Groundwater

Deep injection well technology is a reliable and cost-effective technique to manage hazardous wastewater. However, reduced injectivity is an issue for the performance of an injection well which can happen due to the occurrence of biogeochemical clogging. A class 1 deep injection well located at the Solid Waste Authority of Palm Beach County has long suffered similar problems that occurred due to the formation of chemical precipitation and biofilm. In the case of the biofilm, the dominant microorganism detected in previous work was determined to be Entamoeba dispar. The prime source of the protozoan was identified as the local groundwater, which is employed for different purposes within the solid waste facility, such as cooling water and dilution water. Therefore, it is imperative to examine the effectiveness of the commonly used disinfectant chlorine to inactivate the protozoan to eliminate biofilms and clogging. This study conducted a laboratory-based chlorination of the groundwater sample to reveal the required dosages of chlorine needed for 3.0-log inactivation of E. dispar in various temperature (20°C, 25°C, 30°C, and 35°C) and pH (6.5, 7.0, 7.5) conditions.

Protection of groundwater resources in southeastern Florida is essential because of increasing demands on water quality and supply. Because water is furnished to public and private water systems from production wells that tap the non-artesian surficial aquifer, contamination of groundwater from leaking petroleum storage tanks must be curtailed. In the study, a series of land use maps is developed based on aerial photographs (1970, 1984, and 1991) for a 40 square mile area in southeastern Palm Beach County, Florida. The locations of petroleum storage tank systems and contaminated sites are mapped. The point biserial correlation coefficient is used to examine the strength of the relationships between historical land use, storage tank system capacity, and the presence of petroleum. contamination. The results indicate no correlation between the intensity of urbanization (historical land use) and petroleum contamination and positive correlation between petroleum storage system capacity and petroleum contamination.

Barometric distillation is an alternative method of producing fresh water by desalination. This proposed process evaporates saline water at low pressure and consequently low temperature; low pressure conditions are achieved by use of barometric columns and condensation is by direct contact with a supply of fresh water that will be augmented by the distillate. Low-temperature sources of heat, such as the cooling water rejected by electrical power generating facilities, can supply this system with the latent heat of evaporation. Experiments are presented that show successful distillation with a temperature difference between evaporator and condenser smaller than 10ê C. Accumulation of dissolved gases coming out of solution, a classic problem in lowpressure distillation, is indirectly measured using a gas-tension sensor. The results of these experiments are used in an analysis of the specific energy required by a production process capable of producing 15 liters per hour. With a 20ê C difference, and neglecting latent heat, this analysis yields a specific energy of 1.85 kilowatt-hour per cubic meter, consumed by water pumping and by removal of non-condensable gases.

Deep injection wells (DIW) in Florida are regulated by the U.S. Environmental Protection Agency (USEPA) and the state of Florida through the Underground Injection Control regulations contained within the Safe Drinking Water Act. Underground injection is defined as the injection of hazardous waste, nonhazardous waste, or municipal waste below the lowermost formation containing an underground source of drinking water within one-quarter mile of the wellbore. Municipalities in Florida have been using underground injection as an alternative to surface disposal of treated domestic wastewater for nearly 40 years. The research involved collecting data as of September, 2007 on all the Class I DIWs in the state of Florida and evaluating the differences between them. The analysis found regional differences in deep well practice and canonical correlation analyses concluded that depth below the USDW is the most significant factor to prevent upward migration of the injected fluid.