AGA Releases Zinc in the Water Environment White Paper
The American Galvanizers Association (AGA) has developed a new white paper, Hot-Dip Galvanized Steel's Contribution to Zinc Levels in the Soil Environment, to address the growing misconceptions about zinc in stormwater runoff. Zinc is a natural, abundant element found in the Earth’s crust and essential to all life – from humans to the tiniest micro-organisms. Zinc is required for cells to multiply; and therefore, is pertinent to the growth and evolution of all species.
Though it is possible to consume too much zinc, it is extremely rare for any human, animal, or plant to take in excessive amounts of zinc. However, zinc deficiency is quite common with nearly 450,000 children in developing countries dying annually as a direct result of too little zinc in their diet.
There has been some confusion that during storm events, surges of zinc from galvanized steel elements are discharged into water to the detriment of aquatic life. Hot-Dip Galvanized Steel's Contribution to Zinc Levels in the Soil Environment examines six case studies of galvanized bridges and docks in aquatic environments and studied the existing background zinc levels and flow rates of the waterways, as well as the corrosion rate of zinc and the introduction of zinc during storm events. In each case study, the addition of zinc to the water environment is not enough to exceed the criterion level defined by the U.S. Federal Clean Water Act as the amount of zinc causing toxicity to aquatic organisms. In fact, the additional zinc is at least 100 times less than the permissible level of zinc in drinking water.
For more information, download the full white paper from the AGA website.