Molecules of one type are pulled within another material. Not to be confused with adsorption which refers to surface adhesion only.
One acre-foot of water covers a surface area of 1 acre and is 1 foot deep. Equal to 43,569 cubic feet of water or about 325,896 gallons.
The concentration of a contaminant, at and beyond which, treatment may be required to reduce levels or invoke other treatment measures. Typically, action levels are in reference to concentrations of lead and copper.
Occurring over a short period of time; used to describe brief exposures and effects, which appear promptly after exposure; poses an immediate risk to human health.
Molecules of one type attach to the surface of another molecule or material.
The process of adding air to water either by passing water through air or passing air through water.
Referring to the quality of a water as determined by the senses. Typically color, odor, and taste of a water.
A physical separation between the free-flowing end of a potable water supply pipeline and the overflow rim of an open or non-pressurized, receiving vessel. To be an air gap approved by the department, the separation must be at least: 1. twice the diameter of the supply piping measured vertically from the overflow rim of the receiving vessel, and in no case be less than one inch, when unaffected by vertical surfaces (sidewalls). 2. three times the diameter of the supply piping, if the horizontal distance between the supply pipe and a vertical surface (sidewall) is less than or equal to three times the diameter of the supply pipe, or if the horizontal distance between the supply pipe and intersecting vertical surfaces (sidewalls) is less than or equal to four times the diameter of the supply pipe and in no case less than one and one-half inches.
Valves used to release trapped air or vacuums created in water pipelines.
Referring to waters high in dissolved oxygen, neutral to low pH, and have low alkalinity (below 80 mg/L). Aggressive conditions allow water to easily dissolve metals such as iron, copper, and lead.
A measure of a water's capacity to neutralize acids. The buffering capacity of a water; its ability to resist change in pH when acids are added. Alkalinity is composed of bicarbonates, carbonate, and hydroxide.
Mud and/or sand deposited by flowing water, commonly formed in river valleys and deltas from materials washed down the river after a heavy rain storm.
An electric current of constantly changing value which reverses direction of electrical flow at regular intervals.
A valve that automatically opens and closes to maintain the level of water in a reservoir. Most commonly a wide body globe valve.
Common name for the coagulant aluminum sulfate.
Referring to surrounding conditions or the surrounding atmosphere.
Institute that oversees the creation, promulgation and use of thousands of norms and guidelines that directly impact businesses in nearly every sector: from acoustical devices to construction equipment, from dairy and livestock production to energy distribution, and many more. ANSI is also actively engaged in accrediting programs that assess conformance to standards - including globally-recognized cross-sector programs such as the ISO 9000 (quality) and ISO 14000 (environmental) management systems.
Founded in 1852, the ASCE represents more than 140,000 members of the civil engineering profession worldwide, and is America's oldest national engineering society. ASCE's vision is to position engineers as global leaders building a better quality of life.
AWWA (American Water Works Association) is an association of waterworks personnel, equipment manufacturers, suppliers and engineers.
An inflammation of the colon causing diarrhea of varying degrees of severity that results from infection by an amoeba Entamoeba histolytica.
A negatively charged ion.
The ring-shaped space located between the bore-hole of a well and the well casing; the space between any two pipes fit within each other.
Color of water caused by suspended and dissolved particles.
Portions of a main structure necessary to allow it to operate as intended, but not considered part of the main structure (hydrants, valves, tees, elbows, etc.).
A natural underground layer of porous, water-bearing materials (sand, gravel) usually capable of yielding a large amount of water.
Water held under pressure in porous rock or soil confined by impermeable geologic formations. Also, see CONFINED AQUIFER.
The drawing created by an engineer from the collection of the original design plans, including changes made to the design or to the system, that reflects the actual constructed condition of the water system.
A backflow-prevention apparatus with two shut-off valves and two test cocks that can be tested while in line.
A mechanical device that prevents backflow due to siphoning action created by a partial vacuum that allows air into the piping system, breaking the vacuum.
The smallest part of an element which still retains the properties of that element.
The total quantity of water use from all sources of supply, as measured or estimated over a calendar year, divided by 365. ADD is typically expressed as gallons per day per ERU (gpd/ERU).
Occurs when normal flow in the distribution system is reversed due to an increase in the downstream pressure above the supply pressure. Typically caused by a pump, elevated tank or piping, boiler, etc. on the consumer's side of the service connection that is greater than the pressure provided by the public water system.
Back-siphonage can occur when a negative pressure (below atmospheric pressure, or a vacuum) develops in the distribution system which can allow pollutants or contaminants to be siphoned into the water system.
The undesirable reversal of flow of water or other substances, through a cross-connection, into a public water system or consumer's potable water system.
The reversal of flow through a filter in order to clean the filter by removal of material trapped by the media in the filtration process.
Living organisms, microscopic in size, which consist of a single cell. Most bacteria utilize organic matter for their food and produce waste products as the result of their life processes. Examples are Acidophilus, found in yogurt, E. coli, found in the colon, and Streptococcus, the cause of strep throat.
The water quality data, precipitation data and stream flow data that is accumulated from a drainage basin or groundwater supply when there was little or no activity in the area.
A light-colored valuable clay that expands with the addition of water and is used as a sealant in water wells, as oil-well drilling mud, and as a filler in the building, paper, soap, and pharmaceutical industries.
The best technology, treatment techniques, or other means that EPA finds, after examination for efficacy under field conditions, are available, taking cost into consideration.
A way of indirectly determining the biological quality of a water by measuring how fast oxygen is depleted by biological organisms in the water.
A sample collected from two or more individual sources at a point downstream of the confluence of the individual sources and prior to the first connection.
The output horsepower of an electric motor. The representation of the amount of work that the motor can perform. Providing work of 33,000 foot pounds per minute is equivalent to one horsepower.
Addition of chlorine to water until the chlorine demand has been satisfied. At this point, further additions of chlorine will result in a free residual chlorine which is directly proportional to the amount of chlorine added beyond the breakpoint.
The act of material or contamination making its way through a filter, typically as a result of a failure to maintain or replace the filter.
A substance or mechanism that prevents excessive change in a system.
A valve whose movable closure rotates 90 degrees around a shaft that is set through the center of the closure and the center of the flow path.
Something produced, usually in an industrial or biological process, in addition to the principal product.
The residual disinfectant concentration in mg/L at a point before or at the first consumer.
The factor used in the Hazen and Williams equation for determining headloss. The “C” Factor is a representation of the hydraulic roughness of the pipe. The larger the number the smoother the pipe is hydraulically.
Large pipe placed in a vertical position.
The principal compound of hardness. The term used as an equivalent for hardness and alkalinity. Symbolically CaCO3.
A dry material, of about 65% available chlorine, that comes as a powder, granular or tablet form.
The financial, managerial, and technical abilities of a public water supply system to meet the requirements of the Safe Drinking Water Act. It is also sometimes referred to as system viability.
Carbonic acid (ancient name acid of air or aerial acid) has the formula H2CO3. It is also a name sometimes given to solutions of carbon dioxide in water, which contain small amounts of H2CO3. The salts of carbonic acids are called bicarbonates (or hydrogen carbonates) and carbonates. It is a weak acid.
A positively charged ion.
The enclosure surrounding the pump, where the suction and discharge ports operate.
The formation and collapse of a gas pocket or bubble on the blade of an impeller or the gate of a valve. The collapse of the pocket or bubble drives water into the valve or impeller with enough force to cause pitting. It is accompanied by loud noises which sound like someone pounding on the impeller or gate with a hammer.
A pump consisting of an impeller on a rotating shaft enclosed by a casing that has suction and discharge connections. The spinning impeller throws water outward at high velocity, and the casing shape converts this high velocity to pressure.
A special valve with a hinged disc or flap that opens in the direction of normal flow and is forced shut when flows attempt to go in the reverse or opposite direction of normal flow.
The ability of pipe, valve or tank materials to be in contact with certain chemicals without losing strength or integrity. Corrosive chemicals in particular need compatible materials used for their storage and application.
Berms, walls or other means by which potential chemical spills are limited to a controlled area.
Compounds of organic or inorganic nitrogen and chlorine sometimes used a disinfectant; A nitrogen compound changed to form monochloramines, dichloramines and trichloramines.
The difference between the amount of chlorine added to water and the amount of residual chlorine remaining after a given contact time.
A greenish-yellow gas with a penetrating and distinctive odor used for disinfection. Chlorine gas is 100% available chlorine and is highly toxic in pure form.
A devastating and sometimes lethal disease caused by infection with Vibrio cholera, a comma-shaped bacteria, which thrives in damp, moist places and stools of infected patients. Symptoms include intense vomiting and diarrhea leading to dehydration which, unless immediately treated, may be fatal.
Occurring over a long period of time, either continuously or intermittently; used to describe ongoing exposures and effects that develop only after a long exposure. ….generally caused after long-term and low-level exposure to a contaminant.
A chemical used in water treatment to destabilize particulates and accelerate the rate at which they aggregate into larger particles.
A process, using coagulant chemicals and rapid mixing, to destabilize colloidal and suspended particles and to agglomerate them into floc.
The CFR is the foundation of many regulations implemented in states including regulations regarding drinking water, wastewater and construction.
A group of bacteria found in the intestines of warm-blooded animals (including humans) also in plants, soil, air and water. The presence of coliforms is an indication that the water is polluted and may contain pathogenic organisms.
Any substance in a certain state of fine division in which the particles are less than one micron in diameter.
Used to measure unknown chemical concentrations in water by measuring a sample's color intensity. The specific color of the sample, developed by addition of chemical reagents, is measured with a photoelectric colorimeter or is compared with “color standards” using, or corresponding with, known concentrations of the chemical.
Portion of the residual chlorine that has combined with ammonia, other nitrogen compounds, or organic matter.
Public water systems which serve at least 15 service connections used by year-round residents or regularly serve at least 25 year-round residents.
A sample in which more than one source is sampled individually by the water system and then composited by a certified laboratory by mixing equal parts of water from each source (up to five different sources) and then analyzed as a single sample.
A schedule that describes both the frequency and appropriate locations for sampling of drinking water contaminants as required by state and federal rules.
A thorough review and analysis of a treatment plant's performance-based capabilities and associated administrative, operation and maintenance practices. It is conducted to identify factors that may be adversely impacting a plant’s capability to achieve compliance and emphasizes approaches that can be implemented without significant capital improvements. The comprehensive performance evaluation must consist of at least the following components: Assessment of plant performance; evaluation of major unit processes; identification and prioritization of performance limiting factors; assessment of the applicability of comprehensive technical assistance; and preparation of a CPE report.
A measure of the ability of water to carry an electric current. Conductivity increases with total dissolved solids.
The depression, roughly conical in shape, produced in a water table or other piezometer surface by the extraction of water from a well at a given rate.
An aquifer which is surrounded by formations of less permeable or impermeable material.
As defined by NIOSH, is a space which by design has limited openings for entry and exit; unfavorable natural ventilation which could contain or produce dangerous air contaminants, and which is not intended for continuous employee occupancy.
Means to demonstrate the accuracy of results of a sample by analyzing another sample from the same location within a reasonable period of time, generally not to exceed two weeks. Confirmation is when analysis results fall within plus or minus thirty percent of the original sample results.
A continuous bacterial growth covering a portion or the entire filtration area of a membrane filter in which bacterial colonies are not discrete.
A geologic material whose particles are stratified (layered), cemented or firmly packed together (hard rock).
A type of piston, diaphragm, gear or screw pump that delivers a constant volume with each stroke. They are often used as chemical solution feeders.
An annual report to consumers of each community public water supply system on the source of their water and the levels of contaminants found in the drinking water.
The amount of time in minutes that the disinfectant, measured as a free residual, is in contact with the water; before the water is delivered to the first customer.
An impurity that causes air, soil, or water to be harmful to human health or the environment; something that makes a substance impure, infected, corrupted, or polluted.
That portion of the wellhead protection program section of the water system plan or small water system management program that addresses the replacement of the major well(s) or wellfield in the event of loss due to ground water contamination.
A series of processes including coagulation, flocculation, clarification, and filtration that together result in substantial particulate removal in compliance with Part 6 of this chapter.
A water service shutoff valve located at a street water main. This valve cannot be operated from the ground surface because it is buried and there is no valve box.
The gradual decomposition or destruction of a material by chemical action, often due to an electrochemical reaction. Corrosion may be caused by: stray current electrolysis; galvanic corrosion caused by dissimilar metals; differential concentration cells.
An indication of the corrosiveness of water. The corrosiveness of water is described by the water's pH, alkalinity, hardness, temperature, total dissolved solids, and the dissolved oxygen concentration.
Any actual or potential physical connection between a public water system or the consumer's water system and any source of non-potable liquid, solid, or gas that could contaminate the potable water supply by backflow.
An infectious condition of humans and domestic animals, characterized by fever, diarrhea, and stomach cramps. It is spread by a protozoan of the genus Cryptosporidium.
A cyst-forming protozoan found in water that causes gastrointestinal illness in humans. The primary sources are human and animal feces.
Valve located between the corporation stop on a water main and the customer’s home, business, or other facility. This valve is used to shut off the water supply leading to a facility.
The deliberate removal of chlorine from water. The partial or complete reduction of residual chlorine by any chemical or physical process. A commonly used chemical dechlorinating agent is sodium thiosulfate.
Identification and mapping of the area around a pumping well.
When related to chlorine, the amount of chlorine utilized by iron, manganese, algae and microorganisms in a specified period of time. When related to use, demand is the amount of water used in a period of time. The term is in reference to the “demand” put onto the system to meet the need of customers.
The weight per unit volume of a substance.
The theoretical time required to displace the contents of a tank or unit at a given rate of discharge or flow.
The distance across a circle at its widest point; two times the radius.
A filtration process for substantial removal of particulates (> 2 log Giardia lamblia cysts) in which a pre-coat cake of graded diatomaceous earth filter media is deposited on a support membrane (septum); and water is passed through the cake on the septum while additional filter media, known as body feed, is continuously added to the feed water to maintain the permeability of the filter cake.
A flow of electrons in a single direction at a constant rate so that the value remains stable.
direct filtration A series of processes including coagulation, flocculation, and filtration (but excluding sedimentation) that together result in substantial particulate removal.
A service hookup to a property that is contiguous to a water distribution main and where additional distribution mains or extensions are not needed to provide service.
The use of chlorine or other agent or process the department approves for killing or inactivating microbiological organisms, including pathogenic and indicator organisms.
Chemical compounds formed by the reaction of disinfectants with organic compounds found in water.
The material in water that will pass through a glass fiber filter and remain in an evaporating dish after evaporation of the water.
A sample of water collected from a representative location in the distribution system at or after the first service and analyzed for coliform presence in compliance with this chapter.
An assembly of two independently acting check valves with shut-off valves on each side of the check valves and test ports for checking the water tightness of each check valve.
A method of measuring the chlorine residual in water. The residual may be determined by either titrating or comparing a developed color with color standards. DPD stands for N, N-diethyl-p-phenylene-diamine.
The drop in the water table or level of water in the ground when water is being pumped from a well; the distance between the static level and the pumping level.
A valve utilizing a narrow channel to create a vacuum that draws a chemical into a flowing stream of water; often used in chlorine feed systems.
Water leaving a piped system; often in reference to wastewater systems.
A negatively charged particle that travels around the nucleus of an atom.
An organic catalyst produced by a living cell; a substance the starts or speeds-up a chemical reaction.
The overgrowth of plants, algae, and/or cyanobacteria in a surface water due to the accumulation of excess nutrients such as nitrogen and phosphorous. Eutrophication can cause large fluctuations in dissolved oxygen (DO).
The conversion from water in a liquid state to water in a gaseous state; part of the hydrologic cycle.
The total water removed from an area by transpiration (plants) and by evaporation from soil, snow and water surfaces.
A state-granted relief for a public water supply system which allows the system to not meet a specific MCL, treatment technique requirement, or both, if certain conditions exist. The conditions include consideration of why the requirement cannot be met and that there are not any unreasonable risk to public health as a result of the exemption.
Bacteria found in the intestinal tracts of warm blooded animals. The presence of high numbers of fecal coliform bacteria in a water body can indicate the recent release of untreated sewage and/or the presence of animal feces. These organisms may also indicate the presence of pathogens that are harmful to humans.
The maximum rate and duration of water flow needed to suppress a fire under as required by local fire protection authority standards.
The first service connection associated with any source (i.e., the point where water is first withdrawn for human consumption, excluding connections where water is delivered to another water system covered by these regulations).
The particles produced by flocculation; snowflake-like settleable particles.
A process enhancing agglomeration and collection of colloidal and suspended particles into larger, more easily settleable or filterable particles by gentle stirring.
To be in constant movement, typically in a single direction. In water this term typically relates to a volume per unit of time, gallons per minute, cubic feet per second, etc.
A mechanical device which measures the amount of water passing through a given pipe. Flow is typically recorded as gallons per minute or cubic feet per second. Total flow and rate of flow are commonly recorded by flow meters.
The addition of a chemical to increase the concentration of fluoride in drinking water to a predetermined optimum limit to reduce the incidence of tooth decay in consumers.
A special type of check valve located at the bottom end of the suction pipe on a pump. The valve opens to allow flow of water when the pump operates and closes when the pump shuts off to prevent water from flowing out of the suction pipe.
The amount of chlorine available as dissolved gas, hypochlorous acid or hypochlorite ion that is not combined with an ammonia or other organic compounds. It is 25 times more powerful than the combined chlorine residual.
The section of a stream, river or other surface water body which receives groundwater discharging from an aquifer. (Same as Receiving Stream)
Corrosion caused by the electrochemical reactions created when two dissimilar metals are in contact with each other.
A disturbance of the intestines, causing vomiting, diarrhea, and cramps.
A cyst-forming protozoan found in water that causes gastrointestinal illness in humans. The primary sources are human and animal feces.
A contagious (infectious) form of diarrhea caused by the protozoan parasite Giardia lamblia that is most commonly transmitted through direct contact with infected feces or by eating food or drinking water that are contaminated by feces.
A water quality sample collected at a specific instant in time and analyzed as an individual sample.
Granules of adsorptive carbon obtained by heating carbon (such as wood). These granules have a high capacity to selectively remove certain trace and soluble materials from water.
Naturally occurring silicates of sodium and aluminum that respond as a natural ion exchange medium. Commonly used as the primary filter medium in a potassium permanganate, greensand, iron and manganese removal process.
Any water beneath the surface of the ground that the department determines has the following characteristics: a significant occurrence of insects or other macroorganisms, algae, or large-diameter pathogens such as Giardia lamblia or Cryptosporidium; or significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH closely correlating to climatological or surface water conditions where natural conditions cannot prevent the introduction of surface water pathogens into the source at the system's point of withdrawal.
Material used to fill the annular space between the well casing and the borehole.
The group of chemicals that can form due to reactions of disinfectants with contaminants in the water - monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid.
A characteristic of water, caused primarily by calcium and magnesium ions. Hardness causes deposits and scale to form on pipes and fixtures.
The measure of the pressure of water expressed as height of water in feet: 1 psi = 2.31 feet of head.
As it applies to a water filter, the difference between the pressure or head on the top of a filter and the pressure or head on the underdrain of the filter. As it applies to pipes, the loss of energy, commonly expressed in feet, as a result of friction. The loss is actually a transfer to heat.
A procedure to measure a class of bacteria that use organic nutrients for growth. The density of these bacteria in drinking water is measured as colony forming units per milliliter and is referred to as the HPC.
A measurement of work, 33,000 foot pounds per minute of work is 1 horsepower.
The resulting material from the decay of leaves and other organic plant matter.
Calcium hydroxide used in softening/flocculation processes.
Water-loving; mixes readily with water.
Water fearing or hating; does not mix with water.
A water storage tank in which the water system's water pump is automatically controlled (started and stopped) by the air pressure in a compressed-air tank.
All of the water on Earth.
Chlorinating a water, for the purposes of disinfection, in excess of the maximum concentration safe for drinking water. Dechlorination is required.
Compounds containing chlorine that are used for disinfection. They are available as liquids or solids.
An ion that results from the reaction of chlorine gas and water. Hypochlorite ion (OCL-) along with hypochlorous acid are called free chlorine residual. However, the hypochlorite ion is not as powerful a disinfectant as hypochlorous acid.
An usable strongly oxidizing but weak acid (HOCl) obtained in solution along with hypochloric acid by reaction of chlorine with water.
A rotating set of vanes designed to impart rotation to a mass of fluid.
Not allowing, or allowing only with great difficulty, the movement of water.
Any process that disrupts the genetic material of pathogenic microorganisms rendering them unable to reproduce, and thus, incapable of producing disease.
Bacteria analyzed for in water (such as coliform bacteria) which serve as a surrogate indicator for the potential presence of pathogens in the same water.
The tendency of matter to remain at rest or in motion.
The movement of water from the surface of the land into the subsurface.
A series of processes, including coagulation and filtration (but excluding flocculation and sedimentation) that together result in particulate removal.
Chemical substances that come from mineral origin instead of living matter; usually not containing carbon. Examples are sand, salts, iron, and sulfur.
An atom or group of atoms that carry a positive or negative electric charge as a result of having lost or gained one or more electrons.
A specialized group of bacteria capable of using iron for metabolic processes and which commonly cause red-water, slime or encrustation in well water systems.
A device that pumps fluid by converting the energy of a high-pressure fluid into that of a high-velocity fluid.
A genus of bacteria containing species that cause a type of pneumonia called Legionnaire’s Disease
The solid crust of the earth. It consists of the thin, loose layer known as soil and the mass of hard rock, several miles in thickness, upon which soil lies.
A process of physically locking and tagging a hazardous energy sources to prevent energy during maintenance.
A mathematical relationship relating percent inactivation to logarithmic inactivation. Common inactivations are three log or 99.9% and four log or 99.99%.
A reach of a river, stream, or other surface water body that feeds into the groundwater aquifer.
Informational documents provided by chemical suppliers which detail hazards of the chemical, handling requirements, spill remediation and other safety issues pertinent to the specific product.
The maximum permissible level of a contaminant in water the purveyor delivers to any public water system user.
The “Goal”(MCLG) is the level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.
Also referred to as “blue baby syndrome” is an ailment caused by high levels of nitrate or nitrite in water. When ingested, these compounds interfere with the ability of blood to carry oxygen and result in a blue color of afflicted individuals. It can be fatal for the unborn, infants and young children.
Another word for microorganism. Tiny living organisms that can be seen only with the aid of a microscope. Some microorganisms can cause acute health problems when consumed in drinking water. Also known as microorganisms.
The saltiness of water in commonly measured by total dissolved solids, which is approximated with the specific or electrical conductance which is measured either as umhos/cm or deceseimens/meter.
A specialized analysis of particles in water which are trapped on a cartridge filter. The particles (algae, insects and other debris) are assessed to determine relative populations and types of organisms present. It is useful for GWUDISW determinations and for assessing the performance of water filtration plants.
A measure of the concentration of a dissolved substance. A concentration of one milligram per liter means one milligram of a substance is dissolved in each liter of water. For practical purposes, this unit is equal to parts per million since one liter of water is equal in weight to one million milligrams.
Minimum criteria for construction and design established to ensure provision of a sufficient quantity of water from the source through a reliable treatment and distribution system.
The smallest division that a substance can be broken down to without separating its individual atoms.
A concept for public health protection which involves several steps or barriers to the passage of contaminants to a potable water supply. The independent steps include source protection, treatment, disinfection and assurance of distribution system integrity.
The units used to measure turbidity. The measurement is made with a nephelometric turbidimeter.
A neutral charged particle in the nucleus of an atom. This particle has the same weight as a proton, an atomic weight of 1.
Compounds containing nitrogen that can exist in the atmosphere or as a dissolved gas in water. Inorganic chemical contaminants of water systems which pose an immediate threat to infants under six months of age because they may lead to a condition known as methemoglobinemia. Nitrate reverts to nitrite in the human body, which causes the condition. Nitrates in water can cause severe illness in infants and domestic animals. A plant nutrient and inorganic fertilizer, nitrate is found in septic systems, animal feed lots, agricultural fertilizers, manure, industrial wastewaters, sanitary landfills, and garbage dumps.
Substances that do not exhibit differences in electro-negativity along the axis of its molecules; non-polar substances typically do not mix readily into water. Examples of household non-polar compounds include fats, oil and petrol.
A water system that provides service opportunity to twenty-five or more of the same nonresidential people for one hundred eighty or more days within a calendar year. Examples might include a school, daycare center, a business, factory, motel, or a restaurant with twenty-five or more employees on-site.
Inorganic substances that help plants grow. In drinking water, nutrients include nitrogen and phosphorous.
The 1970 federal act requiring the federal government to establish minimum health and safety standards. Also called the Williams-Steiger Act.
Substances containing carbon that come from plant or animal sources or synthetic chemicals based on tetrahedrally-bonded carbon atoms.
The movement of water across the Earth's surface.
The loss of electrons from an atom; the process that causes metals to rust; a method for disinfecting water.
Any substance that causes another substance to go through an oxidation process; a substances that strips electrons off of another.
A gaseous form of oxygen with three oxygen atoms per molecule. Ozone is formed by electrical discharge in an oxygen-rich environment. It acts as a strong oxidizing agent and is used in water purification. Although considered a pollutant in the lower atmosphere where it is present in very small quantities, it forms a protective ozone layer in the upper atmosphere.
In relation to drinking water, it is that water which does not give off unpleasant taste and odors, is cool in temperature, how low color and low turbidity. Water that is pleasant to drink.
A measure of the concentration of a dissolved substance. A concentration of one part per million means one part of a substance is dissolved in a million parts of water. For practical purposes, this unit is equal to milligrams per liter since one liter of water is equal in weight to one million milligrams.
An organism that is capable of causing disease.
The maximum momentary flow required of a water treatment plant, pumping station or distribution system. This demand is usually the maximum average flow in one hour or less.
The slow passage of water through the subsurface environment; follows infiltration.
The vertical length of a well casing that is perforated, measured from ground surface (e.g. 85-105 feet).
The apertures in the well casing within the water-bearing formation can be drilled holes, slots cut into the casing, or a special screen in place of the casing material.
The property of a material that permits appreciable movement of water through it when it is saturated and the movement is actuated by hydrostatic pressure of the magnitude normally encountered in natural subsurface water.
An expression of the intensity of the basic or acidic strength of water. Mathematically, pH is the logarithm (base 10) of the reciprocal of the hydrogen ion concentration. pH may range from 0 to 14, where 0 is the most acidic, 14 is the most alkaline, and 7 is neutral. Natural waters usually have a pH between 6.5 and 8.5.
A measure of radioactivity. One picocurie of radioactivity is equivalent to 0.037 nuclear disintegrations per second.
The surface defined by the elevation above sea level to which water rises in a well that is open to the atmosphere. This is the same as a potentiometric surface.
An adapter which attaches to the well casing and allows a submersible pump to discharge from below ground level. This eliminates the need for well pits or houses over the wellhead.
The point at which a chemical is applied to water, after thorough mixing of the chemical into the water stream.
Polarity refers to the dipole-dipole intermolecular forces between the slightly positively-charged end of one molecule to the negative end of another or the same molecule. Molecular polarity is dependent on the difference in electro-negativity between atoms in a compound and the asymmetry of the compound's structure. For example, water is thought to be polar because of the uneven sharing of its electrons.
The ratio (usually expressed as a percentage) of the volume of openings in soils or rocks to the total volume of the soil or rock.
A type of piston, diaphragm, gear or screw pump that delivers a constant volume with each stroke. They are often used as chemical solution feeders.
Water suitable for drinking.
The surface defined by the elevation above sea level to which water rises in a well that is open to the atmosphere. This is the same as a piezometric surface.
A solid substance that can be dissolved but is separated from solution as a result of a chemical reaction or change in conditions, such as pH or temperature; the act of substances coming out of solution is “to precipitate” that substance.
An enclosed vessel containing properly sized and graded granular media through which water is forced under greater than atmospheric pressure.
The vertical distance in feet equal to the pressure in psi at a specific point. The pressure head is equal to the pressure in psi times 2.31 ft per psi.
An assembly containing an independently operating internally loaded check valve and an independently operating air inlet valve on the discharge side of the check valve. It is designed to protect against a non-health hazard or a health hazard under the condition of backsiphonage only.
Hydraulically defined areas of a distribution system which pull from a given storage reservoir or water source.
Primary enforcement authority granted to states for implementation and enforcement of federal regulations.
An enforceable drinking water standard.
A positive charged particle in the nucleus of an atom. They have an atomic weight of 1 and an atomic charge of +1.
A varied group of single-celled higher organisms (not bacteria). Many protozoa that are human pathogens can be transmitted through drinking water. Examples are Giardia and Cryptosporidium.
Graphic plots of data which indicate the expected performance of a specific pump at specified head and flow conditions.
The depth below ground surface of the water level in a well when the well is being pumped at a steady rate. The vertical distance in feet from the centerline of the pump discharge to the level of the free pool while water is being drawn from the pool.
An agency, subdivision of the state, municipal corporation, firm, company, mutual or cooperative association, institution, partnership, or person or other entity owning or operating a public water system. Purveyor also means the authorized agents of such entities.
Calcium oxide used in softening processes.
The emission of alpha/beta particles or gamma rays from a natural or man-made element. Radioactivity is a public health concern due to the cancer-causing potential of these particles and rays.
Any man-made or natural element that emits radiation in the form of alpha or beta particles, or as gamma rays.
A line from the center of a circle or sphere to the outer edge; one half the diameter.
The section of a stream, river, or other surface water, that receives groundwater discharging from an aquifer; a gaining stream.
Replenishment of water in an aquifer.
Effluent derived in any part from sewage from a wastewater treatment system that has been adequately and reliably treated, so that as a result of that treatment, it is suitable for beneficial use or a controlled use that would not otherwise occur, and it is no longer considered wastewater.
A backflow prevention assembly containing two check valves, a differential relief valve located between the two check valves, shut-off valves on each end of the assembly and test ports for checking the water tightness of the check valves and the operation of the relief valve.
Any substance that causes another to gain electrons; the opposite of an oxidizing agent
The process of an atom gaining electrons.
A sample collected to confirm the results of a previous analysis. These are also often referred to as “check samples”.
Bacteriological quality samples collected to replace a routine sample that was too old (beyond the 30-hour sample-to-analysis time limit) or had interference from heterotrophic plate count bacteria.
A tank or impoundment used to hold water.
The quantity left over at the end of a process. Residual chlorine is the amount of free and/or available chlorine remaining after a given contact time under specified conditions.
Periodic, usually monthly, water quality monitoring required of all public water supply systems.
An Act passed by Congress in 1974. The Act establishes a cooperative program among local, state and federal agencies to insure safe drinking water for consumers.
This occurs when saltwater invades an aquifer due to over-pumping of a well in the aquifer.
Bacteriological sample collection location plans required of all community public water supply systems which identify the locations used for routine monitoring and any necessary repeat monitoring.
A tap upstream of any customer connection, typically in the pump house, for the purpose of collecting periodic samples of water for chemical and microbiological analysis. If the water is treated there should be sample taps to collect both raw and treated water.
A review, inspection, and assessment of a public water system including, but not limited to: Source, facilities, equipment, administration and operation, maintenance procedures, monitoring, record keeping, planning documents and schedules, and management practices. The purpose of the survey is to evaluate the adequacy of the water system for producing and distributing safe and adequate drinking water.
The area below the water table where all open spaces are filled with water.
The water supplied to the stuffing box to lubricate and flush the packing or the mechanical seal.
A public water system source used on a regular basis, that is not a permanent or emergency source.
Standards based on factors other than health effects; these are not enforceable by law.
A term used to describe geologic formations that are partially cemented such as some limestone and sandstones.
Chemical agents used to prevent precipitation of some metals (such as iron and manganese) from water. These agents surround the metal molecule, preventing it from coming into contact with oxidizing agents.
A connection to a public water system designed to provide potable water to a single-family residence, or other residential or nonresidential population.
The process by which water or wastewater skips or cycles through a step in the treatment train too quickly, rendering it only partially treated.
A filtration process whereby source water moves through a bed of sand at a low velocity, generally less than 0.10 gpm/ft².
One of several forms of chlorine commonly used for chlorination of public water supply systems. Sodium hypochlorite is a liquid available in 6-15 percent solutions.
Any process that controls or removes hardness from water.
The component of a solution that is being dissolved by the solvent.
The component of a solution that does the dissolving.
A measure of the productivity of a well, expressed as the reliable yield divided by the drawdown (gpm/foot).
A measure of well yield per foot of drawdown expressed as gallons per minute per foot of drawdown.
An assembly containing an independently operating internally loaded check valve and an independently loaded air inlet valve on the discharge side of the check valve. It is designed to protect against a non-health hazard or health hazard under backsiphonage conditions only.
A walled, single to multi-celled reproductive body of an organism, capable of giving rise to a new individual either directly or indirectly. A viable body regarded as the resting stage of an organism.
An aquifer that breaks through the Earth’s surface to become surface water.
The 18th edition of the book, titled Standard Methods for the Examination of Water and Waste Water, jointly published by the American Public Health Association, American Water Works Association (AWWA), and Water Pollution Control Federation. This book is available through public libraries or may be ordered from AWWA, 6666 West Quincy Avenue, Denver, Colorado 80235.
The revolving loan program financed by the state and federal governments and managed by the state for the purpose of assisting water systems to meet their capital needs associated with complying with the federal Safe Drinking Water Act.
A non-moving condition.
The elevation or level of the water table in a well when the pump is not operating, or the elevation to which water would rise in a tube connected to an artesian aquifer, basin, or conduit under pressure.
The destruction of all microorganisms.
A layer of the Earth’s crust
The process by which a solid is converted directly into a gas.
A vertical turbine pump with the motor placed below the impellers. The motor is designed to be submersed in water.
A pumping condition where the eye of the impeller of the pump is below the surface of the water from which the pump is pumping.
A pumping condition where the eye of the impeller of the pump is above the surface of the water from which the pump is pumping.
The line through which water enters a pump; that on the “suction side” of the pump.
Also referred to as hydrogen sulfide gas (H2S). It is a colorless gas with the distinct smell of rotten eggs.
See overland runoff.
The SWTR was enacted by EPA in 1989 under the Safe Drinking Water Act. It imposes specific monitoring and treatment requirements on all public drinking water systems that draw water from a surface water source.
The quantity of material deposited when a quantity of water, sewage, or other liquid is filtered through a glass fiber filter.
A man-made carbon-based chemical, considered a contaminant in drinking water.
The time it takes ten percent of the water passing through a system contact tank intended for use in the inactivation of Giardia lamblia cysts, viruses, and other microorganisms of public health concern, as determined from a tracer study conducted at peak hourly flow or from published engineering reports or guidance documents for similarly configured tanks.
Known as the Ten-State Standards, “The Recommended Standards for Water Works”, published by the Great Lakes-Upper Mississippi River Board of Public Health and Environmental Managers, is a commonly used guide for good engineering practices.
The flow from a new well during test pumping, measured in gallons per minute.
A concrete wedge placed between a fitting and the trench wall, used to transfer the force from the fitting to the trench wall. This prevents the fitting from being pushed away from the pipe.
The time required for ground water to move through the water-bearing zone from a specific point to a well.
Indicator bacteria used to detect the possible contamination of water by pathogenic organisms.
All organic and inorganic substances dissolved into a water. These primarily consist of inorganic substances like calcium, magnesium, sodium, and sulfates.
The total energy needed to move water from the center line of a pump (eye of the first impeller of a lineshaft turbine) to some given elevation or to develop some given pressure. This includes the static head, velocity head and the headloss due to friction.
A result of analyses of a water sample for the total amount of organic content in the water.
The amount of available chlorine remaining after a given contact time. The sum of the available residual chlorine and the free available residual chlorine combined.
The solids in water, sewage, or other liquids. It includes the suspended solids (largely removable by a filter) and filterable solids (those which pass through the filter).
All non-settleable solids that do not dissolve into a water and lead to turbidity.
The sum of the concentrations of bromodichloromethane, dibromochloromethane, tribromomethane, and trichloromethane.
System that serves: 25 or more different people/day during 60 or more days/yr. OR 25 or more of the same people/day for less than 180 days/yr and during more than 59 days/yr. OR 1000 or more people for two, or more, consecutive days
The process by which water vapor is lost to the atmosphere from living plants through pores called stomata located (usually) on the undersides of leaves.
One of a family of organic compounds, named as derivatives of methane, where three of the four hydrogen atoms in methane are each substituted by a halogen atom in the molecular structure. THMs may occur when chlorine, a halogen, is added to water containing organic material and are generally found in water samples as disinfection by-products.
Color remaining in water after particles have been filtered from the water sample. True color is composed of color-causing dissolved constituents.
The development or formation of small mounds of corrosion products (rust) on the inside of iron pipe. These mounds (tubercules) increase the roughness of the inside of the pipe thus increasing resistance to water flow.
A condition in water caused by the presence of suspended matter, resulting in the scattering and attenuation of light rays.
A single day or series of consecutive days (not to exceed fourteen) when at least one turbidity measurement each day exceeds 5 NTU.
Acute infectious disease caused by Salmonella typhi. The bacteria is transmitted by milk, water, or solid food contaminated by the feces of typhoid victims or of carriers.
Radiation lying in the ultraviolet range; wave lengths shorter than light but longer than X rays. The sun is an important source of ultraviolet light. This radiation can be used for disinfection of drinking water but has no residual effect. Disinfection wavelengths are targeted at 254 nm.
The difference between the amount of water pumped into the distribution system and the total amount of water recorded as passing through customer meters.
An aquifer that is sitting on an impervious layer, but is open on the top to local infiltration. The recharge for an unconfined aquifer is local. Also called a water table aquifer.
Deposits composed of loose rock or mineral particles of varying sizes. Examples include clay, silt, sand and gravel.
The unsaturated zone of the subsurface where water, soils, and gases freely mix.
Pumps for which as head increases, the flow from the pump decreases. Examples include centrifugal, jet, and air lift pumps.
The amount of energy required to bring a fluid from standstill to its velocity. For a given quantity of flow, the velocity head will vary indirectly with the pipe diameter.
A microorganism, smaller than bacteria, which can not grow or reproduce apart from a living cell. Viruses are common to many human infections and some rare diseases, from the common cold (rhinovirus) to AIDS (human immunodeficiency virus).
A substance that readily transitions into a gaseous state.
A manufactured carbon-based chemical that vaporizes quickly at standard pressure and temperature.
The result of the conversion of velocity head to pressure head. The pressure spike created by suddenly stopping the flow of water. water right A permit, claim, or other authorization, on record with or accepted by the department of ecology, authorizing the beneficial use of water in accordance with all applicable state laws.
The average depth or elevation of the groundwater over a selected area. The upper surface of the zone of saturation, except where that surface is formed by an impermeable body.
The land area that drains into a stream or river. An area that contributes runoff to a specific delivery point.
A group of wells one purveyor owns or controls that: draw from the same aquifer or aquifers as determined by comparable inorganic chemical analysis and comparable static water level and top of the open interval elevations; and discharge water through a common pipe and the common pipe shall allow for collection of a single sample before the first distribution system connection.
A device installed on the terminal end of a well casing which prevents entry of insects, rodents and precipitation to the well.
The report submitted by the driller to the pertinent state agency, concerning a well just completed. Contains a descriptive geological profile, notes on water occurrence in the borehole, and a description or diagram of the well casing and screen.
A type of well cap intended for use indoors. The seal has a rubber gasket which fits inside the well casing and is held in place by metal plates.
The concrete pads surrounding wellheads designed to prevent surface water from flowing down the outside of the well casings.
A down turned, screened opening to the well casing which allows entry of air during drawdown and release of air during water table recovery. They serve the important role of preventing contaminants from being sucked into the well during creation of a vacuum during drawdown, and prevent uncontrolled release of air when the water table recovers and air is forced out of the casing.
The quantity of water pumped from a well per unit time, usually in gallons per minute (gpm).
An inherited disorder which causes the body to absorb and retain excessive amounts of copper. Excess copper can deposit in the liver, kidneys, brain and eyes. Liver failure and damage to the central nervous system are the most common and dangerous effects of this disorder.
The area surrounding a pumping well or spring that encompasses all areas or features that supply groundwater recharge to the well or spring.