1. WASTEWATER DISPOSAL WITH SUBSURFACE DRIP IRRIGATION Donald R. McDonald AgTech Pacific

2. TYPICAL LAYOUT

4. DESCRIPTION Effluent is discharged through subsurface drip tubing often utilizing pressure compensating emission devices allowing effluent to be spread uniformly over an area. Dosing cycles are triggered automatically several times per day with equal amounts of water supplied to each square foot. Dosing allows uniform distribution area. Systems can be controlled by a programmed microprocessor or irrigation simple irrigation controller. Any level of treatment from primary through tertiary can be handled by the system. over time as well as area.

5. Effluent is discharged through subsurface drip tubing often utilizing pressure compensating emission devices allowing effluent to be spread uniformly over an area.

6. Dosing cycles are triggered automatically several times per day with equal amounts of water supplied to each square foot. Dosing allows uniform distribution of effluent over time as well as area.

7. Systems can be controlled by a programmed microprocessor or a simple irrigation controller.

8. Any level of treatment from primary through tertiary can be handled by the system.

9. Advantages over a conventional IWS. Can be used where a high water table will not allow use of a conventional IWS. Or in area with excessively tight soils.

10. How it works General Description

11. TYPICAL LAYOUT

13. Control Options. Computer Control interfaced with a pulsing water meter and telephone interface. Simple Irrigation Controller with a manual read water meter.

14. Self Cleaning Filtration Disc Filters Screen Filters Sand Media Filters

20. Drip Tubing - Two products currently used successfully Netafim Bioline – Pressure compensating Geoflow – Non pressure compensating with Rootguard

25. Design Considerations Design Flow – local regulations for IWS Soil Loading Rate – Soil texture, refer to chart for general guidelines

26. Application Guidelies for the Waste Water Systems Perc-Rite System Soil GroupSoil Texture Classes (USDA Classification) Maximum Hydraulic Loading (gal/day/ft2) ISands (with S or PS structure) Sands –S Loamy Sand - LS 0.4 - 0.3 IICourse Loams (with S or PS structure) Sandy Loam –SL Loam - L 0.30 - 0.15 IIIFine Loams (with S or PS structure) Sandy Clay Loam – SCL Silt Loam – SIL Clay Loam – CL Silty Clay Loam - SICL 0.15 -.10 IVClays (with S or PS structure) Sandy Clay – SC Silty Clay – SIC Clay - C 0.10 - 0.03

27. Additional Considerations Topography Soil Compaction Low areas where ponding might occur Restrictive Layers Setbacks required

28. Additional Considerations Nutrient load – more of a concern with Reuse

30. Design Steps Determine Design flow in gallons per day (GPD) – refer to local regulations Determine Soil Loading Rate (GPD/square foot) Determine area required = Design Flow/Soil Loading Rate

31. Determine dripper spacing spacing, i.e.: 2 feet Determine tubing spacing, i.e.: 2 feet Determine amount of tubing required = area required / tubing spacing Determine total flow rate based on tubing requirements Design Steps – continued

32. Determine Field Layout Maximize lateral length to Minimize flush flow Feed and collect from upper elevations where possible

33. Design Steps – continued Determine Flush Flow required – 1.6 GPM X the number of distal ends Break field into equal zones Calculate head losses and elevation changes Determine Pump Size

37. REFERENCES Netafim – www.netafim-usa.com www.netafim-usa.com Geoflow – www.geoflow.com www.geoflow.com Waste Water Systems – www.wastewatersystems.com www.wastewatersystems.com American Manufacturing – www.americanonsite.com www.americanonsite.com

39. The End