Terra Firma Env. Con. Pvt. Ltd. Chapter – III
Baseline Environmental Conditions
CHAPTER – IIIBaseline Environmental Conditions
3.1 / Land Environment :
3.1.1 / Background :
Syngenta India Ltd., Santa Monica Works, is located at village Corlim about 15km from Panaji along Panaji-Belgaum NH4A. It is at an elevation of 28m above MSL & has 81 Ha of plain terrain land (200 Acres). The site is in land classified as industrial zone. The manufacturing activity is spread over approximately 24 Ha (60 acres) of land. There is a housing colony for Senior Managers located within the complex at distance of about 500m from the manufacturing area.
On the East of the site, there is a chemical manufacturing plant of Ciba Speciality Chemicals Limited adjacent to this factory and village Dhulapi lies beyond it.
To the West is some open land with residential colonies and Corlim Industrial Zone beyond it. This industrial estate houses small scale units manufacturing furniture, plastic molded items, stationary items etc.
Cumbarzua Canal is adjacent to North boundary and has a small island (Cumbarzua) opposite Syngenta site. National Highway (NH 4A) from Panaji to Karnataka is to South and village Ilhas / Karmali beyond it.
Arabian Sea is about 20 kms away to the west of site. There are no National Parks or any reserve forests within 7 km periphery of the site. Dr. Salim Ali Bird Sanctuary encompasses an area of 1.78 sq.km & is located at Chorrao islands about 7.5 km to the North West. Kundeim Hills are 3 km away on east of the site. Old Goa Church is a notified archaeological monument 3 km to west of the site.
The Kundeim Industrial Estate 3 km away on the east is situated on Kundeim Hills and Corlim Industrial Estate 1 km away is on the north west of the site. Karmali Station on Konkan Railway is 2 km away on south west of the site. There are paddy fields, mango trees, cashew nut plantations, coconut plantations mainly to east, north and south of the site within 10 km periphery.
3.1.2 / Study Area :
Study area for REIA is restricted to about 10 km radius from site as per Guidelines of Ministry of Environment & Forests, Govt. of India. Plate I presents map showing geographical / topographical features within the study area. Syngenta is located adjacent to Cumbharzua Canal. Cumbharzua canal is an important water way connecting Zuari and Mandovi rivers. It is about 15 km long forming the eastern boundary of the largest island in Goa that is delimited by Mandovi in the north, Zuari in the South and Arabian Sea in the East. Cumbharzua canal and Zuari confluence in the southern most boundary of the present study area. The Northern extent of the study area is the rocky plateau North of Mayem lake. The Western boundary extends almost up to NH4A Panaji and Agassaim between Mandovi and Zuari Rivers. Mapusa river, north of Mandovi forms the North-West boundary. The eastern boundary goes little beyond Usgao-Bicholim road in the east. Mandovi forms the lifeline of this area with several big and small riverine islands such as Chorao, Diwar, Cumbarzua, Jua (St. Esteevem area) etc. forming part of this system.
3.1.3 / Land Use Pattern
Land use pattern for the study area was ascertained from Topo Sheet (Plate I) & from Satelllite Imagery Photograph in the form of False Colour Composite (LISS III) presented in Plate II. The topo sheet and the LISS III image shows several distinct features in study area. Important land forms are cultivated fields which are generally barren in the summer, mud flats often inundated with water, Khazan lands (reclaimed areas for paddy cultivation), lakes, mangroves, hillocks covered with vegetation (scrubs, dense scrubs, mixed jungles with cashew), settlements and mines. The hillocks form undulating terrain with a maximum altitude of 374 m occurring at Kundeim hills. Some of the important water bodies seen are the lakes at Karmali and Pilar and the water reservoir at Syngenta (within the industry premises).
Varied topographical features influence the land use pattern in the study area. Physiography of the study area can be broadly divided into drainage, undulating rocky hillocks and plains. These three major features show different land use patterns. The drainage is predominantly by Mandovi river along with its tributaries, Cumbharzua canal and Zuari river.
Hillocks : Undulating rocky hillocks are spread throughout the study area. At places, these hillocks also have plateaus as in the case of Kadamba plateau, Kundaim plateau, Chimbel-Bambolim plateau etc. Most of these plateaus are earmarked for various purposes such as Military establishment in Chimbel-Bambolim area, Industrial estate in Kundaim area and real estate on Kadamba plateau. The Usgao-Bicholim belt is predominantly hard rocky belt. These rocky areas are either sparsely vegetated (with shrubs) or show occasional cashew plantation. Extensive mining is seen in this belt.
The hillocks and rocky area east of Cumbharzua canal and west of Mandovi is a thickly vegetated area though strictly not falling in the realm of natural vegetation due to plantation of Cashew & Pineapple (on hillocks) & Coconut & Arecaunt (within valleys) within these vegetation areas. Most of the vegetation seen here is along hill slopes. Similar hillocks are seen North of Mandovi along the Mayem belt, but the proportion of cashew to the natural vegetation is high. However, in few areas, the hard rocks are mostly covered with shrubs and cashew is hardly seen. Another major area of vegetation is slopes of Kadamba plateau, Chimbel, Kurka, Santan and the area between Neura and Old Goa. Cashew is grown in this area, though elements of natural vegetation are seen to dominate here. Small hillocks with similar features could be seen in Chorao too.
Plains : Vast fields that are mostly cultivated during monsoons are seen in Chorao, between Chorao and Mayem, Divar, Near Merces, St. Esteevem, Cumbharzua, between Cumbharzua canal and the road that connects Pilar and Old Goa. In continuation with these fields are the areas that are flooded during high tide that form either mud flats or inhabited by stunted mangroves mainly Avicennia, Sonneratia, Acanthus or Cyperaceae members. Khazan lands, are lands inundated by water during high tides but paddy is cultivated by managing the water. Such Khazaan lands are common in the study area. Apart from these, pure mangrove strands are also seen in smaller or bigger patches along the river banks or river islands as in Chorao, Divar etc. The settlements are either occupying large areas as in the case of Goa Velha to Agassaim or they are in a linear passion along the foot hills as in Santan or the area between Banastari and Kundaim. The inter-mingling of each of these land uses makes it difficult to estimate the area accurately for each land use pattern. The land use estimate for the study area is as follows:
Table 3.1
Land Use Pattern /
Sr. No. / Land use / feature / Extent (%) /
1 / Vegetation (excluding mangroves and that in settlements) / 36
2 / Fields (including Khazans lands) / 12
3 / Mud-flats including Mangroves / 17
4 / Settlements / 9
5 / Industrial area / 2
6 / Drainage / 6
7 / Mining / 4
8 / Hard rocks (vegetation or with scant vegetation) / 7
9 / Water Bodies / 7
3.1.4 / Geology & Soil Cover :
Generally lateritic soil is seen in the study area. The area on the foothills has higher soil cover & hence shows human settlements. The soil is highly fertile & used for agriculture purposes & commercial plantation Table 3.2 presents soil quality in villages surrounding the manufacturing site.
Table 3.2
Soil Analysis Report
Parameter / Unit / Soil samples Paddy Fields at Village
Physico Chemical / Cumbharzua / Dhulapi / Karmali / Corlim
pH of 20 % Solution / -- / 4.17 / 5.13 / 4.25 / 5.73
Conductivity / mmhos / 330.00 / 2400.00 / 370.00 / 32.00
Moisture / % / 16.00 / 14.96 / 13.38 / 10.21
Water Holding Capacity / % / 80.40 / 58.94 / 54.47 / 50.38
Particle size / Clay / % / 50.098 / 9.06 / 8.76 / 30.43
Silt / % / 16.92 / 14.10 / 13.95 / 28.33
Fine Sand / % / 16.83 / 26.51 / 37.97 / 20.23
Coarse Sand / % / 15.27 / 50.33 / 39.32 / 21.01
Textural class / -- / Sandy clay loam / Clay loam / Sandy loam / Sandy loam
Total Organic Carbon / % / 3.75 / 3.30 / 3.75 / 2.70
Available Phosphorous / % / 0.0003 / 0.0003 / 0.0003 / 0.002
Chlorides / % / 0.03 / 0.28 / 0.02 / 0.02
Sulphates / % / 0.05 / 0.13 / 0.03 / 0.006
Nitrogen / % / 0.01 / 0.02 / 0.01 / 0.01
From the Table it can be seen that Soils are generally acidic, of sandy loam type & have moderate nutrient value. The soil has high water holding capacity.
3.1.5 / Hazardous Waste Disposal :
The solid / hazardous waste identified as per Hazardous Waste Rules, 2003 & requiring land disposal include :
§ ETP Neutralisation Sludge
§ Lava from Incinerator
§ Ash from Solid Waste Incinerator
§ Calcium Phosphate Sludge
Analysis of the wastes (Table 2.7 / 2.8 /2.9) indicates that the waste do not have any hazardous constituents exceeding criteria set under Schedule 2 of the HW Rules, 2003. Comparison with CPCB Waste Disposal Criteria indicates that the wastes are suitable for direct landfill (without pre-treatment).
As per previous practice, the wastes were tested to confirm their non-hazardous nature & then disposed off in abandoned quarry under intimation to GSPCB. Presently, the waste is being stored on-site in concrete lined pits.
3.1.5.1 / Impacts Due to On-site Storage :
It was observed that ETP Neutralisation sludges & lava/ash are stored on-site in concrete lined pits. Non-hazardous wastes like Boiler soot / ETP biomass etc are stored separately in designated pits. To assess whether any soil contamination has occurred due to Hazardous Waste Storage (within site), soil samples were collected near the storage area & analysed for heavy metal / pesticide content. Results of analysis are presented in Table 3.3.
Table 3.3
Analysis of soil sample near Hazardous Waste Storage Site within the manufacturing Plant
Parameter / Unit / Soil Sample Near HW Storage Site with in premisesPhysico Chemical
pH of 20 % Solution / -- / 6.44
Total Organic Carbon / % / 2.70
Available Phosphorous / % / 0.002
Nitrogen / % / 0.02
Chlorides / % / 0.02
Sulphates / % / 0.03
Metals
Zinc as Zn / ppm / BDL
Nickel as Ni / ppm / BDL
Cadmium as Cd / ppm / BDL
Chromium as Cr / ppm / 0.01
Lead as Pb / ppm / BDL
Pesticides
Pretilacholor / ppm / BDL
Thiamethoxam / ppm / BDL
MCP / ppm / BDL
Phospomidon / ppm / BDL
DDVP / ppm / BDL
Profenophos / ppm / BDL
Cuman / ppm / BDL
From the values it is seen that no contamination has occurred in the soil near Hazardous Waste storage area.
3.1.5.2 / Assessment of Previous Disposal Area :
In order to assess, whether previous disposal has led to any soil / water contamination, following studies were carried out :
§ Sub-surface geological studies
§ Assessment of Water Environment Features
§ Assessment of Soil / Water Quality
Analysis of various wastes disposed off at the quarry has been presented in Table 2.7, Table 2.8 & Table 2.9 of Chapter 2.0, which indicates their non-hazardous nature.
3.1.5.3 / Sub-Surface Geological Studies :
a) / Physiography:
The area is located south of Usgaon as marked on the location map (Fig. 3.1) & is denoted as stony waste on the map. The ground rises to the southern face of the quarry. The quarry area is bordered on the north by a watercourse which has a deep cut channel. This watercourse joins the major water course situated immediately on the western side of the quarry. Thus, the quarry area is bounded by two watercourses respectively on the north and western side. The western watercourse is perennial, and the northern smaller one is seasonal having small stagnant water pools during summer.
b) / Geology :
The surface is covered by extensively developed laterite masking the lower rock units. The laterite is young in age. Rocks occurring below the laterite profile belong to the Bicholi Group of the Dharwar Super Group, which constitute phyllites, granite gneiss, hornblend gneiss, quartize, etc. In this area, mainly phyllites, weathered phyllites and phyllitic clays are seen depending on the weathering profile.
c) / Findings of ERT study:
The ERT studies revealed that subsurface lithology in the quarry area is highly heterogeneous. The surface is covered extensively by laterite, young in age. This is followed by rocks belonging to Bicholim group or Dharwar Super Group comprising phyllites, weathered phyllites & phyllitic clays. Resistivity studies have also revealed hard compact and fractured rocks underlying the phyllites. However, the second layer below the duricrust is of low resistivity and during monsoon months, a phreatic zone develops in this layer. The deep seated aquifer will be recharged during every monsoon from the phreatic zone. The studies also show that the, subsurface water will move in the direction of northern water course which is located at much lower elevation than the quarry area. The resistivity data do not indicate ground gradient directly towards the major water course on the west. The lateritic clays fall in the category of silt of intermediate compressibility having porosity about 40% and permeability of 10-6 to 10-8 cm/sec. The clays have specific retention of about 15% and specific yield around 25% by volume.
3.1.5.4 / Impact of Hazardous Waste Disposal on Soil Quality / Water Environment :
a) Soil Quality : In order to ascertain the impact of Hazardous Waste disposal on soil quality in the area, soil samples were collected at two locations in immediate vicinity. The results of analysis are presented in Table 3.4.
Table 3.4
Analysis of soil sample near HW Disposal Site
Parameter / Unit / Sample 1 / Sample II
Physico Chemical
pH of 20 % Solution / -- / 6.71 / 6.31
Total Organic Carbon / % / 3.10 / 2.70
Available Phosphorous / % / 0.034 / 0.031
Chlorides / % / 0.56 / 0.61
Sulphates / % / 0.92 / 0.71
Metals
Zinc as Zn / ppm / BDL / 0.1
Nickel as Ni / ppm / BDL / BDL
Cadmium as Cd / ppm / BDL / BDL
Chromium as Cr / ppm / BDL / BDL
Lead as Pb / ppm / BDL / BDL
Pesticides
Preilachlor / ppm / BDL / BDLThiamethoxam / ppm / BDL / BDL
MCP / ppm / BDL / BDL
Phosphomidon / ppm / BDL / BDL
DDVP / ppm / BDL / BDL
Profenophos / ppm / BDL / BDL
Cuman / ppm / BDL / BDL
b) Impact on Water Quality : There are no wells within 1 km of the quarry. The nallah to the north had flow of water. Samples of nallah water were collected to test for contaminants (heavy metals & pesticides). Results of analysis are presented in Table 3.5
Table 3.5