Sari Wastewater

Design Landscape

Sari is located at the foothills of the Alborz Mountains, and includes both flat and mountainous areas. The latitude and longitude of Sari are 53°5' and 36°4' respectively. It is located 25 km away from Northeast Neka , 45 km away from Behshahr, and 130 km Gorgan, and 690 km Mashhad; 35 km away from North Caspian sea; Northeast Farah Abad, Juibar and Larim; 22 km southeast Ghaem Shahr; approximately 30 km away from West Babol, 60 km Amol; and 30 km away from South Shahid Rajaei dam (Solomon Strait) and Aramesh village; and approximately 80 km Dibaj through under construction Kiasar freeway; and then connected to Damghan, Mahdi Shahr and Semnan cities (about 120 km). Moreover, Sari is located less than 150 km Tehran; it reaches Tehran through Firuzkuh road after passing 256 km, through Haraz road after passing 250 km, and through North railway after passing 354 km.

Tajan River passes through Sari city. This river is flowing East Sari. Today, Tajan (Qaem) park was built on the shore of the river, which is the largest park of the Sari city.


Sari's Climate is mild and humid in summers, and relatively cold and dry in winters. In addition, the southern mountainous parts of this city experience long and very cold winters. In recent years, the lowest recorded temperature of the city in winter was -12°Celsius (winter 2008) and the highest recorded temperature of the city in summer was +40 °Celsius (summer 2004). Sari’s population was about 330,000 in 2010, and it is considered to be the largest and the most populated city of Mazandaran province.

Design main components

Some parts of the major and semi-major lines and wastewater (sewage) collection and transport network of Sari city have already been designed and implemented, and one module of city wastewater treatment plant is also under operation. Implementing wastewater branches of Sari city together with developing collection network and avoiding possible segregation to speed up the flow of the wastewater system of Sari city is placed on the agenda and is under completion in different areas of the city. Considering design objectives, preparing tender documents through finance method (supply financial resources) and implementing project in areas in which wastewater transfer lines and network have not been implemented but have a greater potential for being connected, and its primary and secondary wastewater networks and branches have not been completed are placed on the agenda.

Design objectives

On the one hand, the necessity to develop wastewater network of Sari city through establishing the primary and secondary facilities of wastewater collection and transfer network and connecting wastewater branches and building wastewater treatment plant with the aim to provide a healthy urban environment, and on the other hand, recycling the effluent in other uses cycle and preserving healthy soil and water resources is evident to everyone. Financial resources restriction and the work volume have led to a delay in realizing the wishes. In order to accelerate the supply of financial resources required for projects implementation, in addition to development budget, the use of other facilities such as the World Bank loan, Islamic Development Bank loan, the sale of participation bonds,  and other governmental credit facilities have been placed on Mazandaran province Water and Wastewater Company’s  agenda; and the required programming has been done for conducting research and providing designs and executive details with the aim to reduce people’s expectation period and realize this necessity in Sari city.

Design specifications

  • Coverage area:4230 hectares
  • Population covered by network: 420000 persons
  • Length of main pipelines: 170 km
  • Length of semi-major and minor network: 500 km
  • Diameter of wastewater transmission line: 1200 mm
  • Length of transmission line: 5.2 km
  • Pumping station: 1 station
  • Lift station: 1 station
  • Total capacity of the treatment plant: 8.1 m3/s
  • Modules number: 4 modules
  • Population covered by total design: 420000 persons
  • The number of implemented modules at this stage: 1 module
  • Covered population; 105000 persons
  • Wastewater treatment method: activated sludge- (Modified Ludzack-Ettinger Process , MLE)
  • Treatment feature: Nitrogen and phosphorus removal
  • Main units: Screening, grit- chamber, primary sedimentation, aeration, secondary sedimentation, disinfection (UV), gravity thickener, sludge aerobic digestion, mechanical dewatering
  • Sludge treatment method: gravity thickener, aerobic digestion
  • Byproduct: Compost