As used in this part:

1. (1) “Aerobic” means:

   1. (A) Having molecular oxygen as a part of the environment; or
   2. (B) Growing or occurring only in the presence of molecular oxygen;

2. (2)

   1. (A) “Aerobic treatment unit” (ATU) means a mechanical onsite treatment unit that provides secondary wastewater treatment by mixing air and aerobic and facultative microbes with the wastewater.

   2. (B) ATUs typically use a:

      1. (i) Suspended-growth treatment process; or
      2. (ii) Fixed treatment process;
3. (3) “Air/vacuum (A/V) relief valve” means a valve that automatically lets air out of or into liquid-carrying pipe as needed in response to changes in system pressure;

4. (4) “Backwash” means the process of flow reversal to:

   1. (A) Clean a filter; and
   2. (B) Restore it to the normal clean condition for filtering with a minimum resistance to flow through the media or screen;

5. (5)

   1. (A) “Control panel” means an electronic control panel that controls the quantity and time of dose.

   2. (B) This can also control the zone receiving the effluent and automatically:

      1. (i) Flushes the lines;
      2. (ii) Flushes the filters; and
      3. (iii) Monitors the flow rates and pump run cycles or times;
6. (6) “Decentralized system” means an onsite and/or cluster wastewater system used to treat and disperse or discharge small volumes of wastewater, generally from dwellings or businesses that are located relatively close together;
7. (7) “Disk filter” means a type of filter that utilizes a series of grooved rings that overlay each other to form a network of very small openings to trap contaminants;
8. (8) “Distributing valve” means a valve that distributes flow to multiple drainfield laterals, zones, or locations by automatically rotating upon each pump cycle;

9. (9)

   1. (A) “Drainback” means the process of effluent draining along the laterals and manifolds after the pump shuts off.
   2. (B) Drainage occurs both inside and outside the drip tubing and manifolds to lower elevations in the drip field;
10. (10) “Dripline” means tubing constructed from polyethylene with emitters embedded regularly along the length of the tube;

11. (11) “Effluent” means sewage, water, or other liquids, partially or completely treated or in its natural state flowing out of:

    1. (A) A septic tank;
    2. (B) An aerobic treatment unit; or
    3. (C) Another treatment system or systems;

12. (12) “Emitters” means small-diameter openings in a dripline that can:

    1. (A) Dissipate pressure; and
    2. (B) Allow a slow, controlled discharge normally rated in gallons per hour;

13. (13)

    1. (A) “Field flush” means water is passed through the drip lateral for the purpose of removing particles and other debris from the walls of the drip tubing.
    2. (B) The flush water is carried back through the return manifold and return line to the pretreatment unit;
14. (14) “Filter” means a device for the main purpose of removing suspended solids and other debris from the wastewater;
15. (15) “Hydraulic conductivity” means the rate of water movement under unit gradient in a specific soil horizon;
16. (16) “Interceptor drain” means a subsurface drain line usually constructed upgrade from the absorption area to divert seasonal groundwater;
17. (17) “Lateral” means one single run or multiple runs of drip tubing connected at one end to a supply manifold and the other end connected to a return manifold;
18. (18) “Maintenance personnel” means an individual certified by the Department of Health to conduct assessments under the Onsite Maintenance and Monitoring Program;
19. (19) “Monitoring” means periodic inspection of system for performance;
20. (20) “Pressure-compensating (PC) emitters” means drip emitters that allow a constant flow or discharge over a wide range of applied pressure;
21. (21) “Pressure distribution” means a system of small-diameter pipes equally distributing effluent through a trench or bed;
22. (22) “Pressure regulator” means a device used to regulate and maintain a constant discharge pressure;
23. (23) “Pretreatment” means the conditioning of effluent prior to dispersal by a drip system;
24. (24) “Return line” means the return line connects the return manifold to the pretreatment unit for the purpose of carrying flush water from the drip field;
25. (25) “Return manifold” means a collection manifold or piping that returns excessive wastewater and debris to the primary treatment tank during system flushes;

26. (26) “Run” means one continuous length of tubing routed across contour connected to:

    1. (A) A supply line;
    2. (B) A return line; or
    3. (C) Another run;

27. (27) “Soil structure” means the combination or arrangement of individual soil particles in definable aggregates, or “peds”, that are characterized and classified on the basis of:

    1. (A) Size;
    2. (B) Shape; and
    3. (C) Degree of distinctness;
28. (28) “Solenoid valve” means an electric valve actuated by a solenoid, used for controlling the flow or liquid in pipes;

29. (29)

    1. (A) “Spin filter” means a filter that consists of a screen cylinder enclosed in a casing.
    2. (B) The typical filter screen mesh size is one hundred fifty (150) and a micron rating of one hundred (100);
30. (30) “Static plow” means a dripline plow with a shank that remains at a given depth as the plow is pulled through the soil;
31. (31) “Supply line” means the line that extends from the pump to the supply manifold of a given zone;
32. (32) “Supply manifold” means the supply manifold connects the supply line to the drip laterals;

33. (33) “Vertical separation” means the depth of unsaturated, original, undisturbed soil between the:

    1. (A) Bottom of the drip tubing; and
    2. (B) Highest seasonal water table or restrictive layer;
34. (34) “Vibratory plow” means a dripline plow with a shank that vibrates vertically as the plow is pulled through the soil;
35. (35) “Water table” means the level in saturated soil at which the hydraulic pressure is zero; and
36. (36) “Zone” means a group of laterals that are dosed at the same time.