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
Whats 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

9
(No Transcript)
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
Reverse Osmosis

• 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

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
• Wont 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
In-Home Businesses/Hobbies

• Add stronger waste
• Add chemicals
• Increase flow

• Examples of Businesses
• Home photography developing lab
• Barber shops
• Day care
• Bakery
• Dog grooming
• Taxidermy
• Artist

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,
• dont 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?