Abstract:
Industrial pollution to water body is one of the serious problems if there is no well established
wastewater treatment facility. The main focus of this study was to investigate the effects of
wastewater generated from Hawassa Textile Factory on Tikur Wuha River. Composite
wastewater samples were taken from the factory outlet and the outlet of lagoon and a grab water
sample was collected from each selected ten sampling stations on Tikur Wuha River once per
month from April to May 2011. A habitat score was made for each established sampling stations
by using habitat assessment checklist. Macroinvertebrate sample was collected together with
water sample from each selected sampling sites by using surber sampling method from Tikur
Wuha River. The wastewater and river water physicochemical parameters such as Chemical
oxygen demand (COD), biological oxygen demand (BOD), total organic nitrogen (TON), nitrate
nitrogen (NO3-N), ammonia nitrogen (NH3–N), Phosphate (PO4
3-), Sulphate (SO4
2-) and total
suspended solids (TSS) were analyzed. Percent comparability of habitat score showed that both
upstream and downstream study sites were categorized to good habitat conditions. Multi metric
index of Tikur Wuha River was developed using selected metrics. Based on the multi metric
score sites such (U1 – U5) fall to very good biological integrity, while the downstream sites such
as (D1 & D2) categorized under very poor biological integrity. The results from this finding
reveal that the downstream study sites such as (D1 & D2) were categorized as severely impaired
than upstream sites. From the correlation matrices metrics that expected to decrease with
perturbation had a strong negative relationship with pH, COD, BOD5 & orthophosphorus at (r= -
0.839, -0.889, -0.887 & -0.722 respectively with %EPT) on the other hand metrics that expected
to increase with perturbation is % Chironomidae, has strong positive correlation with pH, COD,
BOD5 and orthophosphorus respectively. The study showed that the water qualities of the
downstream study sites on Tikur Wuha River were adversely affected and its aquatic biota was
impaired due to the strong wastewater or poorly treated wastewater discharged from the textile
factory. For sustainable management of this water resource, regional environmental protection
agencies in cooperation with the factory manager should take technical measures to alleviate the
problem. The environmentalist in the factory should continuously monitor the textile effluents and take
necessary actions to change wastewater to environmentally friendly form before discharging it
