Ludhiana (or Lodhiana) is called after the Lodhi dynasty which ruled Delhi from 1451 AD to 1526 AD and  was founded by the then Lodhi General Nihang Singh in 1481 AD. Prior to 1835 when Britishers took over the town, it was a part of Mughul dynasty and later was ruled by Maharaja Ranjit Singh during 18th century.  With the partition of the state in 1947, the area of the city and its population have increased manifolds.  Ludhiana is presently a district headquarter and an important rail and road junction.

Physiography
Ludhiana city was founded on a ridge of Budha Nala, which once was a bed of the River Satluj. The urban area is lying between 30^o 51^'10^" to 30^o 57^'20^"N latitude and 75^o46^'00^" to 75^o56'20^"E longitude, the average height above mean sea level is 247 m. Previously the urban area was confined south of Budha Nala but due to population explosion, the low lying area between Budha Nala and the River Satluj is fast merging in the urban area. Many villages surrounding the city are now part of the Ludhiana Municipal Corporation.

Climate
The climate of Ludhiana is semi arid.  It is influenced by south-west monsoon winds in the summer, and westerly and north westerly winds during the winter. It receives an average annual rainfall of about 708 mm. January is the coldest month with average minimum temperature of 5.8^oC.  June is the hottest month when  temperatures rises to 41.2^oC.

Population
In 1901, the population of Ludhiana was just 48,650. The population in 1991 has crossed a million figure. It indicates that the population has been growing fast recording as much as 50.2% increase in 1961 and 2143% increase in 1991 in comparison to 1901. The population density which was only about 100 persons/ha in 1971 has increased to about 259 persons/ha in 1991.

Grassroot of the problem
In Ludhiana city, the sole source of water supply is ground water.  In order to meet the demand of water supply of the city, ground water is being pumped through deep tube wells and shallow hand pumps without any systematic planning. This over-exploitation  is depleting the ground water resource.  The problem is further aggravated by lack of ground water recharge because of diversion of agricultural land to urban sector. Thus, the fast growing urbanisation, industrialisation and other developmental activities have brought a variable water crisis.

Ludhiana city has 250 large and medium scale units and 41,116 small scale units.  Electroplating, heat treatment, cycle manufacturing, hosiery, machine parts, vegetable oils, dyeing process and chemical industries are the major categories. Nearly 22,000 industrial units of different categories are a major source of pollution. These units, though spreads all over the city are basically concentrated in Industrial Area A, Industrial Area B, Focal Point, along both sides of GT Road towards Ambala and Jalandhar, Gaushalla Road, Ludhiana Chandigarh Road and Rahon Road. The most important category of industries in Ludhiana is hosiery and textile. This uses huge quantity of chemicals and various types of dyes. Other important category is electroplating and heat treatment which uses chrome, nickel and cyanide, which are highly toxic and harmful for public health.

Most of the industries are disposing their untreated industrial effluent in the immediate vicinity as they have either not installed effluent treatment plants and if installed these are not functioning properly.  Most of such industries are located in the north-west part of the city.  Interestingly, the thickly populated central core has the maximum number of tube wells and hand pumps. Thus, there is every likelihood of the movement of the pollutants (leached to ground water) from industrial area to dominantly residential central core of the city especially during the rainy season. This unsystematic disposal of industrial effluent and  solid wastes have therefore affected the ground water quality of the area.

The industrial effluent is also discharged into the sewerage network of the city. The sewerage system takes this sewage to a narrow canal known as Budha Nala (BN) which flowis through the city and finally merges in the Sutlej River.  As a result,  it has become an open sewer. Because of the perennial nature of the sewage and effluent flow, the possibility of the pollutant leaching to ground water is very high along the BN.  Use of Budha Nala water for irrigation has engraved the problem.  This practice is causing land contamination coupled with adverse effects on human health due to the consumption of agricultural produce from the affected areas.

Surface water pollution
Budha Nala, a narrow unlined canal, is the cities sole surface water resource.  It originates from Chamkaur Sahib (district Ropar) and merges in the River Sutlej. It is an important drainage line of Ludhiana district. It passes through Ludhiana city and carries the sewage and industrial sludge of the city. The large volume of domestic and industrial waste water has converted the canal to a virtually sewage drain. In the late nineteenth century, it was a clean water stream as reported in the gazetteer of 1904:

"Immediately under the high bank along the old course of the Satluj now runs a perennial stream called the Budha Nala which takes its rise near Chamkaur, in the Ropar Tehsil of Ambala, and enters this District under Bahlopur. Passing just below the town of Ludhiana, it flows into the Satluj in Tahsil Jagraon, a few miles east of the Firozpur border. When swollen by floods in the rains it has a considerable volume of water and covers the surrounding country but ordinarily, although there is in places a good deal of swamp, the stream is only a few yards across. The water, except during floods, is perfectly clear and is used freely for drinking purposes. It is rarely, if ever, used for irrigation. In explanation of this fact it is reported to contain a strong infusion of salts, but the main reason is that it is easier and more economical to dig small unlined wells, in which water is obtained at from 2 to 10 feet below the surface."

Gill (1974) investigated the physico-chemical characteristics of the waters of Budha Nala in relation to their effect on fisheries. It was reported that there was no dissolved oxygen in polluted zone, BOD ranges 90-350 PPM was high with pH 7.05 to 7.7 and specific conductivity between 0.45-1.46 micro mhos. These parameters were reported to have adverse affects on fish life. Nitrates and phosphorus were also much more than their respective permissible limits. The study reveals that discharge of raw sewage into Budha Nala had considerably increased. The presence of blue-green algae had been reported to have increased the BOD, making water coloured and turbid, and give disagreeable odours.

Azad (1981) studied the metal ion concentration  in Budha Nala water and found the concentration of lead, cadmium, Nickel and cobalt in Nala's water to be much more than their respective permissible limits.

Sharma (1984) conducted the study on Budha Nala for seasonal population dynamics of zoo plankton in polluted water. It was reported that there was adverse affect of sewage, dairy wastes and industrial effluents on the aquatic organisms.

Duggal and Grewal (1985) compared the water qualities of Budha Nala's both upstream and downstream of city. The water quality of Nala was found to be badly impaired at downstream side because of discharge of sewage and industrial effluents from the city.

Present status of Pollution in Budha Nala
To study the variation in physico-chemical parameters in the water of Budha Nala vis-à-vis variation of discharge, a detailed study was undertaken by G. Singh, Civil Engineering Department.  Eight sampling sites were selected along the 25km Stretch of Budha Nala. The first three sampling sites were within city limits, fourth to seventh sampling sites were at downstream of BN whereas eighth was selected at river Sutlej, one kilometre downstream from the point where Budha Nala merges into the river. All sewage drains join to BN before site four. Therefore, the four stations(fourth to sevength) were used for analysing the data and to understand the changes in water quality. The eighth sampling site was also not a true representative of Budha Nala water as the Sutlej water mixed up in it. The data on this site was to determine the effect of Budha Nala water on the Sutlej River.

The samples were collected as per "Standard methods for the Examination of Water and Waste water" (APHA; 1985) during the three seasons city witnesses. One month interval was taken to collect the waste water samples. These samples were collected each time in the morning from 8.00 A.M. to 11.00 A.M. as it was expected to have a peak flow in the stream during this time.  The collected samples were analysed for physico-chemical parameters: turbidity, pH, dissolved oxygen, BOD and ammoniacal-N within 6 hours of the collection.

Summary of the findings shows:

i) All the parameters are at the highest level when the flow in Budha Nala is minimum in month of July and lowest in October. It may be attributed the peak running season of dyeing units before winter falls.

ii) Dissolved oxygen at any site along the course of Budha Nala was absent throughout the year reflecting that the stream is highly polluted.

iii) The BOD, COD and TDS have higher values in summer season as compared to rainy & winter season.

iv) Self-purification mechanism does not exists in Budha Nala.  The stream do not recover from pollution even at extreme downstream station and dissolved oxygen remains absent.

Impact of suface water pollution on ground water
in 1988, a study was carried-out to demarcate the zone of ground water pollution along the Budha Nala by J.P. Singh in the department of Civil Engineering. The study was aimed to predict the spread of pollutant into areas around Budha Nala through ground water.

The site selected for experimental work was in downstream of Budha Nala near Haibowal colony.  The very reason for this selection is that all the city drains have found their entry into the BN before it reaches Haibowal. Thus, the quality of water in this reach of BN is the worst and remains uniform.  Three longitudnal site sections were considered. While selecting sampling points (hand pumps), in and around Budha Nala, care was taken so that the sampling points should fall on either side of the Nala on a perpendicular line that to on the same sub-soil water depth. Equal perpendicular distances were also covered for the analysis work carried out on either side of Nala at each section. Two sampling points for analysing Budha Nala's  water were also selected at each section.

The collected samples from Budha Nala, tubewells and handpumps were tested for different physical, chemical and microbiological parameters.  The conclusions drawn from the present study are:

i) The concentration of most of the water quality parameters of Budha Nala exceeds the in-stream standards set for effluent discharging in rivers.

ii) The water of hand pumps in the adjoining area, is having higher MPN, ammoniacal nitrogen, total solids and total hardness than maximum acceptable limits for potable water.   Thus, the ground water in nearby areas is unfit for drinking.

iii) The pollution traverses from Budha Nala to the ground water on either side.  Its area of influence is more on the right side than that of left, of its flow.  This might be attributed to the ground water flow direction.

iv) Because of perennial flow of pollutants in  Budha Nala, it is found that the it has polluted the ground water upto1200 m on the right side and 250-300 m on the left.

Ground  water pollution
The average water table  varies between 3 to 4 m in the city. In the nearby area of Budha Nala, the surface soil is very thin ranging from 2 to 3 meters and the strata mainly consists of sand, which being highly permeable, directly intercepts the polluted water and transmits to ground water reservoir. The indiscriminate discharge of industrial waste has led to a very serious problem of water and soil pollution. The reckless dumping of residual sludge from effluent treatment plants into low lying areas over the years has also affected the land and polluted the underground water, the sole source of drinking water supply of the city. It is also worth mentioning that many small farmers along Budha Nala are pumping water at various places for irrigation,  thus increasing the hazard.

Punjab Pollution Control Board undertook an extensive study of ground water quality in Ludhiana city.  As many as 150 samples from the potential problem areas viz. Industrial Area A & B, Focal Point, areas adjoining Budha Nala and some of the residential areas, were collected and analysed to assess the ground water quality of the city.  Ground water samples collected from tube wells and hand pumps were grab in nature and were drawn after allowing the water to run for about 20 minutes. Separate samples for cyanide, nitrate, total coliform, heavy metals and other parameters were collected in different containers.  A total of 18 parameters were tested to study the ground water pollution.  Major findings of the study are :

i) The quality of ground water from hand pumps and a few shallow tube wells has been impaired in some of the areas. However deep tube wells have not been affected.

ii) Not only the industrial area but also the residential areas have been adversely affected. Various localities such as Dashmesh Nagar, Joshi Nagar, Janta Nagar and Haibowal dairy complex have such toxic pollutants as cyanides, hexavalent chromium and few other in excessive proportions.

iii) Ground water in the belt along G.T. road has been severely polluted with chrome probably because of the seepage of effluent from electroplating units into groundwater and also because of deliberate callousness of some of industries which pump untreated/partially treated effluent into ground water.

iv) Ground water quality of deep tube well deviates from the laid down standard with respect to hardness, TDS etc..

Soil contamination
At many places in Punjab, industrial effluent/sewage is being utilised for irrigation, the reason being non-availability of fresh water or a feeling that the sewage and some of the effluents, rich in organic matter would restore the soil fertility. However, in addition to nutrients, sewage contains high concentration of heavy metals like nickel, chrome etc., organic substances and other compounds which are toxic to animals as well as human beings. Apart it also has a variety of pathogens, which favour the propagation of faecally or profaecally transmitted diseases.  The water of Budha Nala is highly toxic having high concentration of heavy metals like nickel, chromium and zinc in addition to dyes and numerous other organic and inorganic compounds. The application of such water for irrigation will result in the uptake of pollutants by plants thereby reaching man and animals through the food chain.

To study the longterm effects of waste water use, a study was conducted during the year 1990-91.  The soil samples were collected from the land irrigated by effluents of Budha  Nala. These were collected from 0-2 inch depth after discarding the surface layer. In order to determine the extent of percolation of movable ionic content, samples were also collected from 10-12 inch depth from fields  irrigated by waste water. Reference samples were collected from fields irrigated by tube well.

The samples were analysed to study the change in the physico-chemical characteristics of soil/land irrigated by Budha Nala with reference to the characteristics of reference samples. A direct comparision shows that the pH of soil is below 7.0 in all cases. The building up of sodium ions and the accumulation of metals in the soil is quite obvious. This, along with the acidic nature of soil, increase the tendency of plants to take up heavy metals.

Conclusion
The rapidly increasing urbanisation and indstrilazation have adversely affected the city's water resources.  The only surface water body Budha Nala, an unlined canal, is the main recepter of city's domestic and industrial sewage.  As a result of perrenial flow of sewage in Budha Nala, it has become an open sewer.  The Budha Nala is polluted to the extent that self-purification mechanism does not take place even at the most downstream point where it merges in the River Satluj.  The ground water quality is no better.  On one hand the industries are injecting untreated effluent to it, stagnated effluent in the nearby areas also leaches  pollutants.  In addition, Budha Nala is also playing an indirect key role in ground water pollution.  Ground water in most of the industrial estate and in few residential areas are unfit for drinking. In comparision to deep water aquifer, shallow water is seriously affected. The city not only faces a severe water pollution problem; depletion of ground water resources due to excessive and unsustainable pumping is another serious problem. Therefore, the City is in dire need of a sustainable water resources management scheme.

In Ludhiana, environmental problems are not solely caused by industries, inadequate and inefficient administration and enforecement of regulations aggravate the situation.