Appendix C
Glossary

SOURCES: Adapted from 25 PA Code § 73; EPA, 1997 and 2002; NSFC, 2001; PADEP, 2003 and 2004a, b, c.


Abandoned well

A well whose use has been permanently discontinued or that is in a state of such disrepair cannot be used for its intended purpose.

Absorption area

A component of an individual or community sewage system where liquid from a treatment tank seeps into the soil; it consists of an aggregate-filled area containing piping for the distribution of liquid and the soil or sand-soil combination located beneath the aggregate.

Acid mine drainage (AMD)

Drainage of water from areas that have been mined for coal or other mineral ores. The water has a low pH because of its contact with sulfur-bearing material and is harmful to aquatic organisms.

Aeration

A process that promotes biological degradation of organic matter in water. The process may be passive (e.g., when waste is exposed to air) or active (e.g., when a mixing or bubbling device introduces the air).

Alternate sewage system

Method of demonstrated on-site sewage treatment and disposal not described in 25 PA Code § 73. Such systems may be considered for individual or community on-site use to solve an existing pollution or public health problem, overcome site suitability deficiencies, overcome engineering problems related to the site or its proposed use, or utilize a successful experimental design under varying site conditions.

Assimilative capacity

The ability of a natural body of water to receive wastewaters or toxic materials without deleterious effects and without damage to aquatic life or humans who consume the water.


Benefit-cost analysis

An economic method for assessing the benefits and costs of achieving alternative health-based standards at given levels of health protection.

Biological oxygen demand

A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater is the degree of pollution.

Biological contaminants

Living organisms or derivatives (e.g., viruses, bacteria, fungi, mammal and bird antigens) that can cause harmful health effects when inhaled, swallowed, or otherwise taken into the body.

Borehole disposal

Individual or community systems, discharging to a borehole, abandoned water well, drywell, ventilation shaft, or other subterranean structure.


Cesspool

An outdated (nineteenth to mid-twentieth century) method of sewage disposal that is not permitted in modern regulations. A cesspool may be described as an “igloo-like” structure, built of loose (without mortar) rock or building blocks, that is buried underground. Cesspools are not watertight and allow the sewage entering them to drain



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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania Appendix C Glossary SOURCES: Adapted from 25 PA Code § 73; EPA, 1997 and 2002; NSFC, 2001; PADEP, 2003 and 2004a, b, c. Abandoned well— A well whose use has been permanently discontinued or that is in a state of such disrepair cannot be used for its intended purpose. Absorption area— A component of an individual or community sewage system where liquid from a treatment tank seeps into the soil; it consists of an aggregate-filled area containing piping for the distribution of liquid and the soil or sand-soil combination located beneath the aggregate. Acid mine drainage (AMD)— Drainage of water from areas that have been mined for coal or other mineral ores. The water has a low pH because of its contact with sulfur-bearing material and is harmful to aquatic organisms. Aeration— A process that promotes biological degradation of organic matter in water. The process may be passive (e.g., when waste is exposed to air) or active (e.g., when a mixing or bubbling device introduces the air). Alternate sewage system— Method of demonstrated on-site sewage treatment and disposal not described in 25 PA Code § 73. Such systems may be considered for individual or community on-site use to solve an existing pollution or public health problem, overcome site suitability deficiencies, overcome engineering problems related to the site or its proposed use, or utilize a successful experimental design under varying site conditions. Assimilative capacity— The ability of a natural body of water to receive wastewaters or toxic materials without deleterious effects and without damage to aquatic life or humans who consume the water. Benefit-cost analysis— An economic method for assessing the benefits and costs of achieving alternative health-based standards at given levels of health protection. Biological oxygen demand— A measure of the amount of oxygen consumed in the biological processes that break down organic matter in water. The greater the BOD, the greater is the degree of pollution. Biological contaminants— Living organisms or derivatives (e.g., viruses, bacteria, fungi, mammal and bird antigens) that can cause harmful health effects when inhaled, swallowed, or otherwise taken into the body. Borehole disposal— Individual or community systems, discharging to a borehole, abandoned water well, drywell, ventilation shaft, or other subterranean structure. Cesspool— An outdated (nineteenth to mid-twentieth century) method of sewage disposal that is not permitted in modern regulations. A cesspool may be described as an “igloo-like” structure, built of loose (without mortar) rock or building blocks, that is buried underground. Cesspools are not watertight and allow the sewage entering them to drain

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania into the surrounding area. Unlike septic tanks, cesspools provide very little treatment to sewage before releasing it to the environment, and unlike holding tanks, cesspools do not retain sewage for treatment elsewhere. Chemical stressors— Chemicals released to the environment through industrial waste, auto emissions, pesticides, and other human activity that can cause illness and even death in plants and animals. Chlorination— The application of chlorine to drinking water, sewage, or industrial waste to disinfect or oxidize undesirable compounds. Cistern— Small tank or storage facility used to store water for a home or farm; often used to store rainwater. Clarification— Clearing action that occurs during wastewater treatment when solids settle out, it is often aided by centrifugal action and chemically induced coagulation in wastewater. Cluster OSTDS— An on-site sewage treatment and disposal system under some form of common ownership and management that provides treatment and dispersal or discharge of wastewater from two or more homes or buildings but less than an entire community. (See On-site sewage treatment and disposal system) Coliform index— A rating of water purity based on a count of fecal bacteria. Coliform organism— Microorganisms found in the intestinal tract of humans and animals, their presence in water indicates fecal pollution and potentially adverse contamination by pathogens. Collector sewers— Pipes used to collect and carry wastewater from individual sources to an interceptor sewer that will carry it to a treatment facility. Combined sewer overflows— Discharge of a mixture of stormwater and domestic waste when the flow capacity of a sewer system is exceeded during rainstorms. Combined sewers— A sewer system that carries both sewage and stormwater runoff. Normally, its entire flow goes to a waste treatment plant, but during a heavy storm, the volume of water may be so great as to cause overflows of untreated mixtures of stormwater and sewage into receiving waters. Stormwater runoff may also carry toxic chemicals from industrial areas or streets into the sewer system. Community water system— A public water system that serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents. Consent order— A legal document, also known as a consent decree, signed by the U.S. Environmental Protection Agency (EPA) and an individual, business, or other entity, committing that entity to take corrective action or refrain from an activity. The consent order describes the actions to be taken and can be enforced in court. Contaminant— Any physical, chemical, biological, or radiological substance or matter that has an adverse effect on air, water, or soil. (See also pollutant, these two terms are used interchangeably in this report.) Conventional pollutants— Statutorily listed pollutants that are well understood by scientists. These may be in the form of organic waste, sediment, acid, bacteria, viruses, nutrients, oil and grease, or heat. Conventional sewage system— System employing the use of demonstrated on-site sewage treatment and disposal technology in a manner specifically recognized by 25 PA Code § 73; includes septic tank or gravity absorption trenches, in-ground seepage bed, aerobic treatment system, pressure distribution absorption system, subsurface sand filter, elevated sand mound, and recycling-incinerating-composting toilets.

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania Corrosion— The dissolution and wearing away of metal caused by a chemical reaction—for example, between water and the pipes, chemicals touching a metal surface, or contact between two metals. Criteria— Descriptive factors taken into account by EPA in setting standards for various pollutants. These factors are used to determine limits on allowable concentration levels and to limit the number of violations per year. When issued by EPA, the criteria provide guidance to the states on how to establish their standards. Design capacity— The average daily flow that a treatment plant or other facility is designed to accommodate. Designated uses— Those water uses identified in state water quality standards that must be achieved and maintained as required under the federal Clean Water Act. Uses can include public water supply, aquatic life use, and contact recreation, among others. Direct discharger— A municipal or industrial facility that introduces pollution through a defined conveyance or system such as outlet pipes; a point source. Direct runoff— Water that flows over the ground surface or through the ground directly into streams, rivers, and lakes. Discharge— The flow of surface water in a stream or canal or the outflow of groundwater from a flowing artesian well, ditch, or spring; it can also apply to discharge of liquid effluent from a facility. Dissolved oxygen (DO)— The oxygen freely available in water, vital to fish and other aquatic life and for the prevention of odors. DO levels are considered an important indicator of a waterbody’s ability to support desirable aquatic life. Secondary and advanced wastewater treatment are generally designed to ensure adequate DO in waste-receiving waters. Dissolved solids— Disintegrated organic and inorganic material in water. Excessive amounts make water unfit to drink or use in industrial processes. Drainage— Improving the productivity of agricultural land by removing excess water from the soil by means such as ditches or subsurface drainage tiles. Drainage basin— The area of land that drains water, sediment, and dissolved materials to a common outlet at some point along a stream channel. Effluent— Wastewater, treated or untreated, that flows out of a treatment plant, sewer, or industrial outfall. Generally refers to wastes discharged into surface waters. Effluent limitation— Restrictions established by a state or the EPA on quantities, rates, and concentrations in wastewater discharges. EMAP data— Environmental monitoring data collected under the auspices of EPA’s Environmental Monitoring and Assessment Program. All EMAP data share the common attribute of being of known quality, having been collected in the context of explicit data quality objectives (DQOs), and being subject to a consistent quality assurance program. Environmental indicator— A measurement, statistic, or value that provides a proximate gauge or evidence of the effects of environmental management programs or of the state or condition of the environment. Eutrophication— The slow aging process induced by higher levels of nutritive compounds (e.g., nitrogen and phosphorus) during which a waterbody can evolve into a bog or marsh and eventually disappear. Human activities can accelerate the process.

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania Experimental sewage system— Method of on-site sewage treatment and disposal not described in the Pennsylvania Code that is proposed for the purpose of testing and observation. These systems may be considered for individual or community on-site use to solve an existing pollution or public health problem; overcome site suitability deficiencies; overcome engineering problems related to the site or its proposed use; evaluate new concepts or technologies applicable to on-site disposal; or evaluate the applicability to on-site disposal of established concepts or technologies having successful use in comparable applications in the field of engineering. Facilities plans— Plans and studies related to the construction of treatment works necessary to comply with the federal Clean Water Act. A facilities plan investigates needs and provides information on the cost-effectiveness of alternatives; a recommended plan; an environmental assessment of the recommendations; and descriptions of the treatment works, costs, and a completion schedule. Fecal coliform bacteria— Bacteria found in and emanating from the intestinal tracts of mammals, including humans. Their presence in water or sludge is an indicator of microbial pollution and possible contamination by pathogens. Finished water— The condition of water when it has passed through all the processes in a water treatment plant and is ready to be delivered to consumers through a distribution system for consumption or contact use. Flocculation— Process by which clumps of solids in water or sewage aggregate through biological or chemical action so they can be separated from water or sewage. Groundwater— Freshwater found beneath the earth’s surface, usually in aquifers, that supplies wells and springs. Because groundwater is a major source of drinking water, there is growing concern over contamination from leaching agricultural or industrial pollutants or leaking underground storage tanks. Heavy metals— Metallic elements with high atomic weights (e.g., mercury, chromium, cadmium, arsenic, lead) that can damage living things at low concentrations and tend to accumulate in the food chain. Holding tank— A tank, whether permanent or temporary, to which sewage is conveyed by a water-carrying system; a watertight receptacle that receives and retains sewage and is designed and constructed to facilitate ultimate disposal of sewage at another site. Holding tanks do not treat sewage; they merely store sewage that will be treated at another location. Unlike septic tanks, holding tanks have no outlet to a soil absorption area. Indicator— In biology, any biological entity, processes, or community whose characteristics show the presence of specific environmental conditions. In chemistry, a substance that demonstrates a visible change, usually of color, at a desired point in a chemical reaction. Industrial waste— Unwanted materials from an industrial operation; that may be liquid, sludge, solid, or hazardous waste. Infiltration— The penetration of water through the ground surface into subsurface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls.

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania Influent— Water, wastewater, or other liquid flowing into a reservoir, basin, or treatment plant. Innovative technologies— New or inventive methods to treat effectively hazardous waste and reduce risks to human health and the environment. Interceptor sewers— Large sewer lines that, in a combined system, control the flow of sewage to the treatment plant. In a storm, they allow some of the sewage to flow directly into a receiving stream, thus keeping it from overflowing onto the streets. Also used in separate sewer systems to collect the flows from main and trunk sewers and carry them to treatment points. Land application— Application of wastewater onto the ground for subsequent treatment or reuse. Lateral sewers— Privately owned pipes that run under city streets and receive the sewage from homes and businesses, as opposed to domestic feeders and main trunk lines. Leachate— Water that collects contaminants as it trickles through wastes, pesticides, or fertilizers. Leaching may occur in farming areas, feedlots, and landfills and may result in hazardous substances entering surface water, groundwater, or soil. Leachate collection system— A system that gathers leachate and pumps it to the surface for treatment. Maximum contaminant level (MCL)— The maximum permissible level of a contaminant in water delivered to any user of a public system. MCLs are enforceable standards. Municipal sewage— Waste (mostly liquid) originating from a community; it may be composed of domestic wastewaters and/or industrial discharges. Nonpoint source (NPS)— Diffuse pollution source (i.e., without a single point of origin or not introduced into a receiving stream from a specific outlet). The pollutants are generally carried off the land by stormwater or through the air. Common NPs are agriculture, forestry, urban, mining, construction, land disposal, and city streets. On-site sewage treatment and disposal system (OSTDS)— A system relying on natural processes and/or mechanical components that is used to collect, treat, and disperse or discharge wastewater from single dwellings or buildings. Outfall— The physical location at which effluent is discharged into receiving waters. Overflow rate— One of the guidelines for the design of settling tanks and clarifiers in a wastewater treatment plant; it is used by plant operators to determine if tanks and clarifiers are over- or underused. Package plant— A small sewage treatment plant of compact, prefabricated design to reduce capital costs, utilizing mechanical and/or aerobic treatment; used for sewage flows of greater than 0.002 million gallons per day (mgd) but less than 0.1 mgd; commonly privately owned; requires regular operation and maintenance by professional operators. Pathogens— Microorganisms (bacteria, viruses, or parasites) that can cause disease in humans. Permit— An authorization, license, or equivalent control document issued by the EPA or a state agency to implement the requirements of an environmental regulation (e.g., a permit to operate a wastewater treatment plant or a facility that may generate harmful emissions).

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania Point source— A stationary location or fixed facility from which pollutants are discharged; any single identifiable source of pollution, (e.g., a pipe, ditch, ship, ore pit, factory smokestack). Pollutant— Generally, any substance introduced into the environment that adversely affects the usefulness of a resource or the health of humans, animals, or ecosystems. (See also contaminant; these two terms are used interchangeably in this report) Potable water— Water that is safe for drinking and cooking. Primary drinking water regulation— Rule that applies to public water systems and specifies a contaminant level, that, in the judgment of EPA, will not adversely affect human health. Primary waste treatment— First steps in wastewater treatment in which screens and sedimentation tanks are used to remove most materials that float or will settle. Primary treatment removes about 30 percent of carbonaceous biochemical oxygen demand from domestic sewage. Privy vault— A hole in the ground to receive waste, underlying an outhouse. Public water system (PWS)— A system that provides piped water for human consumption to at least 15 service connections or regularly serves 25 individuals. Pumping station— Mechanical device installed in sewer or water systems or other liquid-carrying pipelines to move the liquids to a higher level. Raw sewage— Untreated wastewater and its contents. Raw water— Intake water prior to any treatment or use. Real-time monitoring— Monitoring and measuring environmental developments with technology and communications systems that provide time-relevant information to the public in an easily understood format that people can use in day-to-day decision making about their health and the environment. Receiving waters— A river, lake, ocean, stream, or other watercourse into which wastewater or treated effluent is discharged. River basin— The land area drained by a river and its tributaries. Runoff— That part of precipitation, snow melt, or irrigation water that runs off the land into streams or other surface water. Sanitary sewers— Underground pipes that carry off only domestic or industrial waste, not storm- water. Sanitary water— Water discharged from sinks, showers, kitchens, or other nonindustrial operations, but not from commodes. Screening— Use of screens to remove coarse floating and suspended solids from sewage. Secondary drinking water regulations— Nonenforceable regulations applying to public water systems and specifying the maximum contamination levels that, in the judgment of EPA, are required to protect the public welfare. They apply to any contaminants that may adversely affect the odor or appearance of such water and consequently may cause people served by the system to discontinue its use. Secondary treatment— The second step in most publicly owned waste water treatment systems in which bacteria consume the organic parts of the waste. This is accomplished by bringing together waste, bacteria, and oxygen in trickling filters or in the activated sludge process. The treatment removes floating and settleable solids and about 90 percent of the

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania oxygen-demanding substances and suspended solids. Disinfection is the final stage of secondary treatment. Seepage— Percolation of water through the soil from unlined canals, ditches, laterals, watercourses, or water storage facilities. Septic system— An OSTDS designed to treat and dispose of domestic sewage. A typical septic system consists of a tank that receives waste from a residence or business and an absorption area for subsequent disposal of the liquid effluent (sludge) that remains after decomposition of the solids by bacteria in the tank, which must be pumped out periodically. Septic tank— An underground storage tank for wastes from homes not connected to a sewer line. Waste goes directly from the home to the tank. Settling tank— A holding area for wastewater, in which heavier particles sink to the bottom for removal and disposal. Sewage— The waste and wastewater produced by residential and commercial sources and discharged into sewers. Sewer— A channel or conduit that carries wastewater and stormwater runoff from the source to a treatment plant or receiving stream “sanitary” sewers carry household, industrial, and commercial waste, “storm” sewers carry runoff from rain or snow, “combined” sewers handle both. Sewerage— The entire system of sewage collection, treatment, and disposal infrastructure. Sludge— A semisolid residue from any of a number of water treatment processes; it can be regulated as hazardous waste. Storm sewer— A system of pipes (separate from sanitary sewers) that carries water runoff from buildings and land surfaces. Straight pipe— One that discharges untreated or partially treated sewage from a single dwelling structure onto the ground surface, or into a ditch, storm sewer, adjacent waterbody, or other water. Stressors— Physical, chemical, or biological entities that can induce adverse effects on ecosystems or human health. Surface runoff— Precipitation, snow melt, or irrigation water in excess of the amount that can infiltrate the soil surface and be stored in small surface depressions; a major transporter of nonpoint source pollutants in rivers, streams, and lakes. Synthetic organic chemicals— Man-made organic chemicals, some are volatile, others tend to stay dissolved in water instead of evaporating. Total suspended solids— A measure of the suspended solids in wastewater, effluent, or waterbodies, determined by tests for “total suspended nonfilterable solids.” Toxic substance— A chemical or mixture that may present an unreasonable risk of injury to health or the environment. Toxicant— A harmful substance or agent that may injure an exposed organism. Toxicity— The degree to which a substance or mixture of substances can harm humans or animals. Acute toxicity involves harmful effects in an organism through a single or short-term exposure. Chronic toxicity is the ability of a substance or mixture of substances to cause harmful effects over an extended period, usually upon repeated or continuous exposure, sometimes lasting for the entire life of the exposed organism. Subchronic

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania toxicity is the ability of the substance to cause effects for more than one year but less than the lifetime of the exposed organism. Treated wastewater— Wastewater that has been subjected to one or more physical, chemical, and biological processes to reduce its potential of being a health hazard. Urban runoff— Stormwater from city streets and adjacent domestic or commercial properties that carries pollutants of various kinds into the sewer systems and receiving waters. Waste load allocation— (1) The maximum load of pollutants that each discharger of waste is allowed to release into a particular waterway. Discharge limits are usually required for each specific water quality criterion being, or expected to be, violated. (2) The portion of a stream’s total assimilative capacity assigned to an individual discharge. Wastewater— The spent or used water from a home, community, farm, or industry that contains dissolved or suspended matter. Wastewater treatment plant— A facility containing a series of tanks, screens, filters, and other processes by which pollutants are removed from wastewater. Water quality criteria— Levels of water quality expected to render a body of water suitable for its designated use. Criteria are based on specific levels of pollutants that would make the water harmful if used for drinking, swimming, farming, fish production, or industrial processes. Water quality standards— State-adopted and EPA-approved ambient standards for waterbodies. The standards prescribe the use of the waterbody and establish the water quality criteria that must be met to protect designated uses. Watershed— The land area that drains into a stream; the watershed for a major river may encompass a number of smaller watersheds that ultimately combine at a common point. Watershed approach— A coordinated framework for environmental management that focuses public and private efforts on the highest priority problems within hydrologically defined geographic areas by taking systematically into consideration both ground- and surface water flow. Wildcat sewer— Community straight pipe or collection system (community sewer) serving more than one equivalent dwelling and discharging untreated or partially treated sewage to the surface of the ground, storm sewers, or other water. REFERENCES 25 PA Code § 73. Standards for On-lot (site) Sewage Treatment Facilities. Available on-line at http://www.pacode.com/secure/data/025/chapter73/chap73toc.html. Accessed August 18, 2004. EPA (U.S. Environmental Protection Agency). 1997. Terms of Environment. Available on-line at http://www.epa.gov/OCEPAterms/. Accessed August 18, 2004. EPA. 2002. Onsite Wastewater Treatment Systems Manual. Available on-line at http://www.epa.gov/ORD/NRMRL/Pubs/625R00008/html/625R00008gloss.htm. Accessed August 18, 2004. NSFC (National Small Flows Clearinghouse). 2001. Poster: Wastewater Collection and Treatment Systems for Small Communities. Morgantown, WV: NSFC.

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Regional Cooperation for Water Quality Improvement in Southwestern Pennsylvania PADEP (Pennsylvania Department of Environmental Protection). 2003. Experimental Systems Guidance. 362-0300-008. Harrisburg, PA: Bureau of Water Supply and Wastewater Management. PADEP. 2004a. Alternate Systems Guidance. 362-0300-007. Harrisburg, PA: Bureau of Water Supply and Wastewater Management. PADEP. 2004b. Act 537: Pennsylvania Sewage Facilities Act with Index. Harrisburg, PA: Bureau of Water Supply and Wastewater Management. PADEP. 2004c. Understanding Holding Tanks. Fact Sheet 3800-FS-DEP2807. Harrisburg, PA: Office of Water Management.