TURF FIELD STORMWATER RETENTION

摘要

The NYC Department of Environmental Protection (DEP) is implementing the Green Infrastructure Research and Development (GI-RD) project to support the City's strategy to manage stormwater through low impact development technologies. The GI-RD project builds upon previous green infrastructure (GI) monitoring activities on bioretention, porous pavement, wetlands, and blue/green roofs. The project includes desktop and field experiments, which quantify the variability and obtain a range of desired information for both stormwater performance and ecosystem services. This paper describes a field experiment conducted as part of the GI-RD project to study stormwater retention of turf fields. Artificial or synthetic turf grass fields are considered permeable surfaces when configured to drain into the underlying soils. Few data sets are available, particularly in New York City (NYC), that demonstrate stormwater management capacity for synthetic turf grass fields. This study developed methods applicable to synthetic turf grass fields to test their performance and capacity to manage stormwater. Specifically, ASTM C1701 was adapted for measurement of surface infiltration rates of synthetic turf grass fields and to evaluate the impact of runoff received, turf age, surrounding land use and maintenance on the surface infiltration capacity. A simulated runoff test method was also established to quantify the sub-surface storage capacity and exfiltration rates into underlying soils. Testing was conducted at six synthetic turf grass fields located in NYC. Results showed that synthetic turf grass fields generally have high surface infiltration rates that meet or exceed design storm intensities, New York City School Construction Authority (NYCSCA) specifications and manufacturer reported turf permeability. Sites with impervious contributing area more than three times the site area had relatively reduced infiltration capacity at the edges of the field. There was no discernible impact of age, land use or maintenance. The sub-surface storage capacity effectively manages the design storm volume (sites tested followed previous requirement of 1-in, 8-hour event) applied at or above the average . design storm intensity.