Glossary - S
Safe Drinking Water Standards Regulations established by the U.S. Environmental Protection Agency that controls the amount of pollutants allowed in the nation's drinking water. See also Impaired Waters.
St. Johns River Florida Water Management District (SJRWMD) One of five Water Management Districts authorized by the Florida Statutes to direct wide-ranging programs including flood control, regulatory programs, water conservation, education and supportive data collection and analysis efforts. The St. Johns River district includes Nassau, Duval, Clay, St. Johns, Putnam, Flagler, Volusia, Seminole, Brevard, and Indian River counties, and portions of Baker, Alachua, Marion, Lake, Orange, Osceola, and Okeechobee counties.
Saline water Water with more than 1,000 milligrams per liter of dissolved solids that is usually considered unsuitable for human consumption and less desirable for irrigation because it damages most crops. Saline levels are usually expressed as milligrams per liter (mg/L) of dissolved solids; 35,000 mg/L is defined as seawater.
Salinity The relative concentration of salts, usually sodium chloride, in a given water sample. It is usually expressed in terms of the number of parts per thousand (0/00) or parts per million (ppm) of chlorine (Cl). Although the measurement takes into account all of the dissolved salts, sodium chloride (NaCl) normally constitutes the primary salt being measured. See also Total Dissolved Solids. More Information Salinity » (NALMS)
Salt marsh A type of coastal wetland found mainly in the northern half of the state, salt marshes are tidal marshes dominated by dense, low-growing grasses and other species that can tolerate fluctuating wet and dry conditions, temperatures, oxygen levels, and salinity levels. These marshes provide essential habitat for most commercially important fish and shellfish, as well as nesting and feeding grounds for many bird species.
Saltwater intrusion The intrusion of salt water into surface waters or groundwater. Salt water underlies all Florida's freshwater supplies, but the fresh water floats because it is lighter. Salt water flows in laterally or vertically to take the place of fresh water for a number of reasons: removing large amounts of fresh water from the aquifer, periodic droughts, building canals that drain underground fresh water to the ocean, allowing poorly built and un-maintained artesian wells, and reducing the amount of freshwater recharge by paving over land.
Sandbar A submerged ridge of alluvial sand in shallow water.
Sandhill upland lake A generally rounded solution depression in deep sandy uplands; predominantly without surface inflows/outflows; typically sand substrate with organic accumulations toward middle; clear, acidic moderately soft water with varying mineral content; ultra-oligotrophic to mesotrophic. Occurs from the panhandle to the southern peninsula.
Saturated zone An area under the ground in which all pores and cracks are filled with water under pressure equal to or greater than that of the atmosphere. See also Groundwater.
Scrub Hot, dry areas of Florida with deep, sandy soils that usually contain sand pine and thick bushes such as small oaks. Both the plants and animals that live in scrub have adapted to desert-like conditions. Scrub is the most endangered of Florida's habitats because it is considered ideal for development. Some of the state's rarest plants and animals live only in scrub habitat, and exist nowhere else in the world. Because of their high elevation and sandy soil, scrub areas are also usually high-recharge areas.
Seagrasses Flowering underwater plants found in beds in bays, lagoons, and other shallow places along the continental shelf. Seagrasses produce oxygen and provide habitat and breeding and feeding grounds for most economically important fish, crustaceans, and shellfish. Because the grasses are especially sensitive to oil spills and pollution, they are rapidly disappearing because of coastal development and offshore oil-drilling operations. Shrimp trawlers and boat propellers also destroy or damage the grasses, which can take decades to recover. More Information Seagrass »
Sea-level rise The rise in the world's oceans that may be occurring as a result of global warming. If atmospheric temperatures continue to rise to the point where polar ice melts, the effects would be dramatic. Many inhabited islands as well as coastal plains and cities would be flooded, forcing millions of people to migrate, affecting drinking-water supplies, altering weather patterns, and destroying wildlife habitats. The United States, with 5 percent of the globe's population, now produces about twenty-five (25) percent of the atmospheric carbon dioxide (CO2) coming from human sources; increased CO2 levels are believed to be the major cause of the global warming that may now be taking place.
Seawall An artificial wall (excluding riprap).
Secchi depth A visual measure of water clarity, this is the depth at which the pattern on a Secchi disk containing black-and-white markings can no longer be distinguished under water. See also Water Quality Index (WQI).
Sediments Soil particles that are or were at one time suspended in and carried by water as a result of erosion and/or re-suspension. The particles are deposited in areas where the water flow is slowed such as in harbors, wetlands, and lakes. More Information Benthic and Sediment Quality
Sedimentary rocks Rocks formed by the consolidation of loose sediment that has accumulated in layers.
Seepage stream Upper perennial or intermittent/seasonal watercourse with clear to lightly colored water derived from shallow groundwater seepage. Occurs from the panhandle to the southern peninsula.
Seeps Places where substances such as water, oil, or gas reach the surface along planes or fractures.
Sewage The human waste from residences and commercial operations that is carried into sewers and drains. It must be treated before discharge into surface waters.
Sewer A channel that carries wastewater to a treatment plant, or stormwater to a receiving body of water.
Sheet flow The slow movement of water over a large, shallow area such as a wetland.
Shoal A relatively shallow place in a stream, lake, or sea.
Sinkhole Sinkholes occur when earth on the surface collapses into a subterranean cavity that has formed in a limestone bed. They are common in Florida because porous, water-soluble limestone underlies much of the state. Although sinkhole development is a natural process, it can be accelerated by large-scale withdrawals of groundwater from aquifers, which leave empty cavities.
Sinkhole lake Typically deep, funnel-shaped depression in limestone base; predominantly without surface inflows/outflows, but frequently with connection to the aquifer; clear, alkaline, hard water with high mineral content (calcium, bicarbonate, magnesium). Occurs statewide.
Silviculture The management of forest lands for timber.
Sky condition Used in forecasts to describe the predominant/average sky condition based upon octants (eights) of the sky covered by opaque (non-transparent) clouds. More Information Weather
Slough A swamp or marsh that is connected by a shallow, natural channel to an inlet or body of surface water.
Sludge A semisolid residue from air or water treatment processes. Depending on its content, sludge can be a hazardous waste.
Snag A dead tree (called a standing snag) or tree branch. Snags provide important habitat for many species. Their rotting bark and wood, which harbor many insects, are an important source of food and also provide nesting cavities for many birds. Snags are often removed in urban areas, reducing wildlife habitat.
Soil The layer of material at the land surface that supports plant growth. More Information Soils »
Soil oxidation In the Everglades and other parts of South Florida, the process by which muck soil that is drained for agricultural use rapidly oxidizes. Using oxygen, the microbes consume the organic carbon in the muck soil for energy. In the process, the phosphorus and nitrogen in organic matter are released; rain then carries these nutrients into adjoining areas, where they alter nutrient balances and encourage the growth of exotic vegetation.
Solid waste Usually refers to municipal waste, including garbage, yard trash, and white goods.
Source reduction A term that means reducing pollution at its source. It includes management systems, technologies, and other practices which reduce or eliminate the amount of any hazardous substance, pollutant, or contaminant entering any waste stream or otherwise released into the environment prior to recycling, treatment, or disposal. The term includes equipment or technology modifications, reformulation or redesign of products, substitution of raw materials and improvements in housekeeping, maintenance, training or inventory control.
South Florida Water Management District (SFWMD) One of five Water Management Districts authorized by the Florida Statutes to direct wide-ranging programs including flood control, regulatory programs, water conservation, education and supportive data collection and analysis efforts. The South Florida district includes Broward, Collier, Miami-Dade, Glades, Hendry, Lee, Martin, Monroe, Palm Beach and St. Lucie counties, and portions of Charlotte, Highlands, Okeechobee, Orange, Osceola and Polk Counties.
Southwest Florida Water Management District (SWFWMD) One of five Water Management Districts authorized by the Florida Statutes to direct wide-ranging programs including flood control, regulatory programs, water conservation, education and supportive data collection and analysis efforts. The Southwest Florida district includes Citrus, Sumter, Hernando, Pasco, Hillsborough, Pinellas, Manatee, Sarasota, Hardee and Desoto Counties, and portions of Levy, Marion, Lake, Polk, Highlands and Charlotte Counties.
Spatial data Information about the location and shape of, and relationships among, geographic features, usually stored as coordinates and topology. See also Geographic Information Systems (GIS).
Species A group of organisms that interbreeds under natural conditions and produces fertile offspring. (In Latin, species means outward appearance.)
Species of special concern A Florida designation for species that are not in immediate danger of extinction but whose numbers are diminishing. More Information Birds
Specific conductance The ability of water to conduct an electrical current. It is an early indicator of changes in water quality because industrial and municipal pollution increase conductivity. More Information Salinity Learn More »
Sprawl The unplanned, widely scattered development of open land.
Spring A place where water from an aquifer flows to the surface through a natural opening.
Spring run A body of flowing water that originates from a karst spring (porous limestone) and whose primary source of water (more than 50% of its volume) is from the spring; a perennial watercourse with deep aquifer headwaters and clear water, circumneutral pH (5.5 - 7.4) and, frequently, a solid limestone bottom. Occurs from the panhandle to the central peninsula.
Stage Height of the water surface above an established datum plane, such as in a river above a predetermined point that may (or may not) be at the channel floor. See also Water level.
Stewardship Taking care of and protecting a valuable resource so that it is preserved for use by future generations.
STORET Short for STOrage and RETrieval, acts as a repository for water quality, biological and physical data which is used by state environmental agencies, EPA and other federal agencies, universities, private citizens and others.
Storm sewer A sewer that carries only surface runoff, street wash, and snow melt from the land. In a separate sewer system, storm sewers are completely separate from those that carry domestic and commercial wastewater (sanitary sewers).
Stormwater Rainwater or irrigation water that runs over the land and then into surface waters. A form of nonpoint source pollution, stormwater runoff can carry many suspended or dissolved contaminants-including oils, greases, and other petroleum products; fecal matter; organic debris; fertilizers and pesticides; trash; and silt and sand-from the air and land into the water. It is usually expressed in inches of water uniformly distributed over the area that contributes the water. The first inch of stormwater runoff, called the first flush, contains the highest levels of pollution.
Stormwater utility A utility that works much like electric, water, or sewage treatment facilities. A user fee is charged for each parcel of land, based on the amount of stormwater runoff it generates.
Stream flow The discharge of water in a natural channel. More Information Stream Flow and Levels »
Stream order A stream order is a way to define the size of perennial streams (those with water continuously throughout the year) and recurring streams (those with water only part of the year). The smallest tributaries are classified as first order, and they often are given a value of one by scientists. A joining of two first-order streams then forms a second-order stream. When two second-order streams combine, they form a third-order stream, and when two third-order streams join, they form a fourth and so on.
Streptococcus Bacteria found in the intestines of warm-blooded animals (called fecal streptococcal). Their presence in water verifies fecal pollution that can cause disease in humans.
Submersed zone The deepest vegetation zone in a water body, where plants grow with their roots, stems and leaves completely under the surface of the water.
Succession The sequence of biological communities that develops after an ecosystem has been damaged or destroyed, until it reaches a state of relative ecological stability called a climax ecosystem.
Sulfur dioxide (SO2) A heavy, pungent, colorless, gaseous air pollutant emitted mainly by utilities and industries that burn fossil fuels such as coal and oil. Mixed with water vapor and oxygen, it changes into other forms, including sulfuric acid. Sulfur dioxide is a major contributor to acid rain. See also Air-quality index.
Superfund The nickname for the 1980 federal Comprehensive Emergency Response, Compensation, and Liability Act (CERCLA), which provides federal funding for the emergency cleanup of major hazardous spills and abandoned or inactive hazardous waste sites.
Surface waters All bodies of water on the Earth's surface that are naturally open to the atmosphere (such as rivers, lakes, reservoirs, streams, impoundments, seas, coastal and freshwater wetlands, lagoons, and estuaries) and all springs, wells, or other collectors that are directly influenced by surface waters. Because water vapor evaporates from surface waters into the air, surface waters play an essential role in the hydrologic cycle through which all water on the Earth moves. More Information Water Quality or Hydrology
Surface Water Ambient Monitoring Program (SWAMP) An effort started in 1991 to revitalize monitoring programs at Florida Department of Environmental Protection to better address the federal and state water quality management and assessment requirements as stated in the Clean Water Act and Florida State Water Policy.
Surface water withdrawal See Withdrawal.
Suspended solids Small particles of solid pollutants that float on the surface of, or are suspended in, sewage or other liquids. They are difficult to remove by conventional means.
Sustainability Development that meets the needs of the present without compromising the ability of future generations to meet their own needs. In order for a project to be considered sustainable it must meet certain key criteria such as, whether it is socially desirable, economically feasible and environmentally neutral.
Suwannee River Water Management District (SRWMD) One of five Water Management Districts authorized by the Florida Statutes to direct wide-ranging programs including flood control, regulatory programs, water conservation, education and supportive data collection and analysis efforts. The Suwannee River district includes Columbia, Dixie, Gilchrist, Hamilton, Lafayette, Madison, Suwannee, Taylor, and Union counties, and portions of Alachua, Baker, Bradford, Jefferson, Levy, and Putnam counties.
Swale A low tract of land, especially moist or marshy ground; also an artificially created trench that contains standing or flowing water after rainfall.
Swamp A kind of wetland, dominated by woody vegetation, that does not accumulate appreciable peat deposits. Swamps can be fresh water, salt water, tidal, or non-tidal.
Swamp lake Generally shallow, open water area within basin swamps; still water or flow-through; peat, sand or clay substrate; variable water chemistry, but characteristically highly colored, acidic, soft water with moderate mineral content (sodium, chloride, sulfate); oligo-mesotrophic to eutrophic. Occurs statewide except in the Florida Keys.
Synoptic Relating to the conditions displayed by the environment, atmosphere or a particular animal as they exist simultaneously over a broad area.