accuracy: the closeness of an observed value or test response to the true or acceptable reference value specified in a reference method. Accuracy is influenced by both random error (precision) and systematic error (bias) (EPA, 2007).
anomalies: data that deviate or are departures from the normal or common order, form, or rule
baseflow: stream discharge that is not a result of direct runoff from precipitation or melting snow, and it is usually sustained by groundwater.
baseline reference site: when using a comparison to a reference site for the site being monitored, this site is the second site in a similar watershed.
Best Management Practices (BMPs): conservation and land management practices that reduce or prevent movement of pollutants to surface and groundwater. Examples of BMPs may include safe management of animal waste, control of pests and nutrients, contour farming, crop rotation, and vegetative buffers near streams.
biological indices: indicators of biological integrity that directly measure an aquatic community.
detection limit: the lowest concentration of a chemical that can dependably be distinguished from a concentration of zero (EPA, 2006).
direct monitoring: collecting samples to measure physical, biological, and chemical variables.
dissolved pollutant: a pollutant that will disintegrate in solution.
embeddedness: the amount of substrate material (sand, clay, and silt) covering river rock.
ephemeral stream: a stream channel that carries water only during and immediately after periods of rainfall or snowmelt.
grab samples: samples collected at a particular location and time that represents the composition of the water, air, or soil only at that location and time (EPA, 2006).
impairment: cause to diminish or degrade in strength, value, or quality.
integrated samples: samples collected at a particular time and different locations (e.g., different sections of the same river) that represent the composition of the water, air, or soil as a less variable sample over a period of time.
intermittent stream: a stream that carries water only during wet periods of the year (30-90 percent of the time).
metadata: “data about data,” i.e., the understanding, documentation use, and management of data.
National Pollutant Discharge Elimination System (NPDES) Permit: a permit program to control water pollution by regulating point sources that discharge pollutants into waters of the United States. The NPDES permit program is administered at a state level (EPA, 2007).
nutrient pollution: contamination of water resources by excessive amounts of nutrients, specifically nitrogen and phosphorus.
outlier: an observation that is numerically distant from the rest of the data.
parameter (statistical): a statistical quantity, usually unknown, such as a mean or a standard deviation, which characterizes a population or defines a system (EPA, 2007).
particulate pollutant: a pollutant that will not dissolve in solution but remains in distinct particles.
perennial stream: a stream channel that has continuous flow throughout the year.
pollutant: substance that contaminates (pollutes) a water body.
pollutants of concern: substances introduced into the environment that adversely affect the use of a resource or the health of humans, animals, or ecosystems, in the watershed or water body where the effectiveness the BMP will be assessed (EPA, 2007).
pollution: the introduction of contaminants into an environment that cause instability, disorder, or harm to the system
precision: A measure of mutual agreement between two or more individual measurements of the same property, obtained under similar conditions.
probes: onsite instruments (sensors) used to collect chemical or physical water data. These data can be stored in a data logger and projected as real-time data, or they can be collected as a grab sample.
protocols: a series of formal steps for conducting a test, service, or procedure (EPA, 2006).
quality assurance and quality control (QA/QC): actions performed to ensure the quality of a product, service, or process.
Quality Assurance Project Plan (QAPP): a written document that outlines the procedures a monitoring project will use to ensure samples collected and analyzed, the management of the data, and the consequent reports are of high enough quality to meet the needs of a project (EPA, 2006).
Sample and Analysis Plan (SAP): a document detailing procedural and analytical requirements for sampling events performed to collect samples.
sampling frequency: the time between successive sampling events.
standard operating procedure (SOP): written documents that describe, in great detail, the routine procedures to be followed for a specific operation, analysis, or action.
stressors: physical, chemical, or biological entities that can induce adverse effects on ecosystems or human health.
surrogate monitoring: monitoring one variable that correlates to the actions of another variable (i.e., the pollutant of concern) that may not be easily measured.
Total Maximum Daily Load (TMDL): is a 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 the pollutant's sources (EPA, 2007).
total phosphorus (TP): a measure of the concentration of phosphorus including soluble phosphorus and the phosphorus in the organic material suspended in wastewater, effluent, or water bodies.
total dissolved solids (TDS): a measure of the combined content of all dissolved inorganic and organic substances in water. The solids are primarily minerals and salts, but can also include organic matter.
total suspended solids (TSS): a measure of the suspended non-filtered solids (e.g., sediment or organic matter) in wastewater, effluent, or water bodies (EPA, 2006).
turbidity: a cloudy condition in water due to suspended solids (EPA, 2006).