Glossary

Glossary

IGNITABILITY:

A characteristic of hazardous waste. If a liquid (containing less than 24% alcohol) has a flash point less than 140° F, it is a hazardous waste in the United States.

IMPERMEABLE LAYER:

A layer of solid material, such as rock or clay, which does not allow water to pass through.

IN-SITU BIOREMEDIATION:

Techniques that stimulate and create a favorable environment for microorganisms to grow and use contaminants as a food and energy source. Generally, this means providing some combination of oxygen, nutrients, and moisture, and controlling the temperature and pH. Sometimes, microorganisms adapted for degradation of the specific contaminants are applied to enhance the process. Bioventing is a common form of in situ bioremediation. Bioventing uses extraction wells to circulate air with or without pumping air into the ground.

IN-SITU SOIL AERATION:

Applying a vacuum to vapor extraction wells to draw air through the soil so that chemicals in the soil are brought to the surface where they can be treated.

IN-SITU THERMAL TREATMENT:

A treatment process that involves heating contaminated soil in place to vaporize organic contaminants in the soil. The surface area to be treated is usually covered with silicone rubber mats to provide insulation and to form a vapor barrier.

IN-SITU:

 In its original place; unmoved; unexcavated; remaining in the subsurface.

INCINERATION:

A treatment technology that involves the burning of certain types of solid, liquid, or gaseous materials under controlled conditions to destroy hazardous waste.

INDICATOR CHEMICALS:

Chemicals selected from the group of chemicals found at the site and used for a public health evaluation. They are selected on the basis of toxicity, mobility and persistence, and are thought to be the chemicals of the greatest potential risk.

INDICATOR PARAMETERS:

Measurable physical or chemical characteristics or attributes of water or soil-pore moisture which are used to detect the presence of waste constituents in water or soil-pore moisture, or the effects of waste constituents on waters of the state. 

INFILL DEVELOPMENT:

Development that takes place within existing communities, making maximum use of the existing infrastructure instead of building on previously undeveloped land.

INFILL SITE:

A site in an urbanized area that has been previously developed, particularly for residential, commercial or industrial use, or an unused or underutilized site that is at least partially surrounded by developed land.

INFILTRATION:

Flow of water from the land surface into the subsurface.

INJECTION WELL:

Any bored, drilled or driven shaft, dug pit, or hole in the ground into which waste or fluid is discharged, and any associated subsurface appurtenances, and the depth of which is greater than the circumference of the shaft, pit, or hole.

INSECTICIDE:

A pesticide compound specifically used to kill or control the growth of insects.

INSTITUTIONAL CONTROL (IC):

A legal or institutional measure that subjects a property owner to limit activities at or access to a particular property.  ICs are used to ensure protection of human health and the environment, and to expedite property reuse. Fences, posting, warning signs, and zoning and deed restrictions are examples of institutional controls.

INTEGRATED RISK INFORMATION SYSTEM (IRIS):

An electronic database that contains EPA's latest descriptive and quantitative regulatory information about chemical constituents. Files on chemicals maintained in IRIS contain information related to both noncarcinogenic and carcinogenic health effects.

INTERFACE METER:

Device that detects the interface depth of non-dissolved contaminants (LNAPL), and the depth of the liquid water interface.

INTERIM REMEDIAL ACTIONS:

Actions taken as required to prevent further spread or damage to the environment from the contaminants, usually takes the form of free product removal.

INTERNAL COMBUSTION UNIT (ICU):

Similar to an automobile engine (often created using an auto engine) used to combust petroleum vapors.