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Brass fittings as a source of lead and nickel in drinking water. Stage 3 Long term testing April 2015 to March 2016

Reference: 16/DW/04/19
ISBN: 1 84057 823 8
Published Date: 15/07/2016

Metal leaching from pipes and fittings into drinking water has been an issue in the UK for several decades, particularly as standards have progressively tightened (the Prescribed Concentration Value (PCV) for lead reduced to 10 µg/l from 25 µg/l in December 2013). This study has examined the leaching of lead, nickel and other metals of interest from UK brass fittings and US low lead fittings in hard and soft water, with and without phosphate dosing. In Stage 1, laboratory and short term (up to 6 month) field experiments on lead leaching were undertaken on a range of brass fittings. In Stage two, longer-term (up to 2 years) lead and nickel leaching characteristics were examined together with experiments on the removal and addition of phosphate dosed water. Stage three, reported here, has continued the study of the long term leaching characteristics of lead and nickel from the brass fittings (up to 3 years including stages 1 and 2) and other metals of interest (Al, Cu, Zn, Fe & Mn), The overall findings show that metal leaching decreases with time in both hard and soft waters.  In non-phosphate dosed waters some individual brass fittings and combinations of fittings can potentially cause failures to Random Daytime Sample for lead and nickel, especially when new or following periods of stagnation. Phosphate dosing was shown to be an effective way of suppressing metal leaching (particularly lead, nickel, copper and zinc) from brass fittings.

Price: £200  

Brass fittings as a source of lead & nickel in drinking water - long term leaching studies

Reference: 15/DW/04/16
ISBN: 1 84057 798 3
Published Date: 25/11/2015

This is one of two reports on Stage 2 of ongoing research to increase understanding of how brass fittings contribute to lead and nickel concentrations in drinking water. It examines yields of lead and nickel, and the effect of the addition and cessation of phosphate dosing on brass fittings deployed on long term test rigs. It also examines the effect of chlorine or chloramine dosed water on leaching from a laboratory trial. It identifies situations where individual brass fittings or combinations of fittings can routinely yield a few µg/l of lead or nickel and circumstances where their respective Prescribed Concentration or Value (PCV), of 10 µg/l and 20 µg/l respectively, could be exceeded following periods of stagnation. The dosing of phosphate is shown to quickly reduce leaching of lead and nickel, whilst the cessation of dosing is shown to increase leaching within a few days.

Price: £200  

Brass Fittings - Metallic composition of fittings

Reference: 15/DW/04/17
ISBN: 1 84057 799 1
Published Date: 25/11/2015

This is one of two reports on Stage 2 of ongoing research to increase understanding of how brass fittings contribute to lead and nickel concentrations in drinking water. It examines the alloy composition of brass taps, connectors, stop taps, meters and ferrules, including some low lead models, using X-Ray Fluorescence (XRF) Spectroscopy and wet chemistry. XRF Spectroscopy is shown to compare favourably with wet chemistry analysis, offering a non-destructive means for screening brass fitting composition. The observed alloy compositions are compared with the composition of alloys currently included in the 4MS Composition List, but few matches were found. The relationship between lead and nickel yields after 16-hour stagnations and the alloy compositions of brass fittings is examined. The report also covers an exercise to examine leaching of other metals of interest, including copper, zinc and iron, from a range of brass fittings deployed on long term test rigs.

Price: £150