You might expect that an up-and-coming town like Kodaikanal would have a municipal sewage treatment plant, and by government policy it should. Still, practically all of Kodaikanal’s houses and most of its institutions just rely on septic tanks, mostly old and inferior in quality. It appears that people are seldom concerned or think about what happens to their own faecal matter—they just flush it down!
There are two kinds of sewage treatment systems in Kodaikanal: sewage treatment plants (STPs), which digest sewage using organic microbes and several further treatments so the water can be reused (though not for drinking purposes), and effluent treatment plants (ETPs), which treat liquid sewage by letting solids settle, allowing several aerations to somewhat oxygenate the waste, and then releasing it into a stream.
Kodaikanal’s Effluent Treatment Plant (ETP)
The Kodaikanal Effluent Treatment Company Ltd is a non-profit company of institutional members that set up the ETP in 1991 under the ghat road and beside the Christian cemetery. It treats the liquid sewage that flows into the plant from above Seven Roads and goes by Carlton Hotel, along Lake Road below the municipal office and below it. The initiative to set it up was by 17 hotels, including Carlton and Hilltop, and Kodaikanal International School (KIS), and the company still has the same four directors who served to establish it. The company management address is at Hilltop Hotel. Its finances are dependent on the monthly fees of member institutions, and it has paid-up capital of Rs 25,02,000. Technical management is contracted through an engineering company in Coimbatore, which has hired the engineer and two others, who have an office at the site. It now serves nearly 100 members, mostly hotels but a few other institutions too, such as Zion School, Government Higher Secondary School, the Government Hospital, and the main campus of KIS, whose effluents join the pipe at two places: near Seven Roads and on the opposite slope, by Lake Road, below the KIS dormitories.
The effluent treatment plant and its settlement and aeration tanks
The effluent (effluent is defined as the stream, effluence as the process) goes to the first and second settlement tanks, where sludge sinks, and then to several aeration tanks (see 4 in photo). Finally, some chlorine is added, and it flows into the stream (of polluted water) from the lake and joins Palani’s drinking water source. While water is running, especially in a hill stream like these, it is further aerated and diluted, and in fact becomes more bio-diverse, according to experts; by flowing so far, it is naturally further purified.
Note: The sludge from the settlement tanks, when collected, goes to farmers as fertilizer. Faecal matter, sludge, and other organics will digest, if put in a good soil pit, without oxygen, over six to seven month sin Kodaikanal, into rich, black fertilizer. We should be conscious to return carbon to the soil and not throw it out to rot, emitting methane into the atmosphere.
This ETP has faced severe financial difficulty for a year because many hotels have not paid their dues since closure. Maintenance has been neglected and it does not run fully at night; people living in that area complain strongly about the bad smell.
Sewage Treatment Plants (STPs) in Kodaikanal
Considering the absence of a municipal sewage system, there are very few private STPs. The Carlton hotel is connected to the ETP, but it set up its own STP as it felt obliged to process and re-use some of the scarce township water it was consuming by using it for gardening and toilet flushing. The hotel Sterling Kodai Lake, following repeated complaints about pollution in the marsh there, set up a full STP in 2010. Earlier, the Jesuit seminary in Shenbaganur, with suggestions from the Palni Hills Conservation Council (PHCC), set up an STP there.
An STP has been set up in the KIS Ganga campus, which is slightly below the lake dam, though most of the drainage takes place away from Ghat Road and the ETP pipe. It has the KIS elementary division, seven dormitories and many staff houses. But the process took years, as setting up an STP requires mandatory approval by the Hill Area Conservation Authority (HACA), and the design had to be approved by the Tamil Nadu Pollution Control Board (TNPCB), Dindigul District. Eventually it was set up in 2014 under a contract with Black and White Infrastructure Pvt. Ltd in Madurai.
The STP design has a capacity of 100,000 litres, as per Ashwin Fernandes, KIS’ executive manager (Fernandes confirmed that the school generates only 40,000 liters per day when all students are in residence). Wastewater from the kitchen and dining room also flows into it, but this has to first go through a tank where the oils are skimmed off, as they hinder digestion by the STP. The STP first enables the separation of unwanted solids, and then long belts skim the bottom and mix it.
Active biological catalysts in the tank and added chemicals such as sodium hypochlorite, with repeated aeration, promote oxidation of the sewage. The top of the tank slides down to open, and rotors rise up and turn, so that aeration takes place in three stages. The oxidizing biomass sticks to the blades, and the biochemical oxygen demand (BOD, one measure of water quality) is reduced, though to a slightly lower level than preferable because of the cool temperatures in Kodaikanal. It then goes to a humus tank (a settling tank which clarifies effluents by removing humus solids washed off filter media), and the sludge is then pumped back to the main processing tank for later removal. Next, the water is filtered for coagulation, then filtered through activated carbon, chlorinated, and stored for use in another big tank (seen in the image on the left).
The system is designed for the water to be used for gardening, cleaning, and flushing dormitory toilets and urinals. The sludge is collected every year or so and can be used as fertilizer. During vacations, when there are no students, the system is kept active by adding cow dung. It is a complex system with many controls, as you can see in the photo.
The Ganga compound is exemplary in being self-sufficient not only in sewage, with its re-useable water, but also in water supply, collected from the roofs of many buildings and going to wells below. In many locations in Kodaikanal, self-sufficiency in both water supply and sewage management would be possible, but people have not bothered to achieve this.
Other sewage in Kodaikanal
A survey based on some 10,000 interviews with questionnaires was conducted in January 2019 (by the Tamil Nadu Urban Sanitation Support Programme). The majority of the interviewees were from households, of which 82% said they had individual toilets, though in ‘slum areas’ only 76% had them, while 9% defecated outside. Out of the establishments in Kodaikanal, only 10% (341) have indoor toilets. There were 8 public toilets, 5 with sewage holding tanks, some which let the effluents flow into an open drain, and others that are not in use. This is far from convenient for tourists, workers and shoppers, who are often seen urinating on the street.
As for septic tanks (which hold the thick sewage also called septage), 74% said they had them, but only 1% were of the recommended quality, plastered water-tight and with 2 or more compartments, with effluents utilised or properly managed and connected to a soak pit. Most septic tanks here have just 1 chamber, not made for the effluents to be utilised but to sink through into the soil drainage, maybe into water sources, and the sludge is seldom removed—something that should take place every 3 years. Homeowners can hire companies such as Shakthi in Vattalagundu to come with a truck and dig out the sludge to take back down for farmers’ fields. They charge far more than the municipality would, but its truck has long been out of order. Many householders just hire local sludge removers, and a few dig it out themselves, as several homes are on paths and mountainsides where trucks cannot go. The government goal for every house to have a toilet is commendable, but consistent use with good septic tanks and proper faecal removal should be promoted.
New government policies for sewage
The central government’s Ministry of Urban Development published a detailed report titled ‘National Policy on Faecal Sludge and Septage Management’ in 2017. The goal was 100% sewage management, though roughly half of urban residents still depend on on-site systems, including old-type septic tanks or pits. Because of the high cost of STPs for cities and towns, governments are now also recommending more decentralised systems for local areas. Finding willing personnel and management, along with finances, is even more problematic. So how can we reduce sewage flowing into India’s rivers and landscapes?
Following the central government’s lead, Tamil Nadu in 2017 published ‘Operative Guidelines for Septage Management for Local Bodies’, which has rules such as: ‘Wherever sewage is being discharged into waterbodies or stormwater drains, the local bodies will have to establish a proper collection and treatment system by using the nearest STP.’ It also mentions that local bodies must ‘start inspecting houses that have septic tanks to see whether the facilities are properly designed; if not, house owners will have to modify the tanks.’
These guidelines have numerous details and requirements, not only for STPs (ETPs are hardly mentioned) but also for decentralised and individual household sewage systems. These guidelines include forms to be used for surveying homes and institutions, as in the example quoted here. The question is, how can this be implemented in Kodaikanal, where there are no public STPs, many homeowners come only for vacations, several houses are rented out or have no Patta-status (land ownership records), and almost all have old-type septic tanks or none at all?
On three separate occasions, plans (with available funding) have been proposed for setting up a public STP in Kodaikanal, and each time, these plans have been aborted. In 2001, the National Lake Conservation Project budgeted Rs 10.22 crore to improve the lake, horribly polluted by organic matter flowing down from the whole watershed. The work was never started because of a dispute over the location of the proposed STP—nobody wanted something that might emit a bad smell nearby. The High Court gave an interim injunction, and the budget was withdrawn.
In 2007 there was a plan to set up an STP in Kallarai Medu, and then in Shenbaganur, but both objected due to the fear of unpleasant smells, so nothing was started. Then, in 2013, under the Eco-restoration of Kodaikanal Lake project, Rs 140 crore was sanctioned for lake works, including a sewage line around it with an STP. The capital and maintenance cost was considered unaffordable, so it was reduced to just a proposed Faecal Sludge Management for Kodaikanal Town project, of which there is no public evidence as yet.
For now, the subject remains in limbo. A Master Plan for Kodaikanal was prepared through the initiative of the municipality but was much criticised by NGOs. It was revised, and the modified Master Plan was published in 2019. It briefly mentions the present situation, including the absence of any public sewage system, but proposes nothing, instead focusing on land use and building regulations.It is the duty of the municipality to see that an STP with public sewage lines is set up and maintained, and to regulate the quality of septic tanks, but there is no new information. A town sewage system is required, including a line connecting buildings around and above the lake to reduce its bad organic pollution (a well-studied topic!). Maybe, with pandemic restrictions fading, under public pressure, under the national Hill Area Conservation Authority, or with new rules from the Tamil Nadu Pollution Control Board, action could begin.
A possible solution for you now: bio-toilets
If your house has a septic tank, you can consider changing it into an installed bio-toilet system. You may have heard that Indian Railways is gradually installing bio-toilets on all 55,000 of its coaches, specially designed after several failed efforts—no more dropping dung onto the train tracks!
There are many kinds and sizes of bio-toilets available. The image above shows one: a multi-chamber septic tank with biodigesting organisms added, and the water is used for the garden.
Image courtesy Clarence Maloney
A small set can be kept in the house; you take out the digested solids in a tray for compost. You would have seen little portable toilet chambers with attached doors, often moved to construction sites. Large biodigesters give off CO2 and methane, which can be piped for cooking. In many Indian farms with biodigesters for cattle dung, human faecal matter is also added. Most bio-toilets do not need energy, but in cooler climates, like we have in Kodai, some organisms act slower, as you may be informed when you ask for estimates for installation. A small solar panel can be added if desired.
Bio-toilets for homes cost between Rs 40,000 to Rs 2 lakh, depending on the kind of system. MAK and ABG Urekha are well known in Tamil Nadu. Alfa-Therm is made for high altitudes. EcoSan squat toilets have a hole in front of the main one so that urine can be separated. Organica Technologies has won awards for innovation. Sun-Mar and Global Loos are international. Banka BioLoo includes a programme often led by village women’s organisations. And more can be seen on websites like IndiaMart. So, if the municipality or other authorities do not fulfil their responsibility here, we can each in good conscience do our part to help reduce lake pollution and put the carbon we excrete back into the soil.
An earlier version of this article stated that the STP capacity is 12,000 litres. It is in fact 100,000 litres, as per KIS.
