International Conference on Rain Water Cistern Systems
St Thomas, Virgin
Islands - June, 1984
E: Quality Considerations
Heavy Metals In The
Drinking Water From Cisterns Supplying Single-Family Dwellings On St. Maarten
Department of Environmental Regulation Florida, USA
Florida Institute of Technology USA
The concentrations of zinc, lead, chromium and cadmium in 46 cistern water
supply systems from single-family dwellings on St. Maarten, Netherlands Antilles,
were evaluated with respect to U.S. drinking water standards. These heavy metal
concentrations were considerably below U.S. drinking water limits Samples from
kitchen taps showed release of zinc, lead and cadmium had occurred in t -e distribution
system (pressure tank and supply lines) with lead and cadmium exceeding the U.S.
drinking water standard for 6.5%: and 2.2% of the cisterns, respectively. The
release of these metals in the distribution system was not related to the corrosiveness
of the cistern water.
Inputs of zinc and lead from aerial and corrosion sources were removed from
the water column to the cistern sediments. Substantial increases in pH, calcium
and alkalinity occurred as the unbuffered and corrosive rainwater came into contact
with the cistern masonry. The cistern water remained mildly corrosive after contact
with the concrete structure. The measured concentrations of each metal were in
close agreement with the calculated thermodynamic equilibrium concentrations.
PDF of full document (24pp,
|Note: The IRCSA proceedings
section is still new and under active management, If you find any problems,
ommissions or corrections please contact
the administrator so we can put things right.