**4. Conclusions**

The study was aimed to determine the concentration levels of heavy metals (Pb, Cd, Cr, and Cu) and selected ions (chloride, Calcium, Sodium, and Magnesium) of

Little Akaki River irrigation water and to test the concentration variation of heavy metals and selected ions between the sampling locations along the river stream. To this end, the study was brought out the following observations and conclusions. The concentration level of Cadmium (Cd) ranged between (0.03–0.4 mg/L) and it was extremely higher than the permissible limits of FAO (0.01 mg/L) for irrigation water and the values of Pb was also varying in (2.5–3.9 mg/L) and it was found in approaching the maximum permissible limit of irrigation water set by FAO (5 mg/L). Both heavy metals (Cd & Pb) have higher concentrations in the middle and upstream than the downstream of the river and their concentration level reached the hazardous condition for irrigation water in Little Akaki River water. The concentration level of Pb and Cd were extremely higher than the previous study findings and this indicated heavy metal contamination problem is progressively increasing in the river stream. Whereas, heavy metals such as Cr and Cu were found below the detectible limits of the laboratory equipment (ICP-OES). Selected ions such as chloride and sodium were reached at the maximum permissible limits of FAO in the Little Akaki River and this can inhibit the growth of vegetables in the irrigation sites of the study catchment area. Other physic-chemical parameters (TDS, pH, and ECw) were found in optimum conditions for irrigation water in all three-sampling locations. The other main point that has been observed is a variation of heavy metals and selected ions between the sampling locations were not statically significant at 0.5 and 0.1. In general, the most important water quality parameters such as heavy metals (Pb and Cd), selected ions like (chloride and sodium) were exceeded the maximum recommendation limits of FAO guidelines for irrigation water in the Little Akaki River. Therefore, the study revealed that irrigation water quality is reached at a great concern for vegetable production and it could be a potential risk for human health through the food chain of vegetable consumption.
