Trabzon (Ortahisar) Integrated Drinking Water and Wastewater Project: Technical and Engineering Perspective

As Pointasal Proje Mühendislik, we provide engineering and consultancy services in Trabzon Ortahisar Integrated Drinking Water and Wastewater Project to improve the city's water and wastewater infrastructure in the 21st century. we are proud to carry it to the century standards. Funded within the scope of the European Union's Instrument for Pre-Accession Financial Assistance (IPA II), this project aims to establish a sustainable, environmentally friendly and future-oriented system by renovating the drinking water and wastewater infrastructure in Ortahisar, the central district of Trabzon, with an integrated approach. The project is designed according to a 30-year master plan and includes advanced engineering applications such as hydraulic modeling, detailed engineering designs, wastewater treatment plant planning and extensive field studies.

The General Purpose and Objectives of the Project

Trabzon Ortahisar Integrated Water Project is designed to solve the existing infrastructure problems of the city and meet its future needs. The project, which covers 51 neighborhoods of Ortahisar district, focuses on the following main goals:

• Improving the Quality of Drinking Water Service: Water outages caused by an old and worn-out network, low pressure problems and water supply deficiencies in high-rise buildings are eliminated, providing water at uninterrupted and sufficient pressure. Jul.< / li>
• Reducing Loss-Leakage Rates: Reducing loss-leakage rates up to 50% in the existing network to 15% with the new network and pressure management, thereby reducing the efficient use of water resources and operating costs.< / li>
• Environmental Protection and Wastewater Treatment: Treatment of wastewater discharged into the Black Sea without treatment with an advanced biological wastewater treatment plant (AAT), thereby reducing marine pollution and ensuring compliance with the EU Urban Wastewater Treatment Directive.< / li>
• Sustainable Infrastructure: The establishment of an integrated infrastructure system for the target year 2045-2050, taking into account the effects of climate change, population growth and urbanization.< / li>

The project is being carried out under the leadership of the General Directorate of Trabzon Metropolitan Municipality TISKI, under the coordination of the EU Investments Department of the Ministry of Environment, Urbanism and Climate Change, and is supported by the technical consulting and engineering services of Pointasal Proje Mühendislik.

30-Year Drinking Water and Wastewater Master Plan

The project has been planned within the framework of a comprehensive master plan targeting the years 2045-2050. The master plan addresses drinking water supply, wastewater management and rainwater separation in an integrated manner and has been prepared with the following basic assumptions and analyses:

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• Population and Water Demand Projections: The current population of Ortahisar, which is ~330,000, has been projected according to the highest scenario for 2045, taking into account tourism and student mobility in the summer months. The total water demand was calculated by analyzing the daily water consumption per person (average 180-200 liters/day) and economic growth trends.< / li>
• Water Resources and DSI Integration: Water resources provided from the Atasu Dam, Akoluk Drinking Water Treatment Plant and Karakaya Dam form the basic backbone of the master plan. The 26 km Atasu-Akoluk-Ortahisar transmission line and the main warehouses with 200 elevations built by DSI have been integrated into the design of the urban distribution network.< / li>
• Wastewater and Rainwater Management: With the assumption that the existing sewer network reaches 100% service coverage and ~150 liters/day wastewater production per person, the capacity of the treatment plant has been determined. Based on the principle of a discrete system, it is planned to completely separate rainwater and sewer lines; the rainwater network has been designed according to 5 and 10-year precipitation periods.< / li>
• Analysis of Existing Infrastructure: Inventory of the existing drinking water and sewer network has been removed, pipe materials (asbestos cement, cast iron, etc.), their diameters, age and failure frequencies have been studied in detail. The analyses have revealed that the renewal of the network is essential.< / li>

The master plan defined priority investments (potable water network renewal) and long-term goals (wastewater treatment plant, rainwater infrastructure) in stages, thus ensuring the viability and financial sustainability of the project.

Hydraulic and Hydrodynamic Modeling Studies

The technical infrastructure of the project was supported by advanced engineering modeling tools. The following modeling studies were carried out for the design of drinking water and wastewater systems:

Modeling of the Drinking Water Network (EPANET)

The design of the drinking water network is modeled with EPANET software developed by the EPA. The model includes the following analyses:

• Hydraulic Performance: Pressures at the nodal points of the network (minimum 2 bar, maximum 6 bar), flow rates and speeds in pipelines (maximum 2 m/s) are simulated. Pressure drops and water aging at remote points during peak demand hours have been analyzed.< / li>
• Calibration: The model has been verified by field measurements (flow, pressure, night minimum flows); the existing network is located in high-altitude neighborhoods (e.g. It has been determined that the garden (Cold Water) is insufficient.< / li>
• Zone Measurement Areas (DMA): The network is divided into 16 DMA and hydraulically balanced; electromagnetic flowmeters and pressure control valves are planned for each DMA inlet. This will optimize loss-leakage control and network management.< / li>
• Future Scenarios: By applying the 2045 demand projections to the model, warehouse levels, pump capacities and additional transmission line requirements have been determined.< / li>

Wastewater and Rainwater Modeling (MIKE Urban Sewer)

The sewer system is dynamically modeled with the DHI MIKE Urban Sewer software:

• Hydrodynamic Analysis: The current capacities of existing sewer lines, the risks of overflow in wet weather and the performance of promotion centers have been simulated. by applying 5- and 10-year precipitation scenarios, critical regions (e.g. coast band, Potter) insufficient diameter lines have been identified.< / li>
• Rainwater Separation: By modeling discrete system scenarios, it has been predicted that rainwater lines will reduce the sewage flow rate by 30-40%. This will optimize the input load of the wastewater treatment plant.< / li>
• Wastewater Tunnel Design: The diameter (Ø1000-Ø2000 mm) and slope of the ~10 km wastewater collector tunnel planned along the coast have been optimized according to the model results. Attractive flow was prioritized; intermediate promotion centers were evaluated in low-Decile regions.< / li>

These modeling studies ensured that the system design was based on scientific data; hydraulic efficiency, operational reliability and cost optimization were aimed.

Field Data Collection and GIS Inventory

During the project preparation process, a detailed inventory of the existing infrastructure was taken out and a database based on the Geographical Information System (GIS) was created:

• Field Studies: With GPS and total station devices, the coordinates of water valves, manholes, fire hydrants and pipelines were measured. The sewer slopes were calculated by determining the pipe depths and manhole elevations.< / li>
• Current Document Analysis: The initial inventory was created by examining the network plans, DSI projects and historical survey reports in the TISKI archives.< / li>
• GIS Database: Drinking water (pipes, valves, warehouses) and sewer (lines, manholes, promotion centers) layers have been created on the ArcGIS platform; attributes such as diameter, material, age have been added to each element.< / li>
• Water and Wastewater Quality: Chlorine persistence, turbidity and microbiological parameters in the drinking water network; environmental effects were analyzed by measuring COD (average 500 mg/L), BOI (average 250 mg/L) and nutrient concentrations in wastewater discharges.< / li>

The GIS inventory has provided TISKI with a digital infrastructure map; it has provided a critical infrastructure for modeling, fault management and SCADA integration.

Detailed Engineering Designs

Within the scope of the project, detailed engineering designs have been prepared at the exact project level for drinking water, sewage and wastewater infrastructure:

Drinking Water Network

• Scope: Renovation of the drinking water network with a length of ~765 km, integration of 16 DMA zones and 26 km DSI transmission lines.< / li>
• Material and Diameter Selection: Steel (Ø300-Ø800 mm) and ductile font pipes were used in transmission lines; PE100 pipes (Ø63-Ø400 mm) were used in distribution lines. Pipe diameters are optimized according to EPANET model results.< / li>
• Promotion Centers: 3 new pumping stations have been designed for high-rise neighborhoods; the existing Değirmendere Pumping Station has been rehabilitated. Pump capacities are determined in the December of 50-100 L/s.< / li>
• Warehouses: The capacity of the main warehouses with 200 Octeters has been increased; a total additional storage volume of 20,000 m3 has been planned.< / li>
• DMA and SCADA: Flow meter and pressure control valve are integrated into each DMA; sensor and data collection infrastructure are designed for the SCADA system.< / li>

Sewage and Wastewater System

• Scope: ~10 km wastewater collector tunnel, diameter enlargements of existing sewer lines and rainwater separation.< / li>