5. ConclusionsTwelve consecutive ye

5. ConclusionsTwelve consecutive years of water quality data were analyzed at drain estuaries discharging to Northern Egypt Lakesand the Mediterranean Sea. In an effort to better understand the trends in these data, a simple linear regression wasconducted on the 12-year dataset from 2002 to 2013, using CCME WQI involving 11 water quality variables. Resultsof the site-specific analysis demonstrate that water quality is improving at 4 sites (Bahr ElBaqar Drain, Drain No. 1,Tabia Drain and No. 11 Drain), but declining at 1 site (Ramsis Drain). Although the total number of sewage watertreatment plants amounted 333 plants in year 2010/2011 in comparison to 301 treatment plants in year 2008/2009 withincrease of 32 plants by ratio 11%. However, most of the sites do not demonstrate any statistically significant trends.This may be due to bad practice in monitoring process, operation and maintenance of wastewater treatment plants.