The Seminole County, Florida solid waste transportation network was examined to determine alternate locations of transfer stations. The scope of this study is limited to transportation and assumed disposal costs. Collection costs are not included. Review of past generation records was conducted and a per capita generation rate of 4 lbs/day was determined. This compared favorably to a 4.06 lbs/day for Orange and Brevard County. The cost per ton for the present solid waste management system was computed and compared to alternative systems. The present system was compared to several alternatives by altering the number and changing the locations of transfer stations to arrive at an optimum cost configuration. Recommended alternate plans are provided which are dependent upon the waste generating districts participating as well as transfer station location in the overall solid waste management system.

No description available.

Inlet baffles in a sedimentation basin should distribute the incoming flow uniformly over the inlet zone. This allows the flow to pass through the tank in a plug flow fashion, giving the solids a more quiescent condition to separate from the liquid. It was the object of the investigation to determine which of the baffles studied performed this function most efficiently. Conventional, statistical, and dynamic analysis techniques were employed to evaluate baffle performance from input-output relationships of salt concentration. The statistical approach appeared to give much more meaningful information than did the "qualitative" or "conventional" parameters. The pulse testing techniques appeared to give more detailed information regarding the hydraulic characteristics of the model system tested. The model study results indicated that a 6-inch horizontal rectangular inlet baffle, positioned 8 inches from the inlet pipe, gave better performances than the other baffles tested. / M.S.

The history of solid waste management in Lake County, Florida is reviewed. The role of governmental agencies is mentioned. Local environmental characteristics and transportation systems are discussed. Existing collection and disposal practices are presented. A land use analysis of the unincorporated areas of the County is given. Projections of population and solid waste quantities are listed. Two computer models are presented. Their optimum solutions are analyzed in detail. The cost associated with implementing either plan is presented. A recommended plan is given based on a combination of transfer stations and sanitary landfills.

When domestic sewage is disinfected it is necessary to destroy the pathogenic organisms before discharge to the environment of mankind. Some of the more resistant pathogens may survive the disinfection process and escape to the environment. To minimize this possibility it is advisable to study the unit process know as disinfection and to determine if the disinfectant is adequately mixed to minimize the number of pathogens surviving. Eliassen et al (2) studied disinfection of sewage subjected to initial mixing. He reported the disinfection in systems subjected to slow initial mixing and systems subjected to rapid initial mixing were approximately equal. The method devised to study the mixing was the determination of the disinfection rate in continuously mixed systems disinfected with iodine. The mixing intensity was evaluated and the rate of disinfection determined by plotting the percent of microorganisms remaining against time ^m on semi-logarithmic paper (3). The slope of the data plotted was approximately -2.0 when the percent remaining was plotted against time ^1/3 for all experiments where the mean temporal velocity gradient (1) was greater than 11 per second and the power to volume ratio (4) was greater than 0.29 foot pounds per second per 1000 gallons. From these results and interpretation of Eliassen's studies (2), the initial mixing time required was estimated as one minute and the approximate quantity of mixing required was estimated as 1.3 tank turnovers corresponding to a product of mean temporal velocity gradient and time of 660 and a power to volume ratio for one minute of 21.6 foot pounds per 1000 gallons. The design and operation of plant scale disinfection processes could be evaluated considering the minimum mixing defined by this thesis, such evaluation might indicate the need for additional mixing other than the turbulence induced by the baffling presently used in the disinfection processes. / Master of Science

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

Master of Science

An alternative on-site wastewater treatment and disposal system (OSWTDS) consisting of a soil infiltrator with low pressure distribution was evaluated in a soil that was unsuitable for a conventional OSWTDS under current Commonwealth of Virginia Sewage Handling and Disposal Regulations, due to a shallow seasonally perched water table and low hydraulic conductivity. The absorption field consisted of two subsystems numbered as 1 and 2 with effluent design loading rates of 5.1 and 10.2 Lpd/m2, respectively (actual loading rates of 2.4 and 4.9 Lpd/m2, respectively). Soil matric potentials compared seasonally for each subsystem and indicated that both provided similar hydraulic performance. Background water quality was generally improved by subsurface movement through the absorption fields. A bacterial tracer was found in shallow (45.7 cm) and deep (213.4 cm) sampling wells within 24 h in the two subsystems (but in low numbers) over both summer and winter sampling periods. A viral tracer was detected within 48 h in both shallow and deep wells, but only in subsystem 2 in the winter. In evaluating denitrification potential, the addition of glucose to soil core samples did increase quantitatively, although not significantly, nitrous oxide production in each subsystem, at each depth, during each season. Overall, the performance of both subsystems was very similar. The soil infiltrator functioned very well, as designed for the site and soil limitations. It appears to be a potential alternative OSWTDS for use in problem soils. / Master of Science

Public concern about surface disposal of municipal waste offers the mining industry potentially enormous economic and environmental opportunities. If underground space created by mining can successfully be utilized for safe waste stowage during the mining process, there will be immediate and substantial benefits to all sectors of the underground mining industry. To investigate an integrated system of mining and waste stowage, an economic and feasibility model was developed. Major issues include waste transportation, emplacement area, waste characteristics after emplacement, and alterations to current mining operations. In this preliminary investigation, economic feasibility is the basis for comparison between alternative systems in this research. Past and existing underground waste disposal systems are used to evaluate the model. / Master of Science

A total of 62 solid waste disposal sites were documented and evaluated in the 18 county study area of southwestern Virginia. The solid waste disposal operations encompassed a combined area in excess of 458.7 ha. An estimated 32 workers and 40 pieces of heavy equipment were utilized for the disposal of the waste at the various dumps, landfills, and sanitary landfills. The largest number of disposal sites were operated as dumps (62%), while only 14% of the sites qualified as sanitary landfills. The dump type of operation was characterized by: erosion, odor, leachate, minimum compaction, burning, lack of final or daily cover, and limited soil, financing, cover material, personnel, equipment, and planning. Generally, the waste was deposited at a remote or obscure site and left unattended. The landfill form of waste disposal, which occurred in 17% of the sites, required the construction of a trench for the disposal of the waste material which was later covered. The landfill form of waste disposal was characterized by shallow soils, limited cover material, steep slopes, and/or underground springs. The sanitary landfills were located in areas of deep soils, with moderate slopes, and showed an absence of interacting water. These sites demonstrated proper management of the resources and limited alteration of the surrounding area. / Master of Science