Public Health and Lead Sampling Protocols for Drinking Water: A Critical Review - Global Drinking Water Management and Conservation - page 214

(3) Informing consumers of test results and corrective measures to reduce lead

exposure. This includes flushing of the plumbing system before use for dietetic

purposes, replacing leaded

fittings and fixtures, replacing lead service lines,

and using water treatment devices.
(4) Implementing corrosion control measures within the distribution system.
These measures can include the adjustment of pH and alkalinity, addition of
corrosion inhibitors, and replacing of lead service lines.
(5) Encouraging homeowners to clean debris from aerators and screens (since
these are not required to be taken off before taking the 1 L sample).

Tier 2 of the sampling protocol is taken when more than 10 percent of the sites
tested under the Tier 1 sampling protocol exceed 15 g/L. Under Tier 2, four

consecutive 1 L samples are taken from the tap after a period of at least 6 h
stagnation. Each 1 L sample is analyzed individually and a stagnation pro

µ

le built.

jurisdictions in which
sampling after a 6 h stagnation time is not practical or regulatory obligations restrict
the use of the two-tier approach

Option 2 of the new Federal Guidelines is intended for “…

(Health Canada 2009 ). For this Option, four
consecutive 1 L samples are to be taken at the tap after the tap is

…”

flushed for 5 min
and left to stagnate for 30 min. Option 2 was intended to evaluate corrosion at
properties that have lead service lines and was not intended for system wide
evaluation of corrosion or corrosion control optimization (Health Canada 2009 ). If
average lead concentration from the four samples is greater than 10 µ g/L in more
than 10 percent of the sites monitored, then additional corrective measures are to be
taken similar to the 5 steps taken in Option 1 above. These measures also include
resorting to the Tier 2 sampling protocol identi

ed in Option1 to assess fully and to
remedy properly the corrosion problem. The sampling frequency and selection of
sites for residential monitoring is exactly the same as that of the EPA protocol (see
Table 10.2 ).

Table 10.2 Suggested number of monitoring sites (adapted from USEPA 2000 , as cited in Health
Canada 2007 )
System size (number of people
served)

Number of sites (initial
monitoring: once per
year)

Number of sites (reduced
monitoring: once per
year)

>100,000 100 50

10,001 - 100,000 60 30

3,301 10,000 40 20

-

501 3,300 20 10

-

101 - 500 10 5

Less than or equal to 100 5 5