Background: In this study quality and quantity characteristics wastewater of hospitals, clinics and health centers of Arak city and the potential impacts of them on Arak wastewater plant investigated.

Methods: In this cross-sectional  study, which done during 2011-2012, the quantity and quality  of wastewater via point of COD,BOD₅, pH, TKN, PO₄and also heavy metals in the hospitals, clinics and health center of Arak were studied. Then, the effects of these pollutants as equal to person on wastewater convey system and wastewater treatment plant were assisted.

Results: Monitoring of BOD₅, TKN, and PO₄ indicated that the daily disposal rate of these pollutants were equal 778.14, 102.7, and 53.6 kg/d, respectively, which equal to 15763, 51351, and 6700 person, respectively. The average water consumption of these centers was equal to 8.2l/s, and the estimated measure of produced wastewater was6.14 l/s. Also, after analysis the measure of heavy metals, Hg production (99.331 g/d) was more than other heavy metals, and the next rank was related to Zn (41.96 g/d) and Ag (41.96g/d), respectively.

Conclusion: Although existence pretreatment process units can help to decrease the side effects of produced wastewater, this kind of wastewater needs complete treatment. Discharge of this kind wastewater to absorption trenches led to adverse health impacts in future. Therefore, a construction separate wastewater treatment plants and proper operation of these systems can reduce ecosystem impacts of wastewater discharges.