Daily Archives: November 9, 2011

Louisville (KY) Water Company to increase rates 3.75%

The average monthly residential water bill for use of 6,000 gallons will increase by 85 cents a month January 1 — raising the average bill to $23.47

That is an average cost of < 1 cent per gallon per month…..click here for news article. 

Water shortage in Yunnan province, China

Availability of water is problem for many locations…..if there’s no water, people may have to move to where there is water…..click here for a short article on Yunnan province.

Lund et al 2011: Long-term study of migration of volatile organic compounds from cross-linked polyethylene (PEX) pipes and effects on drinking water quality

Ten different types of PEX pipe were tested for leaching potential using a 72 hour contact time.  The press release (click here) states…

  • There are no health risks associated with drinking water from PEX pipes 
  • A few types of PEX-pipe may cause prolonged undesirable taste and odour if the water remains in pipes over time 
  • Although the taste and odour usually dissipate with use, water from two of the PEX types still had an unpleasant smell and taste after a year 
  • The level of volatile organic compounds that leaked from new PEX pipes was generally low 
  • The level was further reduced with use 
  • No correlation was found between production method and leaking products

Citation and Abstract are below….

V. Lund, M. Anderson-Glenna, I. Skjevrak, and I.-L. Steffensen. Long-term study of migration of volatile organic compounds from cross-linked polyethylene (PEX) pipes and effects on drinking water quality. Journal of Water and Health In Press, Uncorrected Proof doi:10.2166/wh.2011.165

Abstract: The objectives of this study were to investigate migration of volatile organic compounds (VOCs) from cross-linked polyethylene (PEX) pipes used for drinking water produced by different production methods, and to evaluate their potential risk for human health and/or influence on aesthetic drinking water quality. The migration tests were carried out in accordance with EN-1420-1, and VOCs were analysed by gas chromatography-mass spectrometry. The levels of VOC migrating from new PEX pipes were generally low, and decreasing with time of pipe use. No association was found between production method of PEX pipes and concentration of migration products. 2,4-di-tert-butyl phenol and methyl tert-butyl ether (MTBE) were two of the major individual components detected. In three new PEX pipes, MTBE was detected in concentrations above the recommended US EPA taste and odour value for drinking water, but decreased below this value after 5 months in service. However, the threshold odour number (TON) values for two pipes were similar to new pipes even after 1 year in use. For seven chemicals for which conclusions on potential health risk could be drawn, this was considered of no or very low concern. However, odour from some of these pipes could negatively affect drinking water for up to 1 year.

Click here to obtain a copy of the paper (fee).