Abstract:
Partially treated effluent contributes to water quality degradation of water bodies in Malawi. This
study was aimed at evaluating the overall performance of Livingstonia Wastewater Stabilization
Ponds and their effects on Mpopi stream in Rumphi, Malawi. Representative duplicate grab
samples (n = 40) were collected from five sampling points from the treatment ponds (inlet and
outlet), effluent discharge point (experiment), upstream (control) and downstream in four
sampling campaigns executed from October 2022 to January 2023. Physico-chemical and
microbiological parameter were analyzed and then the effluent was compared with the Malawi
Effluent Standards (MS 539:2013). Data was analyzed using IBM SPSS version 23. The results
showed that effluent does not meet the Malawi Effluent Standard (MS 539:2013). High levels of
5-day Biochemical Oxygen Demand (40.80 mg/L), E. Coli (253 cfu/100 mL), Total Phosphorus
(1.67 mg/L), Total Suspended Solids (746.00 mg/L), Turbidity (42.65 mg/L) above Malawi
Standards specifications for industrial effluents tolerance limits in the effluent (20 mg/L) proved
poor performance of the plant. Similarly, high levels 5-day Biochemical Oxygen Demand (3.38
mg/L), E. Coli (65.00 cfu/100 mL), Turbidity (1.65 mg/L), NO3ˉ (6.00mg/L), NH3 (2.50 mg/L),
Total Dissolved Solids (26.50 mg/L), Dissolved Oxygen (5.10mg/L), temperature (26.48 oC),
Total Suspended Solids (7.48 mg/L) and pH (6.25) on discharge point than upstream point in the
stream, were indicative of water pollution resulting from the effluent. Also the study expressed
lack of professional ponds maintenance, stream monitoring and inadequate laboratory
equipment’s as factors that contribute to poor performance of the wastewater stabilization ponds.
Therefore, there is a need for regular maintenance, specialized staff and adequate laboratory
services for monitoring of the ponds’ performance and their effects on water quality.
