This investigation was primarily a study of the performance of the new sewage treatment plant serving Blacksburg, Virginia and V. P. I. during the initial period of operation, 1948-1949. This plant, designed for a sewage flow of one million gallons per day, provides primary and secondary treatment. Standard analyses were performed on samples at various stages in the treatment process to determine the efficiency of purification afforded by each unit. These tests indicate satisfactory operation of the plant in the reduction of pollution constituents of the influent sewage. Effects of treated sewage discharged to the receiving stream, Strouble’s Creek, were found to be negligible. Performance of Blacksburg - V. P. I. plant generally equaled that of several other sewage treatment facilities serving populations less than 60,000. Supplementary studies in this investigation included: the effects storm water diversion into the sanitary sewage system; and the appraisal and correction of operating problems encountered in this initial period of plant operation. / Master of Science

This thesis presents a model which estimates energy and cost savings that can be realized by implementing Energy Conservation Measures (ECMs) at mechanically aerated wastewater treatment plants (WWTPs) in southeast Florida. Historical plant monitoring data is used to estimate savings achieved by implementing innovative aeration technologies which include : 1) Fine Bubble DIffusers ; 2) Single-Stage Turbo Blowers ; 3) Automatic Dissolved Oxygen (DO) Control. Key assumptions for modeling performance of each technology are researched and discussed, such as trends in the future cost of electricity, efficiency of blowers, and practical average DO levels for each scenario. Capital cost estimates and operation maintenance (O&M) costs are estimated to complete life-cycle cost and payback analyses. The benefits are quantified on an individual and cumulative basis, to identify which technologies are cost-beneficial. The results demonstrate that levels of payback of 20 years or less are available at the three WWTPs studied. / by Eric Stanley. / Thesis (M.S.C.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2012. Mode of access: World Wide Web.

Thesis (M.S.)--State University of New York at Binghamton, Department of Geological Sciences and Environmental Studies, 2008. / Includes bibliographical references.

Municipal water and wastewater systems in Virginia are faced with substantial capital needs for the expansion, replacement, and improvement of existing facilities, and the construction of new facilities. To compound this problem, the financial environment surrounding these utilities is changing from one in which grant financing is being replaced by debt financing, and the overall availability of federal and state aid is declining. The literature on utility management emphasizes the use of a "user-pays" approach that makes use of a comprehensive method of cost analysis. This thesis tests the hypothesis that a uniform, comprehensive cost analysis method can be developed to effectively meet the cost analysis needs of municipal water and wastewater systems in Virginia. This is accomplished in a four step process: development and distribution of a questionnaire to all municipal water and wastewater systems in Virginia; analysis of the survey results; description and analysis of the Government Finance Officers Association's comprehensive cost analysis workbook for water and wastewater utilities; and evaluation of this workbook in several Virginia communities. The results of this work show that a comprehensive cost analysis method can be developed which will effectively meet the cost analysis needs of water and wastewater operations in Virginia. However, such a method does have its shortcomings, and further research is recommended. / Master of Urban Affairs

M.S.

Darvill Wastewater Works (DWWW) receives and treats both domestic and industrial wastewater from the city of Pietermaritzburg, in KwaZulu-Natal. Sludge from the wastewater treatment is sprayed onto surrounding lands, causing odour and fly problems. The plant also discharges treated effluent into the Msunduzi River, compromising water quality. This study uses several economic valuation techniques to estimate the value of the benefits of improving air and water quality to overcome these problems caused by DWWW. The benefits. are then compared with the costs of upgrading DWWW to see whether or not upgrading DWWW to improve air and water quality would be worthwhile. The Contingent Valuation Method (CVM) was used to elicit people's willingness to pay (WTP) for improvements in air quality due to the elimination of odours and flies caused by sludge deposited by DWWW. The WTP estimates reflect individual's preferences for improvements in air quality. The stated WTP amounts were positively related to household income, but negatively related to the age and gender of the respondent and the number of dependants in the household. The mean monthly WTP for the surveyed households is higher for those that are closer to the pollution source (R23.00 and R29.00 for Zones land 2) and less for those further away (RI4.00 for Zone 3). Sobantu residential area had the lowest mean monthly WTP (R18.00), followed by Lincoln Meade (R27.00) and Hayfields (R54.00). This is expected, as Sobantu has relatively high levels of unemployment and lower household incomes. Strategic, hypothetical and free rider bias may have led to the unexpected signs of some estimated regression coefficients in linear regression models used to estimate WTP. The mean WTP was estimated as R307.20 per annum per household, and when this is aggregated over the total population in the residential areas impacted by odours and flies (37192 households), the benefits of eliminating odours and flies are estimated as R11 425 382.00 per annum. A hedonic price method was used to quantify the decline in property values as a result of odours and flies caused by sludge deposited by DWWW. Properties experienced a R6650.08 decline in selling price if the distance from them to DWWW is decreased by one kilometre. Properties that are closer to DWWW were worth RI5 953.90 less than those further away from DWWW. Aggregating these values over all estimated impacted households in the study, gives an estimated benefit of improving air quality of R28 480 518.00 per annum. The impact of water pollution was quantified by estimating the revenue (R3 744 975.00) that would be lost by Pietermaritzburg if the Duzi Canoe Marathon were to be cancelled due to incidences of diarrheoa reported during the race. A cost of illness procedure was adopted to quantify the effect of water pollution on the health of communities that use the Msunduzi River as a source of potable water supply. A value of R1 243 372.50 was estimated as the annual cost of water-related illnesses in these rural areas. This value represents the costs of the river pollution to those communities. Both of these exercises indicated that improving water quality of the Msunduzi River would be beneficial to society. The effect of nutrient enrichment of the Msunduzi River was quantified by estimating the cost of removing water hyacinth from the Inanda Dam, treatment cost at Wiggins water treatment works and the value of recreation at Mahlabathini Park (Inanda Dam). The annual cost of removing water hyacinth was estimated from the direct costs of chemicals and labour as R47 202.15. The increased treatment costs at Wiggins attributable to DWWW were estimated as R1 104 999.20 and R956 924.15 per annum for removal of algae, and tastes and odours, respectively. The value of R706.90 per annum was estimated as the consumer surplus accruing to recreationists, and, therefore, the value of recreation at Mahlabathini Park to an individual. These annual benefits, when aggregated over the total study population (296 590) were over two hundred million rands (R209 659 470.00). The estimated total benefits (R256 662 840.00) of eliminating odours and flies and effluent problems were compared to the actual costs of two alternative methods of upgrading DWWW using cost-benefit analysis. These alternatives were co-disposal option (R170 473 320) and a land disposal option (R168 809377). Benefit-cost ratios of 1.51 and 1.52 suggest that from society's standpoint, it would be beneficial to upgrade the plant in order to eliminate its adverse environmental impacts. The study results have important implications for policy makers, both the DWWW management and the Pietermaritzburg-TLC municipality. At present DWWW is operating beyond its design capacity, and this problem, together with the poor status of Pietermaritzburg's reticulation system, causes overflow of untreated or compromised final effluent into the Msunduzi River during rainy seasons. These problems also impact on the efficient operation of the plant as the sludge is not properly digested before being sprayed onto surrounding land. Thus to prevent further environmental degradation, a fundamental basis of the National Environmental Management Act, DWWW would need to address these issues. Upgrading DWWW would be a short-term solution if the problems with the storm-runoff into the plant is not addressed. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.

published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

One of the consequences of the social and economIc change due to industrialisation is the generation of industrial wastewater which requires treatment before being released into the natural aquatic environment. The municipality has wastewater treatment plants which were initially designed for the treatment of domestic wastewater. The presence of industrial wastewater in these treatment plants introduces various difficulties in the treatment process due to the complex and varying nature of the industrial wastewater. A means needs to be developed, that will allow the municipality to evaluate if a wastewater treatment plant can adequately treat a particular composition or type of wastewater to a quality suitable for release to the environment. Developing a simulation model for a wastewater treatment plant and calibrating it against plant operating data will allow the response of the wastewater treatment plant to a particular wastewater to be evaluated. In this study a model for the Mariamidge Wastewater Treatment Plant is developed in the WEST (Worldwide Engine for Simulation, Training and Automation) software package. The sources of data for modelling were laboratory experiments, historical data from the municipal laboratory and modelling of experiments. Dynamic input files representing the properties of the influent wastewater were generated by characterising the influent wastewater through the use of batch respirometric tests and flocculation filtration on composite samples of wastewater. Kinetic and stoichiometric coefficients of the model were determined from batch respirometric tests on wastewater and activated sludge, and simulation of the batch respirometric experiment. To make the model plant-specific it is calibrated against plant operating data. Influent characterisation and reliable ASM3 model parameters were determined from the respirometric batch test and modelling of experiments. The resulting plant model was able to closely predict the trends of the effluent COD concentration in the plant. Hence it was concluded that the use of laboratory experiments, historical data from the municipal laboratory and modelling of experiments in order to generate information for the modelling of wastewater treatment plants makes up a methodology which can be adopted and improved by additional experiments. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2008.

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