ISZA first began working with YourAid (https://www.youraid.org.au/)on the Buddhist Library Cambodia Project (BLCP) t(https://www.youraid.org.au/about-us-copy)o deliver clean drinking water to rural Cambodian schools with these filters in 2020. Ultrafiltration (UF) water treatment systems are utilized due to the following benefits: • Simple: UF filters require minimal maintenance or knowledge to operate - they have super small pores which prevent pathogens from passing into the output. • Cost-effective: each system is less than $1,000 USD delivered and installed. • Reliable: UF reliably removes bacteria, pathogen and viruses for many years. • Scalable: UF can treat enough water for hundreds of people, something most other cost-effective water treatment technologies fail to accomplish.

• 300 treatment systems have been delivered and installed. • 60 units are currently in fabrication. • $9,500 is all that is needed for an additional 10 units in 10 different schools.

• The filters produce water that exceeds the World Health Organization (WHO) standard by 10 times! • The final water has less than 0.5 NTU turbidity (high turbidity = more particles) • The WHO standard being 5.0 NTU turbidity (10x more than minimum result).

• Filtration tank maintenance is simple - simply flush the system for 2 minutes, once per day in the morning for optimal results. • A chlorine solution can also be used every 6 months for long-term mainetance. • The cleaning solution and instructions/education are provided with each system. • Filtration tanks are inspected and serviced on an ongoing basis by YourAid. • Locals are also trained to perform the inspection to increase efficiency and system reliability

• The pump is most sensitive component of the system. • Malfunction is often due to a manufacture defect and often occurs soon after installation. • Each pump comes with a 1-year warranty. • Replacement after the warranty expires is $105 (USD). • No systems installed within the last 2 years have had pump malfunctions. • The filter membrane is the second most sensitive component • Damage is typically due to improper maintenance or poor source water quality. • Rain or ground water use typically allows for > 5 year filter lifetimes. • If pond water is used, the filter membrane will need to be replaced more frequently (every few years). Prefilters can extend this longevity. • A replacement membrane filter costs $150 (USD).