A Water Neutral Project
- Water Conservation
A notable feature of the Delhi Faridabad Elevated Expressway Project is the level
of attention accorded to ensure minimal operational impact on the environment during
the construction of the project, while simultaneously ensuring convenience to commuters.
HCC has undertaken a number of initiatives for water recharge, recycling and re-use.
A pilot project linked to the UN Water Mandate, the dfskyway™ project includes reuse
of the water table in the construction area, recycling of water used during construction
and rooftop rainwater harvesting.
Rain Water Conservation at dfskywayTM
HCC’s Delhi-Faridabad project is a 4.4 km elevated highway corridor project located
on the outskirts of Delhi and connects the capital to Haryana. The work load of
this project was distributed at two locations i.e. on site where actual road construction
took place, and at Mirzapur – the location of the batching plant and concrete segments
casting. The UN water mandate team assessed the site to identify water reuse and
conservation proposals. Proposals for natural pond recharging and artificial pond
excavation were put forward to conserve water by natural percolation. Roof top rainwater
harvesting was suggested for the store building and labour camp buildings. To optimize
the use of water, a water recycling system for circulating the curing water at the
casting yard was proposed. Similarly, water reuse option for dust suppression was
suggested for the treated waste water from the batching plant. An innovative concept
of recharging groundwater by the storm water from the elevated highway was proposed.
The result will continue to recharge the ground water for the next 18 years. The
rainwater harvesting (RWH) system for the proposed toll building was also suggested.
Steps to save water through installation of water free urinals in the wash rooms
for the building were also implemented.
Water Recharge of Artificially Excavated Pond
HCC constructed an artificial pond of 1,614 KL aiming to recharge 4.6 times the quantity
of water consumed during construction. This ‘water consciousness’ effort is part
of HCC’s commitment to the United Nations Global Compact.
A 400 sq m low lying part of the land was used to create an artificial pond with
a capacity of 1,614 KL. This included recharge of the water table in the construction
area with recharge wells at two different locations to divert rainwater to the ground
water table through an appropriate mechanism. The accumulated storm water collected
at the site was used to fill the pond. With an average 600mm of rainfall, the projected
water conservation is 30,000 KL/year. Owing to the scanty rainfall the estimated quantity
of ground water recharge for 2009 – 2010 is 8,400 KL and for 2010 – 2011 is 6,288 KL.
Roof Top Rainwater Harvesting
Recycling of Curing Water
Rain Water Harvesting Structure for Ground Water Recharge at Badarpur
Rainwater harvesting was carried out at two locations to help increase the ground
water levels in the vicinity.
As the area receives scanty rainfall averaging around 600-800mm, water extraction
from the bore well was used for concrete making in the batching plant and curing.
Water collected on the roof surface areas of the labour camp buildings adjacent to
the bore well was used for recharging the well.
Water from the roof area of the store building was used to recharge the pond. The
intervention projected a total 522KL/year of water conservation. To some extent,
the recharging of the bore well with rain water compensated for the water extracted
from it. Similarly, the rainwater collected at the store helped to increase the
ground water table.
The water utilized for the Batching Plant, Batching Plant Washing, Curing, Miller
Washing was stored and reused. A slope was created in the work area to drive the
excess water to the existing main water channel that carried the water into the
collection sump for reuse after processing.
The concrete segments at the casting yard were cured in the adjacent curing yard.
It was decided to recycle curing water through a proper drainage system with paver
blocks forming an impervious layer. This helped in streamlining the flow of water
into an equalization tank to be reused for curing. Earlier the water used for curing
was extracted from bore wells increasing pressure on ground water storage. The daily
monitoring of water recycled for curing has shown 5,930 KL water was saved during
a period of 11 months
Batching Plant Water Management
Proper management of the waste water treatment process helped the site to retain
clear water. The treated water was reused for dust suppression. This considerably
reduced water extraction from the bore well and conserved the ground water resources.
1,050 KL of water was reused for dust suppression over 11 months
Storm Water Management and Ground Water Recharge -
Elevated Highway Rain Water Harvesting
Pond for Strom Water Management at Mirzapur
The 4.4 km long elevated highway design incorporates storm water drains alongside
the highway. HCC’s Water Mandate team suggested an innovative way to conserve rainwater
in the same area through recharge bore wells at predetermined locations along the
highway. The site appointed a hydro geologist who provided the technical know-how
regard to bore well diameter, depth and locations. The site has implemented a pilot
project of recharge wells at 2 locations at the Company’s own cost. The drains are
designed and executed to divert the storm water towards the recharge wells. Additionally,
it is also proposed to measure the impact of this proposal on the ground water table
in the vicinity of the recharge structure.
As this is a BOT project, it will be under maintenance of HCC for the next 18 years.
This system will be maintained by the Company for the entire period.