To determine changing trends of fecal contamination at TinhTam, CayMung, TanMieu and
HoVe lakes in Hue Citadel (Vietnam), this reseach sampled and monitored the fecal coliform level every
two months from March 2013 to November 2014. There were a total of 11 samples collected at each site.
Samples were determined by MPN method and based on standards of APHA. Mann - Kendall nonparametric
test was used to analyze and assess changing trends based on Theil - Sen slope using ProUCL
4.1 software. The monitoring results in the 21 month study period showed that fecal coliform level at
lakes in Hue Citadel has large fluctuations in rainy season (September, November). The result also
indicated that fecal coliform level at TanMieu Lake is higher than at other lakes. By statistical analysis
and Mann – Kendall non-parametric test, the study indicated that there is a trend of increasing fecal
coliform levels at HoVe lake (p