Innovative ‘Safe Water Kiosk’ Ensures Quality Water for Kenyan Community

Siemens Water Technologies participates in multi–NGO effort with Australian roots to improve potable water access in remote, underdeveloped areas, including developing nations.

By Rhett Butler and Lisa Sorgin

For the village of Obambo–Kadenge in Kenya, a reliable source of clean drinking water was non–existent. This rural community of several thousand people relied mostly on runoff water collected in the Gona Dam, a small shallow dam on the floodplain. This water contained turbidity of 400 NTU and was contaminated by human activity and livestock waste, leading to outbreaks of waterborne diseases such as cholera, typhoid and dysentery.

The potable water problem was solved in March 2007 when the Skyjuice Foundation of Sydney, Australia, in conjunction with the Tweed Shire Council Mentoring Program, installed a “safe water kiosk” containing four SkyHydrant^TM water filtration units.

An Affordable Solution

Designed for affordable community water supply or disaster relief applications, the system combines microfiltration and chlorine disinfection to produce potable water. The microfiltration unit consists of a Memcor low–pressure membrane sub–module in a housing from Siemens Water Technologies. It removes particulate, bacteria, protozoa, virus and other contaminants greater than 0.1 micron (μm).

The SkyHydrant can be operated under low positive or negative head pressure. Raw water flows along the length of the hollow fibers before being forced through the walls of the fiber to produce a filtrate that’s virtually free of suspended solids. The filtrate flow rate is controlled manually. Chlorine is manually added either upstream or downstream, generally in a batch operating sequence, depending on site constraints. A simple membrane wash sequence is manually performed by the operator. The wash cycle lasts approximately 90 seconds, and is usually done every one to two hours, but can be done once every 12 hours, depending on raw water turbidity and flow rate. Wash waters can be disposed of by drain to waste or a 20–liter bucket. A simple membrane chemical cleaning procedure, or clean–in–place (CIP) procedure, is required periodically to remove residual membrane fouling that isn’t removed by the wash sequence, and to limit biological growth. The CIP frequency is determined by the application, but varies generally from daily to weekly.

The system needs no power to operate, as long as there’s one meter differential between the source water tank and clean water tank. It can be installed as a standalone unit or manifolded together for higher capacity. Compact and light weight, it can be easily transported and installed in the field, as well as redeployed from one site to another. It’s easy to operate and maintain, as it has no moving parts, and the robust, long–lasting membrane can be easily cleaned. The unit also produces no harmful toxic sludges, by–products or direct greenhouse gases.

Gona Dam, where residents previously collected their water

SkyJuice has supplied SkyHydrants as part of the Clean–Up Tsunami Cleanwater Project and to OXFAM, the Red Cross, World Health Organization, Samaritan’s Purse and many other relief organizations.

The safe water kiosk works as follows: raw feedwater is drawn into an automatic pump, which is powered by a small solar panel or other power source – in this case, a windmill – that provides an automated “on demand” water flow control system. The feedwater is pumped to a header tank and then flows into the water processing unit, which can produce over 10,000 liters of drinking water per day. The purified water is then sent to a clean water storage tank, and that water flows by gravity to a tap stand, where it can be drawn off into villagers’ portable containers, generally 20–liter buckets.

The SkyHydrant Project

The first step in the safe water kiosk project was developing a representative committee to oversee the site selection, land acquisition, construction of the water kiosk and reservoir tank stand, and selection of windmill and wind generator. The committee decided the wind generator would be the most sustainable option for the community’s water requirements.

Major funding and resources for the project came from the Tweed Shire Council, wider Tweed Shire Community, SkyJuice Foundation and International Riverfoundation. Although members of the community had previously never paid for their water, the committee decided the benefiting families should pay a small contribution once a month for ongoing maintenance and security of the kiosk. Fees are levied on an ability to pay basis. This approach ensures the community will have ownership of the filtration units to encourage the skills and motivation to make sure their access to clean water will continue long term.

Safe water kiosk under construction

The committee nominated a subcommittee, consisting of community members, to be trained in operating and maintaining the filters and pump. The subcommittee members were easily trained on the unit, including the cleaning procedure for the filters. Despite the high turbidity of the feedwater, the cleaning process took approximately five minutes for each filter.

Exceeding Positive Results

The SkyHydrants at the safe water kiosk provide continuous access to clean water from early morning to late afternoon, with a few hours’ break in the middle of the day. The filters are supplying approximately 2,200 L/hour of potable water, an ample supply for the community. The water turbidity is reduced from 400 NTU to <0.1 NTU, and the final water quality exceeds World Health Organization drinking water standards. The community is already benefiting from the kiosk in improved health and prosperity.

Mercelin holds glass of clean kiosk water on left and dirty Gona Dam water on right

“The safe water kiosk is more than just an infrastructure project,” says Jann Hughes, executive officer of the SkyJuice Foundation. “It is a community project both in Australia and Kenya fueled by the creative energy, enthusiasm and generosity of the communities in both countries. This project demonstrated the power of combining community participation, innovative, cost–effective technology and education, to provide an essential service.”

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Authors’ Notes:

Rhett Butler is business development manager for the Memcor product line at Siemens Water Technologies in Australia, and is also the chairman of the SkyJuice Foundation. Contact: +61 (0) 2 9491 5415 or [email protected].

Lisa Sorgini is the global brand manager of the Memcor product line at Siemens Water Technologies, and also serves as a member of the civil engineering advisory board at Worcester Polytechnic Institute in Worcester, Massachusetts, USA, where she received her degree in civil/environmental engineering. Contact: +1–508–849–4612 or [email protected]