Pollution or Protection - What Early Survey Data Shows on Rapid Waterbird Utilisation of a Newly Established Sewage Treatment Plant in Urban Ghana, West Africa?

Heavy urbanisation increasingly isolates and exerts pressure on natural wetlands, particularly in rapidly growing tropical developing countries, including West Africa. Constructed wetlands such as sewage treatment plants, may unintendedly offer wildlife protection due to prohibitive access control and limited use, thereby attracting wary and specialised waterbirds, otherwise heavily disturbed in formally protected wetlands with less polluted waterbodies. We present data from a rapid survey on 1-year post-opening colonisation and use of waterbirds in a recently constructed 11 ha restricted-access sewage treatment plant situated in Ghana’s capital, Accra. During November-December 2013 and January 2014, nine daily counts in each month produced an accumulated count of >4200 observations belonging to 26 species of waterbirds, including several important Afro-Palaearctic and intra-African migrants, hereunder ardeids, piscivorous divers, waterfowl and waders. The distributional patterns of waterbirds clearly reflected local foraging opportunities and water quality parameters in the system of 12 inter-connected waste stabilisation ponds. A nearby semi-natural wetland with cleaner waterbodies, but higher levels of human interference, supported half as many waterbirds, predominantly commensal gregarious species. Our data suggests that strict protection from disturbances outweighs possible negative implications attributed to mere pollution of waterbodies supporting various waterbird guilds, thus highlighting the potential importance of non-formally protected sewage treatment plants distributed in functional networks, as a complement to designated wetlands. We contemplate that establishing similar or larger plants jointly will improve sewage treatment and waterbird conservation in urban Ghana, and West Africa in general.

Diversity Profiling of Helminth Eggs in Waste Stabilisation Ponds in the Tamale Metropolis, Ghana

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Chemical Removal in Waste Stabilisation Pond Systems of Varying Configuration

While nutrient removal has been well studied in waste stabilisation ponds (WSPs), studies of organic micropollutant removal in pond systems are limited. In this study, we investigated organic micropollutant, nitrogen...

Comparison of the treatment performance of a high rate algal pond and a facultative waste stabilisation pond operating in rural South Australia

South Australian community wastewater management schemes (CWMS) treat wastewater using waste stabilisation ponds before disposal or reuse. This study compared the performance of a facultative pond, 6,300 m2, 27.5 d theoretical hydraulic retention time (THRT), with a high rate algal pond (HRAP) operated at depths of 0.32, 0.43 and 0.55 m with THRT equivalent to 4.5, 6.4 and 9.1 d respectively. Both ponds received influents of identical quality, differing only in quantity, and were operated in similar climatic conditions. The depth of HRAP operation had only a minor influence on treatment performance. The study showed that the quality of the treated effluent from the HRAP was equivalent to that of the facultative pond, 5-day biochemical oxygen demand removal >89%, NH4-N removal 59.09–74.45%. Significantly, Escherichia coli log10 reduction values by the HRAP, 1.74–2.10, were equivalent to those of the facultative pond. Consequently, HRAPs could replace facultative ponds within CWMS while maintaining treated effluent quality. The benefit would be halving the surface area requirement from 4.2 m2 capita−1 for the facultative pond to between 2.0 and 2.3 m2 capita−1, depth dependent, for an HRAP, with significant attendant reductions in the capital costs for construction.