Preparation of Ground Water Quality Map under Rajiv Gandhi National Drinking Water Mission – Phase IV in Karnataka

National Remote Sensing Centre (NRSC), ISRO, Govt. of India, in collaboration with partner institutions is preparing ground water quality maps using remote sensing and GIS technology under Rajiv Gandhi National Drinking Water Mission (RGNDWM) project. The project is being sponsored by the Department of Drinking Water Supply (DDWS), Ministry of Rural Development (MoRD). The KSRSAC has been entrusted with the work pertaining to the State of Karnataka

Objectives

The objective of ground water quality mapping is to create a spatial database on ground water quality using mainly the existing point data available with DDWS, MoRD. The output spatial data is to be in the form of an additional layer showing the spatial distribution of the quality of ground water. The ground water quality information is to be provided in terms of its suitability for human consumption, i.e.1) potable, 2) permissible and 3) non-potable as per the norms of the Bureau of Indian Standards (BIS).

Chemical parameters considered for mapping

There are many dissolved minerals and organic constituents present in ground water in various concentrations. Among them, the most common elements are pH, Total Hardness, Iron, Nitrate and Fluoride and the same are considered for mapping and analysis. Table 1 shows the threshold values used for classifying concentration of the elements as per BIS Specifications of 2003.

Table 1 Classification of chemical parameters as per BIS specifications

Sl. No	Chemical parameters	Desirable	Permissible	Non-potable
1	pH	6.5 to 8.5	No Relaxation	<6.5 & >8.5
2	Total Hardness – CaCO3 (mg/l)	<300	300 to 600	>600
3	Nitrate – NO3 (mg/l)	<45	No Relaxation	>45
4	Fluoride - F(mg/l)	<1.0	1.0 to 1.5	>1.5
5	Total Iron – Fe (mg/l)	<0.3	0.3 to 1.0	>1.0

Summary of Work

As for pH, Belgaum and Shimoga districts are more affected; for Total Hardness Tumkur, Mandya and Belgaum districts; for Nitrates Mandya, Kolar and Davanagere districts and for Fluorides Chikkaballapur, Tumkur and Bellary districts are affected. The number of affected villages for various parameters of ground water in different districts is presented in Table 2.

Table 2 Number of problem villages in different districts in respect of chemical parameters

sl.no	District	Total no of villages selected	No of problem villages
			pH	Total hardness	Iron	Nitrate	Fluoride
1	Bagalkote	989	126	197	4	53	65
2	Bangalore Urban	1089	39	199	82	399	29
3	Bangalore Rural	944	16	103	8	118	18
4	Belgaum	1638	185	544	204	89	95
5	Bellary	1228	19	159	5	183	489
6	Chamarajanagar	1422	6	298	10	11	1
7	Chikballapur	1875	81	201	30	232	689
8	Chikmagalur	2150	219	118	22	12	16
9	Chitradurga	1260	28	248	15	103	360
10	Dakshina Kannada	1008	60	5	14	1	21
11	Davanagere	1317	119	461	13	442	272
12	Dharwad	506	34	62	2	47	3
13	Gadag	595	3	208	3	38	80
14	Hassan	2296	186	87	84	17	11
15	Haveri	1190	1	263	15	5	6
16	Kodagu	450	43	0	45	1	0
17	Kolar	1624	0	401	7	647	289
18	Koppal	738	49	153	81	133	100
19	Mandya	2057	14	688	269	767	244
20	Mysore	2449	1	298	30	114	20
21	Shimoga	1774	516	97	59	16	11
22	Tumkur	4294	41	704	298	359	689
23	Udupi	660	0	1	3	0	1