Muck dumping – SJVN leaving no ugly scars behind

Sensitive to the environment wherever SJVN takes up a project to execute, scientific muck dumping is a norm that the corporate has adopted for a culture, ensuring that on completion the project impact area is reclaimed, greened and no construction scars are left behind..

Hydro power projects are often blamed for two major reasons. One, for the displacement of large number of people in the areas of submergence and the work sites, and the other for the environment degradation due to dumping of muck. Truly, the related works are so enormous and voluminous that the public criticism is natural. But in case of run of river projects, the submergences are negligible while the temporary work sites are subsequently dismantled and the lands restored to the owners. Of course the underground excavations generate huge quantities of muck and their disposal becomes a real challenge. But not in cases where scientific planning is done before hand. In the case of India’s largest 1500 MW Nathpa Jhakri Hydro Power Project executed by SJVN Limited, the underground works were so huge and voluminous, but there is hardly any ugly trace of resultant environmental degradation.

And what to speak of the downstream 412 MW Rampur Hydro Electric Project where no dam is being constructed as the project is to work in tendem with the upstream Nathpa Jhakri Hydro Power Station. The tunneling works are also comparatively less and the power house too is partially on the surface.

Sheer scale of excavating a 10.5 meter diameter and 15.127 kilometer long tunnel, besides a 40 meter diameter and 150 meter deep vertical tunnel known as surge shaft and 3 smaller tunnels of 3.8 meter diameter and 54 meters length is enough to leave any development project with a huge logistic problem of managing millions of tons of muck..

Having successfully executed a larger project, SJVN planners of Rampur Hydroelectric project were not deterred from the very outset. Downstream of the 1500 MW Nathpa-Jhakri project on River Satluj in North India, the 412 MW Rampur Project is the second project that SJVN took up in earnest and is scheduled to be completed by September, 2013

Taking a hard look at the topography of River Sutlej Valley basin around Rampur to identify places where sterile muck could be stacked in a manner that it did not flow into the river, did not cause environmental degradation and where it could eventually be reclaimed so as not to leave any scars on the landscape.

Initial designs had estimated that a volume of 30.63 lakh cubic meters of muck from all the civil works would be generated. After re-using some of it for construction purposes space for stacking 28.18 lakh cubic meters of muck was needed to be created.

Four sites for setting up dumping yards along the project impact area were selected, land was acquired and protection structures, which included retaining walls at the edge and slopes in stone walls were constructed.

Being a responsible company that is sensitive to environmental concerns, the civil jobs contracted out mandated that no muck be dumped in the river. Strict supervision has ensured that the terms of agreement have been adhered too..

As work on the tunneling sites progressed, the muck generated slowly began to pile up at the dumping sites. Midway through the job, a geological surprise in one of the tunnel sections upset calculations.

While engineers grabbled with veering around a weak rock section that created obstacles for the tunneling to hold, project designers came up with an alternate strategy of excavating a smaller bypass access tunnel that would let work on the main tunnel progress..

Course correction changes demanded additional space for stacking 8.81 lakh cubic meters of extra muck than what had initially been expected.

It was a stroke of luck that a nearby site being developed by the Union Government of India needed to be leveled. Since they required a large quantity of muck for the purpose, a tie up with mutual benefits helped in meeting the needs of SJVN’s additional dumping requirements.

Other than muck used for leveling of a strategic site of the union government, three residents of Bayal village – Chata Ram, Amar Chand and Tara Devi approached SJVN and asked for dumping muck on their private land so that the steep gradient it had could be leveled. A quick decision was taken to use the opportunity. Besides these two new sites, some muck was also used for leveling grounds at the upcoming SJVN residential colony, across the river at Dattnagar.

Without having to buy more land SJVN management of muck disposal has not caused any environmental degradation at any site.

Strong supporting stone walls ensure that no muck spills past them. Inclined at not more than 250 angle of repose, the dumped muck at the yards has even begun to be restored and reclaimed.

The target is to green all the muck dumping sites before commissioning of the project. Applying an innovated Geo-green Erosion Control Blanket method, a pilot project at one of the yards has succeeded in putting life into the sterile soil and support saplings of trees and shrubs.

With the experimental project getting the nod from the HP State Pollution Control Board, the greening process would be replicated so as to have a green cover over the entire muck dump yards ahead of schedules.