Chapter-III(59-80) - Pollution Control Board, Assam

EIA & RA STUDY FOR NAPHTHA SPLITTER PROJECT AT NUMALIGARH REFINERY LIMITEDBaseline Environmental Status3.9.6 Results & Discussion3.9.6.1 Ambient Noise Level within Refinery CampusThe ambient noise level recorded at the main plants has been presented in Table- 3.48.The 24 hour leq values of noise level in main Units was recorded in the range of 59.5dB(A) to 61.5 dB(A). The noise level recorded during day time was in the range of 54.1 to70.0 dB(A) and the same was found in the range of 46.8 to 60.5 dB(A) during night time.It is concluded that the observed noise level values of the plants located within NRLcomplex are in compliance with and well below the noise level standards for industrialareas.3.9.6.2 Ambient Noise Level outside RefineryThe ambient noise level of the areas located outside NRL complex has been presentedthrough Tables - 3.49. The 24 hour leq values of ambient noise in the nearby villagesaround NRL have been found in the range of 41.5 to 48.4 dB(A). Noise levels in all thevillages located around NRL complex were recorded in the range of 39.5 to 54.5 dB(A)during day hours whereas the same were reported to be 38.4 to 47.9 dB(A) in night hours.It is concluded that the observed noise level values of the areas located outside therefinery complex are in compliance with and well below the noise level standards forresidential and rural areas.3.9.7 Ambient Noise Level StandardsThe Government of India, in exercise of its power under section 16(2)(h) of the Air(Prevention and Control of Pollution) Act 1981, notified the ambient air quality standardswith respect to noise (which has been included as an air pollutant under section 20 of theAmended Air Act of 1987) is presented in Table- 3.47.Table - 3.47National Ambient Air Quality Standard for NoiseAreaCategory of AreaLimits in Decibels, dB(A)Day TimeNight TimeA Industrial Area 75 70B Commercial Area 65 55C Residential Area 55 45D Silence Zone 50 40NOTE:1. Day Time is reckoned between 6 AM and 10 PM.2. Night Time is reckoned between 10 PM and 6 AM.Projects & Development India Limited, Sindri Page 72 of 80