COVER STORY lead update
Galvin Engineering has a new range of stainless steel drinking bubbler called GalvinClear, which is lead free.
20% of total lead intake is attributable to water consumption with the other 80% coming from food, dirt and dust.) “The ADWG is based around health considerations and the total amount of lead you can safely consume in a day. Will you be going to the same tap first thing in the morning and drinking your total 2L for the day in one hit?” AS/NZS 5667.5:1998 provides useful information regarding water testing, but it does leave a lot of variables up to the individual testing facility. This means that different results could be generated from the same site. For example, when testing a distribution system, clause 4.1.4 recommends that samples be collected at distinct locations in the system and from the ends of the distribution system. Samples should be collected after a flushing time of two to three minutes, but sometimes as long as 30 minutes. When looking specifically at a consumer’s taps, clause 4.1.5 states: “The flushing time depends on the sampling purpose; if the effects of material on water quality are being
from further down the line. “How long the water has been stagnant is an important consideration. If people come in first thing in the morning, the water has been sitting all night, so the test will produce the highest reading possible for that location.” Chris says that such vagueness makes current
guidelines in the Standard – then say the test complies with Australian Standards.” Chris has identified two primary areas of contention – sample size and stagnation period. “If you take a very small sample of water from a tap and surrounding fittings, and the water has been sitting there for ages, it will probably have a
testing practice open to interpretation and debate. “You also need to remember that the ADWG of 0.01mg/L is modelled on World Health Organisation recommendations on how many milligrams of lead per litre is OK in the water supply. This number is based on a 13kg child drinking an average of 1L a day - young
higher reading of lead and other metals due to prolonged contact. “My concern about current testing practices is that people take a very small sample, often 80ml, then they multiply the result by 12.5 to get the figure for a litre. “Well, it doesn’t work that way. If you took a 1L sample, it
“My concern about current testing practices is that people take a very small sample, often 80ml, then multiply the result by 12.5.
children, infants and pregnant women are the highest risk groups.” (Note: the WHO assessment is based on the fact
would give you a very different reading. You’d get the first 80ml with a higher reading, and the other 920ml would be
PLUMBING CONNECTION Winter 2018
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