Evaluation of microbial water quality databases of Sulaimani city collected during 2018-2020

Abstract EN

Water is essential to support life and therefore preserving water quality is an effort that should be made.

Due to the possible implications of waterborne illnesses, microbial pollution is currently regarded as the most serious risk factor affecting the quality of drinking water.

This research is analyzing data of fecal coliform and Escherichia coli in drinking water of Sulaimani city from 2018 to 2020.

Sample analysis was based on results that had more than double replications at least during a year.

The samples collected (100 ml) from different points of distribution network (project stations, main store tanks, and domestic tanks) continuously along the year and then transferred to the lab.

Samples analyzed at same day by multiple tube/ most probable number technique for FC (9221 E) and EC (9221 F) in the lab according to American public health association procedures.

High contamination of drinking water by fecal coliform and Escherichia coli in main and domestic tanks was found in 2018 and 2019 with 6.82% and 15.22% , while 2020 had 0.82% and 3.10% respectively.

The most probable number per 100 ml (MPN/100) of coliforms, thermotolerant and Escherichia coli ranged from 2.2 to more than 16.6.

The percent of contamination by total coliform bacteria is different over the past three years.

In 2018 nearly 14% of samples were contaminated by coliform bacteria, of which 4 samples was determined as EC contamination.

In 2019 the contamination by total coliform decreased slightly, of which 3 samples we detected as EC.

In 2020 out of 20% total coliform contamination only one sample detected as EC.

Residual chlorine of drinking water during 2018, 2019 and 2020 was 0.0-1.2, 0.0-0.8 and 0.0-1.0 ml/gm, respectively.

There was negative correlation between residual chlorine and coliform survivability.

Most detected coliform and Escherichia coli was ent (0.0 ppm) of residual chlorine in water networks.

Home tank spoilage in 2019 was greater by 25% compared to 2018 and 2020, which is the highest record among those three years.