The environmental impacts of wastewater discharge on the coastal water quality in the Gaza nearshore region

Abstract EN

Gaza City is considered one of the most densely populated cities in the world.

Several sewage outfalls are discharging about 60,000 m3/ day of untreated and partially treated wastewater into the Gaza Nearshore region.

Therefore, the contamination will cause potential pathogenic infections and diseases, and also will increase environmental threats and eutrophication on coastal water.

On the other hand, coastal water pollution will pose a serious risk on seawater desalination plants.

Therefore, this study aimed to investigate the effect of effluent discharges on coastal water quality concerning bathing water criteria and eutrophication level.

In-Situ measurements were conducted in the nearshore zone.

Seawater quality parameters were tested, including Total Suspended Sediments (TSS), Secchi Disk depth (SDD), Phosphorus (P), Fecal Coliforms (FC), and Chemical Oxygen Demand (COD).

The finding showed that the quality of Gaza coastal water ranges between mesotrophic to highly eutrophic class.

The water clarity was very low and the average SDD less than 4.15 m.

The phosphorous concentration displayed spatial variation ranging from 0.18 mg/l and 3 mg/l.

The COD varied between 32 mg/l and 288 mg/l.

The measurements exhibited high levels of bacterial contaminants with a concentration of 252 cfu/100 ml.

In summary, the results did not coincide with the coastal water quality criteria for bathing or fishing; even more, they will pose a potential health risk to beach visitors and cause a threat to the seawater desalination process in case of direct withdrawal from seawater.