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In Khulna, Bangladesh, mechanical faecal sludge (FS) emptying and transport (E&T) service is provided by community development committees (CDCs) and the Khulna City Corporation (KCC). Without considering capital expenditure and depreciation, financial analysis for one year revealed that a CDC-1 m 3 vacutug made a profit of Bangladeshi taka (BDT) 145,780 (USD $1746) whereas a KCC-2 m 3 vacutug was in the loss of BDT 218,179 (USD $2613). There is a need to engage the private sector for sustainable service provision. Some of the key elements of enabling the environment for private sector engagement are policy/strategy, institutional and regulatory framework, implementation capacity, and financial viability. Existing policy/strategy/frameworks acknowledged the need and suggested plans for private sector engagement, and decentralised authority to city corporations. With increasing private-public partnership projects and collaboration in the sanitation sector, capacity of the KCC and the private sector are increasing. Financial viability of the FS E&T business is primarily dependent on the number of trips and the emptying fee. For the E&T business to be financially viable, a 2 m 3 vacutug should make six trips/day (internal rate of return (IRR)-13%, discount rate-6.5%) with an emptying fee of BDT 750 (USD $9)/m 3 . Despite the lack of operative guidelines for faecal sludge management (FSM), enabling the environment for private sector engagement in FS E&T business in Khulna seems favourable.

The high frequency and intensity of urban floods caused by climate change, urbanisation and infrastructure failures increase public health risks when the flood water contaminated from combined sewer overflows (CSOs) or other sources of faecal contamination remains on urban surfaces. This study contributes to a better understanding of the effects of urban and recreational surfaces on the occurrence of waterborne pathogens. The inactivation of selected indicator organisms was studied under controlled exposure to artificial sunlight for 6 h followed by 18 h in dark conditions. Concrete, asphalt, pavement blocks and glass as control were inoculated with artificial floodwater containing, as indicator organisms, Escherichia coli bacteria, which are common faecal indicator bacteria (FIB) for water quality assessment, Bacillus subtilis spores chosen as surrogates for Cryptosporidium parvum oocysts and Giardia cysts, and bacteriophages MS2 as indicators for viral contamination. On practically all the surfaces in this study, E. coli had the highest inactivation under light conditions followed by MS2 and B. subtilis, except asphalt where MS2 was inactivated faster. The highest inactivation under light conditions was seen with E. coli on a concrete surface (pH 9.6) with an inactivation rate of 1.85 h -1 . However, the pH of the surfaces (varying between 7.0 and 9.6) did not have any influence on inactivation rates under dark conditions. MS2 bacteriophage had the highest inactivation under light conditions on asphalt with a rate of 1.29 h -1 . No die-off of B. subtilis spores was observed on any of the surfaces during the experiment, neither in light nor in dark conditions. This study underpins the need to use different indicator organisms to test their inactivation after flooding. It also suggests that given the sunlight conditions, concentration of indicator organisms and type of surface, the fate of waterborne pathogens after a flood could be estimated., (Copyright © 2019 The Author(s). Published by Elsevier B.V. All rights reserved.)