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Typical septic system questions

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					Understanding
Septic Systems:
 Questions and
   Answers
  Understanding Septic
       Systems
 Common    misconceptions
 Typical septic system questions
 Educational resources
Common Misconceptions
 Disposal   of wastewater is the primary
  concern
 Centralized sewers are better than septic
  systems
 Maintenance is not required
 Out of sight--Out of mind
  Typical septic
system questions
        Typical septic system
             questions
   What is a septic system?
   Why use a septic system?
   How does a septic system work?
   Where are septic systems used and how big
    are they?
   How do I know where the septic system is
    located?
   Do I need to do anything to my septic
    system?
   When is sewer coming?
   Am I on a septic system?
   What is that smell?
   Why are there stripes in my yard?
   Why can’t I plumb my
       Downspouts
       Water softener backwash
       A/C condensate… into my tank
   Why can’t I drive/build on my system?
   Why do I have to pump my tank?
   How often do I have to pump my tank?
   Why is that red light blinking?
     What is a septic system?
       treatment and disposal of
 On-site
 wastewater
Composition of Domestic
    Wastewater

                   Toilet
                   Laundary
                   Bathing
                   Kitchen
                   Garb. Grind.
                   Misc.
      What is a septic system?
4   common components (Conventional)
    Source
    Septic Tank
    Drainfield
    Soil beneath the drainfield
       Types of Septic Systems
 Conventional    or gravity systems
     Standard design
     Modifications
 Pump systems
 Advanced treatment/dispersal
           “Conventional” System
               Components
       Source

Well
                Tank       Drainfield


                       Purification in Soil
        Groundwater
                    Pump to gravity
Source

                   Pump
                   Tank        Drainfield




   Septic Tank                    Soil
   with effluent
      screen
     Advanced pretreatment




Septic Tank     Pump
with effluent   Tank         To drainfield
   screen
    Why use a septic system?
 Safely treat and dispose of sewage
 Protect your family’s health
 Protect public health in the community
 Keep the environment clean
 Help keep housing affordable
  How does a septic system
          work?
 What    takes place in the septic tank?
     Solids separation
       • Heavy solids sink
       • Lighter solids float
     Some pollutant reduction
Typical Septic tank
         LIDS

              RISERS



  INLET TEE

        SCUM           OUTLET TEE
                       W/ EFFLUENT
  CLEAR LAYER          SCREEN

     SLUDGE
  How does a septic system
          work?
 What happens in the drain field and in
 the soil?
     Major source of treatment
     Filtering action
     NH4 converted to NO3
     Adsorption by soil
     Must be aerobic for maximum treatment
Fecal coliform in the soil and
          drainfield

               1’
                          < 200 cfu

                      4,000,000 cfu

                      1,900,000 cfu
      1’                  < 200 cfu

                          < 200 cfu
                           600 cfu
Fecal coliform in the soil and
          drainfield




                        1,900,000 CFU
Fecal coliform in the soil and
          drainfield



                   1’

                         < 200 CFU

            1’
N Cycle in Septic Systems



                        Immobilization




                    Nitrification and Sorption


    Denitrification ?
                 Aerobic zone

Well




                        Aerobic soil
       Groundwater
Where are septic
systems used?
 Where can a septic system be
           used?
 Only in areas were the soil and site is
  suitable for system installation
 The soil must be able to accept AND treat
  the effluent
     No breakouts
     Reasonable treatment before reaching
      groundwater
What kinds of soils are best suited for
          septic systems?
                         or
      Why doesn’t my land perc?
   Thick, gently sloping, well drained, deep soils
    are best
   It should be neither too sandy or clayey and
    have “good” structure.
   Avoid excessively steep or rocky areas, sticky
    clays, or restrictive layers
   Soil should be a uniform
    brown, yellow, or red
   ... it should not be
    gray or contain
    gray spots within
    24” of the
    surface.
          Wetness Conditions
 Evaluated    using soil colors
     mottles and matrix
 Common    (2-20%) gray mottles are
  assumed to indicate the seasonal high
  water table
 Trench bottom is set to be 12” (18” in
  sands) above the seasonal high water
  table
Photo: Too rocky?
Photo: Enough soil?
Topography
Photo: Typical Mountain
       Soil/Site
Landscape position
Being at the base of a slope results in
more surface and subsurface water on
               the lot.
             Head
             Slope




   Being located in a head slope
results in water flow coming in from
              3 sides.
  How is a site evaluated for a
        septic system?
 Have  a county environmental health
  specialist conduct an investigation--Costs
  vary for this service
 Contact Cooperative Extension for
  Investigate Before You Invest
             Site Evaluation
 Drainage  and topography
 Well locations
 Distance to water bodies
 Property boundaries
 Other
 How large is a typical system?
 Size   varies according to
     Soil conditions
     House size (occupants or # of bedrooms)
 There must be enough area for a repair
  area as well as the present system.
 Distances to streams, lakes, wells, etc. are
  also considered.
 Generally dictated by regulation
  Where is my
system located?
How to locate a septic system
 Check the original permit information
 Look for plumbing vent on roof
 Look under the house to determine where
  sewer lines exit
 Tank is often 5-10’ away from house near
  where sewer lines exit
How to locate a septic system

   Look for regular green stripes in the lawn,
    these are the drain lines
How to locate a septic system
   Use a tile probe or thin rod to locate lines,
    septic tank, and D-box
      check for utility lines first!
Do I need to do
anything to it?
 What maintenance is
       needed?
      What maintenance is
           needed?
 Know    where all components of your
  system are located
 Install a watertight riser over septic tank
     To facilitate maintenance
     Water conserving toilets




Conserve   water--50 gal. per day per person.
      What maintenance is
           needed?
 Only   put domestic waste into system
     Don’t use it as a trash can
       • Cigarette butts
       • Kitty litter
       • Hygiene products
 Restrict garbage
  disposal use
 Restrict dumping
  grease/cooking oil
  down drain
  What maintenance is
       needed?
 Pump   the tank regularly
When should I pump the
    septic tank?



 Variesaccording to use and size of tank
 Rough estimate: every 3 to 5 years
 How do I know when to
 pump the septic tank?
 Pump when solids are 25 to 33 % of the
 tank volume
Checking solids



           SCUM LAYER



           CLEAR LAYER




          SLUDGE LAYER
  What is that thing in the outlet of
             the tank?
 It   is clogging up my pipes!
Effluent screens
Inspect and clean regularly
        Servicing Effluent Screens
   Homeowner can perform
    this themselves or contract
    out
   ALWAYS wear gloves
   If tank is pumped, clean
    the screen!
Effluent Screen Cleaning
                 Wash off directly into
                  the septic tank
                 Should be done at
                  the inlet end of the
                  tank to prevent solids
                  bypass
                 Bypass protection on
                  some models
Are there any additives that are
          necessary?
 NO!
 Some  may be harmful
 Research has shown little effect for sludge
  reduction
 May not be cost effective
Additives
  How should the drainfield be
        maintained?
 Start   at the source:
     Conserve water
     Check for and fix leaks promptly
How do I maintain the drainfield?




       Maintain vegetation over the
                drainfield
Gutters and downspouts




  Redirect roof runoff away
        from system
         Proper grading




Divert surface water away from system
          No vehicular traffic




Keep cars and equipment off the drainfield
Do not build in drainfield or repair area
  A septic
tank should
  not to be
 used as a
foundation.
           What is that smell?
 Around    the septic tank
     Check for pipe breakage
     Unsealed riser lid or inspection port
     Look in the drainfield for breakouts
           What is that smell?
 From    roof stack
     Abnormal development of tank biology
     If only during still air or temperature inversion
       • Extend roof stack to above the ridge
       • Install activated carbon filter on the stack(s)
            What is that smell?
 In   the house
      Drift from the roof stack?
      Dry plumbing trap?
Recognizing and
  Identifying
   Problems
  Determining the Cause of the
            Problem
 Abuse   of system
 Construction history
 Age of system
 Are there similar problems in area or with
  installer?
 Maintenance history
 Causes of
 problems
Obvious vs. Obscure
 Red flags: Inside of the House
 Leaky fixtures
 Slow drains
 Garbage grinder
Red flags: Outside of the House
 Guttersand down spouts
 Driveway and patio
 Landscaping
 Uneven vegetation
 Construction
Failure due to water flow
Driving on the system
 should be avoided
Landscaping and Lot Problems
 Surface   drainage
Properly maintained swale
Poorly maintained drainage swale
Damaged tile drainage
 Where’s the system?
Where’s the water table?
Mother Nature’s
   influence
Downed tree
Is there a problem?
After a 1/4” rain
Where’s the system
         Drainfield and Tank Area
 Surfacing effluent
 Wet spots
 Areas of standing water
 Growth patterns in vegetation
       Location
       Pattern
   Odor
Bull's-eye pattern
Striping with problem
Seep on slope
Wet slope with repair
Standing water?
Odor from swamp?
Or from
straight
 pipe?
What to look
   for
             Construction
 Recent  additions
 Out buildings
 New cable for TV, phone, electric, etc.
 New water line, gas line, etc.
Cut into line
Compaction
Nearby system by same
      contractor
Cable
Lawn mower
         Maintenance History
 When was the tank last pumped
 How often pumped


Remember the tank pumper can be your
 septic system’s best friend
The Pumper
What about
 sewer?
Sewer plant
     Sewer vs septic systems
 Sewers  are generally more costly to build
  and maintain
 Septic systems are appropriate in rural
  areas
 Sewers are appropriate in urban areas
    Where can I go for more
        information?
 County Cooperative Extension
 County Health Department
Educational
Resources
   Educational Resources on
       Septic Systems
 Extension   publications
 Programs
 Demonstration   and training sites
       Extension Publications
   Septic System Owners Guide
   Investigate Before You Invest
   Septic System and Their Maintenance
   Management of Single Family and Small
    Community Wastewater Treatment and
    Disposal Systems
   Home*A*Syst
   Choices for Communities: Wastewater
    Management Options for Rural Areas
          Extension Programs
 Video
 Slide   sets
 PSA
 Septic system models
     On-site Wastewater
  Demonstration and Training
            Sites
 Vernon  James Research and Extension
  Center, NCSU, Plymouth
 Lake Wheeler, NCSU, Raleigh
 Guilford County CES, Greensboro
 Brunswick County CES, Bolivia
  Septic System Information on
            the Web
 http://plymouth.ces.state.nc.us/septic/
index.html
 http://onslow.ces.state.nc.us/staff/
drashash/enved/sepsites.html
 http://ces.soil.ncsu.edu/soilscience/
programs/index.htm
Septic systems can be a
 permanent solution to
       wastewater
      management
    if homeowners
understand and maintain
     their systems.

				
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