Changes in water quality in agricultural catchments after deployment of wastewater treatment plant

Abstract

Insufficient wastewater remediation in small communities and nonpoint source pollution are the key factors in determining the water quality of small streams in an agricultural landscape. Despite the current extensive construction of municipal wastewater treatment facilities in small communities, the level of organic substances and nutrients in the recipient catchments has not decreased in many areas. This paper analyzes the changes in the water quality of the small streams after the deployment of wastewater treatment plants that were designed to address sources of pollution from small municipalities. The analysis is based on the results from a water quality monitoring network in the small watersheds in the Czech Republic. Five rural catchments with one dominant municipal pollution source, where a wastewater treatment plant was deployed during the monitoring period, were selected according to a predefined set of criteria, from a series of 317 profiles. Basic water quality indicators were selected for the assessment: O₂, BOD-5, COD, TOC, conductivity, NH₄-N, NO₂-N, NO₃-N, PT, and PO₄-P. Results of the analysis showed that the simple deployment of the water treatment facilities at these streams often did not lead to a reduction of contamination in the streams. The expected post-deployment changes, namely, a significant and permanent reduction of stream contamination, occurred only in one catchment, whereas in the remainder of the catchments, only marginal changes or even increased concentrations of the contaminants were detected. As the critical factors that determined the efficiency of wastewater treatment were studied, the need for the consideration of the local conditions during the design of the facility, particularly regarding the size of the catchments, initial level of contamination, proper system of operation, and process optimization of the treatment facility, emerged as the important factor.

Changes in Water and Sewage Management after Communism: example of the Oder River Basin (Central Europe)

“…The Water Framework Directive has become an inspiration for the rapid improvement of wastewater management, especially in those countries that joined the EU in 2004 [34][35][36][37] . Despite major financial and investment efforts, there is a concern that the goal of achieving good water status in EU river basins by 2027 (including the Oder river basin) will not be achieved.…”

Analysis of efficiency of pollution reduction measures in rural basin using MIKE Basin model. Case study: Olšava River Basin

“…Other problems related to the pollution of small basins are the mismanagement of facilities, lack of systematic approach, and little enforcement of environmental legislation. The key sources of extensive pollution in small streams are local pollution sources that are not connected to the sewage network, and mismanaged wastewater treatment facilities at small municipalities (Langhammer and Rödlová, 2013). These sources have a significant effect on resulting water quality, but they are difficult to measure or estimate, as they are unlisted in official databases (Meals et al, 2010).…”

The Effect of Fish Production and Environmental Factors on Phytoplankton in Hypertrophic Fishponds

“…In recent years, wastewater treatment plants (WWTP) have brought additional problems. Even though a lot of WWTPs in small villages in the Czech Republic were constructed within the last decades, the level of organic substances and nutrients in the recipient catchments is still very high (Langhammer and Rödlová, 2013). With prolonged dry periods, especially during the summer season, and a small capability of dilution, inflow into the fishpond can consist exclusively of WWTP effluents in some cases.…”