Pilot Project for Wastewater Treatment and Reuse at Uhuru Park Nairobi

Aqua Consult Baltic was established in 1997 in Estonia, and the technology presented herein came into existence in Kenya thanks to a local company. This mother company located in Germany in Hanover, grew up from there. She implements projects around the world and mainly in Baltic States. This is an engineering and consulting company which mostly specializes on wastewater treatment and derivatives, secondary waste handling and municipal waste treatment plant. The company is currently working on a Slovenia and Vienna Project, which is 550 000PE and also in Tallinn, Estonia for 400 000 equivalents. Given that industrial municipal waste is difficult to predict, it is important to know its boundaries and behavior; so, for this type of waste, there is need to do a lot of modeling which includes fractionation of the wastewater and doing the piloting before providing the engineered solution to the customer. The company deals with oil and gas industry, chemical foods, agriculture, industrial plant, and projects linked to water reuse systems. Currently, the Tallinn water treatment of 400,000 equivalents transforms the surface water into potable water, using new technologies that are developed. The company has built good relations with universities, where testing and research are carried out.

Besides, Spacedrip – also an Estonian company – is an innovative and young company that focuses on water treatment systems which reuse water in a small scale of 25 to top 2000 people for water companies, real estate developers and defense sector. The defense sector for example has mobile units in different places that need to be supplied with water. Spacedrip thus provides them with showering or toilet systems that reuse water continuously.

Relationship between Aqua Consult Baltic and Spacedrip Group

A few years ago, Aqua Consult informed Spacedrip of the design of a new model of houses prefabricated in the factory and deployed to the sites. However, there is occasionally no infrastructure on the site, neither a wastewater nor a drinking water system. They needed a machine which was able to transform wastewater into drinking water. Spacedrip made the design, which is now used in Aqua Consult Baltic factory and the latter developed it further to what it has become today. It is now a more reliable product that can be fully put on automation, a very nice product. This device was funded by the Government of Estonia as a technology to be exported in other countries, and whose added value is the environment-friendly feature and saving the greenhouse potential.

During the funding, the Estonia President at that time visited Kenya. He knew about the existence of this company making wastewater into drinking water; indeed, there is less than 1 million people or so in Estonia, and everybody know each other. He told his peer, the President of Kenya of this technology, and the latter showed interested, hence the relationship with partners on site and the launch of this Kenya project.

Problem Statement

As President William Ruto put it: “Kenya Government has resolved to not only reclaim Nairobi’s reputation as Africa’s green city but also live up to its ancestral identity as the river of cool and fresh water”. The Kenya project emerged from findings below:

• The river that flows in Nairobi is polluted enough and needs to be cleaned to get the same quality as before the settlements. So, there are a lot of projects ongoing to make this river cleaner and for a better environment.
• Secondly, Nairobi City water production is around 500 000 m³/day, but the amount needed to meet existing demand is 800 000m³; there is a lack of green water to use.
• Furthermore, there is lot of drinking water used for some needs that technically safe recycled water could have met (flushing toilets, irrigation, etc.) Indeed, water reuse systems can reduce the water demand by 50% (800 000m³/day is necessary. If 50% of water are saved, then only 400 000m³ will be needed). To implement this project, infrastructure upgrade is not necessary.

A pilot plant was thus installed at Uhuru Park, Nairobi for two purposes:

1. clean up the Nairobi river a little bit, and
2. help reuse water.

The Solution Implemented

The Spacedrip device (see page 7 in attachment) is a container treatment plant that takes up the wastewater from a channel that flows through the Uhuru Park, Nairobi up to 50 m³/day and cleans it up so it can be reused for irrigation of the park. The system is handled with an automation software so it can be monitored and run up from a far distance and keeps a working order in every cases. This technology is not new per say, but it has a sedimentation tank in front of it. There is a biological part where organics and a bit of nitrogen are removed; then, a filtration unit that micro- filtrates out most of the bacteria; clean water enters a tank in a technical chamber and from there, it is filtrated by UV light and chlorine when necessary. So, water comes into the treatment plant from the stormwater drain channel and goes out the treatment plant through sprinklers in the park. Water arrives through a storm water channel. There are quite no rainy events there, but a lot of water coming from septic tanks and industrial site discharge, which is unknown and difficult to predict. This means that water flowing through is quite dirty, and direct use for the irrigation is not a good idea. However, following treatment, it becomes very clean from organics and bacteria. This technology has been used at the Uhuru Park for two weeks now.

Results Obtained

The commissioning went well a month ago (May 2023), and the system has been running in its full capacity for two weeks now. Currently, up to 25% of the necessary Uhuru Park irrigation water is coming from this treated wastewater device. The implementation of this device aimed to give a proof that this kind of system with sound automated plug and play technology works well. These compact units can be placed anywhere, even in small areas. It can run for a long period of time and is in a testing phase. The input and outputs analyze results are presented in Chart 2 (See Page 9 in attachment), with a 100% bacterial removal thanks to this technology. The influent and output picture shows the water obtained is quite pure. However, it is not safe enough to be consumed and is only for irrigation purposes.

Conclusion

This kind of system is same with Seehausen (Germany) water reuse systems. But this is a smaller unit that is quite compact, and which can be placed in small areas or bigger city centers where the wastewater is reduced. The water obtained can be used for toilet flushing or garden irrigation and there is no need for building new infrastructure to use it. Thanks to the IT Solution enabling the distance monitoring, there is no need to go on site for maintenance.

Therefore, it is possible to predict the maintenance of the system, that will allow it to run for a long time and avoid breakdowns. Pictures of some small three-meters containers are presented in Page 10 (See attachment); these are devices with showering and toilet units that were produced by Spacedrip for military projects, and which can be placed anywhere for continuous reuse of water.