This glossary includes definitions of terms and acronyms that are mentioned within this website and documents that appear in the document library. Glossary terms can be searched by clicking on the first letter of the term.
The varying physical characteristics–including depth, contour, sediment and shape–of the bottom of bodies of water. The bathymetry of the Gowanus varies greatly among the three reaches.
- Benthic Community
The group of organisms living at the bottom of a pond, river, lake or ocean.
A man-made structure to retain land from sliding into the waterway.
- Clean Water Act (CWA)
A federal law passed in 1972 that establishes guidelines for water quality in the United States.
- Cleanup Activities
Cleanup activities at a site include removals, studies, remedy selection, remedy design, remedy implementation, and post-construction activities. The completion of each activity enables the site to move further along in the cleanup process.
-Post-Construction – Superfund Post-Construction is a cleanup phase where several activities are generally undertaken at sites following the construction of response actions. These activities include operation and maintenance and long-term response actions; five-year reviews, close-out reports, and deletion from the NPL. The goal of Superfund Post-Construction is to ensure that response actions provide for the long-term protection of human health and the environment.
- Community Advisory Group (CAG)
A Community Advisory Group (CAG) is made up of representatives of diverse community interests. A CAG is designed to serve as the focal point for the exchange of information among the local community and United States Environmental Protection Agency (EPA), state regulatory agencies, and other pertinent federal agencies involved in cleanup of the Superfund site. The CAG website for the Gowanus Canal Superfund Site can be found at gowanuscag.org.
- Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA)
CERCLA, more commonly known as Superfund, is the law passed by Congress in 1980 that authorizes the United States Environmental Protection Agency (EPA) to clean up sites contaminated with hazardous substances.
- Contaminants of Concern (COC)
Chemicals identified during in-depth site studies (Remedial Investigation (RI)/Feasibility Study (FS)) that need to be addressed by a cleanup action because they pose a potential threat to human health or the environment.
- Contaminated Sediment Technical Advisory Group (CSTAG)
A technical advisory group that is part of the United States Environmental Protection Agency (EPA)’s Superfund process and established to monitor progress and provide technical counsel on complex aspects of a cleanup project. The group is comprised of representatives from EPA and the Army Corps of Engineers.
- Dense Non-Aqueous Phase Liquid (DNAPL)
A Dense Non-Aqueous Phase Liquid (DNAPL) that is heavier than water. These will sink to the bottom of a waterway as opposed to light Non-Aqueous Phase Liquid (NAPL)s, like oil or gasoline, that may float. NAPLs can appear as sheens on top of water.
- Dissolved Oxygen (DO)
A measurement of the amount of oxygen that is dissolved in water and an indicator of the quality of water. Higher levels of DO indicate better water quality.
- Feasibility Study (FS)
A phase in the Superfund process done following the Remedial Investigation (RI). This study develops and evaluates alternative remedial actions based upon the data collected from the RI.
- Flushing Tunnel
Installed in 1911, the flushing tunnel is a large propeller that brings water into the Gowanus Canal from Buttermilk Channel (between lower Brooklyn and Governor’s Island through a brick-lined 1.2-mile (1.9-km) tunnel. Rehab of the tunnel began in 1994 and it was then reactivated in 1999. An upgrade began in 2010 and it was once again reactivated in 2014.
- Gowanus Remediation Team (GRT)
The group of contractors and professionals completing the United States Environmental Protection Agency (EPA) mandated environmental cleanup and remediation of the Gowanus Canal.
- Groundwater Upwelling
The occurrence of groundwater seeping into a body of water through sediments laying at the bottom.
- Hazard Ranking System (HRS)
The numeric screening system the United States Environmental Protection Agency (EPA) uses to place uncontrolled waste sites on the National Priorities List (NPL). The system is based on information collected from the Preliminary Assessment and site inspection to rank the relative potential of sites to pose threat to human health or the environment.
- In-Situ Stabilization (ISS)
A remediation process by which contaminants are rendered immobile through reactions with stabilizing compounds mixed directly into the soil or sediment.
- National Priorities List (NPL)
The list of hazardous waste sites that are eligible for cleanup under Superfund or the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).
- Noise Monitoring
Noise is measured using the decibel scale. For example, normal conversation is typically around 60 decibels, and electric saw is around 100 decibels, and amplified rock music is around 120 decibels.
- Non-Aqueous Phase Liquid (NAPL)
Organic substances that are insoluble in water. An example is spilled oil in a waterway. NAPLs tend to persist for long periods in the environment.
- Oleophilic Clay
A modified clay specially designed to trap contaminants through adhesion while allowing water to pass through. This material is effective in many multi-layer engineered capping applications to prevent transport of contaminants into the water column, particularly Non-Aqueous Phase Liquid (NAPL)s. Commonly found bentonite or hectorite clay is altered to produce the oleophilic clay.
- Polychlorinated Biphenyls (PCBs)
Polychlorinated biphenyls have a range of toxicity and vary in consistency from thin, light-colored liquids to yellow or black waxy solids. PCBs were used in hundreds of industrial and commercial applications including electrical, heat transfer and hydraulic equipment; as plasticizers in paints, plastics and rubber products; in pigments, dyes and carbonless copy paper; and many other industrial applications.
- Polycyclic Aromatic Hydrocarbons (PAHs)
These organic chemicals are formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances. They are found in crude oil, creosote and roofing tar and are common in areas with high rates of development and motor vehicle traffic.
- Potentially Responsible Parties (PRPs)
Parties that may have contributed waste to the site. The United States Environmental Protection Agency (EPA) uses document reviews, site investigations, interviews, information supplied in response to information request letters, and title searches to determine a party’s liability for cleanup at a Superfund site. Contaminants on site may be due to historical, predecessor company actions over the many years of industry along the canal and not solely due to the current PRP.
- Preliminary Assessment
The process used by the United States Environmental Protection Agency (EPA) based on readily available information to determine if a particular site poses any threat to human health or the environment. It also makes recommendations where appropriate about possible further investigation or evaluation for corrective actions.
- Proposed Remedial Action Plan (PRAP)
A study of alternatives considered for remediation of a hazardous waste site and the rationale for selecting a recommended alternative. The PRAP is based on the site’s Remedial Investigation (RI) and Feasibility Study (FS). The PRAP is reviewed by the public, state agencies, and other parties and is a precursor to the Record of Decision (ROD).
- Record of Decision (ROD)
A public document that explains which alternatives will be used for remediation of a hazardous waste site. The ROD is based on the Proposed Remedial Action Plan (PRAP) and comments on the PRAP from the public.
- Remedial Action (RA)
The process following the Remedial Design (RD) phase and involves the actual construction or implementation phase of Superfund site cleanup.
- Remedial Design (RD)
The phase in the Superfund process that determines the best way to implement the Record of Decision (ROD) through technical specifications for cleanup remedies and technologies.
- Remedial Investigation (RI)
A phase in the Superfund process done in conjunction with the Feasibility Study (FS). This investigation characterizes site conditions, determines the nature of the waste at the site, and assesses the threat to health and the environment.
Solid materials, such as dirt, minerals or rocks, that settle at the bottom of a body of water.
- Semivolatile Organic Compounds (SVOCs)
Closely related to Volatile Organic Compounds (VOCs), these compounds change to gas very slowly at a standard temperature.
The federal government’s program, overseen by the United States Environmental Protection Agency (EPA), to clean up the nation’s uncontrolled hazardous waste sites. See the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).
Measures how well light penetrates the water. If small solid particles are present, the water can appear murky or turbid. Turbidity can occur naturally through algae blooms and by human activities, such as rain-storm runoff.
- Types of Contaminants
Individual contaminants are classified into contaminant groups based on their chemical structure and physical properties. Some major contaminant groups include: Polychlorinated Biphenyls (PCBs), Polycyclic Aromatic Hydrocarbons (PAHs), Metals, Volatile Organic Compounds (VOCs), and Pesticides.
- United States Environmental Protection Agency (EPA)
The U.S. regulatory agency overseeing all Superfund sites, including the Gowanus Canal.
- Volatile Organic Compounds (VOCs)
Organic compounds that can become a gas at room temperature. VOCs are the leading cause of ground-level ozone. Common sources which may emit VOCs into the air include housekeeping and maintenance products; paints, coatings, and inks; and building and furnishing materials.