Virginia Administrative Code › Title 12 - HEALTH › Agency 5 - DEPARTMENT OF HEALTH › Chapter 613 - REGULATIONS FOR ALTERNATIVE ONSITE SEWAGE SYSTEMS › Part I - General › Section 12VAC5-613-10 - Definitions

Current through Register Vol. 40, No. 24, July 15, 2024
The following words and terms used in this chapter shall
					 have the following meanings. Terms not defined in this chapter shall have the
					 meanings prescribed in Chapter 6 (§
										32.1-163 et seq.) of
					 Title 32.1 of the Code of Virginia or in 12VAC5-610 unless the plain reading of
					 the language requires a different meaning.
"Alternative onsite sewage system," "AOSS," or "alternative
					 onsite system" means a treatment works that is not a conventional onsite sewage
					 system and does not result in a point source discharge.
"Best management practice" means a conservation or
					 pollution control practice approved by the division, such as wastewater
					 treatment units, shallow effluent dispersal fields, saturated or unsaturated
					 soil zones, or vegetated buffers, that manages nutrient losses or other
					 potential pollutant sources to minimize pollution of water resources.
"Biochemical oxygen demand, five-day" or
					 "BOD5" means the quantitative measure of the amount of
					 oxygen consumed by bacteria while stabilizing, digesting, or treating
					 biodegradable organic matter under aerobic conditions over a five-day
					 incubation period; BOD5 is expressed in milligrams per
					 liter (mg/l).
"Board" means the State Board of Health.
"Chesapeake Bay Watershed" means the following Virginia
					 river basins: Potomac River Basin (see
					 9VAC25-260-390
					 and
					 9VAC25-260-400
					 ), James River Basin (see
					 9VAC25-260-410,
					 9VAC25-260-415,
					 9VAC25-260-420,
					 and
					 9VAC25-260-430
					 ), Rappahannock River Basin (see
					 9VAC25-260-440
					 ), Chesapeake Bay and small coastal basins (see
					 9VAC25-260-520,
					 Section 2 through Section 3g), and the York River Basin (see
					 9VAC25-260-530
					 ).
"Conventional onsite sewage system" means a treatment works
					 consisting of one or more septic tanks with gravity, pumped, or siphoned
					 conveyance to a gravity distributed subsurface drainfield.
"Department" means the Virginia Department of
					 Health.
"Direct dispersal of effluent to ground water" means less
					 than six inches of vertical separation between ground water and the point of
					 effluent application or the bottom of an effluent-dispersal trench or other
					 excavation. Other excavation excludes the following: minor tillage of the soil
					 surface without soil removal; replacement of fill material with better quality
					 fill material as determined by the department to improve the ability of the
					 site to treat wastewater; house foundations; tank excavations; force main and
					 header line excavations; and soil disturbances, including preexisting
					 drainfields installed prior to July 17, 2017, that are not designed for surface
					 or ground water drainage, and do not create a direct conduit to ground
					 water.
"Disinfection" means a process used to destroy or
					 inactivate pathogenic microorganisms in wastewater to render them
					 non-infectious.
"Dissolved oxygen" or "DO" means the concentration of
					 oxygen dissolved in effluent, expressed in mg/l or as percent saturation, where
					 saturation is the maximum amount of oxygen that can theoretically be dissolved
					 in water at a given altitude and temperature.
"Division" means the Division of Onsite Sewage and Water
					 Services, Environmental Engineering, and Marina Programs within the department.
"Effluent" means sewage that has undergone
					 treatment.
"General approval" means that a treatment unit has been
					 evaluated in accordance with the requirements of this chapter and 12VAC5-610
					 and approved for TL-2 or TL-3 in accordance with this chapter.
"GPD/sf" means gallons per day per square foot.
"Ground water" means any water, except capillary moisture,
					 beneath the land surface in the zone of saturation or beneath the bed of any
					 stream, lake, reservoir, or other body of surface water wholly or partially
					 within the boundaries of this Commonwealth, whatever the subsurface geologic
					 structure in which such water stands, flows, percolates, or otherwise occurs.
					 Ground water includes a seasonal or perched water table.
"High-level disinfection" means a disinfection method that
					 results in a fecal coliform concentration less than or equal to 2.2
					 colonies/100 ml. Chlorine disinfection requires a minimum total residual
					 chlorine (TRC) concentration at the end of a 30 minute contact time of 1.5
					 mg/l. Ultraviolet disinfection requires a minimum dose of 50,000
					 µW-sec/cm2. Influent turbidity to the
					 disinfection unit shall be less than or equal to 2 Nephelometric turbidity
					 units (NTU) on average.
"Ksat" means saturated hydraulic conductivity.
"Large AOSS" means an AOSS that serves more than three
					 attached or detached single-family residences with a combined average daily
					 sewage flow greater than 1,000 GPD or a structure with an average daily sewage
					 flow in excess of 1,000 GPD.
"Limiting feature" means a feature of the soil that limits
					 or intercepts the vertical movement of water, including seasonal, perched or
					 permanent water table, pans, soil restrictions, and pervious or impervious
					 bedrock.
"Local health department" means the local health department
					 having jurisdiction over the AOSS.
"Maintenance" means performing adjustments to equipment and
					 controls and in-kind replacement of normal wear and tear parts such as light
					 bulbs, fuses, filters, pumps, motors, or other like components. Maintenance
					 includes pumping the tanks or cleaning the building sewer on a periodic basis.
					 Maintenance shall not include replacement of tanks, drainfield piping, and
					 distribution boxes or work requiring a construction permit and an installer.
"MGD" means million gallons per day.
"MPI" means minutes per inch.
"Operate" means the act of making a decision on one's own
					 volition to (i) place into or take out of service a unit process or unit
					 processes or (ii) make or cause adjustments in the operation of a unit process
					 at a treatment works.
"Operation" means the biological, chemical, and mechanical
					 processes of transforming sewage or wastewater to compounds or elements and
					 water that no longer possess an adverse environmental or health impact.
"Operator" means any individual employed or contracted by
					 any owner who is licensed or certified under Chapter 23 (§
										54.1-2300 et seq.) of
					 Title 54.1 of the Code of Virginia as being qualified to operate, monitor and
					 maintain an alternative onsite sewage system.
"Organic loading rate" means the biodegradable fraction of
					 chemical oxygen demand (BOD, biodegradable fats, oils, and grease and volatile
					 solids) delivered to a treatment component in a specified time interval
					 expressed as mass per time or area; examples include pounds per day, pounds per
					 cubic foot per day (pretreatment), or pounds per square foot per day
					 (infiltrative surface or pretreatment). For a typical residential system, these
					 regulations assume that biochemical loading (BOD5)
					 equals organic loading.
"Owner" means the Commonwealth or any of its political
					 subdivisions, including sanitary districts, sanitation district commissions and
					 authorities, or any individual, any group of individuals acting individually or
					 as a group, or any public or private institution, corporation, company,
					 partnership, firm, or association that owns or proposes to own a sewerage
					 system or treatment works.
"pH" means the measure of the acid or base quality of water
					 that is the negative log of the hydrogen ion concentration.
"Pollution" means such alteration of the physical,
					 chemical, or biological properties of any state waters as will or is likely to
					 create a nuisance or render such waters (i) harmful or detrimental or injurious
					 to the public health, safety, or welfare or to the health of animals, fish, or
					 aquatic life; (ii) unsuitable with reasonable treatment for use as present or
					 possible future sources of public water supply; or (iii) unsuitable for
					 recreational, commercial, industrial, agricultural, or other reasonable uses.
					 Pollution shall include any discharge of untreated sewage into state
					 waters.
"Point source discharge" means any discernible, confined,
					 and discrete conveyance including any pipe, ditch, channel, tunnel, conduit,
					 well, discrete fissure, container, rolling stock, concentrated animal feeding
					 operation, landfill leachate collection system, vessel, or other floating craft
					 from which pollutants are or may be discharged. This term does not include
					 return flows from irrigated agriculture or agricultural storm water run-off.
"Project area" means one or more recorded lots or a portion
					 of a recorded lot owned by the owner of an AOSS or controlled by easement upon
					 which an AOSS is located or that is contiguous to a soil treatment area and
					 that is designated as such for purposes of compliance with the performance
					 requirements of this chapter. In the case of an AOSS serving multiple
					 dwellings, the project area may include multiple recorded lots as in a
					 subdivision.
"Project area boundary" or "project boundary" means the
					 physical limits of the three-dimensional length, width, and depth of the
					 project area, whereby each dimension is identified as follows:
(i) the horizontal component is the length and width of the
					 project area; (ii) the upper vertical limit is the ground surface in and around
					 the AOSS; and (iii) the lower vertical limit is the limiting feature.
"Renewable operating permit" means an operation permit that
					 expires and must be revalidated at a predetermined frequency or schedule in
					 accordance with this chapter.
"Reportable incident" means one or more of the following:
					 an alarm event lasting more than 24 hours; an alarm event that reoccurs; any
					 failure to achieve one or more performance requirements; removal of solids;
					 replacement of media; or replacement of any major component of the system
					 including electric and electronic components, pumps, blowers, and valves. The
					 routine cleaning of effluent filters is not a reportable incident.
"Saturated hydraulic conductivity" means a quantitative
					 measure of a saturated soil's capacity to transmit water when subjected to a
					 hydraulic gradient.
"Settleable solids" means a measure of the volume of
					 suspended solids that will settle out of suspension within a specified time,
					 expressed in milliliters per liter (ml/l).
"Sewage Handling and Disposal Regulations" means 12VAC5-610
					 or its successor.
"Small AOSS" means an AOSS that serves no more than three
					 attached or detached single-family residences with a combined average flow of
					 less than or equal to 1,000 GPD, or a structure with an average daily sewage
					 flow of less than or equal to 1,000 GPD.
"Soil treatment area" means the physical location in the
					 naturally occurring soil medium where final treatment and dispersal of effluent
					 occurs.
"Standard disinfection" means a disinfection process that
					 results in a fecal coliform concentration of less than or equal to 200
					 colonies/100 ml. Chlorine disinfection requires a minimum TRC concentration at
					 the end of a 30 minute contact time of 1.0 mg/l. Influent TSS to the
					 disinfection unit shall average 30 mg/l or less.
"Standard engineering practice" means the care, diligence,
					 competence, and judgment that a reasonably prudent and experienced professional
					 engineer licensed in the Commonwealth of Virginia would exercise given the
					 circumstances, including site and soil conditions, of a particular AOSS design.
"State waters" means all water, on the surface and under
					 the ground, wholly or partially within or bordering the Commonwealth or within
					 its jurisdiction, including wetlands.
"Subsurface drainfield" means a system installed within the
					 soil and designed to accommodate treated sewage from a treatment works.
"Surface waters" means:
(i) all waters that are currently used, were used in the
					 past, or may be susceptible to use in interstate or foreign commerce, including
					 all waters that are subject to the ebb and flow of the tide;
(ii) all interstate waters, including interstate wetlands;
(iii) all other waters such as intrastate lakes, rivers,
					 streams (including intermittent streams), mudflats, sandflats, wetlands,
					 sloughs, prairie potholes, wet meadows, playa lakes, or natural ponds and the
					 use, degradation, or destruction of which would affect or could affect
					 interstate or foreign commerce including any such waters:
(a) that are or could be used by interstate or foreign
					 travelers for recreational or other purposes;
(b) from which fish or shellfish are or could be taken and
					 sold in interstate or foreign commerce; or
(c) that are used or could be used for industrial purposes
					 by industries in interstate commerce; (iv) all impoundments of waters otherwise
					 defined as surface waters under this definition; (v) tributaries of waters
					 identified in clauses (i) through (iv) of this definition; (vi) the territorial
					 sea; and (vii) wetlands adjacent to waters (other than water that are
					 themselves wetlands) identified in clauses (i) through (vi) of this definition.
"Total nitrogen" or "TN" means the measure of the complete
					 nitrogen content of wastewater including all organic, inorganic, and oxidized
					 forms expressed in mg/l as nitrogen.
"Total residual chlorine" or "TRC" means a measurement of
					 the combined available chlorine and the free available chlorine available in a
					 sample after a specified contact time.
"Total suspended solids" or "TSS" means a measure of the
					 mass of all suspended solids in a sample typically measured in milligrams per
					 liter (mg/l).
"Treatment level 2 effluent" or "TL-2 effluent" means
					 secondary effluent as defined in
					 12VAC5-610-120 that
					 has been treated to produce BOD5 and TSS concentrations
					 equal to or less than 30 mg/l each.
"Treatment level 3 effluent" or "TL-3 effluent" means
					 effluent that has been treated to produce BOD5 and TSS
					 concentrations equal to or less than 10 mg/l each.
"Treatment unit" or "treatment system" means a method,
					 technique, equipment, or process other than a septic tank or septic tanks used
					 to treat sewage to produce effluent of a specified quality before the effluent
					 is dispersed to a soil treatment area.
"Turbidity" means a measurement of the relative clarity of
					 effluent as a result of the presence of varying amounts of suspended organic
					 and inorganic materials or color.
"Vertical separation" means the vertical distance between
					 the point of effluent application to the soil or the bottom of a trench or
					 other excavation and a limiting feature of the soil treatment area such as
					 seasonal high ground water, bedrock, or other restriction.
"Wetlands" means those areas that are inundated or
					 saturated by surface or ground water at a frequency and duration sufficient to
					 support, and that under normal circumstances do support, a prevalence of
					 vegetation typically adapted for life in saturated soil conditions. Wetlands
					 generally include swamps, marshes, bogs, and similar areas.
Statutory Authority: §§
												32.1-12
						and
						32.1-164
						of the Code of Virginia.