Wastewater Treatment Plants
DESCRIPTION OF WORKS:
a) Sewerage System Application Designs:
For Kahta (Adıyaman) Sewerage, a preliminary design report was prepared, in which an overall assessment was made for the preliminary designs prepared previously by the General Directorate of Iller Bank and approved in 1986. Findings obtained in the investigations made on site, studies made in the GAP Regional Transportation and Infrastructure Development Project and the design criteria provided in Kahta reports and new development plans were taken into consideration in preparing the report. The existing sewerage system, road condition, basement depths, underground facilities, water supply system and the stormwater system were assessed in this report. In addition, population projections and wastewater quantities (domestic wastewater flow and projection rate) were calculated and the base design data and criteria were determined.
The sewerage application design was prepared according to the criteria defined in the preliminary design report and the topographical surveys. Design horizon was selected as 2028 and population was calculated to be 128,000. Reinforced concrete pipes were used in the sewerage system with 245 km network and interceptor length in total.
b) Wastewater Treatment Works:
Treatment method options likely to be applied for the treatment plants were examined in the preliminary design report. Facultative stabilization pond system, which was the most economical and most simple in operation among the options examined, was selected.
Kahta sewerage system is divided into two drainage catchments, according to the topography of the area. It is not possible to collect all wastewater at one point with gravity. Two appropriate locations for implementation of 2 treatment plants were found at the downstream of the natural drainage catchments where the sewage can be connected to each plant by gravity; one 4.5 ha by the Kahta creek, and one 9 ha by the Humdut creek. According to the feasibility studies, construction of two wastewater treatment plants was found to be more economical compared to construction of one treatment plant. If one treatment plant would be constructed, construction of a pumping station, which need considerable amount of costly and high electrical power, would be required to collect wastewater of the other catchment together with the construction of required forcemain pipeline for transmission the sewage from one catchment to other one.
In the preliminary studies, it was planned to add aerated pond after 2005 to the stabilization ponds, which would serve until 2005 in the first stage. However, in order to keep the investment cost of treatment plant at most economical level, use of aerated facultative ponds was preferred in the treatment system in the first years, and the system was designed accordingly.
Implementation designs were prepared for the pre-treatment (screen and grit removal) and biological treatment (Aerated facultative ponds) units and auxiliary facilities (administration, laboratory, workshop, store). Summer and winter operation diagrams of the systems, piping systems and application design of all manholes in this system were individually prepared.
The geotechnical report was prepared according to the investigation boreholes drilled in the site of treatment works, and design of slope stabilities, water retaining structures, ponds and all other banks, excavation and roads were prepared with this report. Quantities and cost estimates of the treatment works to be constructed in the first stage were prepared separately for both treatment plants.
CONSULTING SERVICES:
Services provided by ER-GE in this project:
- Preparation of the preliminary design report,
- Topographical surveys and measuring,
- Necessary geotechnical surveys,
- Complete implementation design of the plants including all architectural, structural, reinforced concrete, hydraulic, electrical and mechanical calculations,
- Preparation of quantities and cost estimations documents.
CLIENT:
Yeda International Trade Ltd. Co.
(The Contractor of Republic of Turkey, Prime Ministry, Southeast Anotolia Project, Head of Regional Development Administration)
DATE: 1992 – 1993
PROJECT COST: 20,000,000 USD
