A SCHEME FOR MUNICIPAL WASTEWATER TREATMENT IN INDIA By PROF SOLI J ARCEIVALA Formerly, Chief, Environmental Health, UN / WHO SE Asia Region and Director, NEERI, Nagpur

SANITATION After more than 60 years of freedom, sanitation coverage is almost a disgrace It is sometimes joked that we have 5-star hotels in 0-star cities ! In some towns, there is no collection system, and where there is a collection system there is no proper treatment. HOW CAN WE SPEED UP SANITATION COVERAGE IN THE STATE OF GUJARAT, AND IN INDIA AS A WHOLE --- as far as treatment is concerned?

TO SPEED UP TREATMENT It will help if we follow some Rules RULE 1: Give the local bodies what they can afford and what they can maintain Offer the more sophisticated processes to industries, not local bodies RULE 2: For smaller municipalities offer “natural” methods of treatment that do not require electric power. This way treatment remains affordable and plant remains maintainable.

1 st MANTRA: TREATMENT SHOULD BE AFFORDABLE, ACCEPTABLE & MANAGEABLE ww Aerated Lagoon Oxidation Pond Groundwater Recharge Irrigation Field to grow high-value crops PRINCIPLES OF SUGGESTED MODEL 1. AL & OP are simplest processes. One can optimize costs between them 2. Reuse water to grow high-value crops. Conserve whatever water is left 3. Produce something useful for local people. Improve sustainability

THE MODEL FLOW-SHEET The model flow-sheet is affordable, acceptable and manageable. It is also very flexible. It can be used everywhere -- from big cities to small towns

FOR LARGER CITIES Where power and land are available, but land is expensive Use for irrigation, or ww send to River Aerated Lagoon only Reuse in industries Treat further for reuse at industries cost - Provide Aerated Lagoon only ( no oxidation pond). - - Discharge effluent to a river or use in irrigation, or better still - Reuse effluent in local industries after further treatment (in case of big cities)

FOR MEDIUM-SIZED TOWNS where usually electricity and land are both available Aerated Lagoon Oxidation Pond Recharge Groundwater Irrigation Field to grow high-value crops Use a combination of AL + OP depending on relative cost of land and power (optimized for least cost) OR Use only Oxidation Pond, if enough land is available, to avoid any form of mechanization. Follow this by land irrigation & gr water recharge to conserve water

FOR VERY SMALL TOWNS where electricity is not available, but land is available Provide only Oxidation Pond OR Constructed wetland Followed by Land Irrigation + Gr Water recharge In either case, no power is needed, and water is conserved

2 nd MANTRA To speed up application in the State and the whole country - SIMPLIFY - STANDARDISE - LOCALISE

HELP LOCAL BODIES TO HELP THEMSELVES TO SIMPLIFY: We use only aerated lagoons + oxidation ponds Their operation & maintenance are also simple TO STANDARDIZE: Only machinery (Aerators) can be standardized. Costs reduced. Repairs/replacement easy TO LOCALIZE: AL and OP construction are similar & simple and can be done by local people. So also Cultivation of high-value crops. Employment prospects for local people improved. Sustainability also improves

ADVANTAGES 1. Flowsheet is flexible and can be used for any size of town 2. Treatment method is extremely simple. No imports. No machinery 3. Floating Aerators can be standardized and outsourced for manufac 4. AL and OP are similar in construction. Local labour and materials 5. Wastewater is reused for irrigation. Remaining water is conserved 6. A high-value crop is cultivated. Good for local employment 7. Sustainability is improved 8. A renewable source of energy can be used, if desired

THANK YOU