The Dombivli industrial area was established by Maharashtra Industrial Development Corporation (MIDC) in 1964. It is about 45 km from Mumbai and 15 km from Thane city. It is located on the Kalyan-Shil and Kalyan-Dombivli roads. Through road, it is approachable from Mumbai-Pune National Highway 4 via the Kalyan-Shil Phata and also from Mumbai-Agra National Highway 3 via the Bhiwandi-Kalyan Road. It is 3 km from Dombivli railway station while 5 km from Kalyan station. This area comprises of villages like Sagaon-Sonarpada, Asde- Golivali, Gajbandhan-Patharli, and Chole in Kalyan tahasil, Thane district. This area comprised of industrial plots and sheds, Residential and commercial plots (http://www.midcindia.org/Pages/IndustrialPage.aspx). The industrial areas are further divided into two phases; Phase I and II. Phase I comprises area of about 148 Ha while Phase II 97 Ha. There are about 547 industries (Figure 1.1) in both these phases. Industries mainly comprise of textile, chemical and engineering while other include food and commodities, ice factories, paper products, plastics, laboratories, hotels, hospitals, etc.
There are five large industries while remaining are small scale industries (SSI). Large quantity of wastewater is generated from all these industries.
DBESA CETP registered under companies Act 1956 under section 25and that the company is Limited. It has cluster of 130 Member Industries These units are mainly involved in textile processing Industries. The product range results in a set of individual effluents, which have to be provided for a combined treatment. Under the guidelines from Ministry of Environment & Forests, New Delhi, the Common Effluent Treatment Plant facility for industries in DBESA MIDC area was proposed in 1994. The CETP initially was conceptualized for Textile industries. Later on chemical industries effluent were taken in to DBESA CETP as chemical CETP cannot accommodate more than 1.5 MLD and the effluent carrier pipeline is common for Textile and chemical industries.
The CETP of 14 MLD capacity was constructed and brought into operation in January 2001.
In the course of time CETP modifications were carried out. The inefficient ELO 2 in aeration tank were replaced with Surface Aeration system.
Meanwhile, the process of coming up of new units in the industrial area and existing units expanding their production capacities started and resulted in the increase of the effluent quantity considerably. Therefore DBESA CETP decided to go for the expansion of CETP by another 2 MLD. The additional 2 MLD Expansion Project thus has been commissioned in June 2011 and is into operation. Rio Mixers of 2.5 HP capacity in equilisation tank were replaced by 25 HP capacity, thereby effluent mixing process was improved a lot. 6 No.s of new Bio-reactor in plant were also constructed in addition to existing 4 No.s. Latest Technology US make Espirators Valuing Rs. 1.5 Crores have been installed in the new 6 Bio-Reactors. Thereby meeting the outlet norms of CETP prescribed By MPCB