Report Number: 6
Year: 1978

Urban Runoff Pollutant Absorption and Filtering by Selected Northern Guam Soils and Limestone

The concentration of most pollutants in urban runoff percolating through lysimeter columns containing Guam soil and limestone were substantially reduced. This reduction by absorption and/or filtration occurred after percolation through ¾ meter of substrata. Pollutants showing a 70% or greater reduction in concentration included total and fecal coliform bacteria, orthophosphorous, and total phosphorous. Compared to limestone, soils generally showed greater removal of MBAS and oil/grease. The mean removal rate of MBAS for soils averaged 68%. Mariana limestone was particularly permeable to MBAS, generally removing less than 30%.

William J. Zolan
Russell N. Clayshulte
Stephen J. Winter