Predicting Contaminant Sources in Park Waters by Ratios of Contaminants in Overlying Water to Surface Water.

Lakes and ponds are an irreplaceable unit for park landscape. Water quality in lakes and ponds in parks have received high concerns from publics. With improvements of environmental protection measures, contaminated sediments might become an internal source of contaminants in park waters. Fourteen park waters were investigated in the largest Chinese city, Shanghai. Concentrations of nutrients (nitrogen and phosphorus) and zinc in overlying water and surface water did not show a significant difference whereas copper, lead, and cadium presented higher concentrations in overlying water than surface water,suggesting sediments act as an internal source of contaminants. However, the reverse was true for total dissolved chromium,indicating external source of chromium might exist in park waters, like dry deposition suspectably. Results from this study suggests that ratios of contaminants in overlying water to surface water can act as an indicator to predict the sources of contaminants in park waters. Furthermore, urban park waters showed heavier contaminations than suburban park waters.