Public Health and Lead Sampling Protocols for Drinking Water: A Critical Review - Global Drinking Water Management and Conservation - page 213

10.3 The Canadian Federal Guidelines for a Protocol
for Sampling Drinking Water

10.3.1 Stagnation Time and Sampling Protocols

Lead concentrations in drinking water can be largely due to the length of time for
which water dwells in a plumbing system before use for dietetic purposes. Also, the
volume of water (if any) that is not used prior to its use for dietetic purposes plays a
crucial role in human exposure to lead from drinking water. The time taken between
uses for dietetic purposes or inter-use stagnation time is also important and can
result in large variations in lead concentrations (see results of EU Report 1999 and
Bailey et al. 1986a ). As a result the proper sampling protocol used to determine the
amount of lead in drinking water is crucial in minimizing the health risks and social
costs associated with lead in drinking water.
In Canada, the Federal government is responsible for drinking water standards
on federal lands, in areas where the Federal government is the water supply owner
and in areas that fall under federal jurisdiction, e.g. First Nations lands, national
parks, and on-board common carriers (ships, airplanes, etc.) (Canadian Council of
Ministers of the Environment (CCME) 2004 ). The Constitution Act of 1867 gave
ownership of surface and groundwater to the provinces, and provincial govern-
ments have legislative responsibility for providing safe drinking water from those
sources. Municipalities obtain power from the provincial level in order to pass
by-laws that can also impact water resources. The three territories (Northwest
Territories, Nunavut, and Yukon) do not have ownership of their natural resources,
including water, but are still responsible for the provision (and legislation) of safe
drinking water (CCME 2004 ).

10.3.2 Canadian Federal Guidelines for Lead Sampling
Protocols

There appear to be two options for monitoring lead at residential sites under the new
Federal guidelines. Option 1 is a

approach for assessing corrosion control
in a distribution system. With this option the

“ two-tier ”

first tier requires a 1 L sample to be
taken after a period of at least 6 h stagnation. The sample is to be taken at the
kitchen tap or the source where drinking water is most commonly taken. If
10 percent of the sites have lead concentrations above 15 µ g/L, then the following

corrective actions are recommended:

(1) Initiation of a public education program which includes encouraging con-

sumers to

flush water after prolonged stagnation.
(2) Conducting additional sampling from at least 10 percent of the sites with the
highest lead concentrations (above 15 µ g/L).