Recycling and reuse of wastewater is an important aspect of water management providing a way to increase available water while also preventing pollution of water bodies by sewage.
An estimated 62,000 million litres per day (MLD) sewage is generated in urban areas across India, according to the Environment Minister, while there is treatment capacity for only 23,277 MLD as of Dec 2015. A CPCB report further reveals that the actual amount of sewage treated stands at 18,883 MLD as only 522 out of 816 sewage treatment plants listed across India were operational, as of March 2015 (even this claim of 81.1% capacity utilization seems HIGHLY exaggerated). Thus, at least 70% of sewage generated in urban India is being dumped in rivers, seas, lakes and wells, polluting water bodies and contaminating fresh water sources. Partially treated or untreated sewage is responsible for large part of the pollution in streams and water bodies. Up to 80% of water bodies could be polluted.
The wastewater generation from urban India is projected to double by 2051 with rural India generating another 50,000 MLD of sewage. Infrastructure required to address the increasing pace of wastewater generation is lacking. According to a report of the National Institute of Urban Affairs of the urban development ministry, over 60% of houses in mid-size cities (population 50,000–100,000), discharge wastewater into open drains. Open drains often stagnate; creating cesspools that can contaminate surface and ground water.
(Pics Source Google)
The environment ministry decided in Apr 2015 to make sewage collection, transport and treatment mandatory across India in order to stop the discharge of untreated sewage into water bodies and groundwater. The environment ministry also proposed that state authorities prohibit the use of freshwater or groundwater for all non-potable purposes such as cleaning or flushing, etc., industries and for horticulture and irrigation and use treated wastewater instead.
The CPCB issued directions in April, 2015 to the State Pollution Control Board/Pollution Control Committees regarding setting up of Sewage Treatment Plants (STPs) and utilization of sewage generated in their respective States. In Oct 2015, the CPCB directed 178 towns for proper treatment and disposal of sewage generated in their jurisdiction.
States allege lack of funds for developing sewage treatment systems. However, the environment ministry suggested that states generate funds for setting up STPs by themselves such as by charging customers for sewage collection. Additionally they may access finances under the Atal Mission for Rejuvenation and Urban Transformation (AMRUT) programme and the Namami Gange programme.
Sewage Treatment Plants: At least 79 installed STPs across India do not work according to the Central Pollution Control Board’s (CPCB) Inventorization Of STPs report. Operation and maintenance of existing treatment capacity is below par, with 39% plants not conforming to environmental rules for discharge into streams.
Proper planning is required to determine the technology and location for treatment plants. In Delhi, plants were built where plots were vacant, implying non optimal siting, huge transportation costs. Moreover, investments in treatment plants didn’t go along with adequate spending on drains.
According to an RTI response of the CPCB in Mar 2015, Delhi generates 3,800 MLD of waste and has a present installed treatment capacity of 2,693.7 MLD of which the actual utilisation is 1,575.8 MLD. Thus, only 41% of wastewater is treated and the remaining 2,225 MLD of untreated water is either seeping into the ground or being discharged into Yamuna. Many STPs are working 20-30% below their capacity and only 3 are working at their full capacity.
The Delhi Jal Board (DJB) claims to supply around 700 MLD of treated water from sewage treatment plants for non-domestic use. The Delhi Government, in the Twelfth Plan, plans to use treated wastewater for all non-potable purposes and collect, treat and dispose 95% of the total sewage generated.
A spate of constructions has been witnessed in the suburbs of Delhi and in neighbouring Gurgaon and Noida. Existing facilities are insufficient to cope with the increased load. The construction projects have been allowed without making provisions for sewage pipelines indicating lack of regulation and nexus between builders and the Municipal Corporation and Haryana Urban Development Agency (HUDA). In Feb 2016, a city developer, Ansal Buildwell Ltd was found discharging sewage from sectors 56 and 57 of Gurgaon into stormwater drainage flowing into the Yamuna.
Gurgaon City, on an average, generates more than 350 MLD sewerage water while the 3 STPs catering to the city have capacity to treat only 150 MLD. As a result, a large quantity of untreated water directly flows into the Najafgarh drain which flows into the Yamuna. The overflowing of Najafgarh drain has damaged agriculture land over 2,000 acres in five nearby villages. Crops grown here are unfit for consumption and the villages suffer from many diseases, majority being water borne.
In June 2015, the NGT ordered HUDA to fast track the construction of a STP in Gurgaon using emergency clauses of land acquisition law to treat sewage from various areas of Gurgaon city.
Earlier, in May 2015, the NGT directed the Delhi government to acquire land under emergency clauses of the land acquisition law at three locations — Goyla Vihar, Tikri Kalan and Badu Sarai — in West and Southwest Delhi for the DJB’s interceptor sewage project.
Construction projects take years to get completed and buildings are required to obtain sewerage connections. It is disturbing to see avoidance of due process by resorting to urgency provisions of land acquisition law to construct STPs long after the constructions have come up and started generating unmanageable sewage.
Mumbai generates around 2,700 MLD of sewage. Seven treatment plants together treat about 1,384 MLD and the rest, nearly 49%, is discharged untreated into the sea. The CPCB had in October 2015 issued directives tightening norms on quality of water discharged into the sea. The Maharashtra Pollution Control Board (MPCB) and the Maharashtra Human Rights Commission had also objected to the pollution of coastal water by discharging untreated sewage into the sea. The BMC proposed an STP plant which would be the biggest of its kind in Mumbai capable of recycling and reusing up to 847 MLD of sewage at a cost of Rs 4500 crore. The plant is a component of the World Bank funded Mumbai Sewerage Disposal Project-II. However the project is proposed to be built near Malad creek along Mumbai’s western coast which falls in Coastal Regulation Zone area and would involve large scale uprooting of mangroves. The Expert Appraisal Committee (EAC) of the MoEF in its meeting in Feb 2016, denied permission for the proposed plant as it would be in violation of the Coastal Regulation Zone Notification (MCZMA), 2011. Setting up several smaller STPs serving smaller localities might be a better solution for Mumbai, as elsewhere, than a single huge STP.
Kozhikode Land encroached from wetlands seems to be a favourite area where town planners like to build STPs. The Kozhikode Municipal Corporation had proposed to construct a STP in the Kottooly wetlands at Karimpanappalam in Kozhikode city in Kerala with aid from the Asian Development Bank (ADB). Around 5 acres of the wetland was proposed to be filled up at a cost of Rs 8 crore to build the plant on it. Kottooly is one of the only five notified wetlands in the state. It houses a large number of rare plant species, including mangroves. and is a perennial water reservoir while also protecting the surrounding areas from flooding. The project was opposed by the public and the Kerala government was ultimately forced to withdraw permission for the plant in July 2013 after the Kottooly Wetlands Protection Committee approached the high court and the NGT.
The Corporation then identified 2.6 acres of land belonging to the Kerala Water Authority adjacent to the wetlands, to construct the STP. Very soon the consulting agency of the project demanded to acquire additional 4 acres of land for the project which was only possible by reclaiming the wetland. For a second time, the Wetlands Protection Committee approached the NGT which passed an interim stay order on Dec 23, 2015 on the construction of a STP.
Pune India signed a loan agreement with Japan International Cooperation Agency (JICA) on Jan 13, 2016 for pollution abatement of river Mula Mutha in Pune by Jan 2022. The agreement includes construction of 11 new STPs which will create an additional treatment capacity of 396 MLD and laying of 113.6 kms of sewer lines. On completion, the total STP capacity available in Pune will be sufficient to cater to sewage treatment until the year 2027. The project also includes installation of a system for centralized monitoring of functioning of STPs and GIS mapping of sewerage facilities for better asset management.
The major reasons for pollution of Mula Mutha, identified as a polluted river stretch by the CPCB, are discharge of untreated domestic waste water into the river due to inadequate sewerage system and sewage treatment capacity in the town, as well as open defecation on the river banks.
However, the JICA has a poor record. It has been funding Ganga, Yamuna and other action plans, with almost no impact. The plan for Pune is on the same lines – more infrastructure without any attention to democratic governance.
Vrishabhavathy Valley Treatment Plant Banglore (Pic Source Google)
Bangalore The total installed sewage treatment capacity is only 58% of the total sewage generated in Bangalore city. Much of the wastewater is dumped into the lakes in Bangalore. Due to improper management of sewer lines, sewage is also entering storm water drains. A study conducted by researchers from the Ashoka Trust for Research in Ecology and the Environment in Bangalore further found that existing STPs were under utilized and functioning far below acceptable levels of efficiency. Analysis of the effectiveness of the Vrishabhavathy Valley Treatment Plant (VVTP) in Bangalore showed inefficiencies at many levels. First, the VVTP operates only part of its installed capacity of 180 MLD. Second, even the part that is actually treated does not get adequately purified. This is because mixing with river water dilutes the raw sewage resulting in inefficient functioning of biological treatment by microbes in the STP. The water entering the plant also has excessive non-biodegradable component suggesting presence of industrial discharge in the river which the STP is not equipped to handle. Officials of the municipal board said that process to set up 20 STPs has been initiated. The board is seeking funds from the AMRUT scheme and mega city loan to construct some of these STPs.
The Uttar Pradesh High Court on Jan 4 2016 took cognizance of allegations of sewage water flowing into Kathauta Jheel in Gomtinagar and directed immediate blocking of the flow of sewage water into the jheel. The Katautha Jheel is used to supply drinking water in the vicinity. Sewer is allegedly dumped directly into a nullah flowing into the jheel.
Shimla is seeing an outbreak of jaundice after water of Ashwani Khud was contaminated with sewage released by the STP at Malyana in Shimla. As of late February 2016, the number of jaundice cases has reached 1,592 and eight have died because of mixing of sewage in the water source.
According to the Deputy Mayor, the jaundice outbreak took place during winter as the sewage discharge was concentrated and water discharge in the khud was less, unlike during monsoons when the rains diluted the concentration of faecal matter. He said that a similar jaundice outbreak took place in 2011 in the winter and the same sewerage treatment plant was considered to be the prime source of the outbreak. The Irrigation and Public Health (IPH) Department had done nothing since then to improve the treatment plant. The Deputy Mayor claimed that there had been four jaundice outbreaks since 2007 after the city began receiving water from the Ashwani Khud.
In Feb 2016, water samples from Ashwani Khud water treatment plants in both Shimla and Solan tested positive for Hepatitis-E virus. The virus was found in the Ashwani Khud drinking water even after chlorination was carried out by the IPH Department. Virologists have warned that the jaundice outbreak in Solan could show an upswing if the immediate measures are not put in place. 578 cases have been reported from Solan also.
The contractor of Malyana and 4 other sewage treatment plants was arrested in this connection. On Feb 25, 2016 the Himachal Pradesh High Court awarded Rs 2 lakh as interim compensation to legal representatives of those who died of jaundice and directed the Special Investigation Team to investigate which officers were responsible for it.
This incident has shown the necessity to take sewage treatment seriously. Negligence by authorities or cutting corners by private contractors out to make profit can endanger many lives and livelihoods.
Reuse by industries: Reuse of treated water by industries requires proper implementation. One prerequisite for initiating industrial use of treated water is the construction of a distribution network to transport treated sewage to industries. It is also important to ensure that the quality of the treated sewage confirms to the minimum desired need of industries. While the MoEF has prescribed standards for the quality after treatment, most of the municipal STPs treat sewage up to secondary treatment. Water of this quality can be used only for low-end industrial purposes like gardening or as service water.
NTPC’s Thermal Plant at Mouda Maharashtra (Pics Source Google)
The Union Power Minister directed for a time bound program to be developed between Nagpur Municipal Corporation (NMC) and NTPC’s Thermal Plant at Mouda for reuse of the sewage treated water of NMC by NTPC’s Thermal Power Plant at Mouda. NTPC’s Solapur plant would be taken up next for use of sewage treated water. Other Thermal Power Plants on the banks of river Ganga may also take up similar schemes.
In order to ensure recycle and reuse of water, the Delhi Metro Rail Corporation (DMRC) has set up effluent treatment plants (ETP) and sewage treatment plants (STP) at 5 of its depots and at 3 of its residential colonies. The treated water generated by these plants is currently being used for horticultural and toilet-related purposes within the depot and residential premises. According to DMRC officials, the organization has drawn up a detailed water policy to streamline water conservation and treatment facilities are being planned in the depots in the upcoming metro stations also.
In an innovative attempt, the Delhi Jal Board (DJB) in Aug 2015 commissioned the first ever hydropower plant in Delhi which will produce 20,000 kWh of electricity per year. The plant will run through turbines propelled by treated effluent coming out of a STP located in Chilla in East Delhi. The generated electricity will be utilised at the STP itself.
Reuse for irrigation: On May 29, 2014, the NGT ordered destroying of crops grown with sewage water in Bhopal district. According to surveys by the Madhya Pradesh horticulture department, sewage farming was being carried out in around 70 ha of land in Bhopal. In Jan. 2015, the district administration destroyed vegetables worth around Rs 10,000 which was opposed by farmers who had been using sewage for farming for over 40 years. Compared to freshwater, sewage water irrigation increases the yield and earnings of farmers by up to four times. Banning wastewater irrigation would force them to use groundwater for irrigation which would increase their expenditure. Experts have vouched that wastewater irrigation gives a substantial advantage over borewell irrigation by improving vegetable yield. Using sewage allows the farmers to adopt round-the-year intensive vegetable production system.
In March 2015 the NGT directed the Madhya Pradesh Pollution Control Board (MPPCB) to survey the exact amount of toxins in sewage, including coliform levels and heavy metals and pesticides. The MPPCB and the horticulture department of the state are yet to report on the merits and harms of growing vegetables with sewage water. In Feb 2016, the MoEF assured the NGT that installation of Effluent Treatment Plants (ETPs) instead of Sewage Treatment Plants (STP) was under consideration and that would facilitate contamination-free vegetables irrigated with treated water. It is not clear when such ETPs will be in place, though.
(Pics Source Google)
Use of sewage water for irrigation could be highly beneficial in water starved areas. However, careless use of wastewater can cause health problems to farmers and there have been instances where farmers using untreated sewage showed prevalence of diarrhoeal and skin diseases, and infections. It is always better to treat sewage before irrigation as run off from sewage can pollute streams, water bodies and groundwater. While metallic salts present in sewage provide nutrients to plants, but when found in heavy concentrations they may enter the food chain and pose health hazards to the consumers of such farm produce. Periodic monitoring is required to ensure that the sewage used does not have toxic elements or heavy metals in high concentrations.
About 73,000 ha of peri-urban agriculture in India uses wastewater for irrigation. Gujarat has tried to address problems of water scarcity and urban sewage management by using sewage water for agriculture. Using sewage for irrigation reduces the use of groundwater in agriculture, ensures management of sewage, improves agricultural yield and earns the municipalities revenue. However, 90% of the urban bodies in Gujarat do not have STPs and with the exception of Gandhinagar, the sewage supplied to farmers is not treated in most of the cities. In some cities, farmer cooperatives have been operational for the last 40 years which monitor the wastewater used in farms. Wastewater from Gandhinagar is carried via an underground pipeline from which farmers extract water.
Almost 10% of the total irrigated land in the world spread over 50 countries was irrigated with raw or partially treated wastewater in 2000. Countries such as Vietnam, Kuwait, Israel, Tunisia, Jordan, Morocco and China and water scarce regions in North America and Europe extensively use wastewater for irrigation.
Reuse for non-potable use: In Goa, 2 individuals have set up a system for treatment of wastewater that uses natural vegetation and microorganisms producing water for non-potable uses such as flushing and irrigation. The system does not require power, chemicals or machinery or expert monitoring. In contrast, a regular water treatment plant, treating 10 kilolitres of water a day, requires a 5 hp motor running for 18 hours a day. Plant species grown as part of the system whose roots further purify the water, add to the aesthetics of the landscape.
The system today treats 150 kilolitres of water daily in Goa. In Goa the duo have set up the system for the governmental civic agency and for hotels along the tourist belt. The system is being used across the border in Maharashtra and Chhattisgarh and has been proposed to the government of Karnataka.
Delhi CM taking a sip of STP treated water (Pics Source Google)
Reuse for drinking: Delhi chief minister Arvind Kejriwal on July 9, 2015 inaugurated a pilot project at the Keshopur Sewage Treatment Plant in Delhi in collaboration with an NGO called SANA (Social Awareness, Newer Alternatives) that can recycle sewage waste into drinking water. The plant, which is Delhi’s first ‘toilet to tap’ project, was set up at a cost of Rs. 55 lakh, is powered by solar energy and can produce around 4,000 litres of clean water every hour. The plant has a bio filter with 5 layers including earthworms, sand, pebbles and bacteria followed by a nano-filter membrane.
That the setting up of STPs requires land and heavy expenditure without any promise of revenue is a major reason behind the myopia of our planning and civic agencies in not improving sewage treatment infrastructure. But a plant in Bangalore is showing the way to overcome these barriers. A Membrane Bioreactor (MBR)-based wastewater treatment plant at Cubbon Park occupies just 2 acres of land in Bangalore and treats 1.5 MLD of sewage making it fit for drinking. Moreover, the plant is hardly noticeable as a STP; there is no odour anywhere and only the necessary volume for treatment that the system can support at that time is tapped. The plant has been reportedly running successfully and the membranes are yet to be replaced after years of functioning. Improved technology has made such membranes better and cheaper. While the running cost of the plant is about Rs. 14-16 for treating a kilo-litre of waste-water, the non domestic rate of water is Rs. 50 – 100 for a kilo-litre making it possible to recover the cost and additional revenue through the sale of treated wastewater. Currently the BWSSB is planning to set up decentralised small treatment plants. Membrane-based treatment plants are also being proposed by some large apartments and the BWSSB.
Conclusion: Rapid urbanisation is increasing the amount of sewage generated. Strict checks need to be in place to prevent release of sewage into storm water drains or into fresh water bodies, rivers and seas. Mixing of storm water drains with sewer lines should be repaired and they should be kept separate. Industries should be stipulated to install effluent treatment plants and should not be allowed to dump or flush toxic water down the drains. Operations of existing STPs need to be improved and STPs should be constructed in every locality targeting 100% treatment of sewage. Treated waste water should be made available for non-potable urban uses such as flushing, cleaning, gardening and for industries. Awareness should be built among citizens and industries to use the same and conserve water. Treated water should be used immediately to recharge wetlands and reservoirs. This can be aided by setting up sewage treatment plants in decentralised manner, close to the point of generation and reuse or close to reservoirs. These measures need to be adopted earnestly and urgently to avoid sewage management crises in cities.
Most importantly, it needs to be ensured that existing STPs function as per designed criteria qualitatively and quantitatively. This can be possible only when the governance of these STPs is made transparent, participatory and accountable. Lack of such governance is the major reason why most existing STPs are not functioning optimally. This is evident in the National Capital where the existing STP capacity is highest in the country, but none of them are functioning optimally and there is no movement to achieve that either. Same is the situation in Ganga Basin. It is clear that there is no future for Ganga Rejuvenation objectives of the Union government without such governance.
Anuradha email@example.com, SANDRP