Glossary

The erosion control world is filled with a variety of different terms and phrases that may mean one thing to a seasoned veteran but make no sense whatsoever to someone who is just starting out. ErosionControlNetwork.com has comprised a database of many of these phrases and their definitions to help you gain a better understanding of erosion control terminology. How To Use: Click a letter below to see phrases starting with that letter, or enter your word into the text box below and click the Search button. Search by Alphabet A B C D E F G H I J K L M N O P Q R S T U V W X Y Z or Search by Keyword All Search Results are Displayed Below Can't Find A Term? If there are any terms or phrases that are not in our database that you think should be, please click on the button below. We will process your request as soon as possible.

Glossary Results ------------------------------------------------------------------------------------------------------------- Machine Direction The direction in the plane of the fabric parallel to the direction of manufacture Major Facility Any NPDES facility or activity classified as such by the Regional Administrator, or in the case of approved state programs, the Regional Administrator in conjunction with the State Director. Major municipal dischargers include all facilities with design flows of greater than one million gallons per day and facilities with EPA/State approved industrial pretreatment programs. Major industrial facilities are determined based on specific ratings criteria developed by EPA/State. Marsh An area of soft, wet, or periodically submerged land, generally treeless and usually characterized by grasses and other low vegetation Mass-Based Standard A discharge limit that is measured in a mass unit such as pounds per day. Mechanically stabilized earth Use of steel bars or other material to stabilize the earthen mass behind a retaining wall Method Detection Limit (MDL) Defined as the minimum concentration of a substance that can be measured and reported with 99 percent confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte. Microphytes Microorganisms found in soil Microscopic soil particles Clay and silt; particles that cannot be observed by the unaided human eye Million Gallons per Day (mgd) A unit of flow commonly used for wastewater discharges. One mgd is equivalent to 1.547 cubic feet per second. Mining (Coal) Coal mining employs basically the same traditional mining techniques used in hard rock mining - underground and surface ("strip") mining. One of the more efficient but environmentally destructive methods for mining coal involves "strip" mining. This technique is analogous to the open pit mining techniques used in hard rock mining whereby the soil and rock above the coal seam are removed to expose the seam. The seam is then blasted and the coal is scooped up by huge front end loaders or electric shovels and transported to a coal processing plant. These coal preparation plants use a variety of physical (e.g., screening) and chemical (e.g., flotation using high gravity liquids) methods to separate the raw coal from all of the non-combustible waste rock and minerals (e.g., pyrite). The coarser waste rock is piled up adjacent to the mined out area and the finer coal tailings coming from the preparation plant are discharged as a thick slurry into a man-made impoundment. After coal mining operations have ceased, the mine is reclaimed by dumping the waste rock into the pit, regrading the area to approximate the original contours of the land and then replanting the area using native grasses and trees. 1 2 3