Chennai, the capital City of Tamil Nadu is the fourth largest Metropolitan City in India. The Chennai Metropolitan Area (CMA) comprises the city of Chennai, 16 Municipalities, 20 Town Panchayats and 214 Village Panchayats in 10 Panchayat Unions. The CMA falls in three Districts of the Tamil Nadu State viz. Chennai District,part of Thiruvallur District, and part of Kancheepuram District. The extent of the Chennai District (covered in Chennai Municipal Corporation area) is 176 sq.km and comprises 55 revenue villages in five Taluks [viz. (i) Fort-Tondiarpet Taluk, (ii) Perambur-Purasawalkam Taluk, (iii) Egmore-Nungambakkam Taluk, (iv) Mambalam-Guindy Taluk and (v) Mylapore-Triplicane Taluk]. In Thiruvallur District out of total district area of 3427 sq.km, 637 sq.km. in Ambattur, Thiruvallur, Ponneri and Poonamallee taluks fall in CMA. In Kancheepuram Districtout of 4433 sq.km, 376 sq.km in Tambaram, Sriperumbudur and Chengalpattu Taluks fall in the Metropolitan area.