Septic System Issues Solutions: Technical Component

1. Septic System Issues & Solutions: Technical Component Watershed Academy � Athens, GA March 28-30, 2006

4. A Few Facts From Georgia 25% of homes in the U.S. use on-site systems 40+% in Georgia 75% of new homes 50,000+ systems installed annually

5. The Perception of Septic Systems: A Temporary Solution

6. Where did this perception come from? Historically for rural areas Suburban explosion after WWII Concentrated housing at the edge of town Homes temporarily used on-site systems until sewer came With the continued suburban explosion, the reality of sewer extending to the suburban areas did not become a reality USEPA considers decentralized systems an integral part of the nation�s ww management infrastructure. With the continued suburban explosion, the reality of sewer extending to the suburban areas did not become a reality USEPA considers decentralized systems an integral part of the nation�s ww management infrastructure.

7. Today�s Reality: USEPA considers decentralized systems an integral part of the nations wastewater management infrastructure

8. Advantages of Decentralized WW Low cost Capital Cost between $3-$5k Maintenance costs $100/year Environmentally benign if properly sited, installed, and maintained Minor water contamination risk with failure Natural system 20% of soils in Georgia are unsuitable for septic High density housing For sewer need area for system replacement Need at least 0.5 acres for septic Will likely need more area in sensitive areas20% of soils in Georgia are unsuitable for septic High density housing For sewer need area for system replacement Need at least 0.5 acres for septic Will likely need more area in sensitive areas

9. Disadvantages of Decentralized WW Not all soils suitable Not the best system for industrial and commercial No periodic inspections required Sporadic maintenance if at all Greater potential for illicit discharge Limits density Advantage or disadvantage? 20% of soils in Georgia are unsuitable for septic High density housing For sewer need area for system replacement Need at least 0.5 acres for septic Will likely need more area in sensitive areas20% of soils in Georgia are unsuitable for septic High density housing For sewer need area for system replacement Need at least 0.5 acres for septic Will likely need more area in sensitive areas

10. Major Components Septic tank

11. Septic Tank Function 1,000 to 1,500 gallon water tight tank Removal of large solids Limited organic decomposition (30%) Protect absorption field from clogging

14. Household Wastewater Toilet, bath, kitchen, and laundry About 99.9% liquid and 0.1% solids Average production = 70 gal/person/day Systems designed for 150 gal/bedroom/d 2 people in each bedroom

15. Potential Contaminants in Wastewater Bacteria and viruses Nitrate Phosphorous Odors Anything else that goes into the system Cleaners, medicine, drain cleaners, paint, �

16. Wastewater Renovation in the Soil Natural soil processes Rapid organic matter decomposition Organic N in wastewater rapidly converted to nitrate Nitrate is mobile in soil Dilution � only mechanism to keep groundwater nitrate levels low Minimum lot size?

17. Wastewater Renovation in the Soil Phosphorous is �fixed� and immobile in soils Bacteria and viruses Greatest threat to human health Removal by "filtering" and die-off Movement in most soils <2� Reports of movement >100� in sandy soils with high water table

18. Types of Septic System Failures Partially treated ww rising to the soil surface Health hazard Odor Overland flow to surface water?

19. Types of Septic System Failures Wastewater backs up into house �Toilet won�t flush� Health hazard Odor

20. Types of Septic System Failures Inadequate treatment before entering groundwater Commonly not considered - �If toilet will flush, the system is working�

21. Common Causes of Early Failure Unsuitable soils Slow or fast perc rates Seasonal water tables Shallow rock Water restrictive soil horizons

23. Common Causes of Early Failure Installation faults System not at proper grade Damaged components System inspection should discover these

24. Common Causes of Early Failure Site water management Gutter downspouts Run-on from paved areas and/or upslope areas

25. Common Causes of Longer-term Failure Under-designed system Bedroom addition Abnormally high water use Lack of homeowner understanding Lack of periodic maintenance & inspections Nothing lasts forever Properly sited, sized, and maintained system should last 30+ years

26. Extending Life of On-Site System

27. Reduce Water Use(or at least be aware of amount used)

28. Water Conservation Fix leaks Low flow toilets, showerheads, dishwashers, etc. 1994 U.S. Energy Policy Act (EPACT) Reduces per capita water use by 10 to 20 gpd Reduce water pressure

29. Graywater Separation 60-65% of total wastewater Bathtub or shower Laundry Toilet, kitchen and dishwasher not included Surface discharge requires EPD permit Graywater reuse in the future?

30. Reduce Contaminant Loads in WW Use recommended amounts of household cleaners Do not Use �every flush� toilet bowl cleaners Flush unwanted medicines down toilet Drain chlorine-treated water into on-site systems Minimize use of garbage disposal

31. Bacteria Additives Not shown conclusively to enhance performance Generally not recommended Amount of microorganisms added is minor Can result in abnormal amounts of suspended solids added to drainfield

32. Maintenance Often homeowner responsibility Lack of understanding Pump septic tank Every 3-5 years (not required in GA) Minimizes addition of solids to drainfield and soil clogging Inspections Only post-construction inspections req�d Periodic inspections not required in GA

36. Advanced Treatment Systems Aerobic treatment to lower BOD and suspended solids Overcomes soil and site limitations Should extend life of system Reduced solids to clog soil pores Additional maintenance required Additional expense

37. What�s in the Future?

38. Cluster or Community System Same total area as individual on-site systems Septic tank at every house Best soils for on-site system Advanced treatment Nitrogen and phosphorus removal

39. Cluster or Community System Contract maintenance Public? Private? Drainfield can be green space Wastewater concentrated in small area Greater potential for groundwater contamination?

40. Nitrogen and Phosphorus Removal Technology is currently available Not cheap Additional maintenance required May be required in sensitive environments P removal in shallow soils over fractured rock near water bodies N removal may be more widespread

41. Contract System Operation/Ownership Contract operation Homeowner owns system Maintenance/guaranteed performance provided for monthly fee 3rd party ownership Company or government agency owns system Responsible for maintenance and operation

42. Summary On-site systems are an economical and environmentally benign alternative to centralized wastewater treatment if soils are favorable, the system is suitable for the site and properly installed, and the system is properly and regularly maintained

43. Summary Maintenance is the key Simple, but it must be done New technologies are becoming available to improve performance