GLOSSARY OF RELATED TERMS
From The North Carolina University Watershed Project

[ 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 ]

adenosine diphosphate (ADP):
A nucleotide consisting of adenine, ribose, and two phosphate groups; a compound formed by the removal of one phosphate group and a hydrogen ion from an ATP molecule.
adenosine triphosphate (ATP):
A nucleotide consisting of adenine, ribose and three phosphate groups that serves as the energy source for cell metabolism. Energy is released when a phosphate group and a hydrogen ion are lost from ATP during hydrolysis, leaving adenosine diphosphate (ADP).
aerobic:
Any biological process occurring in the presence of molecular oxygen (O2); also applicable to organisms requiring oxygen for survival.
AGNPS-Agricultural Nonpoint Source Pollution model:
An event-based, watershed-scale model developed to simulate runoff, sediment, chemical oxygen demand, nutrient and pesticide transport in surface runoff.
alachlor:
Herbicide (trade name Lasso) used to control most annual grasses and certain broadleaf weeds and yellow nutsedge in corn, soybeans, peanuts, cotton, woody fruits, and certain ornamentals.
algae:
Any of various primitive, chiefly aquatic, one-or multi-celled, nonflowering plants that lack true stems, roots, and leaves, but usually contain chlorophyll. Algae convert carbon dioxide and inorganic nutrients such as nitrogen and phosphorus into organic matter through photosynthesis and form the basis of the marine food chain. Common algae include dinoflagellates, diatoms, seaweeds, and kelp.
algal bloom:
A condition which occurs when excessive nutrient levels and other physical and chemical conditions facilitate rapid growth of algae. Algal blooms may cause changes in water color. The decay of the algal bloom may reduce dissolved oxygen levels in the water.
alkalinity:
Refers to the quantity and kinds of compounds present (usually bicarbonates, carbonates, and hydroxides) that collectively shift the pH below 7.
ambient conditions:
Refers to environmental conditions experienced prior to disturbance.
ambient monitoring:
Monitoring that is done to determine existing environmental conditions, contaminant levels, rates, or species in the environment, against which future conditions can be compared.
ammonification:
One-way reaction in which organisms break down amino acids and produce ammonia.
anadromous:
Migrating upstream to fresh water streams to spawn.
anaerobic:
Any process that can occur without molecular oxygen; also applicable to organisms that can survive without free oxygen.
animal unit:
One mature cow weighing 454 kg or the equivalent. For instance, a dairy cow is 1.4 AU because it weighs almost 1.5 times a mature beef cow. The animal unit equivalents of animals smaller than beef cows are less than one: pigs = 0.4 AU and chickens = 0.033 AU.
animal waste management system:
A BMP designed to minimize pollution originating from livestock and poultry operations by providing facilities for the storage and handling of animal wastes.
anions:
An atom or group of atoms that has a net negative charge.
anoxia:
The absence of oxygen or a pathological deficiency of oxygen.
anoxic:
Without oxygen
anthropogenic:
Effects or processes that are derived from human activity.
aquaculture:
The controlled cultivation and harvest of aquatic plants or animals (e.g., edible marine algae, clams, oysters, and salmon).
aquifer:
An underground layer of rock or soil containing ground water.
artificial redds:
An artificial egg basket fabricated of extruded PVC netting and placed in a constructed egg pocket. Artificial redds are used to measure the development of fertilized fish eggs to the alevin stage (newly hatched fish).
assimilative capacity:
The amount of pollutants that a water body may absorb while maintaining corresponding water quality standards including the protection of best use.
atrazine:
herbicide (trade name Aatrex, Gesa prim, or Primatol) widely used for control of broadleaf and grassy weeds in corn, sorghum, sugar cane, macadamia orchards, pineapple, and turf grass sod.
autocorrelation:
The correlation between adjacent observations in time or space.
availability:
The location or nutrients of pesticides on the soil influences the amount available for loss.
BASIN - Basin-Scale Nutrient Delivery model:
A model that predicts the total annual nutrient load at the outlet of an agricultural basin, based on estimated delivery of average annual nutrient loads from individual fields or cells.
bedding:
A site preparation technique whereby a small ridge of surface soil is formed to provide an elevated planting or seed bed. It is used primarily in wet areas to improve drainage and aeration for seedlings.
bedload:
Sediment or other material that slides, rolls, or bounces along the streambed or channel bed of flowing water.
before-after design:
A term referring to water quality monitoring designs that require collection of data before and after implementation of best management practices.
beneficial use:
The uses of a water resource that are protected by state laws called water quality standards. Uses include aquatic life, recreation, human consumption, and habitat.
benthic:
Living in or on the bottom of a body of water.
benthos:
Collectively, all organisms living in, on, or near the bottom substrate in aquatic habitats (examples are oysters, clams, burrowing worms).
best management practices (BMPs):
Management practices (such as nutrient management) or structural practices (such as terraces) designed to reduce the quantities of pollutants-- such as sediment, nitrogen, phosphorus, and animal wastes -- that are washed by rain and snow melt from farms into nearby receiving waters, such as lakes, creeks, streams, rivers, estuaries, and ground water.
best uses:
Designated uses for a water body which include aquatic life propagation and maintenance (including fishing, fish and functioning primary nursery areas), wildlife, secondary recreation, water supply (fresh waters), and shellfishing (salt waters).
bioaccumulation:
The process by which a contaminant accumulates in the tissues of an organism.
biochemical oxygen demand (BOD):
The quantity of largely organic, materials present in a water sample as measured by a specific test. Although BOD is not a specific compound, it is defined as a conventional pollutant under the federal Clean Water Act.
biological integrity:
The capability of supporting and maintaining a balanced, integrated, adaptive community of organisms having a species composition and functional organization comparable to that of the natural habitat in a region.
bioindicators:
Organisms that are used to detect changes in environmental pollutant levels.
biomagnification:
An increase in the concentration of a substance in each progressive link of the food chain.
biota:
The animals, plants, and microbes that live in a particular location orregion.
BMP:
See best management practices.
BMP system:
A combination of individual BMPs into a "system" that functions to reduce the same pollutant.
broad-based dip:
A surface drainage structure on a logging road specifically designed to tip water out of a dirt road while allowing vehicles to maintain normal haul speeds. Also called a rolling dip.
buffer strip:
A barrier of permanent vegetation, either forest or other vegetation, between waterways and land uses such as agriculture or urban development, designed to intercept and filter out pollution before it reaches the surface water resource.
carcinogenic:
Potentially capable of causing cancer.
cations:
An atom or group of atoms that has a net positive charge.
chelate:
A ligand having more than one atom with a lone pair that can be used to bind a metal ion.
chemical oxygen demand (COD):
Quantitative measure of the strength of contamination by organic and inorganic carbon materials.
chlorophyll a:
A green pigment, found in all plants that undergo photosynthesis, that is used as an indicator of algal growth in a water body.
chopping:
A mechanical treatment whereby vegetation is concentrated near the ground and incorporated into the soil. Chopping may be used to facilitate burning or to increase the organic component of the surface soil.
chromatography:
Separation of complex mixture by percolation through an adsorbing medium, yielding stratified constituent layers.
chronic toxicity:
Any harmful effects to organisms in controlled toxicity tests with long-term exposure during a sensitive period of the life cycle to specific substances or mixtures. Early life stages or reproductive toxicity tests may be used to determine chronic impacts.
clearcutting:
A silvicultural system in which all merchantable trees are harvested over a specified area in one operation.
coldwater fish:
Fish such as trout and salmon; preferred water temperature ranges between 7-18 degrees C (45-65 degrees F); coolwater fish, such as striped bass, northern pike, and walleye, have a range between that of coldwater and warmwater fish.
coliform bacteria:
See Fecal coliform bacteria.
colloidal:
A suspension of finely divided particles in a dispersing medium; particles do not rapidly settle out of suspension and are not readily filtered.
colorimetry:
Process of measuring the concentration of a known solution constituent by comparison with colors of standard solutions of that constituent.
combined sewer overflow (CSO):
A pipe that discharges water during storms from a sewer system that carries both sanitary wastewater and stormwater. The overflow occurs because the system does not have the capacity to transport, store, or treat the increased flow caused by stormwater runoff.
combined sewer system:
A wastewater collection and treatment system where domestic and industrial wastewater is combined with storm runoff. Although such a system does provide treatment of stormwater, in practice, the systems may not be able to handle major storm flows. As a result, untreated discharges from combined sewer overflows may occur.
community water system:
A public water system that has at least 15 service connections for year-round residents or that serves at least 25 year-round residents.
complexation:
The combination of different atoms to form a new compound.
conductivity:
A measure of the ability of an aqueous solution to transmit electrical current.
conservation tillage:
Any tillage and planting system that maintains at least 30% of the soil surface covered by residue after planting for the purpose of reducing soil erosion by water.
contaminant:
See Pollutant.
contour:
An imaginary line on the surface of the earth connecting points of the same elevation. A line drawn on a map connecting points of the same elevation.
cost sharing:
The practice of allocating project funds to pay part of the cost of constructing or implementing a BMP. The remainder of the costs are paid by the producer.
covariates:
Explanatory variables, such as climate, hydrology, land use, or additional water quality variables, that change over time and could affect the water quality variables related to the primary pollutant(s) of concern or the use impairment being measured. Specific examples of explanatory variables are season, precipitation, streamflow, ground water table depth, salinity, pH, animal units, cropping patterns, and impervious land surface.
CREAMS- Chemicals Runoff and Erosion from Agricultural Management Systems model:
A physically-based, field-scale watershed model developed for comparing pollutant loads from alternate management practices.
critical area:
Area or source of nonpoint source pollutants identified in the project area as having the most significant impact on the impaired use of the receiving waters.
critical habitat:
Areas which are essential to the conservation of an officially-listed endangered or threatened species and which may require special management considerations or protection.
crop residue management (CRM):
A year-round system beginning with the selection of crops that produce sufficient quantities of residue and may include limited secondary harvest of residue. CRM includes all field operations that affect residue amounts, orientation and distribution throughout the period requiring protection. Site specific residue cover amounts needed are usually expressed in percentage but may also be in pounds.
culvert:
A metal or concrete pipe, or a constructed box-type conduit, through which water is carried under roads.
cumulative effects:
The combined environmental impacts that accrue over time and space from a series of similar or related individual actions, contaminants, or projects.
cyanobacteria:
Photosynthetic bacteria; often referred to as blue-green algae.
decomposition:
The breakdown of complex organic substances into more simple organic substances.
demonstration project:
A project designed to install or implement pollution control practices primarily for educational or promotional purposes.
denitrification:
Reduction of nitrate-yielding gaseous nitrogen.
deoxyribonucleic acid(DNA):
A molecule that carries genetic information in the cell; composed of two complimentary chains of nucleotides wound in a double helix; capable of self-replication and coding for ribonucleic acid (RNA) synthesis.
deposition:
The settling out of a soil particle or aggregate of particles from the water column.
designated use:
A beneficial use type established by a state for each water resource and specified in water quality standards, whether or not it is being attained.
detachment:
The process of a soil particle, nutrient or pesticide, breaking free from its position in the soil.
detention:
The process of collecting and holding back stormwater for delayed release to receiving waters.
detritovores:
Organisms that feed on fresh to partly decomposed dead organic matter; usually applies to detritus-feeders other than bacteria and fungi.
detritus:
Fresh to partly decomposed organic matter.
dinoflagellates:
Unicellular biflagellate algae with thick cellulose plates. May secrete toxins leading to occurrence of "red tides".
discharge permit:
Legal contract negotiated between federal and state regulators and an industry or sewage treatment plant that sets limits on many water pollutants or polluting effects from the discharges of its pipes to public waters.
disking:
A mechanical method of scarifying the soil to reduce competing vegetation and to prepare a site to be seeded or planted.
disposal:
Methods by which unwanted materials are relocated, contained, treated, or processed. Unless contaminants are converted to less harmful forms or removed from the material before disposal, they may be released again into the environment.
dissolved oxygen:
The amount of oxygen present in the water column. More than 5 parts oxygen per million is considered healthy; below 3 is generally stressful to aquatic organisms.
drainage area:
An area of land that drains to one point; watershed.
dry wash:
A streambed that carries water only during and immediately following rainstorms.
ecological integrity:
A measure of the health of the entire area or community based on how much of the original physical, biological, and chemical components of the area remain intact.
ecoregion:
A physical region that is defined by its ecology, which includes meteorological factors, elevation, plant and animal speciation, landscape position, and soils.
ecosystem:
Interrelated and interdependent parts of a biological system.
eelgrass (Zostera marina):
A type of submerged aquatic vegetation. Eelgrass is a flowering marine plant that grows on intertidal and shallow subtidal sand or mudflats.
effluent:
Treated or untreated liquid waste material that is discharged into the environment from a point source, such as a wastewater treatment plant or an industrial facility.
epilimnion:
Warm, oxygen-rich, upper layer of a stratified water body; usually a seasonal phenomenon.
epiphyte:
A plant that grows on another plant and depends on that plant for mechanical support but not for nutrients.
erosion:
Wearing away of rock or soil by the gradual detachment of soil or rock fragments by water, wind, ice, and other mechanical, chemical, or biological forces.
estuary:
A coastal water resource where fresh water from rivers mixes with salt water from the ocean.
euphotic zone:
Surface layer of water to the depth of light penetration where photosynthetic activity equals respiration, or where 1% of incident light remains.
eutrophic:
Usually refers to a nutrient-enriched, highly productive body of water.
eutrophication:
A process by which a water body becomes rich in dissolved nutrients, often leading to algal blooms, low dissolved oxygen, and changes in community composition. Eutrophication occurs naturally, but can be accelerated by human activities that increases nutrient inputs to the water body.
experimental nonpoint source project:
A scientific study designed primarily to document the effectiveness of specific nonpoint source pollution controls (BMPs) at reducing nonpoint source pollution. The study may also include evaluating the policies and programs employed to implement the BMPs, effects of the implemented BMPs on an impaired water resource, or economic considerations related to the implementation of BMPs.
explanatory variables:
Variables, such as climatic, hydrological, land use, or additional water quality variables, that change over time and could affect the water quality variables related to the primary pollutant(s) of concern or the use impairment being measured. Specific examples of explanatory variables are season, precipitation, streamflow, ground water table depth, salinity, pH, animal units, cropping patterns, and impervious land surface.
facultative anaerobes:
Organisms that flourish in the presence of oxygen, but can also survive in the absence of oxygen (in an anoxic environment).
fault:
A fracture or fracture zone along which there has been displacement of rock parallel to the fracture.
fecal coliform:
Bacteria from the colons of warm-blooded animals which are released in fecal material. Specifically, this group comprises all of the aerobic and facultative anaerobic, gram-negative, non-spore-forming, rod-shaped bacteria that ferment lactose with gas formation within 48 hours at 35 degrees Celsius.
felling:
The process of cutting down standing trees.
fixation (nitrogen):
The conversion of gaseous nitrogen to ammonia or nitrate.
flagellum:
A long, thread-like organelle used by many microscopic organisms for locomotion and feeding.
forest chemicals:
Chemical substances or formulations that perform important functions in forest management. These include fertilizers, herbicides, repellents, and other chemicals.
forest land:
Land bearing forest growth.
forest practice:
Any activity related to growing, harvesting, or processing timber. These activities include, but are not limited to, road and trail construction, final and intermediate harvesting, pre-commercial thinning, reforestation, fertilization, prevention and suppression of disease and insects, salvage of trees, and brush control.
forest road:
An access route for vehicles into forest land.
fry:
Newly hatched or juvenile fish.
geographic information systems (GIS):
Computer programs linking features commonly seen on maps (such as roads, town boundaries, water bodies) with related information not usually presented on maps, such as type of road surface, population, type of agriculture, type of vegetation, or water quality information. A GIS is a unique information system in which individual observations can be spatially referenced to each other.
ground water:
The water that occurs beneath the earth's surface between saturated soil and rock and that supplies wells and springs.
habitat:
A specific area in which a particular type of plant or animal lives.
half-life:
The time required for half of a substance introduced to a living system or ecosystem to be eliminated or disintegrated by natural processes.
haul road:
See Access road.
hazardous waste:
Any solid, liquid, or gaseous substance which, because of its source or measurable characteristics, is classified under state or federal law as hazardous and is subject to special handling, shipping, storage, and disposal requirements.
hepatotoxin:
A poisonous compound that causes injury to the liver.
hectare:
10,000 square meters, .405 acres
herbicide:
A substance used to destroy or inhibit the growth of vegetation.
hepatotoxin:
A poisonous compound that causes injury to the liver.
histological:
Pertaining to the microscopic structure of plant and animal tissues.
holding tank:
An enclosed container used as part of a sewage disposal system on a boat. The tank is used to temporarily store storage for later pumpout at a marina pumpout facility.
homeostasis:
A relatively stable state of equilibrium between different but interdependent elements or groups of elements of an organism, population, or group.
hydrocarbons:
Any of a vast family of compounds originating in materials containing carbon and hydrogen in various combinations. Some may be carcinogenic; others are active participants in photochemical processes in combination with oxides of nitrogen.
hydrophobic:
Having a strong aversion to water.
hydroxylate:
The introduction of a hydroxyl (OH group with a positive or negative charge) into another chemical compound.
hyperplasia:
A non-tumorous increase in the number of cells in an organ or tissue with resulting enlargement of the affected area.
hypolimnion:
Cool, oxygen-deficient, bottom layer of a stratified water body; usually a seasonal phenomenon.
hypoxia:
A condition of low dissolved oxygen in aquatic systems.
igneous rock:
Type of rock formed by the cooling and consolidation of magma.
impaired water:
Surface and ground waters that are negatively impacted by pollution resulting in decreased water quality.
impervious surface:
A surface such as pavement that cannot be easily penetrated by water.
integrated pest management (IPM):
A systems approach that combines a wide array of crop production practices with careful monitoring of pests and their natural enemies. IPM practices include use of resistant varieties, timing of planting, cultivation, biological controls, and judicious use of pesticides to control pests. These IPM practices are used in greenhouses and on field crops. IPM systems anticipate and prevent pests from reaching economically damaging levels.
intermittent stream:
A watercourse that flows only at certain times of the year, conveying water from springs or surface sources; also, a watercourse that does not flow continuously, when water losses from evaporation or seepage exceed available stream flow.
ion:
An atom or group of atoms that has a net positive or net negative charge.
lake:
A man-made impoundment or natural body of freshwater of considerable size, whose open-water and deep-bottom zones (no light penetration to bottom) are large compared to the shallow-water (shoreline) zone, which has light penetration to its bottom.
land treatment:
The whole range of BMPs implemented to control or reduce nonpoint source pollution.
land use:
The way land is developed and used in terms of the types of activities allowed (agriculture, residences, industries, etc.) and the size of buildings and structures permitted. Certain types of pollution problems are often associated with particular land uses, such as sedimentation from construction activities.
LC50:
The amount of a toxin that is sufficient to kill 50% of a population within a specified time.
leachate:
Water or other liquid that has washed (leached) from a solid material, such as a layer of soil or debris. Leachate may contain contaminants such as organics or mineral salts. Rainwater that percolates through a sanitary landfill and picks up contaminants is called the leachate from the landfill.
legume:
Any member of the bean or pea family Fabaceae; a type of dry fruit whose pod forms from one carpel and opens from both sides.
lentic:
Still or standing (water).
ligand:
A neutral molecule or ion having a lone pair of electrons that can form a bond with a metal ion.
limiting nutrient:
The plant nutrient present in lowest concentration relative to need: limits growth such that addition of the limiting nutrient will stimulate additional growth. In north temperate lakes, P is commonly the limiting nutrient for algal growth.
lipophilic:
Having an affinity for fatty tissues.
live stream:
See Perennial stream.
loading:
The influx of pollutants to a selected water body.
log deck:
Also called log landing, log yard, brow or bunching area. A place where logs or tree-length material are assembled for loading and transporting.
logging debris:
The unutilized and generally unmarketable accumulation of woody material, such as large limbs, tops, cull logs and stumps, that remain as forest residue after timber harvesting.
lotic:
Flowing (water).
macroinvertebrate:
Invertebrates visible to the naked eye, such as insect larvae and crayfish.
macrophyte:
A macroscopic vascular plant; a multicellular aquatic plant, either free-floating or attached to a surface.
management BMPs:
BMPs that primarily involve a change in management practices, such as changing the timing, method, and/or amount of the application of a potential pollutant in order to reduce the chance of its contaminating water resources.
Maximum Contaminant Level (MCL):
The enforceable standard, or number against which your system's water samples are judged for compliance with U.S. Environmental Protection Agency regulations.
Maximum Contaminant Level Goal (MCLG):
The number that is associated with no adverse health effects from drinking water containing a particular contaminant over a lifetime. It is an unenforceable goal set for health reasons. Usually the actual level will be whatever level the best available technology can achieve.
metabolic waste:
Waste products formed as a result of metabolic processes.
metabolism:
The chemical changes in living systems by which energy is provided for vital processes and activities and new material is assimilated.
metalimnion:
Zone of rapid temperature change in a stratified water body; marks the transition zone between the epilimnion and the hypolimnion.
metallothionein:
A protein that binds to excess essential metals in the body.
metamorphic rock:
Rock whose original compounds and textures have been transformed to new compounds and textures by reactions that occurred when the rock was subjected to high temperatures, high pressures, or both.
mineralization:
The conversion of humus and soil organic matter into inorganic substances by microbial breakdown.
mitigation:
Actions taken with the goal of reducing the negative impacts of a particular land use or activity.
mitigation bank:
Habitat protection or improvement actions taken expressly for the purpose of compensating for unavoidable, necessary losses from specific future development actions.
model ordinance:
A sample regulation that contains elements and language necessary to achieve a desired effect.
monitor:
To systematically and repeatedly measure conditions in order to track changes.
monocyclic aromatic hydrocarbon:
Organic compound containing one carbon and one hydrogen and consisting of one ring in the molecular structure.
morphological:
Pertaining to the overall body structure of an organism, excluding body functions.
mulch-till:
Disturbance of the soil prior to planting. Tillage tools such as chisels, field cultivators, disks, sweeps or blades are used. Weed control is accomplished with herbicides and/or cultivation.
mulching:
Any loose covering of soil with organic residues, such as grass, straw, or wood fibers, to check erosion and stabilize exposed soil.
mutagen:
A substance or agent that increases the chance of mutation (permanent change in the hereditary material involving a physical change in chromosomes or genes).
National Primary Drinking Water Regulations (NPDWRs):
Developed by the U.S. Environmental Protection Agency, these regulations are designed to keep drinking water clean and to protect the public from waterborne disease. The regulations define either a maximum contaminant level or a treatment technique requirement to control the presence of contaminants in drinking water.
natural community:
A distinct and reoccurring assemblage of populations of plants, animals, bacteria, fungi, and viruses naturally associated with each other and their physical environment.
neurotoxin:
A poisonous compound that acts on the nervous system.
nitrate:
A form of nitrogen which is readily available to plants as a nutrient. Generally, nitrate is the primary inorganic form of nitrogen in aquatic systems.
nitrification:
The oxidation of ammonia to nitrate and nitrite, yielding energy for decomposing organisms.
nitrogen:
An element which in living organisms is a component of protein structures.
nitrogen fixation:
The conversion of gaseous nitrogen to ammonia or nitrate.
no-till:
The practice of leaving the soil undisturbed from harvest to planting except for nutrient injection. Planting or drilling is accomplished in a narrow seedbed or slot created by coulters, row cleaners, disk openers, in-row chisels, or rototillers. Weed control is accomplished primarily with herbicides.
noncommunity water system:
A public water system that does not meet the definition of a community water system.
nonpoint source controls:
General phrase used to refer to all methods employed to control or reduce nonpoint source pollution.
nonpoint source pollution (NPS):
Pollution originating from runoff from diffuse areas (land surface or atmosphere) having no well-defined source.
nutrient management:
A BMP designed to minimize the contamination of surface and ground water by limiting the amount of nutrients (usually nitrogen) applied to the soil to no more than the crop is expected to use. This may involve changing fertilizer application techniques, placement, rate, or timing. The term fertilizer includes both commercial fertilizers and manure.
nutrients:
Chemicals that are needed by plants and animals for growth (e.g., nitrogen, phosphorus). In water resources, if other physical and chemical conditions are optimal, excessive amounts of nutrients can lead to degradation of water quality by promoting excessive growth, accumulation, and subsequent decay of plants, especially algae. Some nutrients can be toxic to animals at high concentrations.
obligate anaerobes:
Organisms that can survive only in anoxic environments.
oligotrophic:
Usually refers to a nutrient-poor body of water with low productivity.
on-site wastewater treatment systems:
Systems that treat wastewater where it is produced and release treated wastewater back into the environment. These systems are smaller in scale than municipal central sewer and treatment plants.
osmosis:
The diffusion of water across a selectively permeable membrane (allows passage of water but retards or prohibits passage of a solute) from the side with the lower solute concentration to the side with a higher solute concentration.
oxidation:
Loss of an electron by an atom, ion, or molecule; an increase in the oxidation state.
oxide:
A compound containing two elements, one of which is oxygen.
oxygen-demanding materials:
Materials such as food waste and dead plant or animal tissue that use up dissolved oxygen in the water as they decompose through chemical or biological processes. Biochemical oxygen demand (BOD) is a measure of the amount of oxygen consumed when a substance decays.
ozone:
A pungent, colorless, toxic gas; one component of photochemical smog.
paired watershed design:
In this water quality monitoring design, two watersheds with similar physical characteristics and, ideally, land uses, are monitored for one to two years to establish pollutant-runoff response relationships for each watershed. Following this initial calibration period, one of the watersheds receives land treatment while the other (control) watershed does not. Monitoring of both watersheds continues for an additional one to three years. This experimental design accounts for many factors that may affect the response to treatment; as a result, the treatment effect alone can be isolated.
parameter:
Information used as input to a water quality model or estimated by a water quality model. Examples of parameters include: slope from a statistical relationship between two variables, mean annual value or standard deviation of a variable, and number of observations for a particular variable.
particulate matter:
Very small, separate particles composed of organic or inorganic matter.
parts per million (ppm):
A volume unit of measurement; the number of parts of a substance in a million parts of another substance. For example, 10 ppm nitrate in water means 10 parts of nitrate in a million parts of water.
pathogen:
An agent such as a virus, bacterium, or fungus that can cause diseases in humans. Pathogens can be present in municipal, industrial, and nonpoint source discharges.
pathogenic:
Causing or capable of causing disease.
perennial stream:
A watercourse that flows throughout the year or most of the year (90%), in a well defined channel. Same as a live stream.
pesticide:
Any substance that is intended to prevent, destroy, repel, or mitigate any pest.
pesticide management:
A BMP designed to minimize contamination of soil, water, air, and nontarget organisms by controlling the amount, type, placement, method, and timing of pesticide application necessary for crop production.
pesticides:
Chemical materials that are used for the control of undesirable insects, diseases, vegetation, animals or other forms of life.
pH:
The negative log of the hydrogen ion concentration (-log10 [H+] ); a measure of the acidity or alkalinity of a solution, numerically equal to 7 for neutral solutions, increasing with increasing alkalinity and decreasing with increasing acidity. The scale is 0-14.
phenolphthalein:
alkalinity A measure of the bicarbonate content.
phosphorus:
An element essential to the growth and development of plants, but which, in excess, can cause unhealthy conditions that threaten aquatic animals in surface waters.
photodegrade:
The decomposition of chemicals by the action of light (radiant energy).
photodissociation:
The process by which a chemical compound breaks up into simpler constituents after absorbing radiant energy.
phytoplankton:
Free-floating microscopic aquatic organisms capable of photosynthesis.
plankton:
Mostly microscopic (some are barely visible to the naked eye) aquatic organisms found in the lighted upper layers of the water column. Includes photosynthetic (phytoplankton) and heterotrophic (zooplankton) organisms.
point source:
Any confined and discrete conveyance from which pollutants are or may be discharged. These include pipes, ditches, channels, tunnels, conduits, wells, containers, and concentrated animal feeding operations.
point source pollution:
Water pollution that is discharged from a discrete location such as a pipe, tank, pit, or ditch.
pollutant:
A contaminant that adversely alters the physical, chemical, or biological properties of the environment. The term includes nutrients, sediment, pathogens, toxic metals, carcinogens, oxygen-demanding materials, and all other harmful substances. With reference to nonpoint sources, the term is sometimes used to apply to contaminants released in low concentrations from many activities which collectively degrade water quality. As defined in the federal Clean Water Act, pollutant means dredged spoil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste discharged into water.
post-BMP implementation:
The period of use and/or adherence to the BMP.
postemergence herbicide:
Herbicide applied after emergence of the crop (treatment).
pre-BMP implementation:
The period prior to the use of a BMP.
preemergence herbicide:
Herbicide applied before emergence of the crop (prevention).
prescribed burning:
The practice of using controlled fires to reduce or eliminate the unincorporated organic matter of the forest floor, or low, undesirable vegetation.
pretreatment:
The initial or preliminary treatment of water, often industrial or municipal wastewater, to remove pollutants or to prepare water for subsequent treatment.
primary treatment:
The first level of wastewater treatment, which uses settling, skimming, and, often, chlorination, to remove solids, floating materials, and pathogens.
priority pollutant:
Chemical designated by the U.S. Environmental Protection Agency as having high priority for control or removal from waste discharges because of its toxicity or potential to cause cancer or mutations.
protozoans:
Single-celled, free-living, animal-like microorganisms that occur in aquatic environments.
red tide:
Discoloration of sea water due to a large number of dinoflagellates which produce a substance that is toxic to many marine vertebrates and to humans consuming contaminated shellfish.
reduction:
Gain of an electron by an atom, ion, or molecule; a decrease in the oxidation state.
regeneration:
The young tree crop replacing older trees removed by harvest or disaster; the process of replacing old trees with young.
reservoir:
A constructed impoundment or natural body of freshwater of considerable size, whose open-water and deep-bottom zones (no light penetration to bottom) are large compared to the shallow-water (shoreline) zone, which has light penetration to its bottom.
restoration:
The renewing or repairing of a natural system so that its functions and qualities are comparable to its original, unaltered state.
retirement of road:
Preparing a road for a long period of non-use. Methods include mulching, seeding, installing water bars, etc.
revetment:
Facing of stone or other material either permanent or temporary, placed along the edge of a body of water to stabilize the bank and/or protect it from erosion.
ribonucleic acid (RNA):
A class of nucleic acids characterized by the presence of the sugar ribose and the pyrimidine uracil; includes mRNA (messenger RNA), tRNA (transfer RNA), and rRNA (ribosomal RNA).
ridge-till:
The leaving of the soil undisturbed from harvest to planting except for nutrient injection. Planting is completed in a seedbed prepared on ridges with sweeps, disk openers, coulters, or row cleaners. Residue is left on the surface between ridges. Weed control is accomplished with herbicides and/or cultivation. Ridges are rebuilt during cultivation.
riffle:
Area of a stream or river characterized by a rocky substrate and turbulent, fast-moving, shallow water.
riparian:
Relating to the bank or shoreline of a body of water.
river:
A watercourse that flows at all times, receiving water from ground or surface water, for example, from other streams or rivers. The terms "river" and "stream" are often used interchangeably, depending on the size of the water resources and the region in which it is located.
runoff:
Water that is not absorbed by soil and drains off the land into bodies of water, either in surface or subsurface flows.
salinity:
The amount of dissolved salts in water, generally expressed in parts per thousand (ppt).
saprobe:
An organism that feeds on non-living organic matter.
saturated flow:
Underground water flow where void spaces in the soil or rock are filled completely with water.
secondary standards:
Standards, sometimes called Secondary Maximum Contaminant Levels, address taste, odor, color, and other aesthetic aspects of drinking water that do not present health risks.
secondary treatment:
The level of wastewater treatment that typically involves biological reduction in concentrations of particulate and dissolved oxygen-demanding pollutants, beyond the level of primary treatment.
sediment:
Particles and/or clumps of particles of sand, clay, silt, and plant or animal matter carried in water.
sedimentary rock:
A type of rock formed by chemical precipitation or by sedimentation and cementation of mineral grains transported to a site of deposition by water, wind, or ice.
sedimentation:
Deposition of sediment.
sidecast:
The act of moving excavated material to the side and depositing such material.
siliceous:
Containing or consisting of silica.
siltation:
The deposition or accumulation of fine soil particles.
silviculture:
The science and art of growing forest crops. More particularly, the principles, theories, and practices for protecting and enhancing the regeneration, growth, development, and utilization of forests for multiple benefits.
single-station design:
A water quality monitoring design that utilizes one station at a point downstream from the area of BMP implementation to monitor changes in water quality.
site preparation:
A forestry activity designed to remove unwanted vegetation and other material, and to cultivate or prepare the soil for reforestation.
skid:
Short-distance moving of logs or felled trees along the surface of the ground from the stump to the point of loading.
skid trail:
A temporary, nonstructural pathway over forest soil used for dragging felled trees or logs to a log landing.
sludge:
The semisolid residue formed from removing wastes from sewage or industrial discharges.
source control:
A practice, method, or technology used to reduce pollution from a source; for example, best management practices or end-of-pipe treatment.
species:
A class of individuals having common attributes and designated by a common name; a particular kind of atomic nucleus, atom, molecule, or ion.
spectrophotometry:
Process of determining the energy distribution in a spectrum of luminous radiation.
stakeholders:
Anyone who lives in the watershed or has land management responsibilities in it. Individuals who represent the major land uses in the watershed. Stakeholders include government agencies, businesses, private individuals and special interest groups.
standard of performance:
An emission limitation imposed on a particular category of pollution sources, either by U.S. Environmental Protection Agency or by a state. Limitations may take the form of emission standards or of requirements for specific operating procedures.
storm drain:
A system of gutters, pipes, or ditches used to carry stormwater from surrounding lands to streams or lakes. In practice storm drains carry a variety of substances such as sediments, metals, bacteria, oil, and antifreeze which enter the system through runoff, deliberate dumping, or spills. This term also refers to the end of the pipe where the stormwater is discharged.
stormwater:
Rainwater that runs off the land, usually paved or compacted surfaces in urban or suburban areas, and is often routed into drain systems in order to prevent flooding.
stratification:
Division of an aquatic community into distinguishable layers on the basis of temperature.
stratosphere:
The layer of the earth's atmosphere that extends from approximately 11 km to 50 km above the earth's surface.
stream:
A watercourse that flows at all times, receiving water from groundwater and/or surface water supplies, such as other streams or rivers. The terms "river" and "stream" are often used interchangeably, depending on the size of the water body and the region in which it is located.
streamside management zone (SMZ):
An area adjacent to the banks of streams and bodies of open water where extra precaution is necessary in carrying out forest practices in order to protect bank edges and water quality.
structural BMPs:
BMPs that require the construction or use of a structure such as a terrace, lagoon, or waste storage facility.
subbasins:
One of several basins that form a watershed.
submerged aquatic vegetation (SAV):
Vegetation rooted in the substrate of a body of water (usually no deeper than 10 feet), that does not characteristically extend above the water surface and usually grows in associations or beds. It serves as nursery area for juveniles and supports adult populations of economically important seafood species. SAV beds also enhance water quality by reducing turbidity and stabilizing sediments. Also referred to as seagrass.
substrate:
The surface with which an organism is associated; often refers to lake or stream beds.
substrate sampling:
Sampling of streambeds to determine the percent of fine particled material and the percent of gravel.
subwatershed:
A drainage area within a watershed.
suspended load:
Sediment that is transported by suspension in the water column of a stream or river.
suspended solids:
Organic and inorganic particles, such as solids from wastewater, sand, clay, and mud, that are suspended and carried in water.
sustainable use:
Conserved use of a resource such that it may be used in the present and by future generations.
symbiosis:
An association between two organisms of different species. Includes mutualism (association beneficial to both), commensualism (association is beneficial to one and neither beneficial nor detrimental to the other), and parasitism (association is beneficial to one and detrimental to the other).
tailwater management:
The practice of collecting runoff, "tailwater," from irrigated fields. Tailwater is reused to irrigate crops.
targeting:
The process of prioritizing pollutant sources for treatment with BMPs or a specific BMP to maximize the water quality benefits of the implemented BMPs.
technology-based standards:
Effluent standards developed by considering the effluent quality that can be achieved using various process or treatment technologies, rather than by considering the environmental effects of different loadings of pollutants.
teratogen:
A substance or agent that increases the chance of birth defects.
thermal pollution:
A temperature rise in a body of water sufficient to be harmful to the aquatic life in the water.
thermocline:
Zone of rapid temperature and density change in a stratified water body; marks the transition zone between the epilimnion and the hypolimnion. Also known as the metalimnion.
total alkalinity:
A measure of the titratable bases, primarily carbonate, bicarbonate, and hydroxide
total Kjeldahl nitrogen (TKN):
An oxidative procedure that converts organic nitrogen forms to ammonia by digestion with an acid, catalyst, and heat.
total Kjeldahl phosphorus (TKP):
An oxidative procedure that converts organic phosphorus forms to phosphate by digestion with an acid, catalyst, and heat.
Total Maximum Daily Load (TMDL):
The loading capacity is the maximum amount of pollution that a water body can receive without violating water quality standards. Total Maximum Daily Loads are the sum of point and nonpoint source loads.
total suspended solids (TSS):
The weight of particles that are suspended in water. Suspended solids in water reduce light penetration in the water column, can clog the gills of fish and invertebrates, and are often associated with toxic contaminants because organics and metals tend to bind to particles. Differentiated from Total dissolved solids by a standardized filtration process, the dissolved portion passing through the filter.
toxemia:
An abnormal condition associated with the presence of toxic substances in the blood.
toxic:
Poisonous, carcinogenic, or otherwise directly harmful to life.
toxic substance, toxicant, or toxin:
A substance or mixture which has the potential to cause death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions, or physical deformities in organisms or their offspring. Organisms are exposed to toxicants after discharge and upon exposure, ingestion, inhalation, or assimilation into any organism, either directly from the environment or indirectly by ingestion through food chains.
tracking:
Documenting or recording the location and timing of BMP implementation.
transport:
The movement of a soil particle, nutrient, or pesticide from its original position. This movement may occur in water or air currents. Nutrients and pesticides can be attached to soil particles or dissolved in water as they move.
tributary:
A stream or river that flows into a larger stream or river.
troposphere:
The lowest, densest part of the earth's atmosphere in which most weather changes occur; extends from the earth's surface to the bottom of the stratosphere.
turbidity:
A measure of the amount of light intercepted by a given volume of water due to the presence of suspended and dissolved matter and microscopic biota. Increasing the turbidity of the water decreases the amount of light that penetrates the water column. High levels of turbidity are harmful to aquatic life.
Universal Soil Loss Equation (USLE):
An empirical erosion model designed to compute long-term average soil losses from sheet and rill erosion under specified conditions.
unsaturated flow:
Underground water flow through soil or rock where the void spaces are filled both with water and air.
upstream/downstream design:
A water quality monitoring design that utilizes two water quality monitoring sites. One station is placed directly upstream from the area where the implementation will occur and the second is placed directly downstream from that area.
vadose zone:
The part of the soil that is generally unsaturated.
variable:
A water quality constituent (for example, total phosphorus pollutant concentration) or other measured factors (such as streamflow, rainfall).
viruses:
A group of infectious agents consisting primarily of a genome that replicates itself within a host cell by using its nucleic acids to direct the host cell to synthesize more viral nucleic acids and proteins. Comprised of highly organized sequences of nucleic acids, either DNA or RNA, depending on the virus.
volatilization:
The transport of a liquid substance by vaporization.
warmwater fish:
Prefer water temperatures ranging between 18-29 degrees C (65-85 degrees F); includes fish such as smallmouth bass, largemouth bass, and bluegill.
water management:
The practice of limiting the amount of water used in activities such as animal waste flushing systems or milking operations in order to reduce the amount of runoff and, therefore, decrease the probability of polluting nearby surface water.
water quality standards:
Established limits of certain chemical, physical, and biological parameters in a water body; water quality standards are established for the different designated uses of a water body.
water table:
The depth or level below which the ground is saturated with water.
watershed:
The area of land from which rainfall (and/or snow melt) drains into a single point. Watersheds are also sometimes referred to as drainage basins or drainage areas. Ridges of higher ground generally form the boundaries between watersheds. At these boundaries, rain falling on one side flows toward the low point of one watershed, while rain falling on the other side of the boundary flows toward the low point of a different watershed.
watershed project:
A group of activities undertaken in a geographic area to restore or protect the beneficial uses of a water resource.
wetland construction:
A subset of wetland creation; creation of wetlands specifically for water quality improvement purposes, typically involving controlled outflow and a design that maximizes chosen treatment functions. Creation of an engineered system to simulate the water purification functional value of natural wetlands for human use and benefits.
wetland creation:
The bringing into existence of a wetland, whether by accident or intentionally, where none existed previously, for purposes including mitigation, habitat provision, and water quality improvement.
wetland enhancement:
Modification of a natural or created wetland to increase the level of one or more functions, typically to the detriment of other functions.
wetland restoration:
Rehabilitation of previously existing wetland functions, from a more impaired to a less impaired or unimpaired state of overall function.
wetlands:
Areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas (40 CFR 232.2(r)).
zoning:
Designating by ordinances areas of land reserved and regulated for different land uses.
zooplankton:
Free-floating or weakly-swimming planktonic organisms not capable of photosynthesis.