Evaluating Technologies for Arsenic Removal: Experiences from Bangladesh Md. Saifur Rahman Executive Engineer, Arsenic Management Division Department of Public Health Engineering (DPHE) Government of Bangladesh 9/20/2018

Background Approximately 96% of population use groundwater for drinking However, in the 1990s widespread arsenic (As) contamination was detected Estimated 22 million people drinking water with As greater than national drinking water standard of 50 µg/L 9/20/2018

Arsenic Mitigation Strategies Awareness building Testing of tubewell water for As by field kits Marking of contaminated and uncontaminated tubewells Patient identification and management Providing Alternative Water Supply Options: Groundwater: Deep tubewells, shallow dug/ring wells Surface water: Pond Sand Filter (PSF) Rain Water Harvesting Arsenic Removal Technologies (ARTs) 9/20/2018

Two projects in Bangladesh to assess the performance of Arsenic Removal Technologies (ARTs) Bangladesh Environmental Technology Verification – Support to Arsenic Mitigation (BETV-SAM) 2001-2008 Deployment of Arsenic Removal Technologies (DART) 2007-2009 9/20/2018

Bangladesh Environmental Technology Verification – Support to Arsenic Mitigation (BETV-SAM) Project Partners: Department of Public Health Engineering (DPHE) Bangladesh Council for Scientific and Industrial Research (BCSIR) Ontario Ctr. for Environmental Technology Advancement (OCETA) Canadian International Development Agency (CIDA) 9/20/2018

Bangladesh Environmental Technology Verification – Support to Arsenic Mitigation (BETV-SAM) Project Objectives of the BETV-SAM project include: Independent, third party verification of technical performance of Arsenic Removal Technologies (ARTs) in Bangladesh Long term monitoring and surveillance of verified ARTs that are deployed in Bangladesh Building a sustainable capacity in Bangladesh Government agencies, third party laboratories and testing agencies, and other local stakeholders to carry out key functions associated with verification and monitoring 9/20/2018

Importance of independent, third party verification process: Operating principles of the ART are described and have a sound scientific basis Parties involved (proponent, test agency, analytical laboratory, verification authority) are technically qualified and independent of each other The test data is credible and complete, QA applied The Performance Claim (cumulative volume of treated water and ART media lifespan) is based on objective, scientific data and proven statistically, at the 95% confidence level 9/20/2018

ART Verification Process: Technology Screening Field Testing Provisional Verification Deployment Rejection of Performance Claims Monitoring Bacteriological Findings Waste Issues Social Issues Fiscal Outcomes Final Verification Report (Arsenic) Recommendations to the Government of Bangladesh ART Verification Process: Screened over 40 vendor ARTs Selected 12 ARTs for field testing Field tested (technical team) 12 ARTs at 5 wells in areas with different water chemistries Monitoring of community use to assess: technical performance social and economic aspects Key items to note: Many ARTs were screened and did not have sufficient technical data to support performance claim 12 most promising ARTs were selected for verification Technologies used oxidation and sorption on different types of media for As removal Some used flocculation, co-precipitation and filtration Conducted field testing to assess the technical performance of the ARTs (i.e., consistently provide water with As-safe for a period of time) Note that field testing comprised: 1. technical operation and testing by a technical team (NGOs, GoB supervision) 2. at 5 different areas of Bangladesh – different water chemistries (different As, Fe, PO4 ranges) 3. raw/treated water analysed (test kits and lab analysis) 4. results analysed, media life estimated - performance verified 4 ARTs were provisionally verified based on field testing 4 ARTs were then deployed to communities and the actual use by users was monitored: Technical aspects monitored (raw/treated water chemistry) Social issues (preference, etc.) Financial aspects 9/20/2018

Results – General Findings Most HH ARTs removed arsenic to < 50 µg/L, providing at least 45 L in 12 hours (cooking/drinking water for a rural family of 5) However, most ARTs did not meet their stated performance claims for media life Groundwater composition had a significant effect on the media life of a given ARTs (in particular, phosphate [PO4] concentration) Spent filter media was not classified as hazardous waste according to tests included: Toxicity Characterization Leaching Procedure (TCLP) Dutch Total Available Leaching Procedure (TALP) Discuss the different chemistries at sites. Full suite of analyses analysed, but main parameters influencing performance: Arsenic concentrations (Higher As concentration = shorter media lifespan) Iron: helps to co-precipitate with As and increases performance BUT media must be backwashed to prevent clogging Higher Fe concentration = longer media lifespan Phosphate – similar chemical properties to As and therefore competes with As (Higher PO4 concentration = shorter media lifespan) Media lifespan estimated based on HH use of 15 L/day/person for family of 5 9/20/2018

Results – Technical Performance Example: READ-F Household (HH) ART READ-F performance verified at 5 locations with different water chemistry Volume treated before breakthrough (i.e., As-unsafe) estimated Phosphate (PO4) had significant influence on ART performance Discuss the different chemistries at sites. Full suite of analyses analysed, but main parameters influencing performance: Arsenic concentrations (Higher As concentration = shorter media lifespan) Iron: helps to co-precipitate with As and increases performance BUT media must be backwashed to prevent clogging Higher Fe concentration = longer media lifespan Phosphate – similar chemical properties to As and therefore competes with As (Higher PO4 concentration = shorter media lifespan) Media lifespan estimated based on HH use of 15 L/day/person for family of 5 9/20/2018

Results – Technical Performance Example: SIDKO Community-scale ART SIDKO performance verified at 5 locations with different water chemistry Higher As-safe volumes produced (community-scale system) Phosphate (PO4) also had significant influence on performance Similar influence of water chemistry on the community system Note the higher volumes treated to serve communities Media life estimated based on assumed 2,250 L/day (50 HHs) 9/20/2018

Four Arsenic Removal Technologies (ARTs) received Provisional Verification SONO ALCAN SIDKO READ-F Key items to note: Based on field testing, only 4 of the ARTs had acceptable performance to consistently produce As-safe water for a long enough period to be practical for actual use in Bangladesh 3 household units (Sono, Alcan and Read-F) 1 community unit (SIDKO) Price: $50 USD $60 $100 $6,500 9/20/2018

Verification Certificates – Technical Performance BCSIR issued Verification Certificates to successful proponents: certify that performance of specific ART was verified state that the ART must be deployed under the terms and conditions stated in the Conditions for Deployment Key considerations for Conditions for Deployment include: Water chemistry Estimated volume treated before breakthrough (i.e., As concentration exceeds 50 µg/L) and when replacement of ART media is required 9/20/2018

Verification Certificates – Technical Performance Key challenge was to provide Conditions for Deployment that were: conservative enough to prevent users from drinking unsafe water after breakthrough (i.e., protect human health) * applicable to the range of groundwater chemistry encountered in Bangladesh maximized the lifespan of the ARTs * Important note: rigorous monitoring and surveillance that would be required to identify when breakthrough occurs for an individual ART not practical (particularly for HH units) 9/20/2018

Verification Certificates – Technical Performance Summary of Conditions for Deployment for four verified ARTs presented below: Arsenic Removal Technology (ART) As (µ g/L) Fe (mg/L) PO 4 Flow rate (L/day) Total volume safe water (L) Media lifespan (months) Household ARTs: ALCAN 330 10 45 8,100 6 READ-F 500 50 36,000 24 SONO 750 Community ARTs: SIDKO 2500 450,000 Raw Water Chemistry Verified Performance 9/20/2018

Water Safety Plans (WSPs) WSPs developed for each verified ART to support water safety from source to point of consumption Key WSP components: system assessment: describes the water supply (including process, intended uses, nature of consumers) and the technology hazard analysis and control measures: includes a flow diagram to illustrate the process and identify hazards, and an analysis of those hazards operational management: schedule to monitor the system and take corrective action when necessary 9/20/2018

Water Safety Plan (WSP) stakeholders policy: technical experts, government (DPHE, local governments), NGOs, etc. monitoring (NGOs and communities) and surveillance (Government of Bangladesh) community workers: hygiene promoters, local community groups, providers of social service programs in rural Bangladesh end users: communities, households, family members 9/20/2018

Deployment of Arsenic Removal Technologies (DART) Project Project Partners: Department of Public Health Engineering (DPHE) UNICEF Local NGO and consultant partners Objectives of the DART project include: Deploy HH and community-based ARTs to provide safe water to arsenic-affected communities Conduct a social and economic assessment to analyze community acceptance of ARTs in the implementation area 9/20/2018

Results – Assessment of HH ARTs Summary of questionnaires and surveys: Arsenic Removal Technology (ART) % ARTs in use Est. daily use (L/day) Positive Comments Negative Comments ALCAN 80 30 Good look, size and flow rate Burden to clean, fragile tap, clogs with iron READ-F 71 24 Small size and portable, good flow rate No reservoir (doesn't store water), must continually be filled, too expensive SONO 77 Can store water, looks good, low price Slow flow rate, plastic is fragile and breaks Not all units were in use at time of surveys (generally within 6-12 months of deployment) Daily use was less than the verification certificate – so the media may last longer than estimated Positive and negative comments to all ARTs Economic aspects must be carefully considered; even subsidized prices were considered high by the users. This had an impact on long term sustainability 9/20/2018

Results – Assessment of SIDKO Community ARTs Results from 2 rounds of questionnaires and assessments mixed: 30%-41% judged to be “good” or “satisfactory” 41%-39% = “poor” 29%-15% = “failed” Assessment criteria included: accessibility of ART location, convenience of hours absence of social conflict among users or resolution of conflict number of user households, sharing of costs competence of caretaker (demonstrated O&M; back-washing) observed condition of the facility 9/20/2018

Current Status of ARTs in Bangladesh Verification Authority: One more HH ART (Nelima) received verification but now verification authority is not actively operating Limited demand by proponents to receive verification Community systems: Over 300 SIDKO ARTs are reported to have been implemented Estimated that over 80% of the ARTs are operational Surveillance program not in place to assess technical performance Household ARTs: Limited demand created in the market Some proponents are producing units, but at limited scale 9/20/2018

Conclusions Independent verification is required to assess the technical performance of individual technologies; however, the verification process must be conducted in a timely manner to support creation of market demand and scaling up ART performance is influenced by raw water chemistry and therefore will be variable in different locations: Deployment conditions must be carefully considered and/or Monitoring & surveillance required to identify breakthrough In addition to As removal, WSPs must be implemented to support overall water safety for ARTs – in particular microbiological quality 9/20/2018

Conclusions cont. ART media must be replaced regularly to provide As-safe water on a consistent basis Government requires proponents to be responsible for collection and disposal of spent ART media; however, no guidance has been provided Costs of HH ARTs influence market demand and long term sustainability 9/20/2018

Thank You 9/20/2018