Ganga and Gandak are perennial rivers flow through the state. In addition Sone, Ghaghraand ---------- are seasonal rivers and are tributaries of Ganga.These have a water potential of about ---------.the state has a network of canals of length------km and drains of length -------km. The total surface and ground water resources in the state are estimated to be about-----------.Water resources in the state are being used mainly for industrial, irrigation and drinking purposes.The ground water is also a major resource of drinking water. With respect to quality of surface & ground water,theyare affected by following ways:

	Direct Point Sources: Discharge of Industrial waste, Domestic waste/Municipal waste and refuse.
	Agricultural Sources: Run off and soil erosion from agricultural lands carrying chemical fertilizers, herbicides and pesticides. and
	Activities potential to pollution: The use of ground water in excess of recharge is leading to a fall in water table. This should be consider on priority basis, since this is the cause of arsenic water pollution in some districts of the state due to decay of underground minerals.

    Rapid increase of population, urbanization, agricultural practices and several human activities are polluting the fresh water resource in the state by adding a lots of pollutants. This resulted in the increase of water pollution. In order to prevent control and abate water pollution, the Water (Prevention and Control of Pollution) Act was enacted in 1974. According to Section 2(e) of Water (Prevention and control of pollution) Act, 1974'water pollution 'means such contamination of water or such alteration of the physical, chemical or biological properties of water or such discharge of any sewage or trade effluent or of any other liquid, gaseous or solid substance into water(whether directly or indirectly) as may, or is likely to, create a nuisance or render such water harmful or injurious to public health or safety, or to the life and health of animals or plants or of aquatic organisms. To ensure that the water quality is being maintained or restored at desired level it is important that it is monitored on regular basis. Water quality monitoring helps in evaluating the nature and extent of pollution control required and effectiveness of pollution control measures already in existence. It also helps in drawing the water quality trends and prioritizing pollution control efforts. It is one of the primary goals of the Water Act to protect our valuable water resources.

  The following surface water quality standards formulated by the central govt.:

	Surface Water Quality Standards (as per IS: 2296)
	Surface Water Quality Standard(By CPCB)
	Water Quality Standards for Coastal Waters Marine Outfalls[By MoEF under The E(P)Rules,1986]
	Primary Water Quality Criteria for Bathing Water[By MoEF under The E(P)Rules,1986]

    This standard has been withdrawn by the Bureau of Indian Standard and it is not valid standard now, as reported by BIS,Patna.

    No coastal water marine outfalls are available in the state Bihar,therefore this surface water quality standard is irrelevant,here.

    In a water body or its part, water is subjected to several types of uses. Depending on the types of uses and activities, water quality criteria have been specified to determine its suitability for a particular purpose. Among the various types of users there is one use that demands highest level of water quality or purity and that is termed as "Designated Best Use" in that stretch of water body. Based on this, water quality requirements have been specified for different uses in terms of primary water quality criteria. The primary water quality criteria for bathing water are specified along with the rational in Table below:

(Water used for organised outdoor bathing)

(Source:STATUS OF GROUNDWATER QUALITY IN INDIA -Part – I byCPCB)
     Since all groundwater resources of the State are classified for more than one use and therefore, the most stringent or protective criteria will be applicable. Therefore, its qualities have been compared with Bureau of Indian standards: IS :10500:1991 and WHO Guideline for Groundwater Sources for Drinking Water which is presented in the form of Table given below:

   Water quality of river Ganga and its tributaries, Lakes and Ponds in Bihar is being monitored by the State Pollution Control Board.The ground water quality of the state is also monitored by the Board. Water quality monitoring programme was started with only six stations earlier, which was extended and now it is being carried out at 86 monitoring stationsin the state under National Water Quality Monitoring Programme(NWMP) sponsored by CPCB.The present network comprises of 13 stations on main river stream,25 on tributaries of river Ganga,03 on Lakes & Ponds water bodies and 45 on groundwater bodies.

   The number of sampling locations on mainstream of the majorrivers and their tributaries, medium and minor rivers, lakes, ponds water bodies are given in parenthesis.

  Monitoring Stations on Ganga River Stream

  Monitoring Stations on Tributaries of Ganga River

  Monitoring Stations on Lakes & Ponds Water Bodies

  Ground Water Quality Monitoring Stations

(Source:BSPCB)

   Water samples are being analysed for core parameters,mainly consisting of physico-chemical and bacteriological parameters like: pH, BOD, DO, Total Coliform and Fecal Coliform because of limited resources by the State Pollution Control Board. No General Parameters, Trace Metals & Pesticides parameters are being monitored. These monitoring works are being carried out under MINARS project sponsored by CPCB.

  Trend of DO

  Trend of BOD

  Trend of Total Coliform

  Trend of Fecal Coliform

   The above diagram indicates that the average dissolve oxygen(DO) of the river Ganga in Bihar stretch is more than 6 mg/l and its DO content is fairly good & meet to DO parameter of class A. pH is vary between max to min . It is clear from the above diagram that there is an increasing trend of average BOD from the location when it enters Bihar at Buxar to down stream last point at Kahalgaon from where it leaves the state. This indicates that there is a gradual addition of organic pollution to water course. This is mainly because of sewage discharged from various towns situated on catchment area of the river as well as agricultural surface run-off water meeting to the river course.

  Trend of DO

  Trend OF BOD

  Trend Total Coliform

  Trend of DO

  Trend OF BOD

  Trend Total Coliform

  Trend of DO

  Trend OF BOD

  Trend Total Coliform

     The above diagram indicates that the average pH, dissolve oxygen(DO),BOD of the tributary Sone at confluence of Ganga river stream near Koelwar is more or less constant.

     The average pH is vary between 8 to 6.5, DO between 6 to 7 (except Motijheel Lake at Motihari,Which DO trend is marginally low.) and BOD between 2.8 to 3.2.

     The groundwater quality of state has been assessed based on 45 monitoring stations and samples were analyzed for various physico-chemical and bacteriological parameters by the State Pollution Control Board, because of limited resources. No heavy metals, pesticides and poly-aromatic hydrocarbons were analyzed. The quality of the groundwater varies from place to place with the depth of water table. The groundwater quality has indicated higher concentration of electrical conductivity, total dissolved solids, hardness, calcium, magnesium, chloride, sulphate, nitrate, fluoride, iron, manganese, nickel, lead and cadmium vis-à-vis drinking water quality standards. The ranges of each parameter and their percent violation along with observations on groundwater quality are presented in Table 1 of Annexure I. The distribution of critical groundwater parameters such as TDS and Nitrates of pre and post monsoon seasons has been presented in Figure 3 & 4. No poly-nuclear aromatic hydrocarbons were detected in any of the groundwater samples of the metropolitan city.