• In Bangalore it is now mandatory for all complexes with 20 or more flats to set up STP within 3 months
  • Big Relief to Bangalore Apartment Owners- MoEF dilutes Discharge standards on 13-10-2017 to make it easy for STP owners
  • Micro STPs for 20 to 30 Apartments- Faster delivery- Prices start at 5.0 lakhs
  • BBMP issues guidelines on setting up STP in apartments in Bangalore. Details in this website
  • Indus launches 'Zero Discharge Sewage Treatment Plants' & Instant Sewage Treatment Plants 'e-STP'
  • Effluent Treatment Plants for Restaurant, Car Wash & Diary Industry
  • We have launched 'Zero Discharge Sewage Treatment Plant' for 100% recycle of Sewage
  • Channel Associates wanted in All State Capitals

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Home -  Septic Tanks or STP - Which one for you

    Septic Tanks or STP - Which one for you

    Selecting the right sewage treatment plant - Septic Tanks & STP



    Mains & Off-Mains Drainage
    Houses are linked to a public sewer pipeline - You flush the toilet, water goes into municipal sewers / drains and have very little to worry about. This is Mains Drainage. In suburban and rural areas many homes are self-contained; there are no municipal underground drains to carry Sewage Treatment Plant ( STP)

    . This has no connection to the public sewer system and is known as Off-Mains. 1) Users have to make their own arrangement to dispose Sewage Treatment Plant (STP) 

    On-site: Critical Factors to Consider
    As the flow chart below shows, site assessment is a vital stage in the system selection process. A septic tank installation in unfavorable conditions is likely to result in failure and expense. To minimize assessment costs, particularly for sites which prove unsuitable, Indus recommends a 3 step STP procedure.

    Step 1: Consultation & Visual Inspection
    • Make an initial visual assessment of the land’s suitability for septic tank drainage:

    • Consult the Environmental Regulator

    • The drainage field should be sited on land sloping away from the property.

    • There should be adequate access for de-sludging vehicles.

    • Any stream, well, borehole or spring on-site can affect the positioning of the unit.

    • The site area and proximity of the site boundaries will help determine whether an adequate Sewage Treatment Plant (STP) drainage field can   be installed.

    • Water loving plant species could indicate poor STP drainage.

    Step 2: The Trial Hole 
    (Proceed with step 2 only if step 1 results are favorable)

    • Well drained soil is usually brown, reddish or yellow. Grey or blue subsoil often means heavy clay or poor drainage.

    • The position of the water table must not rise to within 1 mtr of the Effluent Treatment plant
      distribution trench.

    • There should be at least 0.5 metre of suitable subsoil available below the base of the distribution trench.

    Step 3 - Percolation Testing
    (Proceed with step 3 only if step 2 results are favorable)
    Now that results of Steps 1 & 2 are favorable, it is essential that you carry out a percolation test in accordance with BS 6297 and building regulations. The percolation test will indicate soil porosity values. Excessively rapid percolation can threaten groundwater resources, whilst very slow percolation can result in surface water logging. Percolation test results will help you decide on the area of land needed to provide a sustainable drainage field. Conclusions In the site shown, the left hand soil profile shows:

    • A low water table

    • Suitable subsoil

    • Advantageous topography

    • Good access

    • Adequate land area

    These indicators, when combined with satisfactory percolation, would all suggest that a septic tank system may be sustainable. On the right side of the site a high water table, shallow subsoil and heavy clay suggest that percolation testing results will be unsatisfactory and an alternative disposal system should be installed. Indus will provide further advice.