NTPC Limited
(A Government of India Enterprise)
Talcher Super Thermal Power Station
SALIENT TECHNICAL FEATURE
Sub: Seepage water recirculation system for
SALIENT TECHNICAL FEATURES:
Talcher Super Thermal Power Station is a Unit of NTPC, in Kaniha block under Talcher sub- division of Angul district of ODISHA.
Nearest Town |
: Talcher 26 KMs |
Nearest Railway Station |
: Talcher 29 KMs |
Nearest Airport |
: Bhubaneswar 180 KMs |
INSTALLED CAPACITY
SALIENT TECHNICAL FEATURES
01. Ash dyke, Stage # I & II are situated about 5 to 12 km from main plant respectively.
a. Stage # I:
There are three lagoons in Stage # I. Two for ash disposal and 3rd one is used as Over Flow lagoon (OFL) where decanted clear water is stored and pumped to main plant for recycling purpose. One of the two dykes is always kept in service and other is in construction for raising after completing its service period.
b. Stage # II: Same as Stage # I.
02. The area of ash dykes is having approx. 1700 acres (Stage # I: 750 & Stage II: 850 acres). 03. Connectivity: All the areas of dyke are well connected with plant and the work site of SWRS is mostly connected with WBM road.
04. Construction activities:
a. In Stage # I, 6th raising of
# II. Therefore; near the work site of SWRS mainly in Stage # I, multiple activities shall be going on.
05. The purpose of installation of Seepage Water Recycling System (SWRS) is to collect seepage water from the toe along dykes’ periphery and return it to Overflow Lagoons (OFL) to achieve zero discharge to natural course. At present the seepage water is drained to the natural
course. Storm water passages also have the same routes to flow to natural course.
06. Seepage Water PHs shall only be pumping the seepage water. During rain, the storm water shall be allowed to drain to natural course through the Overflow System provided with sumps attached to respective PHs.
07. Five Pump Houses shall be required to pump the seepage water from sumps of respective Pump houses (PH) which will cater whole area of dykes. Locations of all the PHs have been identified. Initially, four Pump Houses were envisaged. Recently one more PH has been introduced in the scheme with the approval of
a.
b.
c.
d.
e.
08. PHs are to be made mostly at the location having deeper level of the area and these are the points through which most of the seepage/storm water have access to natural course.
09.The seepage water follows the path of natural gradient to reach the natural course. According to the scheme, some stretches of the existing routes shall be followed. In some cases, the minor exit points shall be diverted or reverse gradient is to be provided to give access to the identified route to reach the sumps.
10.The areas along the periphery of the dykes are undulated. Existing paths of Seepage/Storm water flow mostly shall be utilised for
11.During preparation of the scheme, adequate care is taken for leaving space for upcoming RCC Portal work for installation of Cast Basalt pipes, Buttressing of lagoons of Stage # I and Peripheral filling works in Stage # II. Necessary care shall be required during implementation of the scheme as well.
12.The scheme is prepared mostly referring the ‘topography survey’ done in the year 2012 and in some cases taking levels recently. But during the implementation of the scheme detail survey is to be carried out with close levels. Minor changes in the exact location of Pump Houses and its allied works like drains etc. may be occurred for which no major deviation is envisaged.
13.Flow directions of respective PHs are shown in the scheme including the discharge path.
14.Pedestals shall be required to be constructed for the discharge pipes for which general arrangement is provided with the scheme.
15.In some cases, the minor changes may be made for foundation of buildings and sumps to adjust the levels and quantum of seepage/storm water flow but principally there will be no change in the basic design.