In situ treatment technologies for pit latrines to mitigate groundwater contamination by fecal pathogens: a review of recent technical advances

On-site sanitation systems such as pit latrines are extensively used around the world, while there is a growing number of evidence documenting the impact of pit latrines on groundwater quality that may affect human health. Hence, this paper summarizes the various safe-sanitation technologies by broadly categorizing them into fecal pathogen disinfection methods (anaerobic digestion, chemical disinfection, biological additives, solar pasteurization and vermicomposting) and capturing methods (pit lining and permeable reactive barriers, the latter of which simultaneously capture and sanitize fecal sludge in pit latrines). While some of the reviewed technologies have been widely practiced for mitigating microbial contamination of the groundwater, others are still in the early stage of commercialization and field validation. Though there are challenges to the selection and adoption of the most appropriate technology, this paper discusses the readiness of each technology as a stand-alone fecal sludge management solution.

Comparative study between conventional and mechanical technology on fecal sludge treatment plants (FSTP) in Indonesia

In pursuit of access to wastewater services to reach the target of 100%, it is undeniable that the non-sewer system/on-site system should continue to be developed. The non-sewer system provides low-cost options, making access to wastewater infrastructure more affordable. As a further treatment of the fecal sludge produced from on-site technology such as septic tank, FSTP (Faecal Sludge Treatment Plant) is needed. This study was conducted on 4 FSTPs in Java Island, namely 2 conventional system FSTPs (Keputih FSTP, Surabaya and Betoyoguci FSTP, Gresik) and 2 mechanical system FSTPs (Duri Kosambi FSTP, Jakarta and Sumur Batu FSTP, Bekasi). The research was conducted by comparing performance indicators which are collection, treatment, human resources, and cost-efficiency, representing development priority aspects. Analysis of the development strategy was carried out by SWOT analysis. Based on performance indicator comparison, Duri Kosambi FSTP has the highest collection efficiency among the others. Treatment efficiency ranging around 60%, and human resources efficiency in all FSTPs ranging at 80%. Duri Kosambi FSTP has an acceptable cost efficiency level, while the rest are still dissatisfactory. Development strategy derived from SWOT analysis should include an effort to do scheduled desludging, partial investment from government, adjusting tariff, and optimizing FSTP capacity.

Fecal Sludge Management in Low Income Settlements: Case Study of Nakuru, Kenya

Introduction: In order to meet the sustainable development goals targets of sanitation, countries aim to increase access to safely managed sanitation services for its citizens. Safely managed sanitation services refers to improved sanitation technologies that are not shared with other households and where excreta is treated and disposed; or stored, transported and treated off-site. In most Sub-Saharan Africa (SSA) countries, on-site sanitation facilities such as latrines and septic tanks are common, with low-income urban settlements mainly using pit latrines. However, little is documented about the management of sludge from these facilities, especially in low income settlements in secondary and emerging cities. This lack of data is a major hindrance to public health, development and planning efforts by governments and planning agencies. This study specifically assesses practices and challenges along the sanitation value chain related to containment, emptying, transportation, treatment and recycling of fecal sludge.Methods: The study was carried out in low income settlements in Nakuru, a secondary city in Kenya. Over half the population in Nakuru live in low income areas and majority of these residents use pit latrines. A case study design was selected for this study and data was collected using qualitative methods. Data was collected through In-depth interviews and Focus Group Discussions using in depth interview guide and focus group discussion guides that had questions on sanitation practices along the value chain, challenges, opportunities available, and recommendations for improvement. Analysis was done through content analysis by reading the transcripts multiple times to gain a sense of the flow of the discussion. Thereafter, coding was done by following emergent issues and thereafter categories were identified which formed the basis for providing a picture of FWM practices in the settlements.Results: On site sanitation facilities are dominant in the settlements, but they are few and are shared by several households. These facilities were unclean, and they filled up at a fast rate because of the high number of users. The latrines were emptied by manual emptiers who used mechanized equipment but complemented with manual emptying using buckets. Sludge was transported to a central collection point using large and small scale means of transportation, before transfer to the treatment site for final treatment and disposal. Various stakeholders are involved in capacity building of emptiers as well as in the transportation, treatment and disposal of fecal sludge in the settlements. Challenges along the stages of the value chain included negative community perceptions and attitudes toward fecal sludge management.Conclusion: The results highlight the need to address the challenges along the chain by involvement of state and non-state actors. Low income areas have high populations and thus contribute huge amounts of fecal sludge. Deliberate efforts to consolidate such data from low income areas will result in availability of data, and informed decision making for stakeholders at national and international levels.

Inconvenient truth: unsafely managed fecal sludge after achieving MDG for decades in Thailand

In most low- and middle-income countries, due to financial constraints and improper management practices, the expansion of conventional centralized systems to enhance wastewater management services is not practical. Despite the fact that the majority of the world population has met the Millennium Development Goals 7c (MDG7c) targets, more than 2.5 billions are still using unimproved sanitation facilities and affecting the safety of drinking water and public health. Because of this problem, a novel approach on ‘Non-Sewered Sanitation’ with decentralized treatment systems is being recognized as a promising alternative to accomplish the Sustainable Development Goal No. 6 (SDG6) targets on ‘Safe Water and Sanitation’ and bringing health benefits to the people. This study aimed to investigate the current status of access to improved sanitation facilities in relation to the MDG7c and SDG6 in Thailand and comparing with other countries, including the effects of unsafely managed fecal sludge (FS) on the prevalence of diarrhea and liver fluke infections. The prevailing constraints and weaknesses were identified, and effective sanitation management measures to accomplish SDG6 targets were recommended. Based on data collected from 20 cities located in the north and northeastern regions of Thailand during the period of 2015–2020, the sanitation facilities data on conventional centralized systems and FS management facilities that affect the prevalence of diarrhea and liver infections were analyzed and interpreted using statistical and response surface methodology techniques. The findings showed that most of the surveyed cities have achieved the MDG7c targets, but 70% of the FS generated from on-site sanitation systems are still unsafely managed, caused by limited expansion of sewage systems for wastewater collection and conveyance (with inadequate operation and maintenance) as well as the financial constraints, especially in areas outside of urban neighborhoods. The effective sanitation management practices to accomplish the SDG6 targets were proposed such as increasing the capacity of sanitation facilities to be 55,000 m3/day/30,000 households, designing appropriate FS collection program and treatment technology, and providing more awareness programs for safe sanitation management and health risk protection.