Tirumala, the hill town in Tirupati metropolitan area, is considered to be the only place in India that is treating more than 80 percent of the sewage, and has set a target to reach 100 percent.

One of the richest temples in the country, the Tirumala Tirupati Devasthanams (TTD), an autonomous body managing the affairs of the hill shrine, has adequate resources to focus on wastewater reuse. 

Resources apart, one has to draw a lesson on how the town spread over some 27 sq km, with roughly 20,000 inhabitants and over 80,000 floating population per day has dealt with wastewater.

The treated water is used for a number of non-potable purposes such as maintaining and developing all gardens, parks, nurseries and forest area in the town and also replenishing storage tanks for groundwater. Reuse of wastewater not only reduces dependency on freshwater, but also keeps water pollution in check.

The immediate advantage of this project has been of the people of the holy town. Tirumala now enjoys better water table levels as reuse of sewage has helped increase water table, said Chandramouli Reddy, deputy executive engineer at TTD. 

This hill town, located 3,200 ft above sea level, has four sewage treatment plants (STP) – three plants of 3 million litres per day (MLD) capacity each, and one of 0.50 MLD capacity. A fifth plant is under construction, and a proposal has been made for the sixth plant.

“Setting up new treatment plants would enable us to treat 100 percent of the wastewater generated in Tirumala,” said Reddy.

Why the holy town went for treated water

Main sources of water for Tirumala are the Gogarbham dam, Papavinasamam dam, Akasaganga dam, Kumaradhara & Pasupudhara dam, Kalyani dam in Tirupati, and bore wells in Tirumala and Srivarimettu area in Tirupati.

From reservoirs water is supplied to all the guesthouses, cottages, temples, mutts, hospitals and other areas in the town, and all these areas are properly connected to the under-rainage system.

Wastewater at the STPs is treated in three stages – primary, secondary and tertiary. “Around 9 MLD water is treated per day in the existing plants. We are planning to take this treated water to guesthouses and public toilets also,” said Reddy.

Before the sewage system, the cottages and guesthouses, constructed around temple at elevated places used to leave wastewater onto the streets.

To prevent pollution near the Srivari temple the drainage system was started in Tirumala in 1985. During the late 1990s old drainage pipes and sewer lines were removed and new ones were placed. Then sewage treatment plants were installed.

“Since then we have been working towards reuse of wastewater. Sewage treatment plants were upgraded to new technologies and more plants were set up,” Reddy said.
       
Wastewater is integral to smart city

S Raghupathy, executive director, Confederation of Indian Industry (CII) Business Centre, at a conference on Tamil Nadu Smart Cities organised by CII last month in Chennai pointed out that wastewater is an integral part of smart city. “With technologies water can be completely treated and reused. There is phenomenal potential for wastewater reuse. Wastewater has rich content of urea. This water when used for gardening will help plants grow well. “Technologies are available with us. We should act now,” emphasised Raghupathy.

So what are the factors that hinder wastewater treatment in most cities? Sekhar Raghavan, Chennai-based expert and rainwater harvesting pioneer, said, “A good treatment should consist of primary, secondary and tertiary stages. Only then the output water will be fit enough to be discharged into waterways.”

“Whatever I have said before is all about wastewater treatment at the macro level within the old Chennai city (174 sq kms). At the micro level, as mentioned before, wastewater was being discharged into the municipal sewer till 2003, when a law was made making rainwater harvesting mandatory. A paragraph in that law insisted that bath and wash water (a part of the sullage) should be treated organically  and used either for flushing toilets or allow it into the ground for recharge. It was not clear whether this part of the law was for existing buildings also or for only new constructions. Both of them ignored this conveniently. Outside the old city limits (peri-urban areas), in some localities, municipalities had constructed open drains into which both sewage and sullage were discharged, which in turn was led into water bodies (considered as open spaces). In certain other localities, where there was no open drain, the houses had their own septic tanks (well designed or otherwise) into which sewage alone was discharged and the sullage was made to flow into the garden located within houses, with coconut trees or banana plants,” Raghavan said.

“Chennai city is expanding and the present area is 426 sq km which is likely to go up to 1,170 sq kms (also called the Chennai Metropolitan Agglomeration). In these areas, a lot of large apartment complexes (also known as gated communities) are coming up. These areas do not have the necessary infrastructure for water supply and sewage disposal. All these complexes are put up under rated STPs and are supposed to use the treated water for toilet flushing and gardening. They end up having excess treated water and/or untreated sewage, which is removed in tankers for a cost. The scenario is very pathetic. They buy tanker loads of fresh water and send out tanker loads of sewage (both treated and untreated). This is by no stretch of imagination a sustainable way of living. This is all about Chennai and I am sure the other cities are no different, “ said Raghavan.

He pointed out that the key factors that hinder wastewater reuse are: firstly, it is difficult to retrofit in a fairly old city, secondly, it is also difficult when the city is growing vertically, thirdly, there is also a lack of awareness about it both among the state and the society, and lastly, water (leave alone wastewater) in general and rainwater harvesting in particular are still not being given the importance that they richly deserve. Urban people have taken water for granted. Unless they become sensitive, the situation will go from bad to worse.

What are the ways a city should adopt to maximise wastewater reuse? Raghavan said, “According to me, the three most important things that every city should look into immediately are: rainwater harvesting, solid waste management, and urban greening (tree planting). Wastewater reuse is next only to these three. People will have to be sensitised about the need and relevance of reusing wastewater.” Further, water is a state subject and each state government will have to look into it more seriously.

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(The article appears in the March 16-31, 2015, issue)