Harvested Rain Water Quality of Different Roofing material types in Water Harvesting System at Al al-Bayt University/Jordan

The concentration levels of selected chemical compositions in samples of rainwater (precipitation - open atmosphere) and runoff waters from different rooftop buildings and parking lots of Al al-Bayt University premises in Jordan have been presented and analyzed. The runoff from rooftop buildings and parking lots was compared to rainwater collected for the concentrations of the following major cations and anions: Na??, K??, Mg??, Ca??, HCO3??, Cl??, NO3??, SO4??, as well as heavy metals: Al??, Pb??, Mn?? and Cd??. Furthermore, pH and total dissolved solids (TDSs) were measured. Sampling procedures were basically depending on 11 rainstorms taken after rainfall events over a period of 6 months, between December 2010 and May 2011. Average concentrations of Al??, Cl??, HCO3??, Mg??, Na??, Mn??, SO4?? and TDSs were found to be less than or equal to those given in the Jordanian Water Standard (JWS) for drinking water, while for Ca??, the average concentration, exceeds that given in the Jordanian Water Standard (JWS) (=75 mg/l) for all roofing materials. K?? concentration was found to be larger than that given in the JWS (=20 mg/l) for most of the roofing materials. Additionally, the average concentration for NO??3 was found to be larger than that given in the JWS (=50 mg/l) for seal coat. Two categories of water type were found: mixed Ca?? ? Mg?? ? Cl? -type and Ca?? - HCO3? type. The average concentration order of all roofing materials can be arranged as follows in terms of quality of harvested water: metal insulation < mixed concrete insulation < mixed asphalt insulation = concrete insulation < water insulation = seal coat insulation < roll asphalt insulation < thermal insulation.