1. Brian Benham Biological Systems Engineering Center for Watershed Studies Septic Systems Function and Maintenance

2. Outline Review components, function and maintenance of conventional gravity-flow septic system Discuss septic system site considerations Introduce alternative septic systems Briefly review on-site regulations Water quality implications associated with using on site systems General Septic System Dos and Don’ts 2

3. Typical System Components Household Collection System Septic Tank Effluent Distribution Distribution Box Pump/Dosing System Drainfield / Absorption System Replacement Area 3 http://geoscape.nrcan.gc.ca/h2o/bowen/quality_e.php

4. Septic Tank Compartmented tank or series of tanks Concrete, fiberglass, polyethylene Primary treatment – solids separation 4

5. Two Compartment Septic Tank 5 Lesikar, 1999; On-site wastewater treatment systems, L-5234 Sludge

6. Distribution Box 6

7. Drain/Absorption Field 7 http://www.thenaturalhome.com/infiltratorandpipe.jpg

8. Trench w/ gravel 8

9. Infiltration Chamber 9

10. How does septic system work? 10

11. What causes septic systems to fail? Problems: Clogging of distribution system and/or drainfield by solids AND bacterial mats Disruption of septic tank flora Causes: Reduced hydraulic retention time due to excessive solids/sludge build up in septic tank Excessive flow into septic tank and drainfield (too much water, too often) Use of harsh chemicals Addition of oils/greases/fine particles that flow into and clog drainfield 11

12. Signs of septic system failure Bad odors around the drainfield especially after heavy water use or rainfall Soggy soil, wet spots with lush green grass growth over drainfield or septic tank Standing water in drainfield Slow draining fixtures Plumbing back-ups High levels of coliform bacteria or nitrate in nearby wells 12

13. Tips to keep septic system working… Reduce volume entering system Use less water – consider low flow toilets, shower heads, etc. Do laundry a little at a time – 1 to 3 loads a day. Reduce water softener recharge cycle Perform system inspection regularly and pump septic tank when needed or on regular interval Don’t use garbage disposal Avoid harsh cleaners; use all cleaners sparingly Maintain good grass cover over drainfield Protect drainfield from excess runoff 13

14. Practice Water Conservation 14 Objective Reduce volume of water flowing into septic tank Conserve water Outcome Longer retention time (more opportunity for solids settling) Longer usable life for drainfield Reduced energy use

15. Septic Tank Pump Out Frequency Depends on water use (volume of water entering tank) and material put into tank Two rules of thumb Every 3 to 5 years When solids (sludge) accumulation is 30 to 50% of tank volume. 15

16. Pump Out 101: Pumper should: Note liquid level which can indicate leaks (too low) or problems with drainfield (too high) Look for back flow from drainfield Pump tank completely Check tank for signs of damage 16

17. VA Dept. of Health FLASH module 17 http://www.vdh.state.va.us/EnvironmentalHealth/Onsite/howsystemsworks/septictank.htm

18. Septic Tank Pumping Frequency Based on Tank and Household Size Household Size (number of people) 123456 Number of Years Tank Size (gallons) 7509.14.22.61.81.31.0 100012.45.93.72.62.01.5 125015.67.54.83.42.62.0 150018.99.15.94.23.32.6 175022.110.76.95.13.93.1 200025.412.48.15.94.53.7 225028.614.09.16.75.24.2 250031.915.610.27.55.94.8 GET PUMPED!18

19. Regulations State-wide regulations address a cceptable materials and construction standards for septic system components System capacity Tank/treatment unit Drainfield and replacement area Location: minimum distances from buildings, wells, springs, etc. Site suitability and assessment protocols Chesapeake Bay Preservation Act Requires pump out every 5 years 19

20. Sizing Septic Tank 20 Tank size is function of amount of sewage generated and water use (rules of thumb) Lesikar, 1999; On-site wastewater treatment systems, L-5227

21. Site and Soil Assessment Depth to Groundwater Bedrock Impermeable layers Soil mottling (indicates high water table) Permeability (too low and too high) Adjacent features Property lines, structures, wells, springs, surface water, etc. 21

22. 22 Zipper, 2009; On-Site Sewage Treatment Alternatives, VCE448-407

23. Locating & Sizing Drainfield Percolation (perc) tests determine Permeability. Must have sufficient, but not excessivly permeable soils. Drainfield size is function of how much wastewater is generated and soil permeability. Tighter (finer textured) soils require larger drainfields. Slope must be considered. 23

24. Setback Distances 24 12 VAC 5-610-10 et seq., Sewage Handling and Disposal Regulations

25. Alternatives: Mound System Raised drainfield; sand fill above the soil surface. Overcome site restrictions such as slowly permeable soil, shallow permeable soil over creviced or porous bedrock, and permeable soil with high water tables. Effluent is applied to system in timed doses using pump 25 Zipper, 2009; On-Site Sewage Treatment Alternatives, VCE448-407

26. Alternatives: Mound System 26

27. Alternatives: Shallow-Placed Systems Systems with drainfields within 18 inches of the surface 27 Low-pressure Distribution Trickle Irrigation Zipper, 2009; On-Site Sewage Treatment Alternatives, VCE448-407

28. Alternatives: Aerobic Treatment Unit ATU is a mechanical system that treats effluent using processes that require oxygen Includes aeration chamber, a mechanical agitator, and a sludge settling compartment. 28 Zipper, 2009; On-Site Sewage Treatment Alternatives, VCE448-407

29. Alternatives: Constructed Wetland 29

30. VDH FLASH for pumped systems http://www.vdh.state.va.us/EnvironmentalHealth/Onsite/howsystemsworks/pumpsystem.htm 30

31. New Regulations for AOSS New operation and maintenance requirements for owners of alternative onsite sewage systems (AOSS) Annual inspections by a licensed AOSS operator. Additional inspections depending on system complexity First inspection is due by April 7, 2011. Reports filed electronically with VDH by the operator (inspector). Must maintain an Operations and Maintenance Manual and operators log. Documents should transfer on sale. AOSS’s permitted after April 7, 2010 will have sampling requirement to verify the performance. Local Health Department can provide additional dertails. 31

32. 32 For help finding a Onsite Sewage Systems Operator, Call your Local Health Department

33. Septic Systems Costs Vary Greatly Cost vary primarily because of the type of system and site specific factors (soil, slope, etc.) VA Department of Conservation and Recreation bases cost share amounts in TMDL implementation watersheds on the following estimates 33 Pumpout$150 – 300 Repairs$300 – 4,000 Septic system replacement/installation$3,000 – 8,000 Septic system with pump$4,500 – 9,000 Alternative waste treatment systems$15,000 – 20,000 Connection to public sewer$2,000 – 6,000

34. Risks to Water Quality Surface and groundwater contamination possible Nitrogen Nitrogen in effluent 40 mg/L (approx.) 75%, ammonia; 25% organic Ammonium (NH 4 + ) converted to Nitrate (NO 3 - ) NO 3 - mobile in both saturated and unsaturated soil conditions. Limited risk contaminants Chlorides Phosphorus Emerging contaminants 34 Metals Microorganisms http://wrri.nmsu.edu/publish/watcon/proc51/mcquillan.pdf

35. Emerging Contaminants Pharmaceuticals and Personal Care Products (PPCPs) USGS study – 139 streams in 30 states: 82 of 95 antibiotics, prescription & non- prescription drugs, steroids, & hormones were found in at least 1 sample Surface and groundwater at risk Current treatment technologies and monitoring do not target PPCPs Fate and transport in soil and water unclear Environmental/ health impacts unclear Proper disposal is CRITICAL 35 Kolpin, D.W. et al. 2002. “Pharmaceuticals, hormones, & other organic wastewater contaminants in U.S. streams, 1999-2000: A national reconnaissance.” Environmental Science & Technology. 36(6):1202-1211

36. Septic Systems Dos Know where your septic system is. Have your septic system inspected and pumped as needed. Keep records of repairs, pumpings, inspections, permits Use commercial cleaners and detergents in moderation. Mild detergent or baking soda is preferable. Plant only grass over and near your septic system. Keep water usage to a minimum. Divert surface water (runoff, irrigation, etc.) away from the drainfield. 36

37. Septic Systems Don’ts Don’t treat your septic system as a trash can. Avoid introducing fine/floating solids and material that are difficult to digest (avoid using garbage disposal). Don’t drive or park vehicles on any part of your septic system. Doing so can compact the drainfield or damage the pipes, tank, or other septic system components. Don’t build or pave over drainfield or your replacement area. 37

38. Add VT pub 38 www.epa.gov/owm/septic/pubs/homeowner_guide_long.pdf http://pubs.ext.vt.edu/448/448-407/448-407.pdf

39. 39 Brian Benham Extension Specialist Website: www.wellwater.bse.vt.edu www.wellwater.bse.vt.edu Email: benham@vt.edu benham@vt.edu Ph: 540-231-5705