Water Quality Data - Glossary

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Algae - Aquatic non-flowering plants that lack roots and use light energy to convert carbon dioxide and inorganic nutrients such as nitrogen and phosphorous into organic matter by photosynthesis. Common algae include, dinoflagellates, diatoms, seaweeds, and kelp.

Aquifer - A layer of underground rock which stores and carries water

Carbonaceous Biochemical oxygen demand (CBOD) measures how much oxygen is needed by microbes in the water to break down organic matter. High CBOD means that less oxygen is available for aquatic life and usually indicates poor water quality.

Chlorophyll is a green pigment found in plants, is a useful measurement of a water body’s algae levels and trophic state (the rate at which a water body is aging biologically).

Community – all the groups of organisms living together in the same area, usually interacting or depending on each other for existence.

Contaminants are pollutants to a water body. It is a substance that is not naturally present in the environment, or is present in unnatural concentrations, which can alter the environment.

Criteria – statements of the conditions presumed to support or protect the designated use or uses of a water body. Criteria may be narrative or numeric.

Designated Use – classification specified in water quality standards for each water body or segment describing the level of protection from perturbation afforded by the regulatory programs. The designated aquatic life uses established by the stat or authorized agencies set forth the goals for restoration and-or baseline conditions for maintenance and prevention from future degradation of the aquatic life in specific water bodies.

Dissolved oxygen (DO) is the amount of oxygen available in the water to support aquatic life. It is one of the most important indicators of a waterbody’s state of health. Because aquatic plants produce oxygen only when light is available for photosynthesis, DO values will vary during a 24-hour cycle. As temperatures rise, DO levels decrease. Some sensitive aquatic species cannot tolerate extreme fluctuations in dissolved oxygen levels.

Ecosystems are a community of living organisms interacting with one another and with their physical environment.

Effluent is the outflow of water, with or without pollutants, usually from a pipe.

Estuary – A semi-enclosed water costal water body which has a free connection to the open sea and within which seawater is measurably diluted with freshwater.

Eutrophication is a process in which increasing nutrient loads cause changes in the water chemistry and ecological structure of surface water bodies. In addition to ecological and esthetic impacts, excessive nutrient loads can also affect human uses of surface waters by increasing the frequency of nuisance algal blooms, causing taste and odor problems in potable water sources, and contributes to oxygen-related stress or mortality in economically important fish and shellfish species.

Fecal Coliform measures the level of intestinal bacteria in the water. Fecal coliform are found in animal and human feces. High coliform levels suggest that disease-causing bacteria may also be present and that pollution is entering the water from septic tanks, domestic sewage, or stormwater runoff.

Gound water - Water found below the surface of the earth

Habitat – The specific place or environment where a particular plant or animal lives. An organism’s habitat must provide all the basic requirements for life and should be free of harmful contaminants.

Historical Data – data sets from previous studies, which can range from handwritten field notes to published journal articles.

Impact – change in the chemical, physical (including habitat), or biological quality or condition of a water body caused by external sources.

Impairment – detrimental effect on the biological integrity of a water body caused by an impact that prevents attainment of the designated use.

Lagoon – A shallow body of water which is separated from the sea by a sandbar, barrier beach, or coral reef where the salt water from the sea and freshwater runoff from the land meet and mix.

Lake - A body of surface water surrounded by land

Muck – Fine grained sediments that contain a significant amount of clay and silt and about 10% organic matter. Its primary source is runoff from upstream deposits, easily re-suspended to increase turbidity in the water column. This re-suspension can lead to a decline in seagrasses by decreasing light penetration.

Nephelometric Turbidity Units(NTU) – These units are used to measure the amount of turbidity in a water sample. Turbidity measured on an electronic instrument known as a nephelometer is expressed in these units. A nephelometer passes light through the water sample and measures the amount of light scattered by particles in the water.

Nitrates — a class of chemical compounds having the formula NO 3. Nitrate salts are used as fertilizers to supply a nitrogen source for plant growth. Nitrate additions to surface waters can lead to excessive growth of aquatic plants. High groundwater nitrate levels can cause methemoglobinemia in infants.

Nitrogen - an essential element for plant growth, comprising 78 percent of the atmosphere, which is unavailable to most plants in its natural form. It is present in ammonia, nitrate or nitrite or elemental form in water due possibly to Non-point Source pollution or improperly operating wastewater treatment plants.

Non-point Source Pollution – Pollution that is generated over a relatively wide area and may be dispersed into a water body through storm drains or land runoff instead of a pipe. Non-point Source pollution includes stormwater runoff, leaking septic systems, and overboard waste from boats and ships.

Nutrients - Any substance required by organisms for normal growth and maintenance. Mineral nutrients usually refer to inorganic substances taken from soil and water. Excessive amounts of nutrients, including phosphorus and nitrogen may result in nutrient loading, which leads to oxygen depletion and water degradation.

Pathogen – An agent such as a virus or fungus that can cause disease in humans. Pathogens can be present in municipal, industrial, and non-point source discharges into a water body.

pH expresses a water body’s relative acidity or alkalinity. Shifts in pH can affect chemical and biological processes. Increased acidity can cause heavy metals to be released from sediments into the food chain. A pH of 7 is neutral, while a range of 1 to 7 is acidic and a range of 7 to 14 is alkaline. Each one-point change in pH means that alkalinity or acidity is multiplied ten times.

Phosphorus - An element that is essential to plant life but contributes to an increased trophic level (Eutrophication) of water bodies.

Photosynthesis – The synthesis of organic matter from inorganic substrates, using light as a source of energy.

Plankton – Drift Algae. Microscopic, floating, aquatic plants (Phytoplankton), and animals (Zooplankton).

Point Source Pollution – Pollution originating at a particular place, such as a sewage treatment plant, effluent outfall pipe, or other discharge pipes into a water body.

Precipitation - Moisture falling through the atmosphere as rain, snow or ice

Recharge area – A unit of land surface which allows the downward movement of water to an aquifer.

Reservoir – Water held in storage by natural or man-made basins

River – A natural stream of water larger than a creek an emptying into an ocean, lake or another river.

Runoff – The part of precipitation that travels over land and appears in surface streams and other receiving watersheds.

Runoff – Water from rain or irrigation that flows over the ground surface into the nearest body of water.

Salinity – The dissolved inorganic salts in seawater expressed in grams of salt per kilogram of seawater (PPT).

Secchi depth is a measure of water clarity, is the depth at which the pattern on a black-and-white painted disc can no longer be distinguished under water. High measurements are usually, but not always a measure of good quality. Blackwater streams, may have good water quality but a low secchi measurement because of their high tannin content.

Shellfish – An aquatic animal, such as a mollusk (clam or snail) or crustacean (crab, shrimp, or lobster), which has a shell-like exoskeleton.

Specific conductance is the ability of water to conduct an electrical current, is an early indicator of changes in water quality because industrial and municipal pollution increase conductivity.

Spring – A concentrated flow of water which naturally arises from an opening in the ground.

Standard – A standard is an acknowledgement basis for comparing or measuring; criterion; a degree or level of requirement.

Storm Drain – A system of gutters, pipes, and ditches used to carry stormwater from the land to streams, ponds, or other water bodies. Storm drains carry a variety of substances ranging from lawn clippings to motor oil.

Stormwater – Precipitation that is often routed into a storm drain system to prevent flooding.

Surface water – All water on the surface of the earth, in oceans, lakes, rivers and streams.

Total Maximum Daily Loads (TMDLs) – calculation of the maximum amount of a pollutant that a water body can receive and still meet water quality standards and an allocation of that amount to be the pollutant’s source.

Total nitrogen and total phosphorus indicate the levels of nutrients in the system (called nutrient loading), mainly from fertilizers and stormwater runoff. The nutrients accelerate plant growth and speed up the rate at which a water body fills in and becomes unnaturally altered.

Total suspended solids (TSS) is a measurement of the amounts of organic and inorganic particles in the water. High levels of TSS can decrease the amount of oxygen in the water, lower fish growth rates, increase sediments that damage aquatic habitats, and thus reduce available food.

Tributaries - A stream or other body of water, surface or underground, which contributes its water, even though intermittently and in small quantities, to another and larger stream or body of water.

Turbidity, which is closely related to TSS, measures how much light penetrates a water body. As a water body becomes more turbid (cloudy), it is less able to support plant and animal life and thus becomes less biologically productive. Turbidity in water generally refers to water clarity and is caused by suspended and colloidal matter such as clay, silt, finely divided organic and inorganic matter, and plankton and other microscopic organisms. Turbidity is an expression of the optical property that causes light to be scattered and absorbed, rather than transmitted with no change in direction or flux level through the sample. Correlation of turbidity with the weight or particle number concentration of suspended matter is difficult because the size, shape, and refractive index of the particles affect the light scattering properties of the suspension.

Wastewater – Water that has come into contact with pollutants as a result of human activities and is not a product, but is discharged as waste into a water body.

Well – A deep hole drilled into an aquifer to withdraw ground water

Wetland – An area of land where the soil is very wet or soaked with water most of the time.

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