Chlorine is considered as one of the most important disinfectants because of its availability
in a wide form and in acceptable cost. Measurements of residual chlorine are very essential to
assure the presence of disinfection at various locations of the water distribution system. The
aim of the present work is to find the residual chlorine concentrations in potable water which
leaves Tikrit University water supply plants. pH-, water temperature and water turbidity are
also measured. Sixty samples of tap water are tested during November 2009 till April 2010.
The results show that range of residual chlorine is 0.2-4mg/l) and most of the measured values
are higher than the maximum permissible limit according to Iraqi standards( 417/1974 )
The data indicated that pH is within the range of (7-8.2) and there is no clear relationship
between pH and residual chlorine concentration. It is found that there an inverse
proportionality between residual chlorinean and temperature . Same trend is found between residual chlorine and turbitiy. The Conductivity and total dissolved solid of drinking water was
within the permitted level by the Iraqi standers