Water quality assessment and organic pollution identification of Hammam-Grouz dam (Northeastern Algeria)

The water quality of the Hammam-Grouz dam is deteriorating. This deterioration is due to the inputs of pollutants and nutrients from sewage discharges and the use of fertilizers in agriculture. These waters, normally stored to meet growing domestic, industrial, and agricultural needs, are also polluted, and this pollution is increasing over time. The objective of this work is to assess water quality in Hammam-Grouz dam through interpreting some organic parameters analyzed, namely, organic matter (OM), nitrates (NO 3 − ), nitrites (NO 2 − ), ammonium (NH 4 + ), phosphate (PO 4 3− ), dissolved oxygen (DO), biological oxygen demand for 5 days (BOD 5 ), and chemical oxygen demand (COD). The study also aims at identifying the organic pollution levels of dam waters through referring to the methods of the Organic Pollution Index (OPI) and the Institute of Hygiene and Epidemiology (IHE) for the years 1988, 2006, 2015, 2016, and 2017. The results obtained show that the waters indicate high concentrations in NO 2 − , PO 4 3− , NH 4 + , OM, and COD which exceed the Algerian standards recommended by the National Agency for Hydric Resources (ANRH), and the quality of waters is rather poor with an increase of concentrations recorded during 2017, indicating high organic pollution. According to OPI and IHE methods, the dam waters show an organic pollution levels which evolve from low-moderate to high-very high. Therefore, the waters are unsuitable for further use and thus require immediate intervention and measures to eliminate pollution sources and to reduce some human activities that degrade the quality of the dam waters.