Recent studies have shown that the rise in population and industrialization of urban centres leads
to an increase in sewage disposal. Lack of proper waste management presents the likelihood of
environmental and health hazards such as open sewer lines, especially in low-income areas.
Therefore, there is a need to provide methods of wastewater treatment whether on-site or by
conveyance to treatment sites. Due to the likelihood of overloading wastewater treatment plants, it
is paramount to investigate their efficiency in the removal of pollutants to ensure receiving water
bodies are not polluted to an unacceptable degree. For this reason, the National Environment

Management Authority (NEMA) has come up with recommended standards that regulate the level
of wastewater quality parameters in the effluent.
RUJWASCO is licensed to provide wastewater treatment for Ruiru and Juja Constituencies by use
of separate biological waste stabilisation pond systems for each constituency. There is a need to
evaluate the performance of the two plants due to the increased development of both areas.
However, the treatment works is fairly new and there is little documentation on its performance.
This study covers the efficiency and compliance of the two plants at Ruiru and Juja Sewerage
Treatment Works. It also makes a comparison of the wastewater quality parameters of the discharge
from the two treatment plants against NEMA standards.