Free IAS coaching day 65

Solid Waste Management/E-waste Management/Treatment Methods for Waste Management


Solid Waste ManagementE-Waste Management Treatments Methods for Waste Management

Solid Waste Management

India has emerged as the world’s fifth largest electronic waste (e-waste) producer. India discards roughly 18.5 lakh tonnes of e-waste each year and telecom equipment alone accounts for 12% of it.

‘Wastes’
 are materials which are discarded after use at the end of their intended life-span. Waste management is a collective activity involving segregation, collection, transportation, re-processing, recycling and disposal of various types of wastes. Waste management differs for different types of wastes and for wastes in different geographical locations such as urban, rural and hilly areas.
While the management of non-hazardous domestic waste is the joint responsibility of the citizens and the local government, the management of commercial, industrial and hazardous waste is the responsibility of the waste generators like commercial establishments, healthcare establishments, industries and the pollution control boards.
Sustainable waste management can be achieved through strategic planning, institutional capacity building, fiscal incentives, techno-economically viable technologies, public-private partnerships, community participation and such others.
SOLID WASTE
Rapid industrialization and population explosion in India has led to the migration of people from villages to cities, which generate thousands of tons of MSW daily. The MSW amount is expected to increase significantly in the near future as the country strives to attain an industrialized nation status by the year 2020.
The quantity of waste generated in Indian cities reported to be in the range of 0.2-0.6 kg/capita /day as per the “Manual on Solid Waste Management” prepared by Central Public Health & Environment Engineering Organisation (CPHEEO), Ministry of Urban Development, and Government of India.
The Waste Generation pattern is very much dependant on the living style of the population. As the major share of the population is labour force in Dibang, the waste generation factor of 0.3 kg/capita/day has been taken into consideration.
Solid waste management consists:
• Municipal waste: Municipal Solid Waste (MSW) or Urban Solid Waste is a waste that includes predominantly household waste (domestic waste) with sometimes the addition of commercial wastes, construction and demolition debris, sanitation residue, and waste from streets , institutes such as hospitals, collected by a municipality within a given area. They are in either solid or semisolid form and generally exclude industrial hazardous wastes.
• Electronic waste: Electronic metal waste, printed circuits boards, e-equipments, machinery, IC, Sockets connections etc.
• Biomedical waste: Hospitals generate various kinds of wastes from wards, operation theatres and outpatient areas. These wastes include bandages, cotton, soiled linen, body parts, sharps (needle, syringes etc), medicines (discarded or expired), laboratory wastes etc which carry infection and should be properly collected, segregated, stored, transported, treated and disposed to prevent contamination and infection.
India generates a huge quantity of Bio Medical Waste (BMW) every year. Almost 28% of the wastes is left untreated and not disposed finding its way in dumps or water bodies and re-enters our system.
Following are the major sources of generation of waste at urban level:
• Solid waste from Residential areas, Institutional/ Community areas
• Solid waste from vegetables markets (retail and wholesale)
• Solid waste from Hotels, and restaurants
• Solid waste from commercial areas
• Biomedical waste from hospitals and dispensaries
• Waste from domestic / stray animals /dairies
• Solid waste from Industries
• Waste from street cleansing
Solid waste management includes the entire process of dealing with solid waste, starting from the collection from the primary source to ultimately disposing off it hygienically, so that it may not be a nuisance or create any harmful effect on nearby community.
The solid waste management involves- management at waste generation level, storage at the source of generation, primary collection, street cleansing, temporary storage at locality level, regular and periodic transportation of this temporarily collected waste to disposing sites and treatment plants.
Issues in solid waste management in India:
• In most of the cities in India, the scientific and systematic storage of waste at source is not in practice.
• The waste is normally thrown in nearby vacant areas, government vacant land, drains, streets etc.
• Because of waste thrown on the street the environment becomes ugly and unhygienic , so even in case of regular cleaning be Municipal Workers also, the city cannot be kept clean for more than 2-3 hours .
• At sources people generally don’t arrange to provide proper dustbins, in residential, institutional and commercial areas.
• In case of open drains and large drains passing across the city, people throw waste and these drains are clogged, width of large drains is reduced because of continuous dumping.
• People generally use following items to collect waste at source: buckets, polythene packets, plastic bins, metal bins with and without lids.
• People generally don’t take the waste to the designated points they carry it to nearby roads, railway tracks, open plots etc and generally people avoid walking to the designated disposal points.
• So when wind blows the heap of solid waste get carried away by wind and spread in large areas and when there are rain the problem get aggravated.
• There is no system of keeping the Bio degradable and non Bio degradable waste separately. No processing of the waste is done in most cities. Very few cities have the organizational and administrative set – up to subject the waste to treatment process like composting and that too on a very limited scale. Most of the wastes are disposed by the concerned agency at an open dump without going in to the details of either site or wastes. There is no adherence to any standards or norms for disposal and the sites are not scientifically managed.
The land filling practice in most Indian cities is one of the most unscientific and unhygienic practices with serious environmental implications. The wastes are brought to the site and dumped. There is no consideration for leach ate gases and cove. The land fill sites are mostly accessible to scavengers, animals and vectors.
• Sweepers generally restrict themselves only to the sweeping of the streets and cleaning of drains.
• Sweepers avoid door stop collection of wastes in some areas; private sweepers collect the waste and deposit it to the collection points.
• Municipal manpower and financial resources are very less contextual to the gravity of problem, and available resources are not properly used.
WASTE MANAGEMENT
1. Possible Waste Management Options:
(a) Waste Minimization construction waste recycling
(b) Material Recycling
(c) Waste Processing (Resource Recovery)
(d) Waste Transformation
(e) Sanitary Landfilling – Limited land availability is a constraint in Metro cities.
2. Processing / Treatment should be:
(i) Technically sound
(ii) Financially viable
(iii) Eco-friendly / Environmental friendly
(iv) Robust operate & maintain by local community
(v) Long term sustainability

Sangam Age


Sangam Age

Sangam Age

• The Tamil heroic poems, popularly called the Sangam literature, constitute the-major evidence for the old Tamil literary tradition.
• In South India, Tamil had become a literary language, i.e., a full-blown language with its own system of writing, at least by third century BC.
• The Neolithic – Chaleolithic amalgam, which began around 2000 B.C., continued upto the middle of the first millennium B.C. It was then overlapped by the Magalithic culture inhabited by the Megaliths builders.
• The Megalithic culture which dates to C. 500 B.C. and A.D. 100 brings us to the historical period in South India.
• The Megalithic culture is known not from its actual settlements, which are rare, but from its graves. These graves are called Megaliths because they were encircled by big pieces of stone. They contain not only skeletons of peolple (fractional burials) who were buried but also iron objects like swords, spears, arrowheads, axes and pottery (black-and-red pottery).
• Agricultural tools like hoes and sickles found in the graves indicate and advanced type of agriculture.
• The Cholas, Pandyas, Cheras and Satyaputras mentioned in Ashoka’s inscriptions were probably in the Megalithic phase of material culture.
• About the beginning of the Christian era, the Megalithic culture was overlapped by what has been called Andhra Culture, on account of occurrence of Andhra coins.
• The distinctive pottery of the period was a white painted reddish brown ware known as the Russet-coated Painted Ware.
• This is also the time when South India had a large volume of trade with the Roman world, as shown by the occurrence, at numerous sites of Roman coins, glass work and pottery, the most noteworthy in the last item being the arrentine and the amphora.
• The cultural and economic contacts between the north and the deep south paved the way for the introduction of material culture brought from the north to the deep south by traders, conquerors, Jainas, Buddhists and some Brahmana missionaries.
• From the second century B.C., there was formation of state system, rise of social classes, use of writing, beginning of written literature, etc.
• The land south of the Krishna River was divided into three kingdoms – Cholas, Pandyas and Cheras or Keralas.
• The Pandyas are first mentioned by Megasthenes who speaks of the Pandya kingdom being ruled by a woman and that even seven year old mothers were found in the Pandya country; this may suggest some matriarchal influence in the Pandya society.
• According to Megasthenes Pandyan kingdom was celebrated for pearls.
• The three kingdoms – Cholas, Pandyas and Cheras, together with Satiyaputras (Satyaputra) are referred to as independent states by Ashoka in his inscriptions with which he maintained friendly relations.
• The name Satiyaputras is otherwise is an unknown name and has not yet been satisfactorily identified.
• The word ‘Sangam’ is associated with South Indian history where a college or assembly of Tamil scholars and poets flourished under the royal patronage of the Pandya kings at Madurai.
• Hence the age is known as ‘Sangam Age’, which extends roughly between 300 B.C. and 300 A.D.
• According to Tamil legends, there existed three Sangams (Academy of Tamil poets) in ancient Tamil Nadu popularly called Muchchangam.
• These Sangams flourished under the royal patronage of the Pandyas.
• The first Sangam, held at then Madurai, was attended by gods and legendary sages but no literary work of this Sangam was available.
• The second Sangam was held at Kapadapuram but the all the literary works had perished except Tolkappiyam.
• The third Sangam at Madurai was founded by Mudathirumaran. It was attended by a large number of poets who produced voluminous literature but only a few had survived.
• These Tamil literary works remain useful sources to reconstruct the history of the Sangam Age.
Sangam Literature
• The Sangam literature includes Tolkappiyam, Ettutogai, Pattuppattu, Pathinenkilkanakku, and the two epics- Silappathigaram and Manimegalai.
• Tolkappiyam authored by Tolkappiyar is the earliest of the Tamil literature. It is a work on Tamil grammar but it provides information on the political and socio-economic conditions of the Sangam period.
• The Ettutogai or Eight Anthologies consist of eight works – Aingurunooru, Narrinai, Aganaooru, Purananooru, Kuruntogai, Kalittogai, Paripadal and Padirruppattu.
• The Pattuppattu or Ten Idylls consist of ten works – Thirumurugarruppadai, Porunararruppadai, Sirupanarruppadai, Perumpanarruppadai, Mullaippattu, Nedunalvadai, Maduraikkanji, Kurinjippatttu, Pattinappalai and Malaipadukadam.
• Both Ettutogai and Pattuppattu were divided into two main groups – Aham (love) and Puram (valour).
• Pathinenkilkanakku contains eighteen works mostly dealing with ethics and morals.
• The most important among them is Tirukkural authored by Thiruvalluvar.
• Silappathigaram written by Elango Adigal and Manimegalai by Sittalai Sattanar also provides valuable information on the Sangam polity and society.
Other Sources
• In addition to the Sangam literature, the Greek authors like Megasthenes, Strabo, Pliny and Ptolemy mention the commercial contacts between the West and South India.
• The Asokan inscriptions mention the Chera, Chola and Pandya rulers on the south of the Mauryan empire.
• The Hathikumbha inscription of Kharavela of Kalinga also mentions about Tamil kingdoms.
• The excavations at Arikkamedu, Poompuhar, Kodumanal and other places reveal the overseas commercial activities of the Tamils.
Period of Sangam Literature
• The chronology of the Sangam literature is still a disputed topic among the scholars.
• The sheet anchor of Sangam chronology lies in the fact that Gajabhagu II of Sri Lanka and Cheran Senguttuvan of the Chera dynasty were contemporaries. This is confirmed by Silappathigaram as well as the Dipavamsa and Mahavamsa.
• Also the Roman coins issued by Roman emperors of the first century A.D were found in plenty in various places of Tamil Nadu.
• Therefore, the most probable date of the Sangam literature has been fixed between the third century B.C. to third century A.D. on the basis of literary, archaeological and numismatic evidences.
Political History
• The Tamil country was ruled by three dynasties namely the Chera, Chola and Pandyas during the Sangam Age.
• The political history of these dynasties can be traced from the literary references.

The Cholas
• The Cholas Kingdom was situated between the Pennar and the Velar rivers were the most powerful of all three kingdoms.
• Their chief centre of political power was at Uraiyar, a place famous for cotton trade.
• In the middle of second century B.C., a Chola king named Elara Conquered Sri Lanka and ruled over it for nearly 50 years. He was the first important Chola king.
• A firmer history of the Cholas begins in the second century A.D. when their greatest and most famous king Karikala, or the man with charred leg, who founded the port city of Puhar (identical with Kaveripattinam) and constructed 160 km of embankment along the Kaveri River.
• Puhar or Kaveripattanam was Chola capital. Puhar was also a great centre of trade and commerce.
• Trade in cotton cloth was one of the main sources of Cholas wealth.
• The Cholas also maintained an efficient navy.
The Cheras
• The Cheras or the Kerala country was situated to the west and north of the land of the Pandyas covering some portions of Tamil Nadu also.
• The history of the Cheras was marked by continuous fight with the Cholas and the Pandyas.
• Nedunjeral Adan, the first known Chera king, earned the title of ‘Udiyanjiral’.
• He also bore the title of ‘Imayavarambam’ or he who had the Himalayas for his boundary.’
• Senguttuvan, the Red or Good Chera, according to the Chera poets, was the great Chera king. It is said that he had invaded the north and crossed the Ganga.
• He build a temple for Kannagi, the Goddess of Chastity. The worship of Kannagi is known as the Pattini-cult, which was stabilized by him.
• After the second century A.D., the Cehra power declined, and nothing of its history until the eighth century A.D. is known.
• The capital of the Cheras was Vanji or Kaur.
• The Cheras owed its importance to trade with the Romans. They also build a temple of Augustus there.
The Pandyas
• The Pandyan kingdom occupied the south-most and the south-eastern portion of the Indian Peninsula, with Madurai as it capital.
• The Pandyas were one of the most ancient dynasties to rule South India and are mentioned in Kautilya’s Arhasastra and Megasthenes’ Indica.
• The Sangam age started form a Pandya king and, as per Sangam literature, there were at least twenty kings in this dynasty.
• Legendary and traditional accounts mention the loss of many Sangam texts on account of a ‘deluge’ which compelled the Pandyan kings to shift their capital first from Ten-Madurai to Kapatapuram and then from there to Madurai on the Vaigai.
• The most prominent among them was Nedunzalian, who made Madurai his capital.
• Another king was Madaranjeral Irumporai who sent embassies to Roman emperor Augusts and performed Vedic sacrifices.
• Pandya rulers exercised a clan-rule under several lineages, each bearing Tamil names ending with suffixes such as Valuti and Celiyan.
• The Pandyas acquired their resources in inter-tribal conflicts with the Cheras and Cholas, and luxury goods from their maritime trade with countries further west.
• The Pandyas founded a Tamil Literary academy called the Sangam, at Madurai
• They adopted the Vedic religion of sacrifice and patronized Brahmin priests.
• The Pandyas profited from trade with the Roman Empire.
• Their power declined with the invasion of a tribe called the Kalabhras.
• After the Sangam Age, this dynasty lost its significance for more than century, only to rise once again at the end of the 6th century.
• Their first significant ruler was Dundungan (590-620) who defeated the Kalabars and brought the Pandyas back to the path of glory.
• The last known Pandya king, Parakramadeva, was defeated by Usaf Khan a viceroy of Muhmmad-bin-Tughlaq when the Tughlaq dynasty was in process of extending their kingdom up to Kanyakumari.
Minor Chieftains
• The minor chieftains played a significant role in the Sangam period and among them Pari, Kari, Ori, Nalli, Pegan, Ay and Adiyaman were popular for their philanthropy and patronage of Tamil poets.
• They were known as Kadai Yelu Vallalgal. Although they were subordinate to the Chera, Chola and Pandya rulers, they were powerful and popular in their respective regions.
Sangam Polity
• Hereditary monarchy was the form of government during the Sangam period.
• The king had also taken the advice of his minister, court-poet and the imperial court or avai.
• The Chera kings assumed titles like Vanavaramban, Vanavan, Kuttuvan, Irumporai and Villavar, the Chola kings like Senni, Valavan and Killi and the Pandya kings Thennavar and Minavar.
• Each of the Sangam dynasties had a royal emblem – carp for the Pandyas, tiger for the Cholas and bow for the Cheras.
• The imperial court or avai was attended by a number of chiefs and officials.
• The king was assisted by a large body of officials who were divided into five councils. They were ministers (amaichar), priests (anthanar), military commanders (senapathi), envoys (thuthar) and spies (orrar).
• The military administration was also efficiently organized during the Sangam Age and each ruler had a regular army and their respective Kodimaram (tutelary tree).
• Land revenue was the chief source of state’s income while custom duty was also imposed on foreign trade.
• The Pattinappalai refers to the custom officials employed in the seaport of Puhar.
• Booty captured in wars was also a major income to the royal treasury.
• Roads and highways were well maintained and guarded night and day to prevent robbery and smuggling.
Sangam Society
• Tolkappiyam refers to the five-fold division of lands – Kurinji (hilly tracks), Mullai (pastoral), Marudam (agricultural), Neydal (coastal) and Palai (desert).
• The people living in these five divisions had their respective chief occupations as well as gods for worship.
– Kurinji – chief deity was Murugan – chief occupation, hunting and honey collection.
– Mullai – chief deity Mayon (Vishnu) – chief occupation, cattle-rearing and dealing with dairy products.
– Marudam – chief deity Indira – chief occupation, agriculture.
– Neydal – chief deity Varunan – chief occupation fishing and salt manufacturing.
– Palai – chief deity Korravai – chief occupation robbery.
• Tolkappiyam also refers to four castes namely arasar, anthanar, vanigar and vellalar.
• The ruling class was called arasar.
• Anthanars played a significant role in the Sangam polity and religion.
• Vanigars carried on trade and commerce.
• The vellalas were agriculturists.
• Other tribal groups like Parathavar, Panar, Eyinar, Kadambar, Maravar and Pulaiyar were also found in the Sangam society.
• Ancient primitive tribes like Thodas, Irulas, Nagas and Vedars lived in this period.
Religion
• The primary deity of the Sangam period was Seyon or Murugan, who is hailed as Tamil God.
• The worship of Murugan was having an ancient origin and the festivals relating to God Murugan was mentioned in the Sangam literature.
• Murugan was honoured with six abodes known as Arupadai Veedu.
• Other gods worshipped during the Sangam period were Mayon (Vishnu), Vendan (Indiran), Varunan and Korravai.
• The Hero Stone or Nadu Kal worship was significant in the Sangam period and was erected in memory of the bravery shown by the warrior in battle.
• Many hero stones with legends inscribed on them were found in different parts of Tamil Nadu. This kind of worshipping the deceased has a great antiquity.
Position of Women
• There is a plenty of information in the Sangam literature to trace the position of women during the Sangam age.
• Women poets like Avvaiyar, Nachchellaiyar, and Kakkaipadiniyar flourished in this period and contributed to Tamil literature.
• The courage of women was also appreciated in many poems.
• Karpu or Chaste life was considered the highest virtue of women.
• Love marriage was a common practice.
• Women were allowed to choose their life partners.
• However, the life of widows was miserable.
• The practice of Sati was also prevalent in the higher strata of society.
• The class of dancers was patronized by the kings and nobles.
Fine Arts
• Poetry, music and dancing were popular among the people of the Sangam age.
• Liberal donations were given to poets by the kings, chieftains and nobles.
• The royal courts were crowded with singing bards called Panar and Viraliyar. They were experts in folk songs and folk dances.
• The arts of music and dancing were highly developed.
• A variety of Yazhs and drums are referred to in the Sangam literature.
• Dancing was performed by Kanigaiyar.
• Koothu was the most popular entertainment of the people.
Economy of the Sangam Age
• Agriculture was the chief occupation and Rice was the common crop.
• Ragi, sugarcane, cotton, pepper, ginger, turmeric, cinnamon and a variety of fruits were the other crops.
• Jack fruit and pepper were famous in the Chera country.
• Paddy was the chief crop in the Chola and Pandya country.
• The handicrafts of the Sangam period were popular and include weaving, metal works and carpentry, ship building and making of ornaments using beads, stones and ivory.
• There was a great demand for these products, as the internal and external trade was at its peak during the Sangam period.
• Spinning and weaving of cotton and silk clothes attained a high quality.
• The poems mention the cotton clothes as thin as a cloud of steam or a slough of a snake.
• There was a great demand in the western world for the cotton clothes woven at Uraiyur.
• Both internal and foreign trade was well organized and briskly carried on in the Sangam Age. The Sangam literature, Greek and Roman accounts and the archaeological evidences provide detailed information on this subject.
• Merchants carried the goods on the carts and on animal-back from place to place.
• Internal trade was mostly based on the barter system.
• External trade was carried between South India and the Greek kingdoms.
• After the ascendancy of the Roman Empire, the Roman trade assumed importance.
• The port city of Puhar became an emporium of foreign trade, as big ships entered this port with precious goods.
• Other ports of commercial activity include Tondi, Musiri, Korkai, Arikkamedu and Marakkanam.
• The author of Periplus provides the most valuable information on foreign trade.
• Plenty of gold and silver coins issued by the Roman Emperors like Augustus, Tiberius and Nero were found in all parts of Tamil Nadu which reveals the extent of the trade and the presence of Roman traders in the Tamil country.
• The main exports of the Sangam age were cotton fabrics, spices like pepper, ginger, cardamom, cinnamon and turmeric, ivory products, pearls and precious stones. Gold, horses and sweet wine were the chief imports.
End of the Sangam Age
• Towards the end of the third century A.D., the Sangam period slowly witnessed its decline.
• The Kalabhras occupied the Tamil country for about two and a half centuries.
• Jainism and Buddhism became prominent during this period.
• The Pallavas in the northern Tamil Nadu and Pandyas in southern Tamil Nadu drove the Kalabhras out of the Tamil country and established their rule.

Sand Mining and its Impact


Sand Mining and its Impact

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles. River sand has the ability to replenish itself.
Sand is an important economic resource and also a source of silica for making sodium silicate, a chemical compound used for manufacture of both common and optical glasses. Sand is an ingredient in plaster and concrete and is added to clays to reduce shrinkage and cracking in the manufacture of bricks. Sand in the river channel and floodplains constitutes an important raw material in the construction industry and has a variety of uses in this sector. River sand is used along with cement, gravel, water and steel for making reinforced concrete. Along with cement and water, it is used as mortar for joint filling and plastering.
The economic aspects of sands are not confined to its value as raw material and its various uses. Sand production, movement and deposition are of great concern to the engineering geologist and to the geomorphologist, especially those concerned with river basin management, shore erosion and harbour development.
Besides its economic importance, sand also constitutes an important abiotic component in aquatic ecosystems like rivers. lt provides suitable substrate for many benthic organisms. It is an unavoidable component for psammophilic fishes as it provides breeding, spawning, feeding and hiding grounds. Inter-beds of sand within floodplain deposits act as aquifer systems storing large quantities of ground water. In addition to this, sand acts as an efficient filter for various pollutants and thus maintains the quality of water in rivers and other aquatic ecosystems. In earlier days, mining of sand did not create any problem to river ecosystem as the quantity of mining was well within the replenishment limits. However, increase in population and the rise in economic and industrial developments during the past few decades have aggravated mining of river sand many folds higher than natural replenishments which really made a host of damages to river ecosystems in the world.
Impacts of sand mining can be broadly classified into three categories:
• Physical: The large-scale extraction of streambed materials, mining and dredging below the existing streambed, and the alteration of channel-bed form and shape leads to several impacts such as erosion of channel bed and banks, increase in channel slope, and change in channel morphology. These impacts may cause: (1) the undercutting and collapse of river banks, (2) the loss of adjacent land and/or structures, (3) upstream erosion as a result of an increase in channel slope and changes in flow velocity, and (4) downstream erosion due to increased carrying capacity of the stream, downstream changes in patterns of deposition, and changes in channel bed and habitat type.
• Water Quality: Mining and dredging activities, poorly planned stockpiling and uncontrolled dumping of overburden, and chemical/fuel spills will cause reduced water quality for downstream users, increased cost for downstream water treatment plants and poisoning of aquatic life.
• Ecological: Mining which leads to the removal of channel substrate, resuspension of streambed sediment, clearance of vegetation, and stockpiling on the streambed, will have ecological impacts. These impacts may have an effect on the direct loss of stream reserve habitat, disturbances of species attached to streambed deposits, reduced light penetration, reduced primary production, and reduced feeding opportunities.

Illegal Salt Mining and its Impact


Illegal Salt Mining and its Impact

A salt mine is a mine from which halite, commonly known as rock salt, is extracted from evaporite formations.
Illegal salt making and its impacts on Sambhar Lake’s ecology:
• Unrestrained salt production threatens the very existence of Sambhar Lake, which was declared a wetland of international importance in 1990 by the Ramsar Secretariat for being a unique migratory bird habitat and wetland ecosystem.
• The entire stretch is lined with salt refineries, all allegedly manufacturing salt with stolen brine from the lake.
• Bad monsoon for several years and a dry lake surface has further led to the salt manufacturers exploiting groundwater by digging illegal borewells in the land that belongs to Sambhar Salts Ltd.
• The road to Nawa witnesses’ heavy traffic of tractors ferrying clay from Sambhar that the salt manufacturers use to make ‘kyars’ or brine retaining pits.
Impacts:
• Excess water extraction has lowered groundwater levels by over 60 meters in the area.
• Several dams and smaller anicuts blocking the natural drainage to ensure availability of irrigation water barely contribute to the lake. Hence, deprived of recharge from subsurface flows, the lake is dying.
• Pipelines have been dug to illegally extract water from the lake to manufacture salt and the situation is worsening every year. It would soon reach a point where the existence of the Sambhar Lake itself (would be) under threat.
• Presence of salt-tolerant algae makes the lake one of the most important wintering areas for flamingos in country, after the Rann of Kachchh. Both Phoniconaias minor and Phoenicopterus roseus, settle here during winters. But their number has fallen drastically in the past two decades because of overextraction of subsurface brine from the lake and pollution caused by illegal salt-making units.

Groundwater Contamination


Groundwater Contamination

Introduction:
• Any addition of undesirable substances to groundwater caused by human activities is considered to be contamination.
• Groundwater contamination also called Groundwater pollution occurs when pollutants are released to the ground and make their way down into groundwater.
• It can also occur naturally due to the presence of a minor and unwanted constituent, contaminant or impurity in the groundwater.
• Different mechanisms have influence on the transport of pollutants, e.g. diffusion, adsorption, precipitation, decay, in the groundwater.
• The interaction of groundwater contamination with surface waters is analyzed by use of hydrology transport models.
Sources:
• Point sources:
– Municipal landfills.
– On-site septic systems.
– Leaky sewer lines.
– Leaks or spills of industrial chemicals at manufacturing facilities.
– Sludge disposal areas at petroleum refineries
– Underground injection wells (industrial waste).
– Livestock wastes.
– Chemicals used at wood preservation facilities.
– Leaky tanks or pipelines containing petroleum products.
– Fly ash from coal-fired power plants.
• Non-point (distributed) sources:
– Fertilizers on agricultural land.
– Pesticides on agricultural land and forests.
– Contaminants in rain, snow, and dry atmospheric fallout.
Pollutant types:
• Volatile organic compounds: They are generally introduced to the environment through careless industrial practices.
• Pathogens: Pathogens contained in feces can lead to groundwater pollution when they are given the opportunity to reach the groundwater, making it unsafe for drinking.
(Diseases: cholera, diarrhoea).
• Nitrate: Nitrate levels above 10 mg/L (10 ppm) in groundwater can cause “blue baby syndrome” (acquired methemoglobinemia).
• Others: Organic pollutants can also be found in groundwater, such as insecticides and herbicides. Inorganic pollutans might include ammonia, nitrate, phosphate, heavy metals or radionuclides.
Naturally occurring:
• Fluoride: In areas that have naturally occurring high levels of fluoride in groundwater which is used for drinking water, both dental and skeletal fluorosis can be prevalent and severe.
• Arsenic: In the Ganges Plain of northern India and Bangladesh severe contamination of groundwater by naturally occurring arsenic affects 25% of water wells in the shallower of two regional aquifers.
Exposure Pathways:
• Groundwater pollutants can enter the body directly through water supplies or by eating foods prepared with contaminated groundwater or grown in fields using contaminated sources.
• It may also affect humans when they are in direct contact with polluted waters.
Health Effects:
• Health effects from groundwater pollution depend on the specific pollutants in the water.
• Pollution from groundwater often causes diarrhoea and stomach irritation, which can lead to more severe health effects.
• Accumulation of heavy metals and some organic pollutants can lead to cancer, reproductive abnormalities and other more severe health effects.
Prevention:
• Locating on-site sanitation systems: On-site sanitation systems can be designed in such a way that groundwater pollution from these sanitation systems is prevented from occurring.
• The following criteria have been proposed for safe siting (i.e. deciding on the location) of on-site sanitation systems:
a) Horizontal distance between the drinking water source and the sanitation system.
b) Guideline values for horizontal separation distances between on-site sanitation systems and water sources vary widely (e.g. 15 to 100 m horizontal distance between pit latrine and groundwater wells).
c) Vertical distance between drinking water well and sanitation system.
d) Aquifer type.
e) Groundwater flow direction.
f) Impermeable layers.

Sai Praveen

Do You Like This??? Then Hit Subscribe Button. You Will Get Every Post, Which Is Worth Reading

You are Visitor number