the case studies, and all related data collection are included. / Master of Science

Dissertation Submitted to the University of the Witwatersrand in the Fulfilment of the Master’s Degree in Geology (Hydrogeology) Faculty of Science University of the Witwatersrand Date: May 2017 / The state of water quality in the Swartkops River catchment in the Uitenhage area, Eastern Cape Province, South Africa, continues to be degraded by anthropogenic activities, which include municipal waste water, industrial waste and agricultural runoff. The study area consists of two aquifers (Swartkops and Coega) that are separated by the fault (Coega fault). In the study area there are two main rivers, namely: Swartkops River and Coega River, which are situated in the Swartkops Aquifer and Coega Aquifer, respectively. Most of the degrading anthropogenic activities are situated in the vicinity of the Swartkops River. The focus of the study was on the pollution of the stream water and aquifer (groundwater), with particular emphasis on the groundwater management. The study objectives were to establish the relationship between groundwater levels and surface topography using Bayesian interpolation method and groundwater and surface water interaction using environmental isotope and hydrogeochemical techniques. The bacteriological assessment was also conducted to determine if hydraulic connections exist between groundwater and the polluted streams. The results of the Bayesian Interpolation Method indicated that there was a strong relationship between the groundwater level elevation and surface topography with the correlation coefficient of 0.9953. The results also indicated that the fault is permeable; hence it did not have influence on groundwater circulation; however, groundwater does not flow from Swartkops River to Coega Aquifer due to groundwater flow gradient. The environmental isotope results indicated that both Swartkops Aquifer and Swartkops River were characterised by heavy isotopes signatures, which indicated the correlation between the two water components. The results further showed that the Swartkops River was recharging the Swartkops aquifer. However, no correlation was established between Swartkops River and Coega aquifer due to flow gradient. Although the flow gradient allows the flow of groundwater from Coega Aquifer to Swartkops Aquifer, Coega aquifer is a Government Water Controlled Area, which could have a very low to none impact on the other aquifer. Piper diagram and stiff diagrams indicated one water type found in the Swartkops and Coega aquifers, which was: Na-Cl type. The water in the Coega aquifer indicated high salinity in the chemical properties, which was typical old marine water derived from deep groundwater source. It was noted that the electrical conductivity values in the Waste Water Treatment Work were closest to those of the Swartkops River and Aquifer, which was in central to those of Coega Aquifer. The bacterial analysis results indicated that during the wet season most of the bacterial counts were high as compared to dry season. It was noted; however, that during the wet season the bacterial counts appeared similar in both aquifers. It is unlikely that the similarities emanated from the interaction of the two aquifers as the analysis of the results indicated that the bacterial counts found in the Coega Aquifer emanated from the farming activities. The study concluded that the fault act as a pathway for migration of groundwater flow. It was established that the groundwater only flows from Coega Aquifer to Swartkops Aquifer due to difference in the hydraulic gradient. / MT 2017

Groundwater contamination and soil salinisation are a major environmental problem worldwide. Living organisms depend largely on groundwater for their survival and its pollution is of course of major concern. It therefore goes without saying that remedial processes and understanding of the mathematical models that describe contaminant transport is of great importance. The theory of contaminant transport requires understanding of the water ow even at the microscopic level. In this study we focus on macroscopic deterministic models based on di erential equations. Here contaminant will refer to nonreactive contaminant. We aim to calculate Lie point symmetries of the one-dimensional Advection-di usion equation (ADE) for various forms of the di usion coe cient and transport velocity. We aim to employ classical Lie symmetry techniques. Furthermore, reductions will be carried out using the elements of the optimal systems. In concluding, the ADE is analyzed for selected forms of the the di usion coe cient and transport velocity via the potential symmetry method. For the potential symmetries obtained, we investigate the associated invariant solutions.

A widely used roadway runoff best management practice (BMP) used in Florida is an ex.filtration trench. Traditionally, exfiltration trenches are constructed without any filtration media. Therefore, the potential for groundwater contamination by the roadway runoff exists. Roadway runoff contains metals and nutrient pollutants. Nitrogen and Phosphorus are the most common nutrients causing impacts to receiving waters. To reduce the impact these pollutants will have on groundwater quality, Black and Gold™ media, which mainly consists of tire crumb, is evaluated. The Black and Gold™ media was found to be a good filtration media for removal of total nitrogen and nitrate + nitrite. It was found that all of the wells had experienced total nitrogen removal. These reductions ranged from 32% to 56%. The nitrate + nitrite reduction was experienced in the four wells. These reductions ranged from 4 7% to 88% in the three wells. The ortho-phosphorous and total phosphorus concentrations did not change significantly. Also, the metals concentrations did not change significantly.During the post sampling period, the turbidity of the groundwater increased. This was experienced in three of the four wells.

Although the East Central Florida area is not heavily industrialized, its dependence on groundwater resources makes it especially vulnerable to contamination by poor waste disposal practices. The East Central Florida area was studied to discover the nature and disposal of hazardous wastes generated. It was found that a large portion of hazardous wastes in the region were from very small industries, distributors, and even consumers. Three of the most toxic and/or voluminous waste problems in the area--metal plating wastes, pesticide wastes, and hospital wastes--were studied to determine available alternatives for disposal and their costs.

Indiana University-Purdue University Indianapolis (IUPUI) / Groundwater monitoring networks are subject to change by budgetary actions and stakeholder initiatives that result in wells being abandoned or added. A strategy for network design is presented that addresses the latter situation. It was developed in response to consensus in the state of Indiana that additional monitoring wells are needed to effectively characterize water availability in aquifer systems throughout the state. The strategic methodology has two primary objectives that guide decision making for new installations: (1) purposive sampling of a diversity of environmental variables having relevance to groundwater recharge, and (2) spatial optimization by means of maximizing geographic distances that separate monitoring wells. Design objectives are integrated in a discrete facility location model known as the p-median problem, and solved to optimality using a mathematical programming package.

Mine abandonment and the discharge of contaminated mine water is recognised globally as a major source of surface water and groundwater pollution. Contamination generally arises from the oxidation of sulphide minerals, principally pyrite, by the mining process, and the subsequent chemical reactions can lead to the discharge of mineralised, often acidic, iron, and sulphate rich waters. In many historically mined river catchments, mine water discharge is the main cause of poor water quality. Within the UK, managing the legacy of abandoned mines is one of the principal challenges presented by modern environmental legislation, particularly the EU Water Framework Directive, a challenge that is exacerbated by the diverse and widespread nature of historical mining. The impact and hazard associated with abandoned mining in one of the UK’s most intensively mined regions, the Almond River Catchment, Scotland, was examined via: 1) a detailed GIS mapping and investigation of historical mining processes in the catchment, 2) mine site discharge sampling, 3) detailed site investigations, 4) geochemical modelling of four mine waste sites and 5) analysis of temporal and spatial river water quality in the catchment. The results are then brought together to produce a catchment scale mine water hazard map. Mapping has identified over 300 mine sites in the catchment including coal, oil shale and ironstone mine wastes and flooded coal and oil shale mines. The historical development of oil shale retort methods has been shown to have an impact on potential hazard. Sampling of discharge waters from the different mining activities, in conjunction with detailed mineralogical analysis and geochemical modelling at the four mine waste sites has characterised the main hazards. Ironstone and pyrite bearing coal mine wastes discharge waters with highly elevated Fe and sulphate concentrations, up to 160mgl-1 and 1900mgl-1 respectively, due to extensive pyrite oxidation and acid generating salt dissolution (principally jarosite). Coal mine wastes show variable mineralogy, due to the diverse nature of coal bearing strata, and discharge waters with variable chemistry. Oil Shale mine wastes are generally depleted in pyrite due to historic processing and discharge low sulphate waters with moderately elevated Fe concentrations, up to 5mgl-1. Flooded coal mines discharge sulphate dominant alkaline waters, due to the availability of carbonate minerals in the mine complex, with elevated Fe concentrations, up to 50mgl-1, while flooded oil shale mines discharge waters with moderately elevated Fe concentrations, up to 4mgl-1, due to lower pyrite content in mine strata and reduced availability of oxygen related to mine abandonment age. Once in the surface water environment iron and sulphate display significant concentration-flow dependence: iron increases at high flows due to the re-suspension of river bed iron precipitates (Fe(OH)3); sulphate concentrations decrease with increased flow as a result of dilution. Further examination of iron and sulphate loading at low flows indicates a close correlation of iron and sulphate with mined areas; cumulative low flow load calculations indicate that coal and oil shale mining regions contribute 0.21 and 0.31 g/s of iron, respectively, to the main Almond tributary. Decreases in iron loading on river sections demonstrate the deposition and diffuse storage of iron within the river channel. This river bed iron is re-suspended with increased flow resulting in significant transport of diffuse iron downstream with load values of up to 50 g/s iron. Based on this hazard classification, a catchment scale mine water hazard map has been developed. The map allows the prioritisation of actions for future mine water management.