Coarse particulate organic matter (CPOM) is an essential part of the food chain in aquatic ecosystems because it represents a readily available carbon and energy source. The process by which it decomposes in rivers has been well studied and documented. However, the rate and extent of biodegradability of various CPOM components (i.e., twigs, leaves, grass, etc.) in storm drains is not well understood. The Jordan River TMDL study identified storm water generated CPOM as a likely cause of low dissolved oxygen levels in the lower Jordan River, but recent investigations have suggested that dissolved organic matter generated from this CPOM in storm drains and culverts entering into the Jordan River, rather than the CPOM itself, is the main driver of oxygen impairment. The degradability of CPOM components transported and stored in the storm drain system was studied to understand its relative impact on dissolved oxygen and nutrient status in the Jordan River. Results indicate the generation of highly degradable organic material is a function of the starting CPOM, and oxygen consumption is associated with the dissolved portion of organic material leached from CPOM in water. Leaves and grass produced the highest levels of all parameters studied. Between 93% to 95% of total oxygen demand is generated within the first 1 to 3 hours of the 24 hour test. Chemical oxygen demand and dissolved organic carbon proved to be the best indicator of biochemical oxygen demand. By using the results of the leaching study an estimate of water quality indicator levels in the Jordan River was made, and was compared to levels in samples collected from the Jordan River. The estimate proved accurate for dissolved organic carbon but not for total or volatile suspended solids. Results of this study were used to discuss possible solutions to reduce oxygen demand in the Jordan River.

ABSTARCT The aim of this thesis is to treat the problem of wastewater pretreatment on the sewer network with a focus on storm water overflow and their impact on waterways with regard to The Methodological Manual for Assessment of storm water overflow within uniform sewerage systems in urban areas. This work describes the legislation relating to storm water overflow and includes comparison with other countries. Furthermore, there is processed the outline of objects and equipment which can be used for wastewater pre-treatment in the sewer network. In the practical part of the thesis there is designed a new solution for the mobile spillway edge of the storm water overflow OK2A, which is located within the sewer network in Brno. In the practical part of the paper there is depicted the project documentation of newly designed equipment and objects. Water management companies, design offices, students and the general public can use this thesis as an inspiration.