Wednesday, March 22, 2023

A commercial establishment heading towards water security - Fortune Select Trinity hotel

 Fortune Select Trinity is a business hotel in Whitefield which started its operations in 2007. It is located around 1.5 km south of Seetharampalya lake. It was originally built on a plot of 3 acres. This has now been reduced to 2.59 acres after a portion of the land to the north was acquired for Metro construction. There are coconut groves and other farms behind the hotel.


Fig 1: Left: Fortune Select Trinity hotel; Right: Location on the map


Fig 2: Proximity to the Seetharampalya lake

There are a total of 142 rooms and 154 toilets in the hotel. There is a restaurant, kitchen, laundry, staff kitchen/dining, and staff toilets in the main block, and a health club with a spa in another block. There is also a swimming pool to the east from the entrance. There is 1 acre of open space (lawn area) next to the health club and small patches with plants and grass near the entry and exit of the hotel premises.


Fig 3: Fortune Trinity Select land area

1.0 Summary

Fortune Select Trinity hotel is a commercial establishment that is highly dependent on tanker water. This makes water expensive for them. They also lack water security as they are completely at the mercy of tanker water providers. In an effort to secure their future water needs, the hotel has turned to rainwater harvesting as a sustainable solution to this problem. This case study looks at how and to what extent they have been successful in this endeavour.

2.0 Tanker water consumption and its cost

Based on the data shared by the hotel, the daily tanker water demand is around 60 KLD. Total Freshwater demand includes the water cans that are purchased for drinking and cooking purposes and this varies depending on the occupancy of the hotel. The following table captures the water demand of the hotel excluding the water cans.




Daily tanker water consumption (KL)

Annual tanker water demand (KL)

Cost per KL of tanker water ()

Cost per annum of tanker water (₹)

60

21,900

55

12,04,500

Table 1: Tanker water consumption and its cost


As seen in the table above, the current annual freshwater demand (that comes from tankers) of the hotel is ~21900 KL/annum and the total cost incurred by the hotel for tanker water is ₹12,04,500/annum.

3.0 Sources of Water

Tanker water, which is the main source of water for the hotel, is used for all non-potable purposes. Water cans are sourced for drinking and cooking purposes and their quantities vary according to the number of guests staying at the hotel.

There are two borewells with depths of 350 feet and 75 feet in the hotel premises. However, both of them are dysfunctional currently as one of them has run dry and the walls of the other have collapsed.

4.0 Water Storage

There are two underground tanks of 50 KL capacity each. One of these is used to store raw water from the tankers, and the other one is used to store treated water from the WTP. There is also an underground fire tank of 50KL capacity in the same area.

5.0 Water Treatment Plant

The hotel also has a water treatment plant (WTP) installed in its premises. Water from the raw sump is directed into the treated water sump through the WTP.

6.0 Sewage Treatment Plant

A sewage treatment plant that works on SBR technology treats all the wastewater produced by the hotel. Treated water from this plant (~35 KLD based on the information shared by the client) is used for gardening and flushing purposes. All the treated water is used up in the hotel itself, there is no excess treated waste water as of today.


Fig 4: STP at Fortune Select Trinity


7.0 Water management strategies

The first step towards achieving water security for the hotel was rainwater harvesting.  The hotel has also invested in water demand management to reduce its water consumption as much as possible. This section looks at both aspects in detail.

7.1 Rainwater harvesting

The hotel has made efforts in harvesting rainwater from both rooftops and surface runoff. Below are the details of the same.


Fig 5: Rainwater harvesting schema

7.1.1 Rooftop Rainwater harvesting

Rooftop rainwater harvesting for the main block was undertaken in 2020 and that of the health club was undertaken in 2021.


Multiple rainy filters have been installed to filter the rainwater from both blocks. Two HDPE tanks (connected together) are used to store this filtered rainwater from the main block and its overflow is led into the UG raw water sump. Filtered rainwater from the health club is led into a recharge well about 5 meters from the building.

Fig 6: HDPE tanks storing rooftop rainwater


There is, however, the front entrance porch and the south side balcony where rooftop rainwater harvesting hasn’t been implemented yet.


7.1.2 Recharge wells

Currently, five recharge wells with 5 feet diameter and 20 feet depth each were dug in the year 2021. Four of these recharge wells are in the 1-acre lawn area, and one more is in the garden area near the entrance of the hotel.

In September 2022, water was available 2 feet below ground level in these wells and looked clear.  A yield test will determine if there is a potential for an open dug well as a source of water for this hotel.


The pH of the water when tested with a handheld meter on site was 8.64. Based on the pH, the water can be directly used for non-potable purposes like cleaning, washing, etc. If passed through a WTP/RO filter, this can also be used for drinking and cooking purposes. Full water testing would however be required to determine its use.


Fig 7: Left: Recharge well in the lawn area; Right: water level 2 feet below ground in the recharge well


7.1.3 Rainwater harvesting potential

Calculating the rainwater harvesting potential is a method of estimating how much rainwater can be harvested from rooftops and surface runoff annually. It is assumed that 90% of rooftop runoff, 70% of paved area runoff and 30% of landscape area can be harvested.

The following table captures the rainwater harvesting potential of the hotel.


Rainfall runoff from various surfaces

Type of area

Area (sqm)

Runoff coefficient

Annual runoff at 974.5 mm rainfall (KL)

Runoff at 20 mm rainfall (KL)

Runoff at 30 mm rainfall (KL)

Runoff at 60 mm rainfall (KL)

Contribution to total runoff

Rooftop area (Total)

2100


1843

78

57

113

35%

Roof area (hotel building)

1450

0.9

1272

26

39

78

24%

Roof area (health club)

400

0.9

351

7

11

22

7%

Roof area (entrance porch)

150

0.9

132

3

4

8

2%

Roof area (balcony on south side)

100

0.9

88

2

3

5

2%

Non-rooftop area (total)

7689


3507

72

108

216

65%

Paved area (driveway)

3229

0.7

2203

45

68

136

41%

Landscape area

4460

0.3

1304

27

40

80

24%

Grand total

9789


5350

110

165

329

100%

Table 3: Rainwater harvesting potential


Hence, there is a potential to harvest 5350 KL of water annually with rainwater harvesting.


Out of this, 1272 KL of water from the main block is currently being stored and reused.

7.2 Water demand management

Water-saving plumbing fixtures and aerators have been fixed for the wash basins and taps, along with low-flow shower heads in all the bathrooms of the hotels.

Kitchens are also equipped with dishwashers to reduce the consumption of water, and aerators have been fixed for all taps in the Kitchen and laundry rooms. All these measures help in reducing the demand for fresh water in the hotel by reducing wastage.

However, metering has not yet been installed to measure the actual usage of water.

7.3 Outcome

Earlier about 6-7 tankers of water per day were being consumed by the hotel. After implementing some of the water management strategies, their tanker water consumption has come down to about 5-6 tankers per day. This translates to a reduction of about 365 tankers per year. The following table captures these details.


Reduction in the number of tankers/annum

Reduction is tanker water consumed/annum (KL)

Reduction in tanker water cost/annum (₹)

365

3650

2,00,750

Table 4: Reduction in tanker water consumption and cost


This reduction in tanker water consumption can be attributed to rainwater harvested from the main block, water demand management and other factors such as reduced occupancy due to covid etc.


8.0 Future plans

To utilise the shallow groundwater, the hotel plans to get an open well dug in the campus to serve as a cheap and sustainable source of water and to aid its water security by reducing its dependence on tanker water further. A yield test will be conducted before implementing this plan to determine its effectiveness.

9.0 Conclusion

Fortune Select Trinity seems to be on the right path to achieving its goals of becoming environmentally and economically water sustainable. At the very least, their plans would ensure water security for the hotel.


Water from the planned open well could potentially eliminate the need for tanker water in the future. There is also potential for the revival of the borewells due to the groundwater recharge measures put in place by the hotel. Depending on the quality of the water from these two sources, the need to buy bottled water for drinking can also be eliminated.


Mr Snehashish Chakraborty, the General Manager of the hotel is very keen on improving their water management strategies. He says, “We want to maximize the water efficiency of the hotel. That is the reason we make sure not to send any treated water out of our premises. Rainwater is the purest form of water we can get and it would be wasteful to just send it down the drain. We also want to reduce our costs of water in this hotel. Digging a deep borewell doesn’t make sense to me anymore when I see water filled in the recharge wells.”