Population Water Use Research Articles

SANITARY AND MICROBIOLOGICAL ASSESSMENT OF QUALITY OF THE BOTTOM SEDIMENTS OF KHADZHIBEY LIMAN AND ODESA BAY UNDER CONDITIONS OF WASTEWATER DISCHARGE

In the southern part of the Khadzhibey Liman in the warm period, and in Odesa Bay in the cold period of the year, the wastewater from BTS “Pivnichna” is brought in, which leads to bacterial contamination of these ecosystems.The aim of the work was to provide a sanitary and microbiological assessment of the quality of the bottom sediments in the southern part of the Khadzhibey Liman and Odesa Bay in summer 2016 and to assess the distribution of saprotrophic and coliform bacteria under conditions of sewage discharge.Methods. We used methods of general microbiology in determining the number of bacteria.Results. As a result of the research, it was revealed that insufficiently treated wastewaters of BTS “Pivnichna” enter the southern part of the Khadzhibey Liman and Odesa Bay, which leads to the accumulation of opportunistic bacteria in the bottom sediments. The largest number of coliform bacteria in the bottom sediments of the southern part of the Khadzhibey Liman and the shallow part of the Odessa Bay was observed near the place of sewage release from BTS “Pivnichna” in the investigated water areas – 4 ∙ 10³ CFU∙g−1 and 4.35 ∙ 10³ CFU∙g−1, respectively, with decrease towards zero as the distance increased. The majority of the stations (<55%) of the bottom sediments of the southern part of the Khadzhibey Liman belonged to the slightly contaminated class by the number of saprotrophic bacteria, and Odesa Bay – to the sufficiently pure class.Conclusion. The emergency discharge of the waters of the Khadzhibey Liman into Odesa Bay during the warm season may lead to an unfavorable sanitary situation within the boundaries of population water use and may pose a threat to human health. It is necessary to clean the wastewater discharged from BTS “Pivnichna” in accordance with regulatory documents and discharge it outside the boundaries of population water use, that is, at a distance of more than 2 miles from the waterfront.

Price Elasticity of Water Demand in a Small College Town: An Inclusion of System Dynamics Approach for Water Demand Forecast

The relationship between water demand and pricing using the price elasticity of water demand in the City of Pullman, Washington, between 2000 and 2006 shows that the current amount of water depletion is not sustainable. Three different economic scenarios were developed by altering variables in regression equations to investigate the influence of individual variables on estimating the final price elasticity of water demand. Single-family households, total residential households, and total population water use of the City of Pullman, Washington were the three different economic scenarios developed for calculating the price elasticity of water demand. The regression results show that the price elasticity of marginal price is inelastic. The exponents for median household income, fixed price, and precipitation had the expected signs in all applied scenarios. An economic model based on the regression equation of price elasticity was developed using a systems dynamic approach. The economic model projected a decline in water demand when the independent variables were assumed to grow linearly over the coming 25 years. When the household size with higher elasticity values was excluded from the regression equation, the developed economic model was able to forecast reasonable water demand. The time series data with exact service connections are recommended to reduce the uncertainty in the computation of the price elasticity of water demand. Further sensitivity analysis is recommended to understand interrelationship of water demand and pricing from the developed economic model using system dynamics approach.