16 Del. Admin. Code § 4462-2.0
The following words and terms, when used in this regulation, have the following meaning unless the context clearly indicates otherwise:
"Action level" means the concentration of lead or copper in water specified in subsections 10.1.1.1 and 10.1.1.2 which determines, in some cases, the treatment requirements contained in Section 10.0 that a water system is required to complete.
"Air gap" means the unobstructed vertical distance through the free atmosphere between the lowest opening from any pipe or faucet supplying water to a tank, plumbing fixture, or other device and the flood-level rim of the receptacle.
"Alpha particle" means a particle identical with a helium nucleus, emitted from the nucleus of a radioactive element.
"Approved" means approved by the Division.
"Auxiliary water system" means a water supply system on, or available to, a water consumer's premises that is maintained in addition to a public water supply system, including, but not limited to, a private water storage tank, water systems from ground or surface sources, or water from a public water system, which in any way has been treated, processed, or exposed to any possible contaminant or stored in other than an approved storage facility.
"Backflow" means the undesirable reversal of flow in a potable water distribution system as a result of a cross-connection.
"Bag filters" means pressure-driven separation devices that remove particulate matter larger than 1 (one) micrometer using an engineered porous filtration media. They are typically constructed of a non-rigid, fabric filtration media housed in a pressure vessel in which the direction of flow is from the inside of the bag to the outside.
"Bank filtration" means a water treatment process that uses a well to recover surface water that has naturally infiltrated into ground water through a river bed or bank(s). Infiltration is typically enhanced by the hydraulic gradient imposed by a nearby pumping water supply or other well(s).
"Best available technology" or "BAT" means the best technology, treatment techniques, or other means which the Division finds, after examination for efficacy under field conditions and not solely under laboratory conditions, are available (taking cost into consideration). For the purposes of setting maximum contaminant levels for synthetic organic chemicals, any BAT must be at least as effective as granular activated carbon.
"Beta particle" means a particle identical with an electron, emitted from the nucleus of a radioactive element.
"Capacity" means the overall capability of a water system to reliably produce and deliver water meeting all national primary drinking water regulations. Capacity encompasses the technical, managerial, and financial capabilities that will enable a water system to plan for, achieve, and maintain compliance with applicable drinking water standards.
* "Technical capacity" means the physical infrastructure of water system, including but not limited to, the adequacy of the source water, infrastructure (source, treatment, storage, and distribution), and the ability of system personnel to implement the requisite technical knowledge.
* "Managerial capacity" means the management structure of the water system, including but not limited to ownership accountability, staffing and organization, and effective linkages.
* "Financial capacity" means the financial resources of the water system, including but not limited to revenue sufficiency and fiscal controls.
"Cartridge filters" means pressure-driven separation devices that remove particulate matter larger than 1 (one) micrometer using an engineered porous filtration media. They are typically constructed as rigid or semi-rigid, self-supporting filter elements housed in pressure vessels in which flow is from the outside of the cartridge to the inside.
"Clean compliance history" means a record of no MCL violations under subsection 7.2; no monitoring violations under subsections 7.1 or 7.4; and no coliform treatment technique trigger exceedances or treatment technique violations under subsection 7.4.
"Coagulation" means a process using coagulant chemicals and mixing by which colloidal and suspended materials are de-stabilized and agglomerated into flocs.
"Coliform group" means all organisms considered in the coliform group as set forth in the current edition of Standard Methods for the Examination of Water and Waste Water prepared and published jointly by the American Public Health Association, American Water Works Association and Water Pollution Control Federation.
"Combined distribution system" means the interconnected distribution system consisting of the distribution systems of wholesale systems and of the consecutive systems that receive finished water.
"Compliance cycle" means the nine-year calendar year cycle during which public water systems must monitor. Each compliance cycle consists of three three-year compliance periods. The first calendar year cycle begins January 1, 1993 and ends December 31, 2001; the second begins January 1, 2002 and ends December 31, 2010, the third begins January 1, 2011 and ends December 31, 2019.
"Compliance period" means a three-year calendar year period within a compliance cycle. Each compliance cycle has three three-year compliance periods. Within the first compliance cycle, the first compliance period runs from January 1, 1993 to December 31, 1995; the second from January 1, 1996 to December 31, 1998, and the third from January 1, 1999 to December 31, 2001.
"Comprehensive performance evaluation" or "CPE" means 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.
"Confluent growth" means a continuous bacterial growth covering the entire filtration area of a membrane filter, or a portion thereof, in which bacterial colonies are not discrete.
"Consecutive water supply" means a public water system that receives some or all of its finished water from one or more wholesale systems. Delivery may be through a direct connection or through the distribution system of one or more consecutive systems. This part shall apply to each public water system, unless the public water system meets all of the following conditions: a) Consists only of distribution and storage facilities (and does not have any collection and treatment facilities); b) Obtains all of its water from, but is not owned or operated by, a public water system to which such regulations apply; c) Does not sell water to any person; and, d) Is not a carrier which conveys passengers in interstate commerce. The Division may opt to accept a consecutive supply as a single system for monitoring purposes.
"Containment" means a method where the installation of an approved air gap or backflow prevention assembly at the service connection to a water consumer's premises is required to protect the public water system.
"Contaminant" means any physical, chemical, biological or radiological substance or matter in water.
"Conventional filtration treatment" means a series of processes including coagulation, flocculation, sedimentation and filtration resulting in substantial particulate removal.
"Corrosion inhibitor" means a substance capable of reducing the corrosivity of water toward metal plumbing materials, especially lead and copper, by forming a protective film on the interior surface of those materials.
"Cross-connection" means an actual or potential connection between any part of a potable water system and any other environment containing other substances in a manner that, under any circumstances, would allow for such substances to enter the potable water system.
"Cross-connection control program" means a program to eliminate, monitor, protect, and prevent cross-connections from allowing backflow.
"CT" or "CTcalc" means the product of the residual disinfectant concentration (C) in milligrams per liter (mg/L) determined before or at the first customer, and the corresponding disinfectant contact time (T) in minutes, i.e. "C" X "T". If a public water system applies disinfectants at more than one point prior to the first customer, it must determine the CT of each disinfectant sequence before or at the first customer to determine the total percent inactivation or total inactivation ratio. In determining the total inactivation ratio, the public water system must determine the residual disinfectant concentration of each disinfection sequence and corresponding contact time before any subsequent disinfection application point(s). CT99.9 is the CT value required for 99.9 percent (3-log) inactivation of Giardia lamblia cysts. The inactivation ratio is the CTcalc divided by the CT99.9 and the total inactivation ratio is the sum of the inactivation ratios for each disinfection sequence. A total inactivation ratio equal to or greater than 1.0 is assumed to provide a 3-log inactivation of Giardia lamblia cysts.
"Customer" means the owner or person in control of any premises supplied by or in any manner connected to a public water system.
"Diatomaceous earth filtration" means a process resulting in substantial particulate removal in which a precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum), and while the water is filtered by passing through the cake on the septum, additional filter media known as body feed is continuously added to the feed water to maintain the permeability of the filter cake.
"Direct filtration" means a series of processes including coagulation and filtration but excluding sedimentation resulting in substantial particulate removal.
"Direct responsible charge" means accountability for and performance of active, daily, on-site operational duties.
"Disinfectant" means any oxidant, including but not limited to chlorine, chlorine dioxide, chloramines, and ozone added to water in any part of the treatment or distribution process, that is intended to kill or inactivate pathogens (disease causing organisms).
"Disinfectant contact time" or "T" means the time in minutes that it takes for water to move from the point of disinfectant application or the previous point of disinfectant residual measurement to a point before or at the point where residual disinfectant concentration (C) is measured. Where only one (1) "C" is measured, "T" is the time in minutes that it takes for water to move from the point of disinfectant application to a point before or at where residual disinfectant concentration (C) is measured. Where more than one (1) "C" is measured, "T" is for the first measurement of "C", the time in minutes that it takes for water to move from the first or only point of disinfectant application to a point before or at the point where the first "C" is measured and for subsequent measurements of "C", the time in minutes that it takes for water to move from the previous "C" measurement point to the "C" measurement point for which the particular "T" is being calculated. Disinfectant contact time in pipelines must be calculated based on plug flow by dividing the internal volume of the pipe by the maximum hourly flow rate through that pipe. Disinfectant contact time within mixing basins and storage reservoirs must be determined by tracer studies or an equivalent demonstration.
"Disinfection" means a process which inactivates pathogenic organisms in water by chemical oxidants or equivalent agents.
"Disinfection Profile" means a summary of daily Giardia lamblia inactivation through the treatment plant. The procedure for developing a disinfection profile is contained in subsection 10.8 and in 40 CFR subparts P and T (copies are available from the Office of Drinking Water).
"Division" means the Division of Public Health of the Department of Health and Social Services established by 29 Del.C. § 7904(a).
"Domestic or other non-distribution system plumbing problem" means a coliform contamination problem in a public water system with more than one (1) service connection that is limited to the specific service connection from which the coliform positive sample was taken.
"Dose equivalent" means the product of the absorbed dose from ionizing radiation and such factors as account for differences and biological effectiveness due to the type of radiation and its distribution in the body as specified by the International Commission on Radiological Units and Measurements.
"Dual sample set" means a set of two samples collected at the same time and same location, with one sample analyzed for TTHM and the other analyzed for HAA5. Dual sample sets are collected for the purposes of conducting an Initial Distribution System Evaluation (IDSE) under Section 13.0 and determining compliance with the TTHM and HAA5 MCLs under subsection 9.2.1.2.
"Dwelling unit" means one or more rooms arranged for the use of one or more individuals as a single housekeeping unit with cooking, living, sanitary and sleeping facilities.
"Effective corrosion inhibitor residual" means a concentration sufficient to form a passivating film on the interior walls of a pipe.
"Emergency situation" means a condition in which the specific provisions of these regulations cannot be met for a temporary period and which necessitates immediate action because of the potential danger to public health.
"Enhanced coagulation" means the addition of sufficient coagulant for improved removal of disinfection byproduct precursors by conventional filtration treatment.
"Enhanced softening" means the improved removal of disinfection byproduct precursors by precipitative softening.
"Filter profile" means a graphical representation of individual filter performance, based on continuous turbidity measurements or total particle counts versus time for an entire filter run, from startup to backwash inclusively, that includes an assessment of filter performance while another filter is being backwashed.
"Filtration" means a process for removing particulate matter from water by passage through porous media.
"Finished water" means water that is introduced into the distribution system of a public water system and is intended for distribution and consumption without further treatment, except as treatment necessary to maintain water quality in the distribution system (e.g., booster disinfection, addition of corrosion control chemicals).
"First draw sample" means a one (1) liter sample of tap water, collected in accordance with subsection 10.7.2.2, that has been standing in plumbing pipes at least six (6) hours and is collected without flushing the tap.
"Flocculation" means a process to enhance agglomeration or collection of smaller floc particles into larger, more easily settleable particles through gentle stirring by hydraulic or mechanical means.
"Flood-level rim" means the edge of the receptacle from which water overflows.
"Flowing stream" means a course of running water flowing in a definite channel.
"GAC10" means granular activated carbon filter beds with an empty-bed contact time of 10 minutes based on average daily flow and a carbon reactivation frequency of every 180 days, except that the reactivation frequency for GAC10 used as a best available technology for compliance with MCLs under subsection 9.2.1.2 shall be 120 days.
"GAC20" means granular activated carbon filter beds with an empty-bed contact time of 20 minutes based on average daily flow and carbon reactivation frequency of every 240 days.
"Gross alpha particle activity" means the total radioactivity due to alpha particle emission as inferred from measurements on a dry sample.
"Gross beta particle activity" means the total radioactivity due to beta particle emission as inferred from measurements on a dry sample.
"Ground water under the direct influence of surface water" or "GUDI" means any water beneath the surface of the ground with 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 which closely correlate to climatological or surface water conditions. Direct influence must be determined for individual sources in accordance with criteria established by the Division. The Division determination of direct influence may be based on site-specific measurements of water quality and/or documentation of well construction characteristics and geology with field evaluation.
"Haloacetic acids (five)" or "HAA5" mean the sum of the concentrations in milligrams per liter of the haloacetic acid compounds (monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid), rounded to two significant figures after addition.
"Halogen" means one of the chemical elements chlorine, bromine or iodine.
"Health Advisory" or "HA" means an estimate of acceptable drinking water levels for a chemical substance based on health effects information; a Health Advisory is not a legally enforceable Federal standard, but serves as technical guidance to assist Federal, State and local officials.
"One-Day HA" means the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to one day of exposure. The One-Day HA is normally designed to protect a 10-kg child consuming one liter of water per day.
"Ten-Day HA" means the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for up to ten days of exposure. The Ten-Day HA is also normally designed to protect a 10-kg child consuming one liter of water per day.
"Lifetime HA" means the concentration of a chemical in drinking water that is not expected to cause any adverse noncarcinogenic effects for a lifetime of exposure. The Lifetime HA is based on exposure of a 70-kg adult consuming two liters of water per day. The Lifetime HA for Group C carcinogens includes an adjustment for possible carcinogenicity.
"Health hazard" means any condition, device or practice in the water supply system or its operation which creates, or may create, a danger to the health and well-being of the water consumer.
"Initial compliance period" means the first full three-year compliance period which begins at least 18 months after promulgation, except for the following contaminants: Dichloromethane; 1,2,4-Trichlorobenzene; 1,1,2-Trichloroethane; Benzo[a]pyrene; Dalapon; Di(2-ethylhexyl adipate; Di(2-ethylhexyl) phthalate; Dinoseb; Diquat; Endothall; Endrin; Glyphosate; Hexachlorobenzene; Hexachlorocyclopentadiene; Oxamyl (Vydate); Picloram; Simazine; 2,3,7,8-TCDD (Dioxin); Antimony; Beryllium; Cyanide; Nickel; and Thallium, initial compliance period means the first full three-year compliance period after promulgation for systems with 150 or more service connections (January 1993 -December 1995) and first full three-year compliance period after the effective date of regulation (January 1996 - December 1998) for systems having fewer than 150 service connections.
"Lake" or "reservoir" means a natural or manmade basin or hollow on the Earth's surface in which water collects or is stored that may or may not have a current or single direction of flow.
"Large water system" means a water system that serves more than 50,000 persons.
"Lead service line" means a service line made of lead which connects the water main to the building inlet and any lead pigtail, gooseneck or other fitting which is connected to such lead line.
"Legionella" means a genus of bacteria, some species of which have caused a type of pneumonia called Legionnaires' Disease.
"Level 1 assessment" means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and (when possible) the likely reason that the system triggered the assessment. It is conducted by the system operator or owner. Minimum elements include review and identification of atypical events that could affect distributed water quality or indicate that distributed water quality was impaired; changes in distribution system maintenance and operation that could affect distributed water quality (including water storage); source and treatment considerations that bear on distributed water quality, where appropriate (e.g., whether a ground water system is disinfected); existing water quality data; and inadequacies in sample sites, sampling protocol, and sample processing. The system must conduct the assessment consistent with the Division directives that tailor specific assessment elements with respect to size and type of the system and the size, type, and characteristics of the distribution system.
"Level 2 assessment" means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and (when possible) the likely reason that the system triggered the assessment. A Level 2 assessment provides a more detailed examination of the system (including the system's monitoring and operational practices) than does a Level 1 assessment through the use of more comprehensive investigation and review of available information, additional internal and external resources, and other relevant practices. It is conducted by an individual approved by the Division, which may include the system operator. Minimum elements include review and identification of atypical events that could affect distributed water quality or indicate that distributed water quality was impaired; changes in distribution system maintenance and operation that could affect distributed water quality (including water storage); source and treatment considerations that bear on distributed water quality, where appropriate (e.g., whether a ground water system is disinfected); existing water quality monitoring data; and inadequacies in sample sites, sampling protocol, and sample processing. The system must conduct the assessment consistent with and Division directives that tailor specific assessment elements with respect to the size and type of system and the size, type, and characteristics of the distribution system. The system must comply with any expedited actions or additional actions required by the Division in the case of an E. coli MCL violation.
"Locational running annual average" or "LRAA" means the average of sample analytical results for samples taken at a particular monitoring location during the previous four calendar quarters.
"Man-made beta particle and photon emitters" means all radionuclides emitting beta particles and/or photons listed in Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air or Water for Occupational Exposure, NBS Handbook 69, except the daughter products of thorium-232, uranium-235, and uranium-238.
"Maximum contaminant level" or "MCL" means the maximum permissible level of a contaminant in water which is delivered to any user of a public water system.
"Maximum residual disinfectant level" or "MRDL" means a level of a disinfectant added for water treatment that may not be exceeded at the consumer's tap without an unacceptable possibility of adverse health effects. For chlorine and chloramines, a PWS is in compliance with the MRDL when the running annual average of monthly averages of samples taken in the distribution system, computed quarterly, is less than or equal to the MRDL. For chlorine dioxide, a PWS is in compliance with the MRDL when daily samples are taken at the entrance to the distribution system and no two consecutive daily samples exceed the MRDL. MRDLs are enforceable in the same manner as maximum contaminant levels under section 1412 of the Safe Drinking Water Act. There is convincing evidence that addition of a disinfectant is necessary for control of waterborne microbial contaminants. Notwithstanding the MRDLs listed in 40 CFR section 141.65 (copies available from the Office of Drinking Water), operators may increase residual disinfectant levels of chlorine or chloramines (but not chlorine dioxide) in the distribution system to a level and for a time necessary to protect public health to address specific microbiological contamination problems caused by circumstances such as distribution line breaks, storm runoff events, source water contamination, or cross-connections.
"Maximum residual disinfection level goal" or "MRDLG" means the maximum level of a disinfectant added for water treatment at which no known or anticipated adverse effect on the health of persons would occur, and which allows an adequate margin of safety. MRDLGs are non-enforceable health goals and do not reflect the benefit of the addition of the chemical for control of waterborne microbial contaminants.
"Maximum total trihalomethane potential" or "MTP" means the maximum concentrations of total trihalomethanes produced in a given water containing a disinfectant residual after seven days at a temperature of 25° C or above.
"Membrane filtration" means a pressure or vacuum driven separation process in which particulate matter larger than 1 (one) micrometer is rejected by an engineered barrier, primarily through a size-exclusion mechanism, and which has a measurable removal efficiency of a target organism that can be verified through the application of a direct integrity test. This definition includes the common membrane technologies of microfiltration, ultrafiltration, nanofiltration, and reverse osmosis.
"Medium size water system" means a water system that serves greater than 3,300 and less than or equal to 50,000 persons.
"Minor monitoring violation" means the failure of a public water system to collect all required water samples or the failure to follow the prescribed sampling procedure within the prescribed time frame.
"Near the first service connection" means at one (1) of the twenty (20) percent of all service connections in the entire system that are nearest the water supply treatment facility, as measured by water transport time within the distribution system.
"Optimal corrosion control treatment" means the corrosion control treatment that minimizes the lead and copper concentrations at users' taps while ensuring that the treatment does not cause the water system to violate any national primary drinking water regulations.
"Person" means any corporation, company, association, firm, municipally owned water utility, partnership, society and joint stock company, as well as any individual.
"Picocurie" or "pCi" means the quantity of radioactive material producing 2.22 nuclear transformations per minute.
"Plant intake" means the works or structures at the head of a conduit through which water is diverted from a source (e.g., river or lake) into a treatment plant.
"Point of disinfectant application" means the point where the disinfectant is applied and water downstream of that point is not subject to recontamination by surface water runoff.
"Point of entry treatment device" means a treatment device applied to the drinking water entering a house or building for the purpose of reducing contaminants in the drinking water distributed throughout the house or building.
"Point of use treatment device" means a treatment device applied to a single tap used for the purpose of reducing contaminants in the drinking water at that one (1) tap.
"Pollution" means the presence of anything in water which tends to degrade its quality so as to constitute a health hazard or impair the usefulness of the water.
"Potable water" means water which is in compliance with all of the required drinking water standards specified in these regulations and is acceptable for human consumption.
"Premises" means real estate and the structures on it.
"Presedimentation" means a preliminary treatment process used to remove gravel, sand and other particulate material from the source water through settling before the water enters the primary clarification and filtration processes in a treatment plant.
"Primary maximum contaminant level" or "PMCL" means an MCL which involves a biological, chemical or physical characteristic of drinking water that may adversely affect the health of the consumer. This includes the MCLs for: coliform bacteria (includes total coliform and E. coli; antimony; arsenic; asbestos; barium; beryllium; cadmium; chromium; cyanide; fluoride; lead; mercury; nickel; nitrates; nitrites; total nitrate/nitrite selenium; thallium; turbidity; alachlor; atrazine; benzo(a)pyrene; carbofuran; chlordane; dalapon; di(2-ethylhexyl) adipate; di(2-ethylhexyl) phthalate; dibromochloropropane; dinoseb; diquat; 2,4-D; endothall; endrin; ethylenedibromide (EDB); glyphosate; heptachlor; heptachlor epoxide; hexachlorobenzene; hexachlorocyclopentadiene; lindane; methoxychlor; oxamyl (vydate); pentachlorophenol; picloram; polychlorinated biphenyls (PCBs); simazine; 2,3,7,8-TCDD (Dioxin); toxaphene; 2,4,5-TP silvex; total trihalomethanes; benzene; carbon tetrachloride; o-dichlorobenzene; p-dichlorobenzene; 1,2-dichloroethane, 1,1-dichloroetylene; cis-1,2-dichloroethylene; trans-1,2-dichloroethylene; dichloromethane; 1,2-dichlorpropane; ethylbenzene; monochlorobenzene; styrene; tetrachloroethylene; toluene; 1,2,4-trichlorobenzene; 1,1,1-trichloroethane; 1,1,2-trichloroethane; trichloroethylene; vinyl chloride; total xylenes and radioactivity (see Section 9.0).
"Protection by adequate construction, treatment and supervision" means:
Works which are of adequate capacity to meet the maximum demands without creating health hazards and which are located, designed and constructed to eliminate or prevent pollution.
Any one or any combination of the controlled processes of coagulation, sedimentation, absorption, filtration, disinfection or other processes appropriate to the sources of supply, which produces water consistently meeting the requirements of these regulations.
Conscientious operation of a public water supply by an individual in direct responsible charge who is acceptable to the Division, and meets the certification requirements of the Division.
"Public notice tiers" means that public notice requirements are divided into three tiers to take into account the seriousness of the violation or situation and any potential adverse health effects that may be involved.
Tier 1 public notice - required for National Primary Drinking Water (NPDWR) violations and situations with significant potential to have serious adverse effects on human health as a result of short-term exposure.
Tier 2 public notice - required for all other NPDWR violations and situations with potential to have serious adverse effects on human health.
Tier 3 public notice - required for all other NPDWR violations and situations not included in Tier 1 and Tier 2.
"Public water system" or "PWS" means a water supply system for the provision to the public of water for human consumption through pipes or other constructed conveyances either directly from the user's free flowing outlet or indirectly by the water being used to manufacture ice, foods and beverages or that supplies water for potable or domestic purposes for consumption in more than three dwelling units, or furnishes water for potable or domestic purposes to employees, tenants, members, guests or the public at large in commercial offices, industrial areas, multiple dwellings or semi-public buildings including, but without limitation, rooming and boarding houses, motels, tourist cabins, mobile home parks, restaurants, hospitals and other institutions, or offers any water for sale for potable domestic purposes. Public water systems are classified as follows:
"Community water system" or "CWS" means a public water system which serves at least fifteen (15) service connections used by year-round residents or regularly serves at least twenty-five (25) year-round residents;
"Miscellaneous public water system" or "MPWS" means a public water system that is neither community, transient non-community nor non-transient non-community.
"Non-transient non-community water system" or "NTNCWS" means a public water system that is not a community water system and that regularly serves at least twenty-five (25) of the same persons over six (6) months per year;
"Transient non-community water system" or "TNCWS" means a public water system which has at least fifteen (15) service connections or regularly serves an average of at least twenty-five (25) individuals daily at least sixty (60) days out of the year;
"Radioactivity" means the spontaneous, uncontrollable disintegration of the nucleus of an atom with the emission of particles and rays.
"Rem" means the unit of dose equivalent from ionizing radiation to the total body or any internal organ or organ system. A millirem is one one-thousandth (1/1000) of a rem.
"Repeat compliance period" means any subsequent compliance period after the initial compliance period.
"Residual disinfectant concentration" or "C" means the concentration of disinfectant measured in mg/L in a representative sample of water. Disinfectant levels of <0.04 mg/L shall be considered non-detectable.
"Sanitary defect" means a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a failure or imminent failure in a barrier that is already in place.
"Sanitary survey" means a review of the water source, facilities, equipment, operation and maintenance of a public water system for the purpose of: evaluating the adequacy of such source, facilities, equipment, operation and maintenance for producing and distributing potable drinking water; or updating the inventory information.
"Seasonal system" means a non-community water system that is not operated as a public water system on a year-round basis and starts up and shuts down at the beginning and end of each operating season.
"Secondary maximum contaminant level" or "SMCL" means an MCL which involves a biological, chemical or physical characteristic of water that may adversely affect the taste, odor, color or appearance (aesthetics), which may thereby affect public confidence or acceptance of the drinking water. This includes the MCLs for aluminum, chloride, color, copper, corrosivity, foaming agents, iron, manganese, odor, pH, silver, sulfate, total dissolved solids and zinc.
"Secretary, Delaware Health and Social Services" means the agency defined in 29 Del.C. § 7933.
"Sedimentation" means a process for removal of solids before filtration by gravity or separation.
"Service connection" means a water line to a dwelling unit or building.
"Service line sample" means a one (1) liter sample of water collected in accordance with subsection 10.7.2.3 that has been standing for at least six (6) hours in a service line.
"Significant deficiency" means a defect in design, operation, or maintenance, or a failure or malfunction of the sources, treatment, storage, or distribution system that the Division determines to be causing, or has the potential for causing the introduction of contamination into the water delivered to consumers.
"Single family structure" means a building constructed as a single family residence that is currently used as either a residence or a place of business.
"Slow sand filtration" means a process involving passage of raw water through a bed of sand at low velocity (generally less than 0.4 meters per hour) resulting in substantial particulate removal by physical and biological mechanisms.
"Small water system" means a water system that served 3,300 persons or fewer.
"Source" means the place from which a system obtains its water. This may be either from underground or from the surface. Surface water may include rivers, lakes, reservoirs, springs, impoundments or a body of water with a surface exposed to the atmosphere.
"Standard sample" means the sample size for bacteriological testing and shall consist of:
For the fermentation tube test, five (5) standard portions of either twenty (20) milliliters (ml) or one hundred (100) ml.
For the membrane filter technique, not less than one hundred (100) ml.
"Subpart H systems" means public water systems using surface water or ground water under the direct influence of surface water as a source that are subject to the filtration and disinfection requirements of these regulations.
"Supplier of water" means any person who owns or operates a public water system.
"Surface water" means all water which is open to the atmosphere and subject to surface runoff.
"SUVA" means Specific Ultraviolet Absorption at 254 nanometers (nm), an indicator of the humic content of water. It is a calculated parameter obtained by dividing a sample's ultraviolet absorption at a wavelength of 254 nm (UV254) (in m-1) by its concentration of dissolved organic carbon (DOC) (in mg/L).
"System with a single service connection" means a system which supplies drinking water to consumers via a single service line.
"Too numerous to count" means that the total number of bacterial colonies exceeds two hundred (200) on a forty-seven (47) millimeter (mm) diameter membrane filter used for coliform detection.
"Total coliform-positive sample" means any Presence-Absence (P-A) Coliform Test with a result of present (P), any Minimal Medium ONPG-MUG (MMO-MUG) Test with a result of P, any Membrane Filter Technique test with a result of one (1) or more colonies per one hundred (100) ml, or any Multiple Tube Fermentation test with a result of one (1) or more positive tubes.
"Total organic carbon" or "TOC" means total organic carbon in mg/L measured using heat, oxygen, ultraviolet irradiation, chemical oxidants, or combinations of these oxidants that convert organic carbon to carbon dioxide, rounded to two significant figures.
"Total trihalomethanes" or "TTHMs" means the sum of the concentration in milligrams per liter of trihalomethane compounds [trichloromethane (chloroform), dibromochloromethane, bromodichloromethane and tribromomethane (bromoform)] rounded to two significant figures.
"Treatment technique requirement" means a requirement which specifies for a contaminant a specific treatment technique(s) demonstrated to the satisfaction of the Division to lead to a reduction in the level of such contamination sufficient to comply with these regulations.
"Trihalomethanes" or "THMs" means one of the family of organic compounds, named as derivatives of methane, wherein three (3) of the four (4) hydrogen atoms in methane are each substituted by a halogen atom in the molecular structure.
"Turbidity" means a measure of the clarity or cloudiness of water in Nephelometric Turbidity Units or NTUs.
"Two-stage lime softening" means a process in which chemical addition and hardness precipitation occur in each of two distinct unit clarification processes in series prior to filtration.
"Uncovered finished water storage facility" means a tank, reservoir, or other facility used to store water that will undergo no further treatment to reduce microbial pathogens except residual disinfection and is directly open to the atmosphere. Finished water storage facilities that are properly covered, screened and vented are excluded from this definition.
"Virus" means a virus of fecal origin which is infectious to humans by waterborne transmission.
"Vulnerable" means subject to contamination, a determination which shall be made by the Division based on previous monitoring results, the number of persons served by the public water system, the proximity of a smaller system to a larger system, the proximity to commercial or industrial use, disposal or storage of volatile synthetic organic compounds (VOCs), and the protection of the water source or sources.
"Waterborne disease outbreak" means the significant occurrence of an acute infectious illness, epidemiologically associated with the ingestion of water from a public water system which is deficient in treatment, as determined by the Division.
"Water distribution system" means any pumps, piping, or storage facilities from the source/treatment plant or, for consecutive water supplies, the interconnection to the wholesale system, to the property line of the ultimate consumer.
"Water supply system" means any structures, equipment, and appurtenances for collection, treatment, storage, or distribution of potable water from the source of supply or, for consecutive water supplies, the interconnection to the wholesale system, to the free-flowing outlet of the ultimate consumer.
"Wholesale system" means a public water system that treats source water as necessary to produce finished water and then delivers some or all of that finished water to another public water system. Delivery may be through the distribution system of one or more consecutive systems.
16 Del. Admin. Code § 4462-2.0
25 DE Reg. 713( 1/1/2022) (Final)