Glossary

action level - chemical concentration in food above which consumption of that food would pose a health risk

baleen - the boney plate in the mouths of certain kinds of whales that was used to make corset stays, hoops for women's skirts, frames for hats, fans, umbrella ribs, and fishing rods

benthic - bottom-dwelling, at the surface of or in the sediment

carcinogenic - a chemical or substance that produces or incites cancer

combined sewer overflow (CSO) - a system of waste removal where storm runoff from streets empties into the same pipes as domestic and industrial wastes. In periods of high rain, the wastewater treatment plant can not handle the increased volume and the wastewater empties through the combined sewer overflows into adjacent waterways without being treated.

contained disposal facility (CDF) - a structure built along a shoreline (or sometimes as an island) to contain solid material from dredging. The facility is lined with impervious material to contain the dredged material. The surrounding water and ground water is tested periodically to insure that toxic chemicals are not leaching from the dredged material in the CDF.

diversity - number and variety of different organisms in the environment in which they naturally occur

dredge spoil - the sediment dredged (removed) from the bottom of a harbor, river, or lake

estuarine - having to do with or found in an estuary

estuary - regions of interaction between rivers and near-shore ocean waters, where river flow and tidal action mix fresh and salt water

gyre - a circular movement

habitat - place where a population or community lives and its surroundings (both living and non- living)

hydrographic - having to do with the description and study of bodies of water (seas, lakes, rivers): as in surveying and charting; measuring flow, currents, and tides; and sounding (measuring depth)

monitoring - a study to assess the status of physical and biological conditions of a particular area at specified intervals (e.g., monthly, seasonally, yearly) over a given time period (usually years)

mutagenic - a substance that increases the frequency of mutation, the alteration in hereditary material

non-point sources - pollution that enters water from a dispersed and uncontrolled source, such as runoff from land or from the atmosphere, rather than through a pipe

nuisance - a term used in the late nineteenth century to refer to any environmental problem, for example, odor nuisance, garbage nuisance

nutrients - essential chemicals, nitrogen and phosphorous, needed by plants for growth

opportunistic species - a species that can take advantage of adverse conditions and thrive in locations where more sensitive species will not survive

organic compounds - generally all compounds that contain the element carbon, with a few exceptions, e.g., CaCO3

permeable - having openings that liquids (or gasses) can pass through

point sources - a well defined source of pollution from a single point, such as a pipe (e.g., discharges of wastewater from municipal or industrial plants)

polychlorinated biphenyls (PCBs) - a group of closely related, manufactured chemicals made up of carbon, hydrogen and chlorine (two 6-carbon rings (biphenyl - C6H5+) with two or more chlorine atoms substituted for hydrogen). Depending on the number and position of chlorine atoms attached, 209 different PCB congeners can be formed that have varying chemical and toxicological properties. PCBs were first manufactured in 1929. They were used in industry for their insulating and nonflammable properties. In 1978, manufacture of PCBs was banned after they were found to be toxic, to persist in the environment, and to concentrate upward in the food chain. For humans, the primary non-occupational source of PCBs is the ingestion of PCB-contaminated fish. The action level (concentration above which is harmful to humans) for PCBs in food, set by the U.S. Food and Drug Administration (FDA), is 5mg/kg.

polycyclic aromatic hydrocarbons (PAHs) - a group of over 100 different chemicals (composed of fused six-carbon rings) that are formed during the incomplete burning of carbon-containing fuels such as wood, coal, diesel, oil and gas, fat (e.g.,charbroiled meat), or tobacco. Also, coal tar, crude oil, creosote, and roofing tar contain PAHs. PAHs enter the air mostly as releases from volcanoes, forest fires, burning coal, and automobile exhaust. Most PAHs do not dissolve easily in water. They stick to solid particles and settle to the bottoms of lakes or rivers. Some PAHs are known or suspected carcinogens.

primary sewage treatment - a relatively uncomplicated physical process that primarily removes solids. First, the sewage passes through screens that filter out large debris such as pieces of wood, cardboard, rags, etc. It then flows to a grit chamber where sand and other heavy particles are removed. Next, the sewage enters large sedimentation tanks where suspended solids slowly settle to the bottom as sludge, and grease floats to the top and is skimmed off. In plants that provide no further level of treatment, the water is chlorinated to kill any remaining pathogens and returned to the environment at this point. Primary sewage treatment alone is no longer considered sufficient.

remediation - action to remedy or correct damage to the environment

residence time - amount of time water remains inside a specified area, e.g., harbor, bay, etc.

sewage treatment - the process of removing contaminants from sewage. Treatment includes physical, chemical and biological processes to remove physical, chemical and biological contaminants. The objective is to produce a treated effluent and a solid waste (sludge) that are suitable for discharge into the environment or for reuse. See below for various categories of sewage treatment.

secondary sewage treatment - The Federal Clean Water Act of 1972 mandated that all plants provide secondary sewage treatment. Secondary treatment begins where primary treatment leaves off. It is a biological process that uses bacteria to remove dissolved organic matter from wastewater. The microorganisms absorb organic matter from sewage as their food supply. In the final step, chlorination or ultraviolet light treatment kills pathogens before the wastewater is released to the environment.

species composition - the species found in a particular area

Superfund - a special trust fund, established by a federal law passed in 1980, modified in 1986 (Comprehensive Environmental Response, Compensation & Liability Act, CERCLA), to help finance the investigation of waste sites

teratogenic - a substance that causes developmental malformations

tertiary or advanced sewage treatment - The potential pollutants remaining after secondary sewage treatment include nutrients (nitrogen and phosphorus) and toxic chemicals. (Industries are required to pre-treat their wastewater to remove toxic chemicals before discharge into the sewer.) Advanced sewage treatment could include more than one process at a plant depending on which substances are to be removed. For example, nitrogen and phosphorus required different treatment processes for removal.

topographic - the configuration of a surface showing relief (elevations) and position of natural and man-made features

toxic - a substance that is poisonous, carcinogenic, or otherwise harmful to plants and animals

toxicity - the quality, state, or relative degree of being toxic or poisonous

watershed - the entire area of land whose runoff of water, sediments, and dissolved materials (nutrients, contaminants) drain into a lake, river, estuary, or ocean

water quality criterion - the maximum concentration of a chemical in ambient waters that would be safe for aquatic species. The criterion is determined from the results of toxicity tests using a variety of aquatic species, and consider both short-term and long-term exposures.

Glossary

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