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Delaware General AssemblyDelaware RegulationsMonthly Register of RegulationsNovember 2013

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7 DE Admin. Code 7101
The Department of Natural Resources and Environmental Control (the Department) finds that a substantial portion of the State’s population lives where centralized water supplies or wastewater treatment services are limited. It is the intent of the Department to aid and assist the public in the installation of on-site wastewater treatment and disposal systems, where possible, by utilizing the best information, techniques and soil evaluations for the most suitable system that site and soil conditions permit.
Statewide Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and Disposal Systems have existed since 1968. Inappropriate installations and poor operation and maintenance practices have resulted in disposal system malfunctions. Inadequately renovated wastewater has contaminated the State’s groundwater and presented a threat to the public health, safety, and welfare. Corrective measures required the replacement of water supply and wastewater systems, sometimes at a very high cost which is sometimes borne by the general public. After years of working under the Regulations which were first implemented in the 1960’s, numerous deficiencies were found to be present within the same. Given this, the Department concluded that significant revisions to its Regulations.
The proper siting of systems is addressed by the establishment of various soil criteria which lead to the selection of the most suitable on-site wastewater treatment and disposal system for local conditions. System selection and sizing are determined using the results of the site specific soil evaluations and percolation tests. Density is addressed by the adoption of minimum lot sizes tied to appropriate treatment and disposal techniques, and in some cases, the use of scientific ground water and geological analyses that both assure renovation of degradable pollutants and dilution of wastes which are inadequately treated in the soil. Site evaluation and system selection, design, installation and pump-outs are required to be performed by individuals licensed under these Regulations. Alternative system design criteria were established to enable proper waste treatment and disposal to occur in locations where conventional systems would be inappropriate. With the advent of mortgage companies requiring wastewater system inspections prior to loan approval, the Department took a pro-active approach to create a new licensee category (Class H System Inspector) and standardized format to perform the inspection so all inspections will be evaluated under the set of criterion. Finally, a specific variance procedure is established to provide an opportunity to reconsider any provision of these Regulations, provided that proper public disclosure and adequate consideration of the consequences are provided.
1.3 These Regulations shall supersede and replace Water Pollution Control Regulations #2 Governing The Installation and Operation of Septic Tank Sewage Disposal Systems, the Guidelines for Septic Tank Systems, and Part II of Section 9 of the Regulations Governing the Control of Water Pollution. With respect to the other provisions of the Regulations Governing the Control of Water Pollution these Regulations shall supersede such Regulations only to the extent of any inconsistency. These Regulations shall apply throughout the State of Delaware.
“Absorption Facility”: System of open‑jointed or perforated piping, alternative distribution units, or other seepage systems for receiving the flow from septic tanks or other treatment facilities and designed to distribute effluent for oxidation and absorption by the soil within the zone of aeration.
“Aggregate-free Chambers”: A buried structure used to create an enclosed unobstructed soil bottom absorption area and side-wall absorption area for infiltration and treatment of wastewater which can be use to replace the filter aggregate and distribution pipe in an absorption facility.
“Alteration”: Any physical change in the design capacity of an existing system or any part thereof.
“Alternating System”: Two or more disposal fields, equal in size with dosing provided alternatively to each field.
“Alternative Treatment and Disposal System”: A wastewater treatment or disposal system not specified in these Regulations which has been proven to provide at least an equivalent level of treatment as the conventional systems included in these Regulations.
“Applicant”: The owner or legally authorized agent of the owner as evidenced by sufficient written documentation.
“Authorization to Use Existing System Permit”: A written document issued by the Department which states that an on‑site wastewater treatment and disposal system appears adequate to serve the purpose for which a particular application is made.
“Aquifer”: A part of a formation, a formation, or a group of formations that contains sufficient saturated permeable material to yield economically useful quantities of water to wells or springs.
“Backfill”: Soil which is clean and free of foreign debris, placed over the disposal area and fill extensions.
“Blackwater”: Waste carried off by toilets, urinals, and kitchen drains.
“Building Sewer”: Piping which carries wastewater from a building to the first component of the treatment and disposal system.
“Cesspool”: A covered pit with a porous lining into which wastewater is discharged and allowed to seep or leach into the surrounding soils with or without an absorption facility.
“Commercial Facility”: Any structure or building, or any portion therefore, other than a residential dwelling.
“Community System”: An on‑site wastewater treatment and disposal system which will serve more than three (3) lots or parcels or more than three (3) condominium units or more than three (3) units of a planned unit development.
“Completed Application”: One in which the application form is properly completed in full, is signed by the applicant, is accompanied by all required exhibits, detailed plans and specifications, and required fee.
“Confined Aquifer”: An aquifer bounded above and below by impermeable beds or by beds of distinctly lower permeability than that of the aquifer itself and containing ground water. An aquifer containing ground water which is at a pressure greater than atmospheric pressure and from which water in a well will rise to a level above the top of the aquifer.
“Confining Layer”: A body of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers.
“Construction Permit”: A permit issued by the Department for the construction, alteration, repair or replacement of an on‑site wastewater treatment and disposal system.
”Construction Report”: A report prepared by the Class E Systme Contractor and submitted to the Department within 10 calendar days after the absorption facility has been completely installed.
“Conventional On-Site Wastewater Treatment and Disposal Systems”: Gravity, low pressure pipe, pressure-dosed, sand-lined and elevated sand mound.
“Department: The Department of Natural Resources and Environmental Control of the State of Delaware (DNREC).
“Developer”: A person, persons, partnership, firm, corporation, or cooperative enterprise undertaking or participating in the development of a subdivision, manufactured home community, or multi‑unit housing project. “Director”: The Director of the Division of Water Resources for the State of Delaware or his/her authorized representative.
“Disposal Area”: The entire area used for the absorption facility.
“Distribution Box”: A box for distributing wastewater equally to separate distribution laterals of the absorption facility.
“Distribution System”: Piping or other devices used in the distribution of wastewater within the absorption facility. (Also referred to as distribution laterals)
“Dosing”: The pumped or regulated flow of wastewater to the absorption facility.
“Dosing Chamber”: A receptacle for retaining wastewater until pumped or regulated to the absorption facility.
“Down Gradient”: An area that has a lower potentiometric surface (hydraulic head) than a comparative reference point.
“Dwelling”: Any structure or building, or any portion thereof which is used, intended, or designed to be occupied for human living purposes including but not limited to, houses, houseboats, boathouses, mobile homes, manufactured homes, travel trailers, hotels, motels, apartments, and condominiums.
“Easement”: An interest in land owned by another that entitles its holder to a specific limited use or enjoyment.
“Effluent Filter”: A device placed in the outlet compartment of a septic tank which conforms to ANSI/NSF Standard 46 for the purpose of removing particulate matter before the effluent enters the absorption facility.
“Effluent Line”: The pipe beginning at the treatment unit or septic tank and terminating at the absorption facility.
“Elevated Sand Mound”: An on-site wastewater treatment and disposal system which maintains a 36 inch separation distance above the limiting zone which is pressurized into suitable fill material constructed above existing grade.
“Emergency Repair”: Repair of a broken system component where immediate action is necessary to protect public health.
“Escarpment”: Any naturally occurring slope greater than thirty (30) percent which extends vertically six (6) feet or more as measured from toe to top, and which is characterized by a long cliff or steep slope which separates two (2) or more comparatively level or gently sloping surfaces, and may intercept one (1) or more layers than limit soil depth.
“Existing On‑Site Wastewater Treatment and Disposal System”: Any installed on‑site wastewater treatment and disposal system constructed in conformance with the rules, laws and local ordinances in effect at the time of construction, or which would have conformed satisfactorily with system design provided for in Department Regulations.
“Feasibility Study”: A site/soil investigative report identifying the suitability of a parcel of land for on-site wastewater treatment and disposal systems. The report includes information pertinent to the Department and other local government agencies in the determination of certain land use decisions.
“Fill”: Soil material which has been transported to and placed over the original soil or bedrock and is characterized by a lack of distinct horizons or color patterns as found in naturally developed, undisturbed soils.
“Filter Aggregate”: Washed gravel or crushed stone ranging in size from 3/4" to 2 l/2" in any dimension and clean and free of fine materials (dust) or meeting grading specifications in §6.4.2.
“Filter Fabric”: Any material approved by the Department which is permeable but does not allow soil particles to pass through for the purpose of protecting the filter aggregate or aggregate free chambers within the absorption facility.
“Full Depth Gravity”: A gravity fed on-site wastewater treatment and disposal system which maintains a 36 inch separation distance above the limiting zone where the trench or bed is installed 24 inches into the natural soil.
“Governmental Unit”: The state or any county, municipality, or any part thereof.
“GPD”: Gallons per day.
“Grade”: The inclination or slope of a conduit or ground or plane surface.
“Gravity Capping Fill”: A gravity fed on-site wastewater treatment and disposal system which maintains 36 inches separation distance above the limiting zone where the trench or bed is installed between 12 and 23 inches into the natural soil below a soil cap of a specified depth and texture.
“Greywater”: The untreated wastewater that has not come into contact with toilet waste. Greywater includes wastewater from bathtubs, showers, bathroom wash basins, clothes washing machines, laundry tubs and other wastewater which does not present a threat from contamination by unhealthy processing, manufacturing or operating wastes. It does not include wastewater from kitchen sinks or dishwashers.
“Grease Trap”: A watertight tank for the collection and retention of grease that is accessible for periodic removal.
“Groundwater”: Any water naturally found under the surface of the earth.
“Holding Tank”: A watertight receptacle used to store wastewater prior to being removed by a licensed Class F Liquid Waste Hauler.
“Hydraulic Conductivity”: A specific mathematical coefficient (quantitative) that relates the rate of water movement to the hydraulic gradient. A term of Darcy’s law Q = KAi where K represents hydraulic conductivity and is the current standard for measuring a soils ability to transmit water.
“Impervious Strata and Formation”: An underground or surface layer of soil or rock which will not allow water to pass through it at a rate permissible for subsurface disposal and having a percolation rate slower than one hundred twenty (120) minutes per inch.
“Invert”: The floor, bottom or lowest portion of the internal cross section of a closed conduit or structure.
“Isolation Distance”: The horizontal distance between a system component and selected site features or structures.
“Large System”: Any on‑site wastewater treatment and disposal system with a projected wastewater design flow rate greater than two thousand five hundred (2,500) gallons per day.
“Lift Pump Station”: A receptacle for pumping wastewater to a system component to overcome slope differentials for the use of gravity distribution.
“Limiting Zone”: Any horizon or condition in the soil profile or underlying strata which includes:
“Lot: A portion of a subdivision or parcel of land.
“Low Pressure Pipe Capping Fill”: A pressurized on-site wastewater treatment and disposal system which is installed as trenches and maintains 18 inch separation distance above the limiting zone. The trenches are installed between 9-17 inches into natural soil below a soil cap of a specified depth and texture.
“Low Pressure Pipe Full Depth”: A pressurized on-site wastewater treatment and disposal system which is installed as trenches and maintains 18 inch separation distance above the limiting zone. The trenches are installed 18 inches into natural soil.
“Malfunctioning System”: A system which is not adequately renovating or hydraulically eliminating the wastewater it is receiving as evidenced by, but not limited to, the following conditions:
“Manifold”: A pipe with numerous branches to convey effluent between a large pipe and several smaller pipes, or to permit choice of diverting flow from one of several sources or to one of several discharge points.
“Manufactured Home”: A home built entirely in the factory under a federal building code administered by the Department of Housing and Urban Development (HUD). Manufactured homes may be single or multi-section and are transported to the site and installed.
“Mineral Soil”: A soil that is saturated with water less than 30 days (cumulative) per year in normal years and contains less than 20 percent (by weight) organic carbon; or is saturated for greater than 30 days or more cumulative in normal years, and has an organic carbon content (by weight) of less than 18 percent if the mineral fraction contains 60 percent or more clay; or less than 12 percent if the mineral fraction contains no clay.
“Monitor Well”: A well installed for the sole purpose of the determination of subsurface conditions and collecting groundwater samples.
“Mottling: Soil irregularly marked with spots of different colors that vary in number and size which may indicate poor aeration, lack of drainage and the upper extent of the seasonal high water table.
“Observation well”: A well used for the sole purpose of determining groundwater levels.
“On‑Site Wastewater Treatment and Disposal System”: Conventional or alternative, wastewater treatment and disposal systems installed or proposed to be installed on land of the owner or on other land to which the owner has the legal right to install the system.
“On-Site System Advisory Board (OSSAB)”: A panel of licensee’s representing the on-site industry, asked to serve by the Secretary, on all matters pertaining to the issuance and revocation of all on-site licenses.
“Owner”: The person who has a vested legal or equitable title to real or personal property, including an on‑site wastewater treatment and disposal system.
“Percolation rate”: The rate of water movement through a soil. Percolation rate is usually measured and assigned on the basis of elapsed time per unit volumetric water level drop. The most commonly used unit for expressing percolation rate is minutes per inch (mpi).
“Permeability”: The property of a soil horizon that enables the soil to transmit gases, liquid, or other substances.
“Permit”: The written document approved by the Department which authorizes the installation of an on-site wastewater treatment and disposal system or any part thereof, which may also require operation and maintenance of the system.
“Permittee”: Any individual, partnership, corporation, association, institution, cooperative enterprise, agency, municipality, commission, political subdivision or duly established entity to which a permit is issued.
“Piezometer”: A small diameter non-pumping well with a short screen that is used to measure the elevation of the water table or potentiometric surface.
“Platy Structure”: Soil aggregates that are developed predominantly along the horizontal axes, laminated and flaky.
“Pollution or Water Pollution”: Any alteration of the physical, chemical or biological properties of any waters of the state, including change in temperature, taste, color, turbidity, silt or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the state, which will or tends to, either by itself or in connection with any other substance, create a public nuisance or which will or tends to render such waters harmful, detrimental or injurious to public health, safety or welfare, or to domestic, commercial, industrial, agricultural, recreational or other legitimate beneficial uses or to livestock, wildlife, fish or other aquatic life or the habitat thereof.
“Potentiometric Surface”: A surface that represents the level to which water will rise in tightly cased wells.
“Pressure Dosed Capping Fill”: A pressurized on-site wastewater treatment and disposal system which maintains a 36 inch separation distance above the limiting zone where the trench or bed is installed between 12 and 23 inches into the natural soil below a soil cap of a specified depth and texture.
“Pressure Dosed Full Depth”: A pressurized on-site wastewater treatment and disposal system which maintains a 36 inch separation distance above the limiting zone where the trench or bed is installed 24 inches into the natural soil.
“Pressurized Distribution”: A network of piping with orifices designed to evenly distribute wastewater under pressure through the entire absorption facility.
“Primary Treatment”: A wastewater treatment process that takes place in a tank and allows those substances in wastewater that readily settle or float to be separated from the water being treated.
“Professional Engineer”: A person registered by the Delaware Association of Professional Engineers to practice professional engineering in the State of Delaware.
“Professional Geologist”: A person registered by the Delaware State Board of Registration of Geologists to practice professional geology in the State of Delaware.
“Project Site”: The total area within the property lines of an individual lot or within the division lines of a parcel or subdivision.
“Public Health Hazard”: A condition whereby there are sufficient types and amounts of biological, chemical or physical, including radiological, agents relating to water or sewage which are likely to cause human illness, disorders or disability. These include, but are not limited to, pathogens, viruses, bacteria, parasites, toxic chemicals, and radioactive isotopes.
“Redoximorphic Features”: Characteristic soil patterns formed by the reduction, translocation and oxidation of iron and manganese oxides. The occurrence of these features may be indicative of poor drainage, or lack of aeration associated with the upper most extent of the seasonal high water table.
“Repair”: Any modification to an existing on-site wastewater treatment and disposal system necessary to fix a problem or malfunction.
“Replacement System”: An on-site wastewater treatment and disposal system to replace the existing on-site wastewater treatment and disposal system or a portion thereof.
“Sand”: Individual mineral particles in a soil that range in diameter from the upper limit of silt (0.05 millimeters) to 2.0 millimeters.
“Sand Lined System”: A type of seepage trench or seepage bed soil absorption facility constructed in sandy fill material below the natural soil surface and may require pressurization. The fill material is used to replace a natural impermeable or slowly permeable soil layer or to completely remove an existing absorption facility.
“Sandy Fill”: Materials that consist of medium sand, sandy loam, loamy sand/sandy loam mixtures (see sieve requirements in §6.4.1).
“Scarifying”: Scraping or loosening the bottom and sidewall soil surfaces in the preparation of percolation test holes, seepage trenches, beds, or similar excavations.
“Scum”: A mass of sewage solids floating at the surface of effluent and buoyed up by entrained gas, grease or other substances.
“Seasonal High Water Table”: The highest zone of soil or rock that is seasonally or permanently saturated by a perched or shallow water table. A planar surface below which all pores in rock or soil (whether primary or secondary) is seasonally or permanently saturated.
“Secondary Treatment”: A combination of unit processes that will consistently remove 85% or more of the organic and suspended material in domestic wastewater and produce an effluent of sufficient quality to satisfy the following requirements; monthly average effluent BOD5 and TSS concentrations of 30 mg/L; daily maximum effluent BOD5 and TSS concentrations of 45 mg/L.
“Secretary”: Secretary of the Department of Natural Resources and Environmental Control or a duly authorized designee.
“Seepage Bed”: An absorption facility consisting of an area from which the entire earth contents have been removed and replaced with a network of perforated pipe, filter aggregate or aggregate-free chambers and covered with suitable backfill material.
“Seepage Pit”: A covered pit with a porous lining into which wastewater is discharged and allowed to seep or leach into the surrounding soil and is preceded by a septic tank.
“Seepage Trench”: A soil absorption facility consisting of ditches with vertical sides and flat bottoms partially filled with filter aggregate and containing perforated pipe or aggregate-free chambers and covered with suitable backfill material.
“Septage”: The liquid and solid contents of a septic tank.
“Septic Tank”: A watertight receptacle which receives the discharge of wastewater from a structure or part thereof and is designed and constructed so as to permit settling of solids from the liquid, digestion of the organic matter by detention, and discharge of the liquid portion into an absorption facility.
“Single Family Dwelling”: A residence intended for single family residential use.
“Siphon”: A hydraulically operated device designed to rapidly discharge the contents of a dosing tank between predetermined hydraulic levels.
“Site Evaluation”: The practice of investigating, evaluating and reporting basic soil and site conditions which apply to the on‑site wastewater treatment and disposal system type and design criteria.
“Slope”: Deviation of a plane surface from the horizontal. It is usually expressed as a ratio or percentage of number of units of vertical rise or fall per unit of horizontal distance.
“Soil Horizon: A layer of soil or soil material approximately parallel to the land surface and differing from adjacent genetically related layers in physical, chemical, and biological properties or characteristics such as color, structure, texture, consistence and pH.
“Soil Profile”: A vertical cross-section of a soil that shows the various soil horizons. Soil drainage or moisture status are soil characteristics that can be inferred from the soil profile.
“Soil Structure”: The combination or arrangement of primary soil particles into secondary compound particles or clusters, the principle forms of which are: platy (laminated); prismatic (prisms with rounded tops); blocky (angular or subangular); granular and columnar.
“Soil Texture”: The grain sizes that comprise a soil consisting of three textural classes; sand, silt and clay. Field methods for judging the texture of a soil consist of forming a cast of soil, both dry and moist, in the hand and pressing a ball of moist soil between thumb and finger.
“Sand”: Individual grains can be seen and felt readily. Squeezed in the hand when dry, this soil will fall apart when the pressure is released. Squeezed when moist, it will form a cast that will hold its shape when the pressure is released, but will crumble when touched.
“Sandy Loam”: Consists largely of sand, but has enough silt and clay present to give it a small amount of stability. Individual sand grains can be readily seen and felt. Squeezed in the hand when dry, this soil will readily fall apart when the pressure is released. Squeezed when moist, it forms a cast that will not only hold its shape when the pressure is released, but will withstand careful handling without breaking. The stability of the moist cast differentiates this soil from sand.
“Loam”: Consists of an even mixture of sand and of silt and a small amount of clay. It is easily crumbled when dry and has a slightly gritty yet fairly smooth feel. It is slightly plastic. Squeezed when moist, it forms a cast that will not only hold its shape when the pressure is released, but will withstand careful handling without breaking. The stability of the moist cast differentiates this soil from sand.
“Silt Loam”: Consists of a moderate amount of fine grades of sand, a small amount of clay, and a large quantity of silt particles. Lumps in a dry, undisturbed state appear quite cloddy, but they can be pulverized readily; the soil then feels soft and floury. When wet, silt loam runs together in puddles. Either dry or moist, casts can be handled freely without breaking. When a ball of moist soil is pressed between thumb and finger, it will not press out into a smooth, unbroken ribbon, but will have a ribbon appearance.
Clay Loam”: Consists of an even mixture of sand, silt, and clay, which breaks into clods or lumps when dry. When a ball of moist soil is pressed between the thumb and finger, it will form a thin ribbon that will readily break, barely sustaining its own weight. The moist soil is plastic and will form a cast that will withstand considerable handling.
“Silty Clay Loam”: Consists of a moderate amount of clay, a large amount of silt, and a small amount of sand. It breaks into moderately hard clods or lumps when dry. When moist, a thin ribbon or one‑eighth (1/8) inch wire can be formed between thumb and finger that will sustain its weight and will withstand gentle movement.
“Silty Clay”: Consists of even amounts of silt and clay and very small amounts of sand. It breaks into hard clods or lumps when dry. When moist, a thin ribbon or one‑eighth (1/8) inch or less sized wire formed between thumb and finger withstand considerable movement and deformation.
“Clay”: Consists of large amounts of clay and moderate to small amounts of sand. It breaks into very hard clods or lumps when dry. When moist, a thin, long ribbon or one‑sixteenth (1/l6) inch wire can be molded with ease. Fingerprints will show on the soil, and a dull to bright polish is made on the soil by a shovel.
“Silt”: Consists largely of silt with very small amounts of clay. The soil feels very silky or floury. When pressed between thumb and finger, it will readily pulverize without forming a ribbon.
“Loamy Sand”: Is predominately composed of sand, but has enough clay so that it can be formed into a weakly developed ball with careful handling.
Sandy Clay Loam”: The predominant particle size found within this soil textural class is sand, although it contains relatively high levels of clay with lesser amounts of silt. When moist, it will form a thin ribbon that does not readily break.
“Sandy Clay”: Consists of relatively even amounts of sand and clay with very small amounts of silt. When moist, a thin ribbon can readily be formed between thumb and finger without considerable deformation or movement.
“Solum”: The upper part of the soil profile (A, E and B horizons) above the parent material in which the processes of soil formation are active.
“Spare Area”: An area set aside for construction of a second absorption facility to be used in the event the original absorption facility malfunctions or is expanded.
“Subdivision”: Any tract or parcel of land which has been divided into two or more lots for which development is intended.
“System”: Refers to an on‑site wastewater treatment and disposal system.
“System Inspector”: A person licensed by the Department to inspect, investigate, collect data and make determinations regarding the present operational condition of an on-site wastewater treatment and disposal system.
“Test Pit”: An excavation used to examine a soil profile in order to assess soil permeability and depth to a seasonal high water table using soil texture, structure, and redoximorphic features as a basis for assessing site suitability.
“Topography”: Ground surface variations or contours of the earth's surface, both natural and anthropogenic.
“Unconfined Aquifer”: An aquifer in which no relatively impermeable layer exists between the water table and the ground surface and an aquifer in which the water is at atmospheric pressure.
“Undisturbed Soil”: Soil or soil profile unaltered by filling, removal, or other man‑made changes with the exception of agricultural activities.
“Upgradient”: An area that has a higher potentiometric surface (hydraulic head) than a comparative reference point.
“Wastewater”: Water‑carried waste from septic tanks, water closets, residences, buildings, industrial establishments, or other places, together with such groundwater infiltration, subsurface water, and mixtures of industrial wastes or other wastes as may be present.
“Wastewater Utility”: Any person who engages in the business of providing wastewater disposal and related services to the public for a fee, charge, or other remuneration in the State of Delaware.
“Watercourse”: Any ocean, bay, lake, pond, stream, river or defined ditch that will permit drainage into any surface water body, excluding ephemeral watercourses as defined below.
“Ephemeral”: A watercourse which flows briefly, only in direct response to precipitation in the immediate vicinity, and whose invert is above the seasonal high water table.
“Water Table”: The surface of an unconfined aquifer where the groundwater pore water pressure is equal to atmospheric pressure.
“Waters of the State”: Public waters, including lakes, bays, sounds, ponds, impounding reservoirs, springs, wells, rivers, streams, creeks, estuaries, marshes, inlets, canals, the ocean within the territorial limits of the State, and all other bodies of surface or underground water, natural or artificial, inland or coastal, fresh or salt, within the jurisdiction of the State of Delaware.
“Well”: Any excavation that is drilled, cored, bored, washed, driven, dug, jetted, or otherwise constructed when the intended use of such excavation is for the location, testing, acquisition, use; for extracting water from or for the artificial recharge of subsurface fluids; and where the depth is greater than the diameter or width. For the purpose of this regulation this definition does not include geotechnical test, soil, telephone and construction piling borings, fence posts, test pits, or horizontal closed loop heat pump circulation systems constructed within twenty (20) feet of the ground surface.
“Zone of Aeration”: A subsurface zone containing water under pressure less than that of the atmosphere, including water held by capillary and containing air or gases generally under atmospheric pressure. This zone is limited above by the land surface and below by the surface of the zone of saturation, i.e., the water table.
3.4 Any county may assume responsibility and authority for administering its own regulatory program for on‑site wastewater treatment and disposal systems pursuant to 7 Del.C. Ch. 60, §6003(d), if the delegated program establishes standards no less stringent than the standards established in these Regulations.
4.14 Licenses issued pursuant to this Section are not transferable and shall expire on December 31st of each year. A license may be renewed yearly without examination for an ensuing year provided the licensee makes application for renewal by November 30th of each year, shows proof of the number of hours of continuing education training and pays any applicable renewal fees adopted by the Department. If the licensee fails to renew the license he/she may reapply, without examination, within the first year. If more than a year passes the licensee must reapply for the license and take all necessary examinations. A reminder will be sent to the licensee to renew his/her license by the Department. The reminder will be sent to the address on file for the licensee. It is the licensee’s responsibility to renew the license yearly and notify the Department of any changes.
5.2.1.7 The preferred monitoring is from December 1st through May 15th of the following year to verify the depth and duration of the zones of saturation during years of near normal precipitation for fall, winter and spring seasons. However, the Class D Soil Scientist may, at his/her discretion, allow clients to install wells at any time he/she deems appropriate. Depending on when peaks are observed, the State may or may not accept the monitoring for that season. A near normal monitoring period is defined as a period that has plus or minus one standard deviation of the long term mean annual precipitation. (Long term refers to 30 or more years). Also, the mean monthly precipitation during a normal period must be plus or minus one standard deviation of the long term monthly precipitation for 8 of the 12 months. For the most part, normal years can be calculated from the mean annual precipitation.
5.5.1 The Department shall make a decision on the application which it determines will best implement the purposes of 7 Del.C. Ch. 60 and these Regulations. Providing of the requisite information in the application procedure by the applicant shall not be construed as a mandatory prerequisite for the issuance of the permit by the Department.
5.11 Repair and Replacement of Existing Systems
5.11.1 Steps to repair a malfunctioning system shall be initiated immediately and continued until system repair is completed. However, if, at the sole discretion of the Department, it is determined that adverse soil conditions exist due to climatic conditions that would likely preclude a successful repair, the Department may allow a delay in commencing repairs until the soil conditions improve. If this allowance is made, a compliance date and interim system maintenance requirements shall be specified in system construction deficiencies to the system owner.
5.13.9 Responsibility for operation and maintenance of community systems shall be vested in a governmental unit or a Council on behalf of the unit property owners pursuant to 25 Del.C. Ch. 22 or for subdivisions with an owners' association duly incorporated within the State with specific authority to operate, maintain, and repair the community system, to collect fees and special assessments and to enforce any covenants, restrictions or agreements (see §5.13.4).
5.14.1.2 The applicant shall provide a Preliminary Groundwater Impact Assessment (PGIA). The PGIA shall assess the potential impact of the large system upon waters of the State and upon public health. The PGIA shall comply with current guidelines established by the Department.
5.14.1.4 Ground-water mounding analysis may be required for proposed large on-site wastewater treatment and disposal system sites where a potential for significant water-table mounding is probable due to (1) low aquifer transmissivity (low hydraulic conductivity), (2) shallow depth to seasonal high water table, or (3) high wastewater loading rate. Slug test(s) may be necessary to obtain horizontal hydraulic conductivity values for the aquifer. A report documenting the ground-water model utilized to perform the analysis must be provided along with all aquifer parameters and design criteria needed to run the model. Only Certified Professional Geologists registered in the State of Delaware are qualified to perform the ground water mounding analysis.
5.14.3.1 Permit applications must be designed in accordance with the prescribed system type and design considerations as specified in the SIR and PGIA for that parcel.
5.15.5.5 The property deed shall be amended with an Affidavit of Ownership at the time of permit issuance, which states that the dwelling is served by a permanent holding tank. The Affidavit of Ownership must be recorded at the Recorder of Deeds; and
6.5.4 A minimum distance of four (4) feet and a maximum distance of six (6) feet shall separate adjacent laterals in a bed. Laterals shall be placed no farther than three (3) feet from the sidewalls of the bed. The length to width ratio for seepage beds and elevated sand mounds shall be 4 : 1 or greater and maximum bed width shall not exceed twenty five (25) feet, unless approved by the Department. A minimum distance of six (6) feet shall separate laterals in a trench disposal system.
6.17.1 All Full Depth Gravity and Capping Fill Gravity Trench and Bed Treatment and Disposal Systems shall be designed in accordance with the following criteria (see Exhibits K, L, M or N).
6.17.6 All Low Pressure Pipe Treatment and Disposal Systems shall be designed in accordance with the following criteria (see Exhibits O & X).
6.17.8 The depth to the bottom excavation shall be nine (9) inches to eighteen (18) inches. Trench width shall be no larger than twelve (12) inches, unless otherwise approved by the Department.
6.17.11 All Elevated Sand Mound Treatment and Disposal Systems shall be designed in accordance with the following criteria (see Exhibit P).
6.17.16 All Pressure-Dosed Full Depth and Capping Fill Treatment and Disposal Systems shall be designed in accordance with the following criteria (see Exhibits Q & R).
6.17.22 All Sand-lined Treatment and Disposal Systems shall be designed in accordance with the following criteria (see Exhibit S).
6.21.2 Gravity dosing and distribution systems may be used when the design wastewater flow requires less than two-thousand (2,500) ft2 of disposal area for seepage trenches or seepage beds and the percolation rate is equal to or slower than six (6) minutes per inch.
6.22.2 All gravity transmission pipes shall be placed on a firm undisturbed or well compacted soil. All joints shall be watertight. A minimum grade of one-eigths (1/8 ) inch per foot shall be provided for gravity transmission piping. Clean backfill shall be placed around and over the pipe and hand tamped to provide compaction.
6.22.3 All gravity distribution laterals shall be thin walled or Sch. 40 PVC and shall be four (4) inches in diameter. Perforated PVC pipe shall have three-eigths (3/8 ) to three-quarters (3/4 ) inch diameter holes a maximum of thirty (30) inches on center. Coiled and corrugated piping shall not be used. A grade of less than two (2) inches per one hundred (100) feet shall be provided for all gravity distribution laterals.
Sussex – 24 inches
Kent – 24 inches
New Castle – 30 inches
6.22.17.3 All pressure distribution laterals shall be Sch. 40 and SDR 26 PVC pipe with diameters as determined by a Class C Designer. Minimum hole diameters for perforated pressure distribution laterals shall be five-thirtyseconds ( 5/32 ) to one-half ( 1/2 ) inch maximum and spacing intervals as determined by a Class C Designer and be placed on center along the length of the pipe. Maximum hole spacing shall be determined by percolation rates as follows:
NOTE: Balanced trench loading rates (gpd/ft2) must be considered where slopes are encountered. This can be accomplished by varying the number of lateral perforations (and spacing) and perforation diameter.
6.26.2.6 Grade: A building sewer shall be installed in a straight line to the maximum extent practicable with a uniform continuous grade not less than l/8 inch/foot, unless it can be demonstrated to the satisfaction of the Department that an alternative design can maintain adequate flow from the source and is approveable under the applicable local building code.
6.26.2.7 Cleanouts: Building sewer cleanouts shall be installed at minimum intervals of fifty (50) feet for three (3) inch diameter pipe and one hundred (100) feet for four (4) inch and larger diameter pipe. Cleanouts shall be provided at all changes in direction greater than 45o. Wherever possible, bends should be limited to 45o. Every house or building sewer shall have at least one (1) cleanout fitting to provide access to the plumbing. Cleanouts may be placed at greater distances provided National Standards are used to design the total collection system.
7.2.2 For commercial facilities the maximum siting density shall be established by dividing the projected design flow by five hundred (500) gallons per day per one‑half (1/2) acre and shall be based on the net pervious area (i.e., unpaved, without structures) available for groundwater recharge after total project completion. Campgrounds intended for overnight or transient use are evaluated as commercial facilities as opposed to manufactured home communities, which are evaluated as single family residential facilities.
8.2 Each on‑site wastewater treatment and disposal system shall be pumped by a licensed class F Liquid Waste Hauler once every three (3) years and alternative treatment systems shall be pumped according to manufacturer recommendations unless determined that the tank is less than one-third (1/3) full of solids. The schedule shall be prescribed in accordance with current Department guidelines based on the size of the treatment unit and anticipated number of residents. The owner of the on‑site wastewater treatment and disposal system shall maintain a record indicating the system has been pumped and provide such documentation to the Department upon request.
10.2.2.1 The requirements of 7 Del.C. Ch. 60, §6011 have been satisfied; and
"Absorption facility" means a system of open jointed or perforated piping, alternative distribution units or other seepage systems for receiving the flow from septic tanks or other treatment facilities and designed to distribute effluent for oxidation and absorption by the soil within the zone of aeration.
"Advanced treatment unit" means any process designed to produce an effluent of higher quality than normally achieved by secondary treatment processes or containing unit operations not normally found in secondary treatment which also incorporates nutrient removal processes that achieve PSN3 requirements.
"Affidavit of Ownership" means a formal sworn statement of ownership, signed by the declarant (who is called the affiant or deponent) and witnessed (as to the veracity of the affiant's signature) by a taker of oaths, such as a notary public.
"Aggregate-free chambers" means a buried structure used to create an enclosed unobstructed soil bottom absorption area and side-wall absorption area for infiltration and treatment of wastewater which can be used to replace the filter aggregate and distribution pipe in an absorption facility.
"Agricultural land" means land cultivated for the production of crops or used for raising livestock.
"Agricultural wastes" means wastes normally associated with the production and processing of food and fiber on farms, feedlots, ranches, ranges, and forests which may include animal manure, crop residues, and dead animals; also agricultural chemicals, fertilizers and pesticides which may find their way into surface and subsurface water.
"Agricultural well" means a non-potable well used for watering livestock, aquaculture, or watering household yards and gardens, or for other purposes related to farming but not for irrigating lands or crops.
"Alternating system" means two or more disposal fields, equal in size with dosing provided alternatively to each field.
"Applicant" means the owner or legally authorized agent of the owner as evidenced by sufficient written documentation who has submitted an application to the Department for review and approval.
"Aquifer" means a part of a formation, a formation, or a group of formations that contains sufficient saturated permeable material to yield economically useful quantities of water to wells and springs.
"Authorization to use existing system permit" means a written document issued by the Department which states that an on site wastewater treatment and disposal system appears adequate to serve the purpose for which a particular application is made and that the system may be placed into operation.
"Authorized agent" means a person given the authority to act on the owner's behalf for filing an application with the Department either to sign on behalf of the owner or to act as the contact person to receive all correspondence.
"Backfill" means a soil which is clean and free of foreign debris, placed over the disposal area and fill extensions.
"Biosolids" means the nutrient-rich organic materials resulting from the treatment of sewage sludge: the solid, semisolid or liquid untreated residue generated during the treatment of domestic sewage in a treatment facility.
"Blackwater" means waste carried off by toilets, urinals, and kitchen drains.
"BOD5" means biochemical oxygen demand which is the amount of oxygen required by bacteria to stabilize decomposable organic matter under aerobic conditions.
"Building drain" means the piping coming from inside a building that extends five (5) feet beyond the exterior walls of the building and conveys wastewater to the building sewer.
"Building sewer" means piping which carries wastewater from a building drain to the first component of the treatment and disposal system.
"Capping fill gravity" means a gravity fed on-site wastewater treatment and disposal system which maintains a minimum 36 inches of separation distance above the limiting zone where the trench or bed is installed between 12 and 23 inches into the natural soil below a soil cap of a specified depth and texture.
"Certified service provider" means any of the following responsible parties:
"Cesspool" means a covered pit, with a porous lining, into which wastewater is discharged and allowed to seep or leach into the surrounding soils with or without an absorption facility. Note: Cesspools cannot be certified for real estate transfers.
"Class H inspection" means the inspection of an existing OWTDS by an individual licensed as Class H system inspector by the Department to inspect, investigate and collect data detailing the current operating condition and type of system on Department authorized forms as observed on a specific date and time.
"Commercial facility" means any structure or building, or any portion therefore, other than a residential dwelling.
"Community system" means an on-site wastewater treatment and disposal system which serves more than three (3) lots, parcels, condominium units or units of a planned unit development.
"Completed application" means the application form is properly completed in full, is signed by the applicant, is accompanied by all required documents, exhibits, detailed plans and specifications, and required fee.
"Confined aquifer" means a saturated layer of permeable geologic material bounded above and below by confining layers, and in which water pressures are greater than atmospheric.
"Confining layer" means a stratum of impermeable or distinctly less permeable material stratigraphically adjacent to one or more aquifers.
"Construction permit" means a permit issued by the Department for the construction, repair or replacement of an on site wastewater treatment and disposal system.
"Construction report" means a Department approved form prepared by the contractor and submitted to the Department within 10 calendar days after the absorption facility has been completely installed.
"Conventional on-site wastewater treatment and disposal systems (OWTDS)" means those small systems which are referred to as; gravity, low pressure pipe, pressure-dosed, Wisconsin at-grade and elevated sand mound.
"Crops" means a plant growing where it is desired for man and his welfare as opposed to weeds which interfere with the activities of man, his welfare and are growing where it is undesirable.
"Crops for direct human consumption" means crops that are consumed by humans without processing to minimize pathogens before distribution to the consumer.
"Declaration of Covenants & Restrictions" means a legal obligation imposed by the seller upon the buyer of real estate.
"Department" means the Department of Natural Resources and Environmental Control of the State of Delaware (DNREC).
"Developer" means a person, persons, partnership, firm, corporation or cooperative enterprise undertaking and/or participating in the development of a subdivision, manufactured home community, or multi unit housing project.
"Director" means the Director of the Division of Water for the State of Delaware or his/her authorized representative.
"Disposal" means the discharge, deposit, injection, dumping, spilling, leaking, or placing of wastewater, other liquid waste, or any constituent of it on or in the land, the air or any waters, including groundwater, and includes any method of utilization that involves reuse of the nutrients at greater than agronomic rates.
"Disposal area" means the entire area used for the absorption facility.
"Distributed wastewater" means treated and filtered wastewater provided for disposal, reuse or any other purpose consistent with the intent of these Regulations.
"Distribution box" means a box for distributing wastewater equally to separate distribution laterals of the absorption facility by means of gravity.
"Distribution system" means piping or other devices used in the distribution of wastewater within the absorption facility (also referred to as distribution laterals).
"Domestic waste" means solid waste, composed of garbage and rubbish, which normally originates in a private home or apartment house and may contain toxic or hazardous waste.
"Dosing" means the pumped or regulated flow of wastewater to the absorption facility.
"Dosing chamber" means a tank/receptacle for retaining effluent until pumped by timing and/or measured volumes to the pressurized absorption facility.
"Down gradient" means an area that has a lower potentiometric surface (hydraulic head) than a comparative reference point.
"Dwelling" means any structure or building, or any portion thereof which is used, intended, or designed to be occupied for human living purposes including, but not limited to, houses, houseboats, boathouses, mobile homes, manufactured homes, travel trailers, hotels, motels, apartments and condominiums.
"Easement" means an interest in land owned by another that entitles its holder to a specific limited use or enjoyment.
"Effluent" means the wastewater flow from a tank or treatment process.
"Effluent filter" means a device placed in the outlet compartment of a septic tank which conforms to ANSI/NSF Standard 46 for the purpose of removing particulate matter before the effluent enters the absorption facility.
"Effluent line" means the pipe beginning at the treatment unit or septic tank and terminating at the absorption facility.
"Elevated sand mound" means an on-site wastewater treatment and disposal system which maintains a minimum 36 inches of separation distance above the limiting zone in which wastewater is pressurized into suitable fill material constructed above existing grade.
"Emergency permit" means a permit allowing a repair and/or replacement of a broken system component on an emergency basis where immediate action is necessary to protect public health. Repairs/replacements of this kind are considered emergencies occurring when Department offices are closed. Repairs and/or component replacements to cesspools, seepage pits or tank(s) associated with cesspools/seepage pits are not permitted unless approved by the Department.
"Encumbrance" means anything non-financial that affects or limits the area available to site, design and install an OWTDS on a property such as easements, right of ways and restrictions. The Department also includes, but is not limited to, these physical encumbrances; dwellings, outbuildings, driveways, or concrete pads.
"Engineered sandy fill" means sand that must have a uniformity coefficient of < 5. A minimum of 95% by weight must pass through a #4 sieve and a maximum of 10% by weight through a #100 sieve.
"Escarpment" means any naturally occurring slope greater than 30% which extends vertically six (6) feet or more as measured from top to toe, and which is characterized by a long cliff or steep slope which separates two (2) or more comparatively level or gently sloping surfaces, and may intercept one (1) or more layers that limit soil depth.
"Existing on site wastewater treatment and disposal system" means any installed on site wastewater treatment and disposal system constructed in conformance with the rules, laws and local ordinances in effect at the time of construction or which would have conformed satisfactorily to the system design provided for in Department regulations.
"Fill" means soil material which has been transported to and placed over the original soil or bedrock and is characterized by a lack of distinct horizons or color patterns as found in naturally developed, undisturbed soils.
"Filter aggregate" means washed gravel or crushed stone ranging in size from 3/4" to 2l/2" in any dimension and clean and free of fine materials (dust) and meeting grading specifications in Section 5.4.2.
"Filter fabric" means any material approved by the Department which is permeable but does not allow soil particles to pass through for the purpose of protecting the filter aggregate or aggregate free chambers within the absorption facility.
"Food chain crops" means tobacco, crops grown for human consumption, and crops grown to feed animals whose products are consumed by humans.
"Free liquids" means liquids which readily separate from the solid portion of a waste under the following tests:
"Full depth gravity" means a gravity fed on-site wastewater treatment and disposal system which maintains a minimum of 36 inches of separation distance above the limiting zone where the trench or bed is generally installed 24 inches into the natural soil.
"Governmental appointee" means any state, county, municipal employee or someone contracted by any of these agencies for the purpose of doing official business for the business aspects of the State.
"Governmental unit" means the state, any county, municipality, or any part thereof.
GPD" means gallons per day.
"Grade" means the inclination or slope of a conduit, ground or plane surface.
"Greywater" means the untreated wastewater that has not come into contact with toilet waste. Greywater includes wastewater from bathtubs, showers, bathroom wash basins, clothes washing machines, laundry tubs and other wastewater which does not present a threat from contamination by unhealthy processing, manufacturing or operating wastes. It does not include wastewater from kitchen sinks or dishwashers.
"Grease trap" means a watertight tank for the collection and retention of grease which is accessible for periodic removal.
"Groundwater" means any water naturally found under the surface of the earth.
"High potential for phosphorus mobility" means an area where:
"Holding tank" means a watertight receptacle used to store wastewater prior to being removed by a licensed waste hauler.
"Hydraulic conductivity" means a specific mathematical coefficient (quantitative) that relates the rate of water movement to the hydraulic gradient. A term of Darcy's law Q = KAi where K represents hydraulic conductivity and is the current standard for measuring a soils ability to transmit water.
"Hydrogeologic suitability report (HSR)" means a report that characterizes the hydrogeologic properties present on a given site through direct observations and computer modeling.
"Impervious strata and formation" means an underground or surface layer of soil or rock which will not allow water to pass through it at a rate permissible for subsurface disposal and having a percolation rate > 120 minutes per inch.
"Infiltrometer" means a device for measuring the rate of entry of liquid into soil; single or double rings that may be read by falling or constant head methods.
"Innovative/Alternative treatment and disposal system" means a wastewater treatment and/or disposal system not specified in these regulations which has been proven to provide at least an equivalent level of treatment as the conventional systems as defined in these regulations. Also referred to as alternative technologies.
"Interceptor drain" means a gravel trench excavated and installed to collect and remove groundwater. The trench is typically placed across a contour of a slight to moderate sloping area to intercept groundwater at a higher elevation than an on-site wastewater treatment and disposal system.
"Invert" means the floor, bottom or lowest portion of the internal cross section of a closed conduit or structure.
"Isolation distance" means the horizontal distance between a system component and selected site features or structures.
"Land application" means the placement of liquid waste or treated liquid waste within two (2) feet below the surface of land used to support vegetative growth.
"Land treatment" means a technology for the intimate mixing or dispersion of wastes into the upper zone of the plant-soil system with the objective of microbial stabilization, immobilization, selective dispersion, or crop recovery leading to an environmentally acceptable assimilation of the waste.
"Large system" means any on site wastewater treatment and disposal system with a projected wastewater design flow rate greater than or equal to 2,500 gallons per day.
"Lease" means an agreement by which an owner of property (lessor) transfers the possession, control, use, or enjoyment of the property to another (lessee) for a specified term.
"Lessee" means a person who holds the right to possession, control, use, or enjoyment of property by means of an agreement (lease) with the property owner.
"Lift package" means a pre-engineered package which includes pump, filter, floats and alarm that is specifically designed to be installed in the liquid (effluent) side of a standard septic tank.
"Lift station" means a pre-engineered tank/receptacle package which includes pump, filter, floats and alarm or pre-engineered "lift package" inserted into the liquid (effluent) side of a standard septic tank. The lift station is designed to overcome slope differentials for pumping effluent to another system component for gravity distribution.
"Limited public access" means public access is limited to specific periods of time and spraying activities occur when the public is excluded from accessing the site.
"Limiting zone" means any horizon or condition in the soil profile or underlying strata which includes:
"Liquid waste" means any waste which is not a solid waste as defined for the purposes of these Regulations.
"Lot" means a portion of a subdivision or parcel of land.
"Low pressure pipe capping fill" means a pressurized on-site wastewater treatment and disposal system which is installed as trenches and maintains a minimum 18 inches of separation distance above the limiting zone. Trenches are installed between 9-17 inches into natural soil below a soil cap of a specified depth and texture.
"Low pressure pipe full depth" means a pressurized on-site wastewater treatment and disposal system which is installed as trenches and maintains a minimum 18 inches of separation distance above the limiting zone. Trenches are installed 18 inches into natural soil.
"Lysimeter" means an instrument (pore-liquid sampler) for sampling the water percolating through soils that will be used to determine the nutrients and their levels dissolved in the water percolate.
"Malfunctioning system" means a system which is not adequately renovating or hydraulically eliminating the wastewater it is receiving as evidenced by, but not limited to, the following conditions:
"Manifold" means a pipe with numerous branches to convey effluent between a large pipe and several smaller pipes, or to permit choice of diverting flow from one of several sources or to one of several discharge points.
"Manufactured home" means a home built entirely in the factory under a federal building code administered by the Department of Housing and Urban Development (HUD). Manufactured homes may be single or multi-sectioned and are transported to the site and installed.
"Mineral soil" means a soil that is saturated with water less than 30 days (cumulative) per year in normal years and contains less than 20% (by weight) organic carbon; or is saturated for greater than 30 days or more cumulative in normal years, and has an organic carbon content (by weight) of less than 18% if the mineral fraction contains 60% or more clay; or less than 12% if the mineral fraction contains no clay.
"Monitor well" means a non-potable well used primarily for collecting groundwater samples.
"Mottling" means a soil irregularly marked with spots of different colors that vary in number and size which may indicate seasonal or perennial saturation in some part or all of the soil matrix and geogenic in nature.
"New system" means a proposed system which has not started the initial steps of the permitting process (e.g. site evaluation for small and letter of intent for large). Note: An expansion of an existing (in place) system, including any modification of treatment or disposal methodologies, is not considered a new system.
"Non-Hazardous liquid waste" means any industrial waste or sewage or other wastes or any combination thereof which may potentially alter the chemical, physical or biological integrity of water from its natural state. For the purpose of this regulation this includes septage, sewage, grease trap/cooking oil waste, municipal or industrial biosolids, biosolids from package treatment plants, etc.
"Observation well" means a non-pumping, non-potable well used for measuring groundwater levels or potentiometric surface.
"Offset" means compensating for the loading of a pollutant of concern from a point or nonpoint source with a reduction in the loading from a different source or sources, in a manner consistent with meeting water quality standards.
"On-site regulations" means the Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and Disposal Systems.
"On-site system advisory board (Board)" means a panel of licensee's representing the on-site industry, asked to serve by the Secretary, on all matters pertaining to the issuance, suspension, discipline and revocation of all on-site licenses and licensees.
"On site wastewater treatment and disposal system" means conventional or innovative/alternative wastewater treatment and disposal systems installed or proposed to be installed on land of the owner or on other land to which the owner has the legal right to install the system.
"Owner" means the person who has a vested legal or equitable title to real or personal property, including an on site wastewater treatment and disposal system.
"Percolation rate" means the rate of water movement through a soil. Percolation rate is usually measured and assigned on the basis of elapsed time per unit volumetric water level drop. The most commonly used unit for expressing percolation rate is minutes per inch (mpi).
"Performance standard nitrogen level 1 (PSN1)" means where total nitrogen levels achieve either:
"Performance standard nitrogen level 2 (PSN2)" means where total nitrogen levels achieve either:
"Performance standard nitrogen level 3 (PSN3)" means where total nitrogen levels achieve either:
"Performance standard phosphorus level 1 (PSP1)" means where total phosphorus levels achieve either:
"Performance standard phosphorus level 2 (PSP2)" means where total phosphorus levels achieve:
"Permeability" means the property of a soil horizon that enables the soil to transmit gases, liquid, or other substances.
"Permit" means the written document approved by the Department which authorizes the installation of a system or any part thereof, which may also require operation and maintenance of the system.
"Permittee" means any individual, partnership, corporation, association, institution, cooperative enterprise, agency, municipality, commission, political subdivision or duly established entity to which a permit is issued.
"Person(s)" means any individual, trust, firm, joint stock company, federal agency, partnership, corporation (including a government corporation), association, state, municipality, commission, political subdivision of a state, any interstate body and other legal and commercial entities.
"Piezometer" means an alternative word for an observation well.
"Platy structure" means soil aggregates that are developed predominantly along the horizontal axis, laminated and flaky; commonly used to indicate compaction on many coastal plain soils.
"Pollution or water pollution" means any alteration of the physical, chemical or biological properties of any waters of the state, including change in temperature, taste, color, turbidity, silt or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive or other substance into any waters of the state, which will or tends to, either by itself or in connection with any other substance, create a public nuisance or which will or tends to render such waters harmful, detrimental or injurious to public health, safety or welfare, or to domestic, commercial, industrial, agricultural, recreational or other legitimate beneficial uses or to livestock, wildlife, fish or other aquatic life or the habitat thereof.
"Potentiometric surface" means a surface that represents the level to which water will rise in tightly cased wells.
"Pressure-dosed capping fill" means a pressurized on-site wastewater treatment and disposal system which maintains a minimum 36 inches of separation distance above the limiting zone where the trench or bed is installed between 12 and 23 inches into the natural soil below a soil cap of a specified depth and texture.
"Pressure-dosed full depth" means a pressurized on-site wastewater treatment and disposal system which maintains a minimum 36 inches of separation distance above the limiting zone where the trench or bed is installed 24 inches into the natural soil.
"Pressurized distribution" means a network of piping with orifices designed to evenly distribute wastewater under pressure through the entire absorption facility.
"Primary treatment" means a wastewater treatment process that takes place in a tank and allows those substances in wastewater that readily settle or float to be separated from the water being treated.
"Professional engineer" means a person registered by the Delaware Association of Professional Engineers to practice professional engineering in the State of Delaware.
"Professional geologist" means a person registered by the Delaware State Board of Professional Regulation to practice professional geology in the State of Delaware.
"Professional soil scientist" means a person registered by the ARCPACS (a federation of certifying boards in Agriculture, Biology, Earth and Environmental Sciences) to practice professional soil science in the State of Delaware.
"Project site" means the total area within the property lines of an individual lot or within the division lines of a parcel or subdivision.
"Public health hazard" means a condition whereby there are sufficient types and amounts of biological, chemical or physical, including radiological, agents relating to water or sewage which are likely to cause human illness, disorders or disability. These include, but are not limited to, pathogens, viruses, bacteria, parasites, toxic chemicals, and radioactive isotopes.
"Public Service Commission" means an agency created to regulate investor-owned public utilities. The Delaware Public Service Commission (PSC) works to ensure safe, reliable and reasonably priced cable, electric, natural gas, wastewater, water and telecommunications services for Delaware consumers.
"Rapid infiltration basins" means earthen basins designed for a repetitive cycle of flooding, infiltration/percolation, and drying of treated wastewater.
"Redoximorphic features" means characteristic soil patterns formed by the reduction, translocation and oxidation of iron and manganese oxides. The occurrence of these features may be indicative of seasonal or perennial saturation in some part or the entire soil matrix.
"Reducing condition" means a geochemical condition where dissolved oxygen is depleted (< 1 mg/L).
"Regeneration water" means all water consumed in the regeneration steps: backwash, regeneration (brining), dilution (and brine displacement), and rinse. Raw water or treated water may be used for the rinse down.
"Regional wastewater treatment and disposal facility" means a large on-site wastewater treatment and disposal system which serves any entity within the designated service area(s) approved by the Public Service Commission.
"Repair" means any modification to an existing on-site wastewater treatment and disposal system necessary to fix a problem or malfunction.
"Replacement system" means a new on-site wastewater treatment and disposal system to replace the existing on-site wastewater treatment and disposal system.
"Responsible party" means the person, corporation, owner, utility or other entity that will assume full financial and operational control of the facility.
"Sand" means individual mineral particles in a soil that range in diameter from the upper limit of silt (0.05 millimeters to 2.0 millimeters).
"Sand-lined system" means a type of seepage trench or seepage bed absorption facility constructed in the sandy fill material below the natural soil surface and may require pressurization. The sandy fill material is used to replace a natural impermeable or slowly permeable soil layer or to completely remove an existing absorption facility.
"Sandy fill" means materials that consist of medium sand, sandy loam, loamy sand/sandy loam mixtures.
"Scarifying" means scraping or loosening the bottom and sidewall soil surfaces in the preparation of percolation test holes, seepage trenches, beds, or similar excavations.
"Scum" means a mass of sewage solids floating at the surface of effluent and buoyed up by entrained gas, grease or other substances.
"Seasonal high water table" means the highest zone of soil or rock that is seasonally or permanently saturated by a perched or shallow water table. A planar surface, below which all pores in rock or soil (whether primary or secondary) that is seasonally or permanently saturated.
"Secondary treatment" means a combination of unit processes that will consistently remove 85% or more of the organic and suspended material in domestic wastewater and produce an effluent of sufficient quality to satisfy the following requirements; monthly average effluent BOD5 and TSS concentrations of 30 mg/L; daily maximum effluent BOD5 and TSS concentrations of 45 mg/L.
"Secretary" means the Secretary of the Department of Natural Resources and Environmental Control or a duly authorized designee.
"Seepage bed" means an absorption facility consisting of an area from which the entire earth contents have been removed and replaced with a network of perforated pipe, filter aggregate or aggregate-free chambers and covered with suitable backfill material.
"Seepage pit" means a covered pit with a porous lining into which wastewater is discharged and allowed to seep or leach into the surrounding soil and is preceded by a septic tank. Note: seepage pits cannot be certified for real estate transfers.
"Seepage trench" means an absorption facility consisting of ditches with vertical sides and flat bottoms partially filled with filter aggregate and containing perforated pipe or aggregate-free chambers and covered with suitable backfill material.
"Septage" means the liquid and solid contents of a septic tank.
"Septic tank" means a watertight receptacle which receives the discharge of wastewater from a structure or part thereof and is designed and constructed so as to permit settling of solids from the liquid, digestion of the organic matter by detention, and discharge of the liquid portion into an absorption facility.
"Sewage" means water-carried human or animal wastes from septic tanks, water closets, residences, buildings, industrial establishments, or other places, together with such groundwater infiltration, subsurface water, admixture of industrial wastes or other wastes as may be present.
"Sewage sludge" means sludges which derive in whole or in part from sewage.
"Single family dwelling" means a residence intended for single family residential use.
"Site evaluation" means the practice of investigating, evaluating and reporting basic soil and site conditions which apply to the on site wastewater treatment and disposal system type and design criteria.
"Slope" means the deviation of a plane surface from the horizontal. It is usually expressed as a ratio or percentage of number of units of vertical rise or fall per unit of horizontal distance.
"Sludge" means the accumulated semi-liquid suspension, settled solids, or dried residue of these solids that is deposited from (a) liquid waste in a municipal or industrial wastewater treatment plant, (b) surface or groundwaters treated in a water treatment plant, whether or not these solids have undergone treatment. Septage is included herein as sludge.
"Small system" means any on site wastewater treatment and disposal system with a projected wastewater design flow rate < 2,500 gallons per day.
"Soil feasibility study" means a site/soil investigative report identifying the suitability of a parcel of land for a large, community or individual on-site wastewater treatment and disposal systems. The report includes information pertinent to the Department and other local government agencies in the determination of certain land use decisions.
"Soil horizon" means a layer of soil or soil material approximately parallel to the land surface and differing from adjacent genetically related layers in physical, chemical, and biological properties or characteristics such as color, structure, texture, consistence and pH.
"Soil investigation report (SIR)" means a report that characterizes the soils present on a given site through direct observations and analysis.
"Soil profile" means a vertical cross-section of a soil that shows the various soil horizons. Soil drainage or moisture status are both soil characteristics that can be inferred from the soil profile.
"Soil structure" means the combination or arrangement of primary soil particles into secondary compound particles or clusters, the principle forms of which are: platy (laminated); prismatic (prisms with rounded tops); blocky (angular or subangular); granular and columnar.
"Soil texture" means the grain sizes that comprise a soil consisting of three textural classes; sand, silt and clay. Field methods for judging the texture of a soil consist of forming a cast of soil, both dry and moist, in the hand and pressing a ball of moist soil between thumb and finger.
"Solid waste" means any garbage, refuse, rubbish, and other discarded materials resulting from industrial, commercial, mining, agricultural operations and from community activities which does not contain free liquids. Containers holding free liquids shall be considered solid waste when the container is designed to hold free liquids for use other than storage (e.g. radiators, batteries, transformers) or the waste is household waste which is not sewage or septage.
"Solum" means the upper part of the soil profile (A, E and B horizons) above the parent material in which the processes of soil formation are active.
"Spare area" means an area set aside for construction of a second absorption facility with the equivalent design capacity of the operational absorption facility to be used in the event the operational absorption facility becomes inoperable.
"Spray irrigation" means the controlled application of treated wastewater to a vegetated soil surface.
"Storage" means the interim containment of liquid waste or treated liquid waste before disposal or utilization.
"Subdivision" means any tract or parcel of land which has been divided into two or more lots for which development is intended.
"Surface impoundment" means a natural topographic depression, and/or man-made excavation, and/or diked area formed primarily of earthen materials (although it may be lined with man-made materials) or remains unlined, and which is designed to hold an accumulation of liquid wastes or wastes containing free liquids. Examples of surface impoundments are holding, storage, settling, and elevation pits, ponds, and lagoons.
"Surface water assessment report (SWAR)" means a report that characterizes the potential nutrient impacts of a wastewater treatment system to a site from future development through background data and computer modeling.
"System" means an on site wastewater treatment and disposal system.
"System inspector" means a person licensed by the Department to inspect, investigate, collect data and make determinations regarding the present operational condition of an on-site wastewater treatment and disposal system.
"System operator" means an individual, who at a given time, through observation, interpretation or decision operates a wastewater facility or a segment of a system or facility.
"Tertiary treatment" means the removal of pollutants, including nitrogen and phosphorus, to meet discharge or reuse criteria with respect to specific parameters and followed by disinfection.
"Test pit" means an excavation used to examine a soil profile in order to assess soil permeability and depth to a seasonal high water table using soil texture, structure, and redoximorphic features as a basis for assessing site suitability.
"Topography" means ground surface variations or contours of the earth's surface, both natural and anthropogenic.
"Total nitrogen" means the sum of all the forms of nitrogen; ammonia, ammonium, nitrate, nitrite and organic nitrogen present in wastewater.
"Total phosphorus" means the sum of the water soluble and citrate-insoluble phosphorus present in wastewater.
"Total suspended solids (TSS)" means a measure of the suspended solids in wastewater, effluent, or water bodies, determined by tests for "total suspended non-filtered solids."
"Treatment" means a process which alters, modifies or changes the biological, physical or chemical characteristics of sludge or liquid waste.
"Treatment works" means any device and system used in the storage, treatment, recycling and reclamation of municipal sewage, or industrial wastes of a liquid nature, or necessary to recycle or reuse water at the most economical cost over the estimated life of the works, including intercepting sewers, outfall sewers, sewage collection systems, pumping, power and other equipment, and their appurtenances, extensions, improvements, remodeling, additions and alterations thereof; elements essential to provide a reliable recycled supply such as standby treatment units and clear well facilities and improvements to exclude or minimize inflow and infiltration.
"Unconfined aquifer" means an aquifer in which a relatively impermeable layer does not exist between the water table and the ground surface and in which the water surface is at atmospheric pressure.
"Undisturbed soil" means soil or soil profile unaltered by filling, removal, or other man made changes with the exception of agricultural activities.
"Unlimited public access" means public access to the site may occur at any time.
"Upgradient" means an area that has a higher potentiometric surface (hydraulic head) than a comparative reference point.
"Wastewater" means water carried waste from septic tanks, water closets, residences, buildings, industrial establishments, or other places, together with such groundwater infiltration, subsurface water and mixtures of industrial wastes or other wastes as may be present.
"Wastewater treatment plant" means a facility designed and constructed to receive, treat, or store waterborne or liquid wastes.
"Wastewater utility" means any person, partnership, association, corporation, joint stock company, agency or department of the State or any association of individuals engaged in the business of providing wastewater disposal and related services to the public for a fee, charge, or other remuneration in the State of Delaware.
"Watercourse" means any ocean, bay, lake, pond, stream, river or defined ditch that will permit drainage into any surface water body, excluding ephemeral watercourses as defined below.
"Watershed" means a region or area delineated by a topographical divide and draining ultimately to a particular watercourse.
"Water softener backwash" means the wastewater by-product generated by the water softening process (see regeneration water).
"Waters of the state" means public waters, including lakes, bays, sounds, ponds, impounding reservoirs, springs, wells, rivers, streams, creeks, estuaries, marshes, inlets, canals, the ocean within the territorial limits of the State, and all other bodies of surface or groundwater, natural or artificial, inland or coastal, fresh or salt, within the jurisdiction of the State of Delaware.
"Water table" means the surface of an unconfined aquifer where the pore water pressure is equal to atmospheric pressure.
"Well" means any excavation which intersects the water table, and is installed for the purpose of obtaining geologic or hydrologic information and for locating, testing, measuring, extracting, and/or recharging water and other fluids, and where the depth is greater than the width. Such excavations may have been drilled, augered, cored, bored, driven, dug, jetted, or otherwise constructed. This definition does not include excavations for utility poles, construction pilings, building foundations, fence posts, test pits, or horizontal heat pump systems that are constructed above the water table.
"Wisconsin at-grade" means a pressurized on-site wastewater treatment and disposal system which maintains a minimum 24 inches of separation distance above the limiting zone placed on the natural soil below a soil cap of a specified depth and texture.
"Zone of aeration" means a subsurface zone containing water under pressure less than that of the atmosphere, including water held by capillary and containing air or gases generally under atmospheric pressure. This zone is limited above by the land surface and below by the surface of the zone of saturation, e.g., the water table.
3.3 Any governmental unit may assume responsibility and authority for administering its own regulatory program for on site wastewater treatment and disposal systems pursuant to 7 Del.C. §6003(d) if the delegated program establishes standards no less stringent than the standards established in these Regulations.