Protecting Public Health and the Environment

List of Acronyms and Abbreviations

AST - aboveground storage tank

bgs - below ground surface

CAMEO – Computer-Aided Management of Emergency Operations

CERCLA - Comprehensive Environmental Response, Compensation, and Liability Act

EPA - US Environmental Protection Agency

ESS – enhanced sanitary survey

DEQ - Idaho Department of Environmental Quality

GIS - geographic information system

IDAPA - Idaho Administrative Procedures Act

IOC - inorganic chemical

LUST - leaking underground storage tank

MCL - maximum contaminant level

µg/L - micrograms per liter

mg/L - milligrams per liter

NPA – nitrate priority area

NPDES - National Pollutant Discharge Elimination System

PCI – potential contaminant inventory

PWS - public water system

RCRA - Resource Conservation and Recovery Act

SDWISS - Safe Drinking Water Information System, state version

SOC - synthetic organic chemical

SWA – source water assessment

TOT - time of travel

TRI - toxic release inventory

UST - underground storage tank

VOC - volatile organic chemical


Aquifer – A geologic formation of permeable saturated material, such as rock, sand, and gravel, capable of yielding economically significant quantities of water to wells and springs.

Low permeable unit – A layer of rock or sediment that does not transmit water easily (i.e., clay and unfractured rock) protecting the aquifer below from contamination.

Analytical model – A model that provides approximate or exact solutions to simplified forms of the differential equations for water movement and solute transport. Analytical models can generally be solved with calculators or computers.

Brownfields site – A vacant or underused property where redevelopment or reuse is complicated by actual or perceived environmental contamination.

Community water system – A public water system that supplies water to at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.

Comprehensive Environmental Response, Compensation, and Liability Act (CERLA) site – Commonly known as Superfund, CERCLA is federal legislation passed in 1980 designed to clean up hazardous waste sites that are on the US Environmental Protection Agency’s National Priorities List. See for more information on CERCLA.

Confined animal feeding operation (CAFO) – CAFOs are agricultural operations where animals are kept and raised in confined situations. CAFOs congregate animals, feed, manure and urine, dead animals, and production operations on a small land area. Feed is brought to the animals rather than the animals grazing or otherwise seeking feed in pastures, fields, or on rangeland. See dairy and feedlot definitions.

Dairy – A place or premise where one or more milking cows, sheep, or goats are kept, and from which all or a portion of the milk produced is sold for human consumption. Dairies are regulated by the Idaho State Department of Agriculture.

Deep injection well – An injection well used to dispose of or store fluids in the subsurface. Deep injection wells, generally used for disposing stormwater runoff or agricultural field drainage, are deeper than 18 feet below ground surface and are regulated by the Idaho Department of Water Resources.

Delineation (delineate) – The process of defining or mapping the boundary of the area that contributes water to a particular water source used as a public water supply.

Drain location – Historical method of draining excess water resulting from flood irrigation on agricultural fields by digging a hole from the land surface to an underlying tunnel.

Enhanced contaminant inventory – See potential contaminant inventory (PCI).

Enhanced sanitary survey – A routine, on-site inspection of a public water system’s water sources, facilities, equipment, operation, and maintenance of a public water system to evaluate the adequacy of those elements for producing and distributing safe drinking water. A sanitary survey protects public health by identifying system deficiencies and recommending possible solutions. Sanitary surveys in Idaho are conducted by a DEQ staff member or a representative of the local district health department. (DEQ contracts with Idaho’s seven district health departments to assist the state in providing service to small public water systems.)

Feedlot - A lot or facility where slaughter and feeder cattle or dairy heifers are confined and fed for a total of 45 days or more during any 12-month period, and crops, vegetation forage growth, or postharvest residues are not sustained in the normal growing season over any portion of the lot or facility.

Floodplain – – The flat or nearly flat land along a river or stream or in a tidal area that is covered by water during a flood. DEQ uses data from the Federal Emergency Management Agency to determine the 100–year floodplain for any given area. The 100-year floodplain is the area likely to be inundated during a flood that has a 1% chance of being equaled or exceeded in any given year.

Geographic information system (GIS) – A collection of computer hardware, software, geographic data, and interactive maps used to efficiently capture, store, update, analyze, and display the delineation and potential contaminant sources for source water assessments.

Ground water – Any water that occurs beneath the surface of the earth in a saturated geologic formation of rock or soil.

Ground water flow – The movement of ground water through openings in sediment and rock that occurs in the zone of saturation. This flow is typically under the influence of gravity.

Ground water under the direct influence of surface water (GWUDI) - Any water beneath the surface of the ground with (1) significant occurrence of insects or other macroorganisms, algae, or large diameter pathogens such as Giardia lamblia, or (2) significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH that closely correlate to climatological or surface water conditions.

Hydrologic sensitivity - The susceptibility of a public water system to contamination based on the hydrologic conditions at the source. A well’s hydrologic sensitivity score depends on four factors: (1) composition of surface soil, (2) composition of material in the vadose zone, (3) depth at which ground water is first encountered, and (4) presence of a low permeable unit.

IDAPA - A numbering designation for all administrative rules in Idaho promulgated according to the Idaho Administrative Procedures Act.

Infiltration – The penetration of water through the ground surface into subsurface soil.

Inorganic chemical (IOC) – A chemical substance of mineral origin without carbon in its atomic structure. Examples include nitrate and arsenic. IOCs can be present in drinking water including ground water and surface water.

Landfill – Areas of land or excavations in which wastes are placed for permanent disposal.

Leachable contaminant – Water collects contaminants as it migrates through wastes, pesticides, or fertilizers. Leachable contaminants dissolve into water and filter through the soil in a process known as leaching. Leaching may occur in farming areas, dairies, feedlots, and landfills and may result in hazardous substances entering surface water, ground water, or soil.

Leaking underground storage tank (LUST) – A tank that is leaks or spills hazardous fluids into the soil or ground water.

Maximum contaminant level (MCL) – The maximum permissible level of a contaminant in water delivered to any user of a public water system. MCLs are set by the US Environmental Protection Agency and are enforceable standards.

Microbial contaminants – Contaminants that include viruses such as hepatitis; protozoa such as Giardia; and bacteria such as coliform. Coliform is a bacteria found in the digestive tracts of mammals. Their presence in water can indicate fecal pollution. E. coli is one type of coliform bacteria.

mg/L - milligrams per liter.

Mine site – A site where geologic materials are extracted from the earth.

Nitrate (NO3) – An inorganic compound containing nitrogen and oxygen. Excessive nitrate concentrations in water can cause severe illness in infants, elderly, and pregnant women. Nitrate is typically introduced to the environment by human activities, including septic systems, animal facilities, fertilizers, manure, industrial wastewaters, and landfills. The US Environmental Protection Agency MCL for nitrate is 10 mg/L.

Nitrate priority area – Area where greater than 25% of wells and/or springs that have been sampled have nitrate concentrations greater than or equal to 5 mg/L.

National Pollutant Discharge Elimination System (NPDES) location – These sites, which represent sites with NPDES permits, may be indicated on the delineation and potential contaminant sources map. The federal Clean Water Act requires that any discharge of a pollutant to waters of the United States from a point source must be authorized by an NPDES permit.

Noncommunity public water system – A public water system that is not a community water system. Two types of noncommunity water systems are transient and nontransient.

Nontransient noncommunity public water system – A water system that does not meet the definition of a community supply and serves at least 25 of the same persons, 4 hours or more per day, for 4 or more days per week, for 26 or more weeks per year. Examples of nontransient noncommunity systems include schools, offices, and factories.

Organic compound – Any substance (produced by animals, plants, or humans) that contains mainly carbon, hydrogen, nitrogen, and oxygen in the cellular structure.

Permeability – Ability of a porous medium to transmit fluids under a hydraulic gradient. The property or capacity of a porous rock, sediment, or soil for transmitting a fluid; it is a measure of the relative ease of fluid flow under unequal pressure.

Pesticide management area – An area that is susceptible to pesticide contamination of ground water indicated by elevated pesticide detections in the ground water and requires additional restrictions on pesticide use as determined by the Idaho State Department of Agriculture.

Phosphate mine – Sites where phosphate ore is extracted from the earth.

Potential contaminant source – Any facility or activity that stores, uses, or produces, as a product or by-product, the contaminants regulated under the federal Safe Drinking Water Act, and has a sufficient likelihood of releasing the contaminants at levels that could potentially harm drinking water sources.

Potential contaminant inventory (PCI) – DEQ conducts a PCI to locate and describe facilities, land uses, and environmental conditions within the source water assessment delineation that are potential sources of contamination to ground water or surface water. The PCI is one of three factors used in the susceptibility analysis to evaluate the overall potential contamination risk to a drinking water supply. During the first phase of the PCI, known as the primary contaminant inventory, DEQ staff use computer databases and GIS maps created by DEQ to identify and document potential contaminant sources within the water system’s source water assessment delineation. During the second phase of the PCI, known as the enhanced inventory, DEQ contacts the water system to review the list of potential contaminants identified in the first phase and add any additional potential contaminants not already identified.

Public water system (PWS) - A PWS supplies drinking water to at least 25 people or has at least 15 service connections. Water systems not meeting one or both of these requirements are considered private systems and are not regulated by DEQ.

Recharge – The addition of water to the zone of saturation; also, the amount of water added. Sources of recharge may include, but are not limited to, precipitation, irrigation practices, seepage from creeks, streams and lakes, injection (including stormwater injection wells and agricultural drainage injection wells), and land application of wastewater. Recharge can be expressed as a rate (i.e., inches per year) or a volume.

General waste site – A site where the DEQ Waste and Remediation Program has initiated remediation actions, including aboveground storage tanks, leaking UST, RCRA, mining, and emergency response sites.

Resource Conservation Recovery Act (RCRA) site – RCRA is a federal program established to manage hazardous waste for its entire existence and to ensure that hazardous waste is handled in a manner that protects human health and the environment. Facilities that receive hazardous wastes for treatment, storage, or disposal (TSDs) are regulated by RCRA, which serves as the basis for developing and issuing permits.

Road salt location - A location where the Idaho Department of Transportation stores road salt and sand.

Safe Drinking Water Act – Originally passed by Congress in 1974, the act protects public health by regulating the nation's public drinking water supply. The law authorized the US Environmental Protection Agency and states to oversee public water systems and set standards for drinking water. The law was amended in 1986 and 1996 and requires many actions to protect drinking water and its sources (i.e., rivers, lakes, reservoirs, springs, and ground water wells).

Shallow injection well - A well less than or equal to 18 feet deep in which fluids are injected as a means of disposal or for storage in the subsurface, such as stormwater, agricultural water, and facility heating/cooling water.

Source water – Any aquifer, surface water body, or watercourse from which water is taken either periodically or continuously by a public water system for drinking or food processing purposes.

Source water assessment – This assessment provides information on the potential contaminant threats to public drinking water sources. Each source water assessment consists of a delineation of the water source area, contaminant inventory, and susceptibility analysis.

Static water level - This level refers to the level of water in a well under normal, no-pumping conditions.

Surface water(s) - All water open to the atmosphere and subject to surface runoff, including lakes, ponds, streams, rivers, and other water bodies that lie on the surface of the land. Surface waters may be partially or fully supplied by ground water.

Susceptibility score – The susceptibility to potential contamination for each well, spring, or surface water intake in a public water system. Before analyzing susceptibility, DEQ defines the source water assessment delineation.

Synthetic organic chemical (SOC) - Any humanmade organic compound. SOCs include pesticides, herbicides, and many chemicals with industrial uses. SOCs may be present in ground water and drinking water.

Tier II (formerly Computer-Aided Management of Emergency Operations [CAMEO] chemical facility) – A facility that stores or uses hazardous material and is included in the CAMEO database. Idaho’s database is maintained by the Idaho Bureau of Homeland Security.

Time of travel (TOT) – The number of years necessary for a particle of water to travel in the aquifer to reach a well.

Toxic release inventory (TRI) site – These sites may be indicated on the delineation and potential contaminant sources maps. TRI sites indicate locations of potential contaminants identified on the federal Toxics Release Inventory, which is a database made available to public by the US Environmental Protection Agency. The TRI contains information on toxic chemical releases and waste management activities reported annually by certain industries and federal facilities. The TRI list was developed as part of the federal Emergency Planning and Community Right to Know Act passed in 1986. This act requires the reporting of any release of a chemical found on the TRI list. Visit for a full list of chemicals on the TRI.

Transient noncommunity public water systems – A public water system that does not regularly serve at least 25 of the same persons over 6 months per year (e.g., tavern, restaurant with less than 25 regular employees, motel, church, campground, state or federal park, an RV park, or highway rest area).

Tunnels - A drainage tunnel historically constructed to drain excess flood irrigation water from agricultural fields. A series of drains in the field empties the excess water into the tunnel.

µg/L - micrograms per liter.

Underground storage tank (UST) site – While many types of storage tanks may be buried underground, the term underground storage tank refers specifically to tanks regulated under RCRA. These tanks are buried at least 10% underground and store either petroleum products (gasoline, diesel, kerosene, or jet fuel) or certain hazardous substances. The underground piping connected to the tanks is also considered part of the UST. USTs are most often found at gas stations and other fueling facilities. For more information, see

Vadose zone - Referring to ground water, this zone lies between the land surface and water table.

Volatile organic chemical (VOC) – Any organic compound that easily evaporates at room temperature. VOCs are emitted by thousands of products. Examples include paints and lacquers, paint strippers, cleaning supplies, pesticides, building materials and furnishings, office equipment such as copiers and printers, correction fluids and carbonless copy paper, graphics and craft materials including glues and adhesives, permanent markers, and photographic solutions. VOCs may be present in ground water and drinking water.

Wastewater lagoon – Humanmade impoundments used for storing or treating wastewater.

Water reuse area – Areas where municipal or industrial wastewater is applied for land treatment purposes.

Well casing – The tube or pipe placed inside a well to protect the water from contamination and prevent the well from caving in.

Wellhead – The physical structure, facility, or device at the land surface from or through which ground water flows or is pumped from subsurface water-bearing formations.