Definitions

Definitions. 1. Applicant – an owner, lessee, or developer. 2. Available Space – the area necessary for the system and space allowance for future expansion, repair or replacement. 3. Board – the Mississippi State Board of Health. Section 41-67-2(c). 4. Department – the Mississippi State Department of Health. Section 41-67-2(h). 5. Drainage way – a course or channel along which water moves in draining an area. 6. Department of Environmental Quality – the Mississippi Department of Environmental Quality (MDEQ), Office of Pollution Control. 7. Flooding – the temporary covering of the soil surface by flowing water from any source, such as streams overflowing their banks, runoff from adjacent or surrounding slopes, inflow from high tides, or any combination of sources. The frequency of the event determines the limitation assigned to each category: a. Rare: Flooding unlikely but possible under unusual weather conditions; 1 to 5 percent chance of flooding in any year or 1 to 5 times in 100 years. (Slight limitations; includes: None or no chance of flooding.) b. Occasional: Flooding occurs infrequently under usual weather conditions; 5 to 50 percent chance of flooding in any year or more than 5 to 50 times in 100 years. (Moderate limitations.) c. Frequent: Flooding is likely to occur often under usual weather conditions; more than a 50 percent chance of flooding in any year or more than 50 times in 100 years, but less than a 50 percent chance of flooding in all months in any year. (Severe limitations.) d. Very Frequent: Flooding is likely to occur very often under usual weather conditions with more than a 50 percent chance of flooding in all months of any year. (Extreme limitations.) 8. Flood-prone Area – an area that is generally subject to being flooded 50 times in 100 years or greater than a 50 percent chance in any year. This definition refers to an area that is subject to frequent flooding as observed, or as indicated by soil characteristics defined in the standards of the National Soil Survey Handbook, United States Department of Agriculture. 9. Fragipan – a dense, natural subsurface layer of hard soil with relatively slow permeability to water, mostly because of its extreme density or compactness rather than its high clay content or cementation. 10. Generator – any person whose act or process produces sewage or other material suitable for disposal in an Individual On-site Wastewater Disposal System. Section 41-67-2(i). 11. High Shrink Swell Soils (H3S) – soils that have relatively high clay content and a dominant mineral type that causes significant swelling when wet and shrinking when dry. 12. Hydric Soils – soils that formed under conditions of saturation, flooding or ponding long enough to develop anaerobic conditions in the upper part. 13. Impervious – resistant to penetration by air, water, and roots. 14. Maximum Flexibility – the latitude of judgment to be used by the Department to recommend all applicable wastewater disposal systems in compliance with statutes, regulations and rules of the State of Mississippi. 15. Munsell Soil Color Chart – a color space standard that specifies colors based on 3 color dimensions: hue, value (lightness) and chroma (color purity). 16. Natural Ground Surface – the more or less naturally occurring surface of the earth which has not been significantly altered or disturbed by artificial means such as cutting and/or filling (does not include plowing for agricultural purposes). Except where severely eroded, the ground surface normally begins with a dark, organic matter enriched layer (topsoil) of varying thickness followed usually with a brighter colored layer (subsoil) increasing with clay content with depth. 17. Permeability – a qualitative estimate of the relative ease with which soil transmits water. 18. Person – any individual, trust, firm, joint-stock company, public or private corporation (including a government corporation), partnership, association, state, or any agency or institution thereof, municipality, commission, political subdivision of a state or any interstate body, and includes any officer or governing or managing body of any municipality, political subdivision, or the United States or any officer or employee thereof. Section 41-67-2(m). 19. Ponding – standing water in a depression that is removed only by percolation, evaporation, and/or transpiration that lasts greater than 7 days. 20. Redoximorphic Features – a color pattern in a soil due to loss (depletion) or gain (concentration) of pigment compared to the matrix color, formed by oxidation/reduction of Fe (iron) and/or Mn (manganese) coupled with their removal, translocation, or accrual; or a soil matrix color controlled by the presence of Fe+2. Field Book for Describing and Sampling Soils, NRCS, USDA. 21. Restrictive Horizon/Layer (Water Movement) – a layer in the soil more than 3 inches thick that significantly retards the downward movement of water or hinders acceptable treatment and renovation of effluent. A restrictive horizon/layer generally has Redoximorphic Features associated with it, at least in the upper part of the restrictive layer, as well as in the horizon above it. 22. Seasonal High Water Table – the water table that is part of a discontinuous saturated zone in a soil, as indicated in the Munsell Soil Color Chart, by a value of 4 or more and a chroma 2 or less (Munsell Soil Color Chart) Redoximorphic Feature. 23. Sensitive Water – public or private waters used for recreation (swimming, skiing, fishing), shellfish harvesting, potable water intake or other situations where people are likely to come into contact. 24. Slope – deviation of a plane surface from the horizontal; when given in percent, it is the rise or fall of the land surface in feet per 100 feet of horizontal distance (i.e., linear, concave and convex). 25. Soil – a medium used to filter effluent from an Individual On-site Wastewater Disposal System in order to remove bacterium, nutrients, and viruses. The ideal medium is 25 percent water, 25 percent air, 45 percent mineral and 5 percent organic matter. 26. Soil Auger – a short cylinder with a cutting edge attached to a rod and handle. 27. Soil and Site Evaluation – the evaluation to determine if a property can support an Individual On-Site Wastewater Disposal System by use of a soil auger to a depth up to 5 feet to determine the soil texture, color, mottling and seasonal water table. 28. Soil Horizon – a layer of soil approximately parallel to the land surface and differing from adjacent genetically related layers in physical, chemical, and biological properties or characteristics including but not limited to color, structure, texture, consistence and pH. 29. Soil Profile – a description of a soil horizon based on depth, texture, color, and mottles resulting in the correlation of the seasonal water table and restrictive horizon. This refers to Soil Horizons O, A, E, B, C and R. 30. Soil Resource Map – a general representation. [See Figure 3: Soil Resource Areas of Mississippi.] 31. Soil Texture – the numerical proportion (percent by weight) of sand, silt, and clay in a soil, United States Department of Agriculture (USDA). 32. Soil Mapping Unit – a soil series based on texture of the surface Soil Horizon. Examples include: SME – Smithdale sandy loam 12 to 17 percent; SbA – Savannah loam, 0 to 2 percent slopes. 33. Texture Class – standardized terms used to convey textural makeup of the fine-earth fraction less than 2 millimeters in diameter. The fine earth fraction includes sand (2.0– 0.05mm in size), silt (0.05mm–0.002mm in size) and clay (less than 0.002mm in size) particles, United States Department of Agriculture (USDA). [See Figure 4: Texture-by- Feel Analysis and Figure 5: Texture Class Triangle.] 34. Topography – the relative position and elevations of the natural or manmade features of an area that describe the configuration of its surface (i.e., hilly, rolling, level, steep, severe, moderate, etc.). 35. Vertical Separation – the vertical separation between the bottom of the trench and a restrictive layer/horizon or Seasonal High Water Table. 36. Watercourse – any natural lake, river, creek, cut, or other natural body of fresh water or channel having definite banks and bed with visible evidence of the flow or occurrence of water, except such lakes without outlet to which only one (1) landowner is riparian. 37. Water Table – the highest part of the soil or underlying rock that is wholly saturated with water. In some places an upper or Seasonal High Water Table may be separated from a lower one by a dry zone.