Risk Assessment for Safe Drinking Water Supplies - Global Drinking Water Management and Conservation - page 117

In addition, the Risk Assessment Plan describes an approach to conducting the
risk assessment. Note that cation of stressors and their sources is

essential to ensure the effectiveness of risk assessment. For example, the Tennessee
Valley Task Force developed an inventory of environmental stressors to store
information about nonpoint sources and point sources, and also developed solutions
to solve the priority problems (USEPA 2007 ).
Step 2: The risk analysis phase searches for critical and in

the identi

uential stressors,
forecasts how the stressors impact assessment endpoints via exposure pathways,
and examines what human activities lead to changes in the ecological environment.
Step 3: The risk characterization represents the causes of uncertainties in both
the problem formulation and analysis phases, and estimates the likelihood and the
consequences of effects based on exposure and impacts. During the risk charac-
terization phase, risk estimation is a challenge since natural resources respond to the
multiple stressors through various pathways. Risk assessment should be evidence
based. Furthermore, the quantitative information summarized and described by the
risk description phase can be used to prioritize the estimated risks.
Step 4: Risk management refers to all the stakeholders making decisions based
on the information made available by the previous steps. For example, they may
rank and prioritize stressors and their consequent impacts. Past history may help in
determining the degree of risk.

6.3 Risk Management Methods for Producing Potable
Water Supplies

Major approaches for risk management to produce potable water discussed below
include (a) the HACCP protocol, (b) WHO Water Safety Plan and the Bonn
charter, and (c) Quantitative Microbial Risk Assessment (QMRA).

6.3.1 Hazard Analysis and Critical Control Point Protocol

The adoption of increased safety and reduced risk in drinking water has its origins
in concern for food safety, and the realization that drinking water safety could and
should be treated like food safety. Historically, in the Austro-Hungarian Empire
(1897 1911), a collection of standards and product descriptions for a wide variety

of foods was developed as the Codex Alimentarius Austriacus. This was a voluntary
effort on the part of experts in the food industry and universities; the Codex
Alimentarius Austriacus was not a legally enforceable set of food standards but was
nevertheless used by the courts to determine standards for food safety (Davies
1970 ). It was to lend its name to the present-day international Codex Alimentarius

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