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e . e severely compromised. Water quality impairment results, in part, because a number of pollutants are preferentially absorbed onto mineral or organic particles found in fine sediment. The interconnected process of'lrosion (detachment of the soil particles), sediment transport and delivery is the primary pathway for introducing key pollutants, such as nutrients (particularly phosphorus), metals, and organic compounds into aquatic systems. In watersheds experiencing intensive construction activity, the localized impacts of water quality may be severe because of high pollutant loads, primarily composed of sediments. Siltation is the second largest cause of impaired water quality in rivers and lakes. 1 Introduction of course sediment (course sand or larger) or a large amount of fine sediment is also a concern because of the potential of filling lakes and reservoirs, as well as clogging stream channels. Large inputs into stream channels will initially reduce stream depth and minimize habitat complexity by filling pools. A primary concern at most construction sites is the erosion and transport process related to fine sediment because rainfall impact and runoff encourage the detachment and transport of this material to waterbodies. Although streams and rivers naturally carry sediment loads, erosion from construction sites and runoff from developed areas can elevate these loads to levels well above those in undisturbed watersheds. It is generally acknowledged that erosion rates from construction sites are much greater than from almost any other land use. This highlights the need to control the erosion and sediment transport processes at these sites. Erosion control involves practices to prevent displa.:ement of soil particles by precipitation or moving water, after earth moving activities have been completed. Sediment control involves practices to remove and retain soil particles that are susp{:nded in moving water. Sediment control is required in situations where the soil is continually subjected to disturbance. Properly implemented erosion control practices reduce the need for sediment control. When land disturbing activities prevent the implementation of erosion control, then sediment control measures must be maximized. Because of their proven p{:rformance, geosynthetic mattings are one of the fastest growing product groups in the erosion and sediment control industry. The key is the ability of these materials, known as turf reinforcement mats (TR1\fs), to be used with grass or other plants to -2-