Your Aerobic Treatment System is part of the Family

1. Your Aerobic Treatment System is part of the Family Texas AgriLife Extension Service

2. Overview • Wastewater flows to the treatment system. • All system have two loading rates. • How much water do you use (hydraulic loading)? • How much waste do you generate (organic loading)? • How activities in the home impact the treatment system.

3. Aerobic Treatment Unit with Spray Distribution

4. Microbes • Microbes • Provide treatment • Must keep them healthy • Water • Food • pH • Dissolved Oxygen - DO • Temperature • Types of Microbes • Anaerobic – no DO • Aerobic – need DO • Facultative – either way • Healthy microbes result in happy customers

5. What’s in Wastewater? • 99.9 % water • 0.1 % pollutants or constituents of concern • Organics/Inorganics • Solids • Pathogens • Nutrients • Fats, oils, grease • Metals • Persistent organic chemicals • Hydraulic and Organic Loading Wastewater

6. Hydraulic Loading • Flow quantity • Volume • Flow period • Daily • Weekly • Monthly • Seasonal • Special events

7. Residential Wastewater UsageTexas 30 TAC Chapter 285

8. Estimating Hydraulic Loading • Number of bedrooms • Square footage of a facility • Water conserving devices • Special fixtures • Multi-head showers • Garden tubs

10. Organic Loading • BOD – Biochemical Oxygen Demand • TSS – Total Suspended Solids • FOG – Fats, Oil and Grease • Oxygen Demand • Oxygen States

11. Organic Material • Waste from plant or animal sources • Can be dissolved, a solid or a liquid • Broken down and consumed by microbes (aerobes and anaerobes) • As it decays, dissolved oxygen is depleted

12. Biochemical Oxygen Demand • Biochemical oxygen demand, or BOD is the amount of oxygen used during the breakdown of organic material • Take sample to commercial laboratory • Measured as a five-day laboratory test • BOD is considered an indirect measure of the organic content of a sample

13. Biochemical Oxygen Demand • Amount of oxygen consumed by microbes during decomposition of organic matter • Indicates overall organic strength of wastewater • High BOD5 means high levels of organics • Expressed in mg/L (ppm) • Domestic wastewater ranges from 100 to 300 mg/L BOD5

14. Oxygen Demand • The oxygen demand is the amount of oxygen required to aerobically oxidize a material • Aerator delivers the oxygen to meet demand • Organic material • Nitrogen • Other compounds • Water (low DO)

15. Oxygen States • Dissolved oxygen • Free O2 • Oxygen that has been incorporated into water • Many aquatic animals require it for their survival • Bound oxygen • Attached to other compounds, NO3 • Anaerobic microbes break oxygen bonds

16. Wastewater Loading Rates Goldstein and Moberg, 1973 Mass loading (lbs) = # people (4) x BOD loading (0.23 lbs/cap/day) = 0.92 lbs/day

17. Feeding the System • Water – Hydraulic load • Flow volume, gpd • Flow rate, gpm or gph • Appropriately sized system • Food – Organic load • BOD • Concentration, mg/L • Mass, Pounds per day • Appropriately sized system • Food to Microorganism Ratio - Consistency • Other Compounds

18. Impacts on Feeding ATU by Water Use • Effects on hydraulic loading • Whirlpool tubs • Water treatment devices • Clear water • Dishwasher • Laundry

19. Whirlpool Tubs • Use large volumes of water • Add hydraulic surges • New larger capacities can be greater than the design flow for the home

20. Clear Water Flows • Water Treatment Devices • Water Softeners • Reverse Osmosis • Other? • Other Flow • Condensate - AC • Ice Machines • Basement drains • Footing drains

21. Water Softeners • DIR – Demand Initiated Regeneration • September 1, 2003 – date requiring - DIR • May bypass the pretreatment component. • Connect directly to the pump tank. • Must go through a p-trap

22. Point of Use Under the sink Connect to OSSF No upgrade required Point of Entry Whole house system Greater volume Need to add to size of OSSF Reverse Osmosis

23. Laundry - 20% of Flow • Use should be spread out • Liquid soap is recommended • Use less • Remove risk of fillers in powders

24. Dishwasher • Adds surges of wastewater • Hydraulically overload system • Homeowner should space out loads • Organic load • Clean/Scrape dishes

25. Impacts on Feeding ATU by Organics • Effects on organic strength (loading) • Water-saving devices • Garbage disposal • Using wastewater system as a trash can.

26. Water Conserving Fixtures • Water Saving Devices • 60 gallons/person/day • Reduce Flow (lower hydraulic loading) • Increase strength (same organic loading unless change of habits)

27. Garbage Disposal • Increases total solids: scum, sludge • System should be pumped 1-2 years sooner than without a garbage disposal • Increases Organic Loading • Organic matter had not been digested, so it will take longer to break down • More water is used to wash out sink • Smaller particles will take longer to settle • Potential for fats and oils

28. Impacts by Feeding System • General Adverse Effects • Prescription antibiotics and drugs • Bath and body oils • In-home businesses • Antibacterial soap • Chemicals • Cleaners • Trash and non-digestible material

29. Prescription Drugs and Antibiotics • Can kill microbes living in system • Won’t discriminate against organisms living in the system • Additional treatment components may be necessary • Increase maintenance

30. Bath and Body Oils • Increases FOG • If usage is great, may need more maintenance

31. Add stronger waste Add chemicals Increase flow Examples of Businesses: Home photography developing lab Barber shops Day care Bakery Dog grooming Taxidermy Artist In-Home Businesses/Hobbies

32. Hand Washing Soap • Antibacterial soap affects biology of tank • Liquid soaps tend to be overused

33. CHEMICALS • All problems • Kill microbes • Upset system

34. Appliances and Cleaning Products • Look at Labels! • DANGER;Means the chemical will kill the bacteria, and its use should be minimized or eliminated • WARNING; Means limited use should have a minimal impact on the system. • CAUTION: Typically means the product will have little effect.

35. Septic System Additives • Not been proven to be beneficial to system performance • Not recommended • Break up particles that are settled at the bottom and make them suspended • Potential solids loading to downstream components

36. Cleaning Products • List commonly used brands • Cleaning • Antibacterial • They have cumulative effects on system performance

37. Drain Cleaner • Toxic drain cleaners can impact ability to properly treat wastewater • Affect bacteria activity

38. Toilet Cleaning • Product brand • Automatic cleaners • Not recommended • Continual impact causes long-term problems

39. Toilet Paper • Number of rolls used per week • Results in faster sludge build up • Treated toilet paper (with lotions) prevents paper from settling • Wet wipe disposal is discouraged

40. Bathroom - 60% of Flow • Only urine, feces, soap, toilet paper and limited amounts of cleaner should be going down drain • No feminine products, prophylactics, cigarette butts, etc • No every-flush toilet bowl sanitizers or every shower cleaner

41. Feeding the System If it will hurt the system, don’t let it go down the drain!

42. Extended Absences • No or low flows for an extended period of time • Low or no microbial activity • Caution needs to be used upon return

43. Summary • Wastewater flows to the treatment system. • All systems have two loading rates. • How much water do you use (hydraulic loading)? • How much waste do you generate (organic loading)? • How activities in the home impact the treatment system.

44. Questions?