Section 5. Definitions

Part I. General Provisions

The following words and terms when used in this chapter shall have the following meanings unless the context clearly indicates otherwise:

"Agent" means a legally authorized representative of the owner.

"All weather stream" means any stream that will, at all times, dilute point source discharge effluent from a pipe at least 10:1 as measured during a seven consecutive day average of a 10-year low flow (7-Q-10).

"Alternative discharging sewage treatment system" or "discharging system" means any device or system that results in a point source discharge of treated sewage for which the board may issue a permit authorizing construction and operation when such system is regulated by the SWCB pursuant to a general VPDES permit issued for an individual single family dwelling with flows less than or equal to 1,000 gallons per day on a monthly average.

"Alternative onsite sewage treatment system" means a treatment works that is not a conventional onsite sewage system and does not result in a point source discharge.

"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).

"Biological treatment unit" means a method, technique, equipment, or process other than a septic tank or septic tanks that uses biological organisms to treat sewage to produce effluent of a specified quality.

"Board" means the State Board of Health.

"Combined Application" means a Virginia Department of Health Discharging System Application Form for Single Family Dwellings Discharging Sewage Less Than or Equal to 1,000 Gallons Per Day and a State Water Control Board Virginia Pollutant Discharge Elimination System General Permit Registration Statement for Domestic Sewage Discharges Less Than or Equal to 1,000 Gallons Per Day.

"Commissioner" means the State Health Commissioner or his subordinate who has been delegated powers in accordance with subdivision 2 of 12VAC5-640-80.

"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.

"Dechlorination" means a process that neutralizes chlorine in the final effluent.

"Department" means the district or local health department with jurisdiction over the site or proposed site of the alternative discharging sewage treatment system.

"Disinfection" means a process used to destroy or inactivate pathogenic microorganisms in wastewater to render them noninfectious.

"Disinfection unit" means a separate treatment component that disinfects wastewater.

"District health department" means a consolidation of local health departments as authorized in § 32.1-31 C of the Code of Virginia.

"Division" means the Division of Onsite Sewage, Water Services, Environmental Engineering, and Marina Programs.

"Dry ditch" means a naturally occurring swale or channel that is topographically connected to an all weather stream. In some cases, a dry ditch may have a manmade component that provides a topographical connection to an existing, naturally occurring swale or channel. A dry ditch may have observable flow during or immediately after a storm event or snow melt. For the purposes of this chapter, all dry ditches shall have a well defined natural channel with sides that have at least a 1:10 (rise:run) slope.

"Emergency pump and haul" means an emergency condition to pump out the treatment systems tanks by a licensed sewage handler as needed to not allow a discharge to protect public health and the environment.

"Failing alternative discharging sewage treatment system" means any alternative discharging sewage treatment system that discharges effluent having a BOD_5, total suspended solids, pH, chlorine residual, dissolved oxygen, or bacteria value that is out of compliance with the General Permit or fails to comply with 12VAC5-640-430. The failure to discharge due to exfiltration may indicate system failure.

"Failing onsite sewage disposal system" means an onsite sewage disposal system where the presence of raw or partially treated sewage on the ground's surface or in adjacent ditches or waterways or exposure to insects, animals, or humans is prima facie evidence of a system failure. Pollution of the groundwater or backup of sewage into plumbing fixtures may also indicate system failure.

"General approval" means that a treatment unit has been evaluated and approved for TL-2 effluent or TL-3 effluent in accordance with the requirements of this chapter and 12VAC5-610.

"General Permit" means a Virginia Pollutant Discharge Elimination System (VPDES) General Permit for domestic sewage discharges less than or equal to 1,000 gallons per day on a monthly average issued by the State Water Control Board.

"Intermittent stream" means any stream that will not, at all times, dilute point source discharge effluent at least 10:1 as measured during a seven consecutive day average of a 10-year low flow (7-Q-10). For the purposes of this section, an intermittent stream is identified as a dashed or dotted line on a United States Geological Survey 7.5 minute topographic map or an all weather stream that provides less than 10:1 dilution of the effluent based on 7-Q-10 flow.

"Local health department" means the department established in each city and county in accordance with § 32.1-30 of the Code of Virginia.

"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.

"Modify" means to alter a treatment works, excluding actions taken to "operate" the treatment works and "maintenance" activities as those terms are defined in § 32.1-163 of the Code of Virginia.

"National Pollutant Discharge Elimination System" or "NPDES" means the national program for (i) issuing, modifying, revoking and reissuing, terminating, monitoring, and enforcing permits and (ii) imposing and enforcing pretreatment requirements under §§ 307, 402, 318, and 405 of the Clean Water Act (33 USC § 1251 et seq.). The term includes an approved program.

"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.

"Operation and maintenance contract" means an agreement between an owner and a licensed operator that the operator will provide services to operate, maintain, monitor, repair, and report on the treatment system in accordance with this chapter.

"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.

"Person" means any and all persons, including individuals, firms, partnerships, associations, public or private institutions, municipalities or political subdivisions, governmental agencies, or private or public corporations organized under the law of this Commonwealth or any other state or country.

"Point source discharge" means any discernible, confined, and discrete conveyance including, but not limited to, 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 stormwater run-off.

"Post-aeration unit" means a treatment component that is designed to add oxygen to an effluent.

"Post-filtration unit" means a treatment component that physically removes total suspended solids.

"Reliability" means a measure of the ability of a component or system to perform its designated function without failure or interruption of service. Overflow criteria, such as an allowable period of a noncompliant discharge, are utilized solely for the establishment of reliability classification for design purposes and are not to be construed as authorization for, or defense of, an unpermitted discharge to state waters. The reliability classification shall be based on the water quality and public health and welfare consequences of a component or system failure.

"Reliability Class I" means a measure of reliability that requires a treatment system design to provide continuous satisfactory operation during power failures, flooding, peak loads, equipment failure, and maintenance shut-down. For the purposes of this chapter, continuous operability shall be defined as restoring proper operation or otherwise eliminating the out-of-compliance discharge within 24 hours. This class includes design features, such as additional electrical power sources, additional flow storage capacity, and additional treatment units that provide operation in accordance with the issued permit requirements.

"Reliability Class II" means a measure of reliability that requires a treatment design that limits out-of-compliance discharges due to power failures, flooding, peak loads, equipment failure, and maintenance shut-down to less than 36 hours. This class includes design features such as alarms with telemetry to the operator, additional treatment units, or additional flow storage capacity that provide operation in accordance with the issued permit requirements.

"Reliability Class III" means a measure of reliability that requires a treatment design that limits out-of-compliance discharges due to power failures, flooding, peak loads, equipment failure, and maintenance shut-down to less than 48 hours. This class includes design features such as onsite alarms and owner initiated operator notification to address the alarm condition to provide operation in accordance with the issued permit requirements.

"Sanitary survey" means an investigation of any condition that may affect public health.

"Sewage" means water carried and non-water carried human excrement, kitchen, laundry, shower, bath, or lavatory wastes separately or together with such underground, surface, storm, and other water and liquid industrial wastes as may be present from residences, buildings, vehicles, industrial establishments, or other places.

"Site sketch" means a scale drawing of a proposed site for a discharge system, with pertinent distances shown. The scale shall typically be 1" = 50' for lots of three acres or less and 1" = 100' for larger lots. Site sketches may be made by the homeowner or any agent for the homeowner.

"Surface waters" means:

1. 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;

2. All interstate waters, including interstate wetlands;

3. 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;

4. All impoundments of waters otherwise defined as surface waters under this definition;

5. Tributaries of waters identified in subdivisions 1 through 4 of this definition;

6. The territorial sea; and

7. Wetlands adjacent to waters, other than water that are themselves wetlands, identified in subdivisions 1 through 6 of this definition.

"SWCB" means the State Water Control Board and its designees.

"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 solids in effluent samples that can be removed readily by standard filtering procedures in a laboratory and expressed as mg/l.

"Treatment level 2 effluent" or "TL-2 effluent" means effluent that has been treated to produce BOD₅ and TSS concentrations less than or equal to 30 mg/l each.

"Treatment level 3 effluent" or "TL-3 effluent" means effluent that has been treated to produce BOD₅ and TSS concentrations less than or equal to 10 mg/l each.

"Treatment system" means the combination of treatment components that together produce the required quality of effluent.

"Variance" means a conditional waiver of a specific regulation that is granted to a specific owner relating to a specific situation or facility and may be for a specified time period.

"VPDES permit" means a Virginia Pollutant Discharge Elimination System permit issued by the SWCB under the authority of the federal NPDES program.

"Water well" or "well" means any artificial opening or artificially altered natural opening, however made, by which groundwater is sought or through which groundwater flows under natural pressure or is intended to be artificially drawn. This definition shall not include wells drilled for the following purposes: (i) exploration or production of oil or gas, (ii) building foundation investigation and construction, (iii) elevator shafts, (iv) grounding of electrical apparatus, or (v) the modification or development of springs.

"Wetlands" means those areas that are inundated or saturated by surface water or groundwater 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.

Historical Notes

Derived from Volume 32, Issue 06, eff. December 16, 2015.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.