IMPACT OF GAP SCHEMES ON WATER QUALITY

 

Under GAP Phase I, only about 35% of the total sewage generated presently in towns along the river has been tackled. On the other hand, the facilities created to tackle the targetted pollution load are not being maintained properly in States like Bihar and U.P. Therefore, the impact of the completed works is not fully visible.

(ii) However, with the completion of 260 schemes, the water quality of Ganga has shown improvement over the pre-gap period quality in terms of both the bio-chemical oxygen demand (BOD) and dissolved oxygen, the two important parameters to assess the river water quality.  

(iii) Despite the problems of operation & maintenance in U.P. and Bihar, the improvement in river water quality can be attributed to have been achieved as a result of diversion of large quantities of sewage in towns like Kanpur, Allahabad and Varanasi for sewage farming.

(iv) The minimum acceptable level of DO is 5 mg/l. Across all the above towns, the levels were higher than 5 mg/l in 1986. This level increased further in 1998 and 1999 in Rishikesh, Allahabad, Varanasi, Haridwar and Garhmukteshwar. However, the level of DO decreased in Kanpur, Patna, Kannauj and Rajmahal. As regards Bio-chemical Oxygen Demand (BOD), The base year levsls were higher then the acceptable limit of 3 mg/l for four towns and lower than this limits for the other six towns. The situation improved in 1998 and 1999 as compared to 1986 for most of the towns. However, the BOD levels are higher than the norms especially in Kanpur, Allahabad and Varanasi. It would, therefore, appear that the plan has achieved only partial success. However, this is also to be seen against the background that GAP-I proposed only for the treatment of 882 mld of sewage as against the 1340 mld of sewage estimated to be generated in 1985 in the 25 class I towns along the river where the plan was taken up. An estimated quantity of 1861 mld of sewage is proposed of interception and treatment under GAP-II. This, it is anticipated, will make the impact of the Ganga Action Plan more perceptible. Moreover, emphasis on eco-friendly and result oriented technologies aimed at reducing the pollutants which are hazardous for human health is being increasingly given under GAP-II.

(v) Reduction in faecal coliforms was not built into the design of GAP-I. The treatment technologies implemented under GAP-I only bring an incidental reduction in bacterial levels. The data on faecal coliform levels is available for 1986 and 1998 is listed below. Since the exact number of towns which have levels close to the minimum or the maximum is not available it is not possible to say whether the water quality improved in terms of faecal coliform during the period 1986 to 1998. Considering 1986 alone, the levels of coliform are higher in the stretch from Kannauj to Varanasi as compared to the stretch from Rishikesh to Garhmukteshwar. Buxar to rajmahal shows still higher levels than Kannauj to Varanasi. It is the same scenario in 1998 indicating that coliform levels increase as the river moves eastwards.

 LEVELS OF FAECAL COLIFORMS IN SOME STRETCHES OF THE RIVER GANGA

Stretch of River	Faecal coliform (MPN/100ml)
	1986	1998
Rishikesh to Garhmukteshwar Kannauj to Varanasi Buxar to Rajmahal	400-700 350.1.6x105 3000-7.3 x 104	80-1600 230-1.1 x 106 800-9.0 x 103