A Comparative Study on Fecal Sludge Management in Three Municipalities of Bangladesh

Abstract

The sanitation needs of 2.7 billion people worldwide are served by onsite sanitation technologies, and that number is expected to grow to 5 billion by 2030. Bangladesh provides a striking example of progress to meet the Millennium Development Goal (MDG) - 7 to halve, by 2015, the “proportion of urban population with access to improved sanitation”. Open defecation has been reduced to only 1%, a milestone change from 42% in 2003. But the increase in fixed-place defecation has created an urgent need for Fecal Sludge Management (FSM) in the cities of Bangladesh, where most human waste is dumped untreated into waterways or onto marginal land, harming the health of the country’s poorest. The draft national regulatory framework identifies municipalities as responsible for FSM.

This research was carried out in Khulna City Corporation, Kushtia Municipality and Jhenaidah Municipality. The study involved data collection, field visits, fecal sludge sampling and laboratory analysis, investigation on emptying, treatment and disposal services.

Khulna City Corporation (KCC) covers an area of 45.65 km2 with tax-payee holdings of 66,257 of population 15,00,689. Manual sweepers are providing emptying services. KCC is providing both manual (by boggy) and mechanical emptying (vacutug) services since ten years. But there was no designated disposal site and the septage/fecal sludge was disposed here and there specially in drains which ultimately flows to river. 84% of the septic tanks have no soak wells and is connected directly to drains. Besides, City Corporation, Community Development Committee (CDC) have three smaller (1m3) vacutugs and those are much popular in services. Annual fecal sludge generation was estimated to be around 7,10,000 m3. Recently, KCC has started to construct a fecal sludge treatment plant (FTP) with financial assistance from Bill & Melinda Gates Foundation (BMGF).

Kushtia Municipality is a class “A” municipality and recently been extended to total land area of 42.79 sq.km with population 3,75,149. In this municipality, 68% septic tanks have no soak well and are connected to drains. Fecal sludge generation was estimated to be around 104,581 m3/year. In this municipality, vacutug services have been launched since ten years. They have a treatment plant with two drying beds and coco-peat filter and compost is being produced here. Recently, the emptying demand has been increased tremendously, but capacity of the treatment plant is less. Thus, another FTP is under planning to meet the additional demands for FSM.

Jhenaidah municipality is a small town of 32.42 Sq.km with 1,57,822 population. About 80% of the septic tanks have soak wells. Annual fecal sludge (FS) generation was estimated to be around 58,705 m3. A constructed wetland was built by the Department of Public Health Engineering (DPHE) in 2012 and handed over to the municipality for field operation and maintenance (O & M) using two vacutugs. But the municipality didn’t have any experience for the O & M of those and eventually left unused.

Characterization of FS has been done for three municipalities. Experiments have been performed for sixteen wastewater quality parameters for each FS sample such as solids concentration, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), nutrients, pathogens, etc. The Solid contents in Fecal Sludge of these three towns varied between 3% to 6%. The range of COD concentrations were 7600-9600 mg/L. BOD5 concentrations were 819-1662 mg/L while the acceptable limit for disposal into inland water bodies is only 40 mg/L (ECR, 1997). Thus, it’s a big challenge to reduce the BOD5 in fecal sludge treatment plant for its ultimate disposal.

Based on the entire value chain of FSM in three municipalities, proposals have been suggested for the overall improvement. There are 38.3%, 46% and 54.5% of pit toilets in Khulna, Kushtia and Jhenaidah, respectively. Placement of water seal, Y-junction of pit toilets and proper maintenance of the toilets can keep the toilets hygienic and improved. In Khulna and Kushtia municipalities, around 84% and 68% of septic tanks, respectively are connected to drains and thus stringent regulatory enforcement seemed imperative for its control and revision following Bangladesh National Building Code (BNBC). Manual emptiers can be registered by Municipal Authority so that only they can provide the services ensuring health and safety. Small devices such as Gulper and Diaphragm-Pump for emptying, Excrevator/Augur for extracting the hard solids from bottom of septic tanks, promotion and encouragement of local manufacturing process of Vacutugs, provision of secondary transfer station (STS), FSM as market based solution, simple treatment technology, raising Social Awareness, addressing Health and Safety issues, etc. have been proposed for the improvement of fecal sludge management in the study areas.