Algal Blooms: Sudden spurts of algal growth, which can affect water quality adversely. Often, excessive blooms indicate nutrient enrichment. Some species cause potentially hazardous changes in local water chemistry.

Anadromous: Fish that spend their adult life in the sea but swim upriver to freshwater spawning grounds to reproduce.

Atmospheric Deposition: Airborne pollutants which are deposited back on land and water either in wet form (i.e., in precipitation) or dry form (i.e., as particles), often having undergone chemical transformation and often having been transported great distances in the atmosphere.

Bench-Scale: A very small scale demonstration of a technology process, performed in the laboratory. See also pilot scale.

Best Management Practice (BMP): A method of preventing or reducing the pollution resulting from an activity. The term originated from Section 208 of the Federal Clean Water Act.

Bioaccumulation: The uptake of toxic chemicals leading to elevated concentrations of those substances within plant or animal tissue.

Coliform (Bacteria): Widely distributed micro-organisms found in the intestinal tract of humans and other animals and in soils. Their presence in water indicates fecal pollution and potentially dangerous contamination by disease-causing micro-organisms.

Combined Sewer Overflow (CSO): These occur in combined sewer systems when large volumes of water generated during rain events combine with the regular sanitary waste stream, overwhelming the capacity of sewage treatment plants. The resultant sewage overflow goes directly into the Harbor with little or no treatment. See also combined sewer system.

Combined Sewer System: A sewer system which combines storm water and sanitary sewage.

Depuration: A process to purge pollutants from shellfish, done at a plant. See also shellfish relay.

Dioxin: 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). The most highly toxic of a group of structurally similar polychlorinated aromatic hydrocarbons, differing in the number and location of chlorine atoms in their molecular structure, often collectively referred to as dioxins. Dioxins are produced as a byproduct of industrial processes such as the manufacture of certain herbicides, manufacture of paper, and high-temperature processes such as incineration; some of the less toxic dioxins are produced in small amounts in natural combustion. Dioxins have a strong tendency to bioaccumulate. Dioxins are quite stable, and therefore persist in the environment for long periods of time. 2,3,7,8-TCDD is classified by USEPA as a known human carcinogen.

Dissolved Oxygen (DO): Oxygen dissolved in water and therefore freely available to aquatic organisms

Dredging: Mechanical removal of sediment from the bottom of water bodies, usually done to allow navigation in areas which are naturally shallow.

Dredged Material: Bottom sediments which are removed by dredging.

Effluent: Wastewater-treated or untreated-that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters.

Eutrophication: A process in which a water body becomes rich in dissolved nutrients, often leading to algal blooms, low dissolved oxygen, and changes in the composition of plants and animals in the water body. This occurs naturally, but can be exacerbated by human activity which increases nutrient inputs to the water body.

Flux: The amount of some substance flowing across a given area per unit time.

Geographic Information System (GIS): A computer system used to analyze and display data in a geographic context, e.g., on a map.

Hypoxia: Low concentrations (e.g., less than 3 ppm) of dissolved oxygen in water.

Indicator: In biology, an organism, species, or community whose characteristics define the presence of specific environmental conditions.

Leachate: A liquid containing the soluble constituents of materials which have been dissolved by water or other liquids percolating through the soil where the materials are located.

Loading/Load: The rate at which a pollutant enters a system, such as a water body. Expressed as mass per unit time, e.g., kg/day or tons/year.

Mass Balance: A mathematical accounting of the sources and sinks of a substance within a system, such as a water body. A mass balance model for a water body is useful to help understand the relationship between the loadings of a pollutant and the levels in the water, biota, and sediments.

Modeling: An investigative technique using a mathematical or physical representation of a system or theory, usually on a computer, that accounts for all or some of its known properties. Models are often used to test the effect of changes of system components on the overall performance of the system.

'No Discharge' Zone: Waters where vessel discharge of sanitary waste is prohibited.

Non-Point Source Runoff: Runoff entering a water body as "sheet flow", i.e., not through a discrete conveyance. Most prevalent in areas that are unsewered. See also runoff.

National Pollutant Discharge Elimination System (NPDES): A program established under the Clean Water Act (CWA) of 1972 to control the discharge of pollutants to surface waters from point sources. The CWA gives USEPA the authority to issue permits, including pollutant limits and other requirements. USEPA has delegated this authority to the States of New York and New Jersey.

Nutrient: Any substance assimilated by living things that promotes growth. The term is generally applied to nitrogen and phosphorus, but is also applied to other essential and trace elements including carbon and silica.

Organic: 1) Referring to or derived from living organisms. 2) In chemistry, any compound containing carbon and hydrogen.

PAHs (polycyclic aromatic hydrocarbons); also known as PNAs (polynuclear aromatics): A group of petroleum-derived hydrocarbon compounds, present in petroleum and related materials, and used in the manufacture of materials such as dyes, insecticides, and solvents. The higher molecular weight PAHs (e.g., fluoranthene, benzo(a)pyrene) are products of combustion. The lower molecular weight PAHs (e.g., naphthalene, fluorene) generally derive from unburned petroleum sources. In general, the lower molecular weight PAHs are more soluble, more volatile, and more acutely toxic than the higher molecular weight PAHs, whereas the higher molecular weight PAHs have a stronger tendency to bioaccumulate and many are known or suspected carcinogens.

PCBs (polychlorinated biphenyls): A group of synthetic polychlorinated aromatic hydrocarbons formerly used for such purposes as insulation in transformers and capacitors and lubrication in gas pipeline systems. Production, sale, and new use was banned by law in 1977 following passage of the Toxic Substances Control Act. PCBs have a strong tendency to bioaccumulate. They are quite stable, and therefore persist in the environment for long periods of time. They are classified by USEPA as probable human carcinogens.

Pilot-Scale: A small scale project intended to demonstrate a technology process. See also bench scale.

Point Source: A stationary location or fixed facility from which pollutants are discharged or emitted. Also, any single identifiable source of pollution, e.g., a pipe, ditch, ship, ore pit, factory smokestack.

Pretreatment: Processes used to reduce, eliminate, or alter the nature of wastewater pollutants from non-domestic sources before they are discharged into publicly owned treatment works.

Primary Waste Treatment: First steps in wastewater treatment; screens and sedimentation tanks are used to remove most materials that float or will settle. Primary treatment results in the removal of about 30 percent of carbonaceous biochemical oxygen demand from domestic sewage.

Resuspension (e.g., of sediments): When bottom sediments are mixed back into the water column. May be caused by natural processes (e.g., floods, tidal currents) or by human activities (e.g., dredging).

Runoff: That part of precipitation, snow melt, or irrigation water that runs off the land into streams or other surface water. It can carry pollutants from the air and land into the receiving waters.

Sediments: Particulate organic and inorganic matter that accumulates in a loose unconsolidated form. It may be chemically precipitated from solution; secreted by organisms; transported by air, ice, wind, or water; or washed off the land after rainfalls and deposited.

Shellfish-Relay: A process to purge pollutants from shellfish, done by moving them to clean marine areas. See also depuration.

Storm Water Discharge: Runoff entering a water body through a discrete conveyance, such as a pipe, in an area with separate sanitary and storm sewers. See also CSO and non-point source runoff.

Subaqueous Borrow Pit: Underwater depressions that were left after the mining of large volumes of sand and gravel for projects ranging from landfilling and highway construction to beach nourishment. They are semi-permanent features covering more than 1000 acres of bottom in the Hudson-Raritan Estuary.

Water Quality Criteria: Acceptable limits for pollutants in water, derived by USEPA, nationally, or the states.

Water Quality-Limiting: Violating or predicted to violate water quality standards.

Water Quality Standards: State-adopted and USEPA-approved ambient standards for water bodies. The standards cover the use of the water body and the water quality criteria which must be met to protect the designated use or uses (e.g., drinking, swimming, fishing).

Watershed: The land area that drains into a stream, river, estuary, or other water body; same as drainage area.