Results and discussion
In hazard analysis emphasis was given to
events, incidents or situations that could lead to
hazards being introduced into or not being removed
from the water [5]. Risk assessment is the
key to the entire process -identifying risks, assessing
their significance and the controls in the
system that manage those risks in a systematic
fashion- starting from the catchment and working
down. A flow diagram of the Aspropyrgos
Water Treatment Plant was drawn up as depicted
in Fig. 1 [14]. At each step in the process, the
potential hazard to water quality and the controls
to prevent the hazard entering the water were identified
[15]. A semi-qualitative risk assessment of
Aspropyrgos Water Treatment Plant was applied
and a simplified example is given in Table 1. It is
noted that the water treatment plant is not responsible
for the quality of water coming from the
catchment area. The CCPs are determined going
through the decision tree of the method [15]. The
conceptual approach is shown in Fig. 2. An application
of the CCP decision tree on the catchment
area and the post-chlorination process is
depicted in Table 2.
The application of preparatory activities and
the principles of HACCP resulted in the HACCP
plan, part of which is described in Table 3 [15].
The HACCP plan includes the process steps of
the treatment, the identified hazards, the preventative
measures, the determined critical control
points, a monitoring system,