4. description of the environment - Gujarat Pollution Control Board

Final Feasibility Report
Preparation of Feasibility– cum-Preliminary Design for 4/6 Laning
of Jetpur-Somnath section of NH 8D, Package No:
NHAI/DBFOII/DPR/02
VOLUME III:
ENVIRONMENTAL IMPACT ASSESSMENT
the surface waters. There is no faecal contamination as the Total Coliform bacteria and E.Coli
are nil. Nil turbidity indicates that there is no sediment load in the water bodies and negligible soil
erosion. Oil and grease, toxic constituents like phenolic compounds and cyanides are found to be
absent.
While comparing with the CPCB Norms for Surface Waters, all parameters are found to be within
the standard limits.
Ground Water: The ground water sources had agreeable colour, taste and odour. The pH value
ranged between 7.40-7.78, generally above the neutral mark and within the permissible limits for
drinking water. TDS value ranged between 31-32 mg/l, in some stations and is within the
permissible limit for drinking water (500 mg/l). Chloride values ranged from 335mg/l to 482 mg/l,
iron content was nil, thus within permissible limits. BOD is also absent. There is no significant
bacteriological contamination of these sources. Total alkalinity is found to be within the
permissible limits. Total Hardness ranged between 258-325 mg/l and exceeds the limit in Jetpur
Industrial Area. Heavy metals like iron, zinc, arsenic, mercury, lead, cadmium, chromium and
selenium are absent.
In general, the ground water quality in the project corridor is found to be in compliance with
IS:10500 Standard for Drinking Water.
4.6 NOISE ENVIRONMENT
4.6.1 Noise Quality
To assess background noise levels in the study area, ambient noise monitoring is conducted. A
total of fourteen (14) locations were identified along the project road, based on different
categories of area.
Ambient noise level or sound pressure levels (SPL) are measured by a portable sound level
meter having built in facilities to read noise level directly in dB(A). From the SPL values,
equivalent continuous sound pressure level values (Leq) are calculated. Noise measurement is
conducted as per IS: 4954 as adopted by CPCB.
Ambient noise level monitoring has been carried out during October 2008. At each location
monitoring was conducted continuously over a period of twenty- four hours to obtain Leq values
at uniform time intervals of 1 hour. Description of the noise monitoring stations and the Leq
values at each station are given in Table 4-11.
The noise monitoring stations have been depicted in Figure 4-9
4-17