Kerala is one among the most thickly populated region in the world and the population is increasing at a rate of 14% per decade.As a result of the measures to satisfy the needs of the huge popualtion,the rivers of Kerala have been increasingly polluted from the industrial and domestic waste and from the pesticides and fertilizer in agriculture.Industries discharge hazardous pollutants like phosphates, sulphides, ammonia, fluorides, heavy metals and insecticids into the downstream reaches of the river.The river periyar and chaliyar are very good examples for the pollution due to industrial effluents. it is estimated that nearly 260 million litres of trade effluents reach the Periyar estuary daily from the Kochi industrial belt.

              The major water quality problem associated with rivers of Kerala is bacteriological pollution.The assessment of river such as Chalakudy, Periyar, Muvattupuzha, Meenachil, Pamba and Achenkovil indicates that the major quality problem is due to bacteriological pollution and falls under B or C category of CPCB classification.There are local level quality problems faced by all rivers especially due to dumping of solid waste, bathing and discharge of effluents.With regard to groundwater, water quality charecteristics of wells in Kerala are found to be affected by chemical and biological contaminants.The ground water quality problemas in the coastal araes are mainly because of the presence of excess chloride.The chloride concentration >250mb/l was detected in the well water samples of Azhicode, Kakkathuruthy, Edathinjil, Kadalundi, Chellanum, nallalam, Mankombu and Haripad. in Alappuzha district, flouride concentration in the pumbing wells was observed to be high.In midland region, with regard to ionic concentraion, the concentration of flouride iron and chlorid were found to be on the higher side.The flouride content was observed to be beyond the permissible limit of 1 mg/1.Deep wells in Chittur taluk and Knajikod areas of Palakkad district are found to contain flouride concentration greater than 1mg/l.

 

             Open well of Kerala are under threat of bacetriological comtamination.In Kerala about 60% of the population relies on ground water for drinking.At the same time studies have shown that faecal contamination is present in 90% of drinking water wells.The open character of the wells, and conventional maintanance habits, and use of buckets and rope to draw water, kitchen wastes and pit latrines with average family load factor (5 members) at a distance of less than 5 meters from wells are some of the factors, which are contributing to the bacteriological contamuination.Ground water contamination due to industrial pollution has been reported from places of Kochi (eastern part of Aluva), Palakkad and some parts of Kollam, Kozhikode and Kannur.

 

Guidelines for Water Quality Management

 

(i) CCME Water Quality Index: Water Quality Index (CCME WQI) based on Canadian Council of Ministers of the Environment provides a convenient means of summarizing complex water quality data that can be easily understood by the public, water distributors, planners, managers and policy makers. The CCME WQI incorporates three elements:

 

(a) Scope: The number of water quality parameters (variables) not meeting water quality objectives (F1)

(b) Frequency: The number of times of the objectives are not met (F2)

(c) Amplitude: The extent to which the objectives are not met (F3).The index produces number between 0 (worst) to 100 (best) to reflect the water quality.

 

           A zero value signifies very poor water quality whereas a value close 100 signifies excellent water quality. The assignment of CCME WQI values to different categories is a somewhat subjective process and also demands expert judgement and public’s expectations of water quality. The water quality is ranked in the following 5 categories:

1.      Excellent: CCME WQI values 95-100

2.      Good: CCME WQI values 80-94

3.      Fair: CCME WQI values 60-79

4.      Marginal: CCME WQI values 45-59

5.      Poor: CCME WQI values 0-44

      

(ii) CPCB Classification:Central Pollution Control Board classified the inland surface water into five i.e.; from A to E on the basis of their designated best use and desired class. The classification has been made in such a manner that with the degradation in quality, the water quality requirement becomes progressively lower from A to E.

 

Primary Water Quality Criteria for Various Uses (CPCB) 

Sl. No	Characteristics	A	B	C	D	E
1	Dissolved Oxygen(DO),mg/l, Min	6	5	4	4	_
2	Biochemical Oxygen Demand (BOD) ,mg/l, Max	2	3	3	_	_
3	Total Coli forms MPN/100ml, Max	50	500	5000	_	_
4	pH Value	6.5-8.5	6.5-8.5	6.5-8.5	6.5-8.5	6.5-8.5
5	Conductivity ,micromhos, Max	_	_	_	1	2.25
6	Total dissolved solids	500	_	1500	_	2500
7	Nitrates as NO3, mg/l	20	_	50	_	_

 

 

 

 

 

 

 

 

 

 

 

Water Quality Data and Parameters

            Water quality determines the ‘goodness’ of water for particular purposes. Water quality tests will give information about the health of the waterway. By testing water over a period of time, the changes in the quality of the water can be seen. Observations of water quality mainly refer to concentrations of dissolved constituents in the water in terms of physical (like turbidity, conductivity etc.), chemical (like sodium, potassium, cadmium etc.) and biological parameters (like algae, bacteria etc.). Data on water quality requires collection of a water sample followed by analysis (measurement) for specific water quality parameters. Some of these water quality parameters can be measured at site, the so-called field parameters. The other parameters are analysed in a laboratory. Laboratories of different levels are distinguished.  Level I laboratories are small laboratories located at or near the sampling location. These were originally established for determination of sediment load only, but now can also be used for determination of the water quality field parameters. Higher level laboratories (levels II and II+) are usually located in major cities and provide analytical capacity to a larger region covering more sampling locations.Sixty eight (68) water quality parameters are considered to be the Water Quality Parameters.

 

Some Terms Related to Water Quality

 

Minimum and Maximum:  The maximum value represents the highest values that may be expected for the parameter under natural conditions in surface waters in India. The minimum value is also used for checking the validation. The minimum value represents the lowest value that may be expected for the parameter under natural conditions in surface waters in India. This implicates that the most parameters cannot be reported as zero (0.0) and a minimum value (a non-zero) is therefore present in the database. Exceptions are all trace organic substances and the following parameters that may be reported as zero (0.0).

 

Upper Warning Limit and Lower Warning Limit: These limits are provided in the database to warn the user in case the values are exceeding the usual lower or upper limits. UWL and LWL can be edited by the laboratory, but must meet the criteria:UWL-Maximum and LWL-Minimum.

 

Limit of Detection: The lowest concentration that can be detected by a specific analytical method is indicated here. The LOD value is only used for validation purposes in case of trace metals and trace organics.

 

Calculated Parameters: Some of the parameters need not be entered in the form because they are automatically calculated. These parameters are called indirect parameters. Eight (indirect) parameters are calculated based on the measured results of other (direct) parameters. These are

Sodium Adsorption Ratio (SAR), Percent Sodium, Residual Sodium Carbonate (RSC), Calcium Hardness, Total Hardness, Calculated Total Dissolved Solids, Phenolphthalein Alkalinity, and Total Alkalinity.

 

Ion balance for cations and anions: The relative imbalance between the sum of the major cations and the sum of the major anions s expressed in % and should not exceed 5-10%. The percent difference may be somewhat lower for samples with low TDS values. Na and Cl ratio-Normally, in sodium dominated waters, most of the Na is associated with Cl, and thus, the ratio between Na and Cl (in meq/L) remains within 0.8 to 1.2.

 

EC and TDS ratio: for fresh water conductivity (EC, in µmhos/cm) and Total Dissolved Solids (in mg/L) usually obey the following relationship: EC = TDS*a, Where a ranges from 0.55 to 0.9. The constant a is usually high for chloride rich waters and low for sulphate rich waters.

 

TDS-calculated and TDS-measured: The measured TDS concentration should be higher than the calculated one because the significant contributor may not be included in the calculation.

 

COD and BOD ratio: Values measured for COD should always be higher than BOD values.SWDES checks if the ratio COD/BOD >1 and indicates if the values do not meet this criteria.

 

Carbonate and pH relation: At pH values below 8.3 the CO32- (phenolphthalein alkalinity) alkalinity should be zero.

 

Water Quality Parameters

Certain parameters of water quality and their categorization are given in Table: 1.

 

 Table 1:  Water quality and their categorization

 

Table 2: Water Quality Parameters and Analysis Method:

Sl. No.	Parameter	Equipment Required for Analysis
Level- I Lab
1	Temperature	Thermometer/ Water Analysis Kit
2	Colour	Visual / colour kit
3	Odour	Physiological Sense
4	Electrical Conductivity/ Total Dissolved Solids (TDS)	Conductivity Meter/ Water Analysis Kit
5	pH	pH Meter/ Water Analysis Kit
6	Dissolved Oxygen	Titration/ Water Analysis Kit
Level-II Lab (In addition to Level-I Parameters)
1	Temperature	Thermometer/ Water Analysis Kit
2	pH	pH Meter/ Water Analysis Kit
3	Electrical Conductivity/ Total Dissolved Solids (TDS)	Conductivity Meter/ Water Analysis Kit
4	Calcium	Complexometric Titration
5	Magnesium	Complexometric Titration
6	Sodium	Flame Photometer
7	Potassium	Flame Photometer
8	Iron	Spectrophotometer
9	Carbonate	Titration
10	Bicarbonate	Titration
11	Sulphate	Nephelometer / Turbidity meter
12	Chloride	Argentometric Titration
13	Fluoride	U.V.Visible Spectrophotometer/ Ion Meter
14	Nitrate	U.V.Visible Spectrophotometer/ Ion Meter
15	Nitrite	U.V.Visible Spectrophotometer/ Ion Meter
16	Silicate	U.V.Visible Spectrophotometer /Ion Meter
17	Phosphate	U.V.Visible Spectrophotometer/ Ion Meter
18	Boron	U.V.Visible Spectrophotometer
19	Dissolved Oxygen	Titration/ Water Analysis Kit
20	Biochemical Oxygen Demand (B.O.D.)	Incubation followed by Titration
21	Chemical Oxygen Demand (C.O.D.)	C.O.D. digester
22	Total Plate Count	Colony Counter
23	Total Coliform	By Culture Technique
24	F. Coliform
25	E. Coliform
Level-II+ /Level-III (In addition to Level-I & II Parameters)
1	Total Kjeldhal Nitrogen	Kjeldahl Apparatus
2	Cyanide	Ion Meter
3	Ammonia (Nitrogen)	U.V.Visible Spectrophotometer/ Ion Meter
4	T.O.C. (Total Carbon Analyser)	T.O.C.Analyser
Pesticides (4 to 9) (06 Nos.) including:
5	2,4-D	Gas Chromatograph
6	Aldrin	Gas Chromatograph
7	D.D.T.	Gas Chromatograph
8	Endo Sulphan	Gas Chromatograph
9	Cadmium	Atomic Absorption Spectrophotometer/ Inductively Coupled Plasma Spectrophotometer
10	Mercury
11	Chromium
12	Lead
13	Zinc

 

Characterestics of Drinking water

 

 Sources:

• Kerala State Pollution Control Board
• Water Resource Information System of India (http://india-wris.nrsc.gov.in/)