1. Introduction The pollution of surface water has brought so much frustration over the past years nationally and globally. Surface water pollution occurs when the quality of water degrade to an extent that it becomes uneasy to use due to the entering of harmful substances into the water systems. When surface water is polluted the environment is affected as a whole. Aquatic species such as plants and fish are threatened by poor water conditions (Botkin, D.B., 2014).
Direct sources of water pollution include runoff, industrial waste, sewage, and human waste. Indirect sources include air pollution and sediment from construction sites. Industrial waste can lead to air pollution, which can ultimately lead to the pollution of water. This is also called atmospheric pollution. Atmospheric pollution is caused by pollutants such as smoke from factories entering the atmosphere and being carried to waterways.
Millions of people have faced with living-and-death issue due to constant use of contaminated water. Polluted water source causes the deleterious impact on the community. The common consequence is the rising rate of people at higher risk of acute and chronic diseases relating to water pollution such as dermatitis, digestive diseases, diarrhea, and cancer has risen. In several regions, patients diagnosed with cancer, gynecologic infections account for 40-50% of cases, due to polluted water sources. Polluted water and poor sanitation claim the lives of about 9,000 people per year in Vietnam, according to the Ministry of Health and the Ministry of Agriculture and Rural Development.
The water-borne diseases are a worldwide major cause of morbidity and mortality in humans (WHO, 1996). Even though the rural communities are indigent, lack access to portable water supplies and rely mainly on boreholes, rivers, streams and ponds for their daily water needs (Nevondo and Cloete, 1999). In most cases water from these sources is used directly without treatment and even though some of the water sources may be faecally contaminated (WHO, 1993). Simple low-cost on-site sanitation methods have been developed to dispose faecal matter, mainly because of their economic advantage. However, the biggest drawback is the well-recognized potential to pollute groundwater resources (ARGOSS, 2001; Lewis et al., 1980), which conﬂicts with Integrated Water Resources Management principles, in particular to preserve the integrity of vital ecosystems and to maintain water quality and quantity.
The land turned fertile in these areas as the water was allowed to seep in. These regions had successful wheat crop despite the deficient monsoon this year. The real solution lies in the decentralized and community-based water preservation. The right to use water should lie with the common people and not the industrialists. We will have to raise awareness regarding water conservation among the masses and give them their due rights.
Wastewater discharges with high nutrient loads from diffuse sources such as run-off from livestock feedlots or agricultural land fertilized with organic and inorganic fertilizers are becoming common sources of water pollution. Due to expansion of populations in urban areas urbanization and water pollution is closely linked. Specially in developing countries untreated urban waste is a prime source of water pollution. Due to many such reasons water quality rarely remains static and vary at spatial and temporal scales. Water quality data are essential in many situations such as for effluent description, when monitoring health of aquatic environments and to develop management programs and action plans to protect water resources.
Introduction Water pollution is one of the most pressing problems in the world nowadays. Water is an integral part of the biosphere, which depends on the state of flora and fauna. More than 98% of all water resources of the planet are represented with high salinity waters, which are unsuitable for economic activity. Water pollution is a change in the chemical and physical state, or biological characteristics of water, limiting its further use. With all types of water change or physical condition or the chemical composition of the water - when entering the pollutants, which are divided into two main groups: changes over time in water and remaining there unchanged.
The monitoring of groundwater quality for the villages, towns and districts as whole are not part of groundwater supply program and this district is no exception. Thus, communities, especially those in areas not served by township water supply, drink water from boreholes and wells whose quality are not monitored regularly. Drinking water which quality is not being monitored can pose a great danger to human health since untreated water, which might be contaminated, is known to contribute to about 80% of all diseases in developing countries (WHO, 2008). Most people who dig borehole and hand dug wells do not test the water quality before using for drinking and domestic and irrigation purposes in the
 As of 2007, half a billion Chinese had no access to safe drinking water.  In addition to the acute problems of water pollution in developing countries, developed countries also continue to struggle with pollution problems. For example, in the most recent national report on water quality in the United States, 45 percent of assessed stream miles, 47% of assessed lake acres, and 32 percent of assessed bays and estuarine square miles were classified as polluted.  The head of China 's national development agency said in 2007 that one quarter the length of China 's seven main rivers were so poisoned the water harmed the skin.  Water is typically referred to as polluted when it is impaired by anthropogenic contaminants and either does not support a human use, such as drinking water, or undergoes a marked shift in its ability to support its constituent biotic communities, such as fish.
Due to this, human population suffers from water borne diseases. It has, therefore, become necessary to check the quality of water at regular intervals of time. This brief overview about lake, various factors affecting its water quality, eutrophication has made it important aspect to study the quality of the aquatic ecosystem at regular interval of time so that the quality of the water can be monitored and timely suggestions can be recommended to the lake water monitoring authorities to take necessary measures. Hence, this investigation aims at studying seven necessary lake ecosystem of Mandya district as social contribution to the society by studying its quality. 2.1.