After seeing two UDD toilets, a group of 15 of us visited two flower farms north of Nairobi in search of constructed wetlands. The community group at KPSP05 is also exploring sanitation options, and despite currently) lacking funding for wetlands for the site, we still thought it would be great to show them an example of something that could be implemented in the future. Neither of the farms are using constructed wetlands to treat sewage; however, we were interested in seeing their treatment systems for their industrial wastewater.
Our hosts at each of the farms were incredibly gracious, taking a lot of time and care to help the community fully understand what they were seeing. The first farm, Enkasiti Flowers in Thika, Kenya, used sand filters to treat agricultural runoff before recycling the water back into a holding pond. The water is then reused in a drip irrigation system to water the hundreds of thousands of roses that grow in their greenhouses. The general manager, Narayanan, showed us the entire process from start to finish – from testing the rose varieties to grafting, harvesting, and shipping. It was an interesting process and the community members were interested in their large-scale farming techniques since several of them have their own gardens at home.
After the tour, they served us tea, coffee, sodas, and, what had to have been, their entire supply of cookies! Touring a flower farm certainly builds up an appetite. I should also mention that Enkasiti has offered to donate materials to help us build the sanitation blocks. It is a generous offer, and we were happy to take them up on it so as to stretch our budget just that much further!
We were then on our way to a town called Ruiru to visit a the Red Lands Roses farm. Our host, general manager George Kimani is an enthusiastic environmentalist and runs a great operation to ensure that their business does not cause harm to the land. They use constructed wetlands to treat their industrial wastewater, and on our arrival we found out that they are in the process of connecting their sewerage system to the wetlands as well! It was a perfect example for us to better understand how this type of system could work on our site.
They took us inside to see the origins of the wastewater. They use their wetlands to treat waste water from their processing center. The best part about touring flower farms? Being surrounded with beautiful roses.
The system we looked at uses a septic system for primary treatment and constructed wetlands for secondary treatment of the liquids. We got down and dirty, opening up the hatch to the septic tank and peering down into piles of poo. Currently, Red Lands drains the liquids into a soak pit nearby, but construction is underway to send the liquids to the wetlands as we are envisioning for our site.
The piping below carries the water to a tank where any solid materials are strained out before entering the wetlands.
The water then flows into the first of a series of ponds. The ponds contain soil and plants that are specifically planted to “eat” up pathogens and harmful contaminants in the water. By the end, their water is potable! KPSP 05 community member, Frederic filled his water bottle with the effluent, though, in the end, he chose not to drink it.
The final effluent flows into a beautiful pond. In my mind, the beauty of these wetlands is one of the major benefits of using them, particularly at a public space. The greenery is so inviting, KPSP05 community member Prisca, went down to check it out for a while.