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    Advanced sewage treatment plant

    Ultra:Polylok™ sewage treatment plants

    Advanced biological processing for off-mains wastewater

    Marsh Ultra Polylok commercial sewage treatment plants provide advanced biological treatment to off-mains wastewater on sites ranging from 50-1000PE.

    The units are ideally suited for large residential, commercial, industrial and leisure sites – particularly where onerous consent standards preclude the use of standard ‘off the shelf’ units.

    Proven reliability of the simple but effective Submerged Aeration Filtration (SAF-MBBR) system offers both operating and financial benefits when compared to more complex alternatives that require frequent servicing and maintenance to sustain performance.

    Gaia Sege© Process design software for Ultra:Polylok sewage treatment plants

    Developed by Marsh Industries, the unique Gaia Sege process design software uses core information to accurately calculate and tailor key variables, ensuring total optimisation for individual applications.

    These precise calculations provide assurance to consultants, engineers, specifiers and contractors that the system is specifically designed to meet the appropriate standards of regulatory bodies.

    For Ultra:Polylok sewage treatment plants, the programme employs core process equations to precisely calculate and modify critical variables, ensuring total processing optimisation for Biological Oxygen Demand (BOD), Total Suspended Solids (TSS) and Ammonia (NH4) reduction and removal.

    Gaia Sege software also uses ‘British Water Flows & Loads’ data to calculate initial flows and loadings whilst also calculating peak flows and levels.

    The programme can also calculate accurate sludge generation and storage on a daily basis, dependent upon final effluent standards required, ensuring the optimisation of primary chambers, individual clarifiers, diffused oxygen feed and final settlement chamber.

    Marsh has launched a direct quotation website for the merchant and engineer/specifier; www.bespokesewagetreatmentplant.com. This user-friendly site caters to the design of sewage treatment plants for domestic, commercial and industrial sectors.

    Configuration and components are shown for illustration purposes only


    1. Inlet
    2. Primary chamber
    3. Aeration chambers
    4. Diffusers
    5. Final (or ‘humus’) chamber
    6. Polylok filter
    7. Outlet

    8. Recirculation to primary chamber

    9. Turret guard

    10. Carbon covers

    11. High level alarm

    12. Eco-friendly process contol

    13. GRP kiosk


    Plant sizing
    Bespoke design with optional tank sizes ranging from Ø1.9-3m satisfies the demands of site conditions. Each option is the same price.

    Class-leading effluent quality
    20:30:20mg/ltr (BOD:suspended solids:ammonia) effluent quality ensures discharge is well within national consent standards. Improved effluent quality to meet tighter consent standards can be achieved by Gaia design.

    Heavy duty shell as standard
    Structurally sound and built to last. Enables installation in all ground conditions.

    High media surface area
    High specification bio-media  (310m3 per m2) and membrane diffusers provide even circulation to eliminate ‘dead spots’.

    Eco-friendly process control
    Energy-efficient, economical and flexible process control for minimal running, maintenance and servicing costs (see pages 24-25).
    For sites that do not need the ability to regulate process control, Marsh can offer diaphragm compressors for sewage treatment plants up to 150PE

    Internal recirculation
    Continues the treatment process to provide higher effluent quality whilst balancing flow over 24 hour period or periods of intermittent use.

    Polylok tertiary filter
    All plants fitted with the patented Polylok tertiary filter to reduce suspended solids in the final effluent by a further 35%, whilst also reducing residual BOD and Ammonia levels.

    Carbon covers (optional)
    600mm carbon covers provide significant strength and durability, and helps to reduce possible odours.

    Optional extras
    Optional extras include extensions for deep installations, pumped outlets for sites with adverse levels, sample chambers, Degrilleur trash barriers, phosphate reduction and UV treatment chambers.


    Specifications table
    Model up to Width Ø
    +/- 50mm
    Length Height Inlet invert Inlet Ø Outlet invert Outlet Ø Turret Ø Desludge (days)
    55PE 1900 6540 2500 750 160 900 160 600 90
    60PE 1900 7050 2500 750 160 900 160 600 90
    75PE 2500 5730 3100 900 160 1000 160 600 90
    100PE 2500 7080 3100 900 160 1000 160 600 90
    125PE 2500 7980 3100 900 160 1000 160 600 75
    55PE 1900 6540 2500 750 160 900 160 600 90
    150PE 2500 8640 3100 900 160 1000 160 600 60
    175PE 2500 9930 3100 900 160 1000 160 600 60
    200PE 2500 10200 3100 900 160 1000 160 600 45
    225PE 2500 11360 3100 900 160 1000 160 600 45
    250PE 2500 12530 3100 900 160 1000 160 600 45
    275PE 3000 9060 3800 1100 160 1300 160 750 30
    300PE 3000 9780 3800 1100 160 1300 160 750 30
    350PE 3000 11220 3800 1100 160 1300 160 750 30
    400PE 3000 12660 3800 1100 160 1300 160 750 30

    Please contact us for plants ranging from 500-1000PE
    The dimensions given on this page are for guidance only.
    For precise tank sizes and configurations, please contact Marsh Industries.
    All dimensions in mm.
    Due to production processes, dimensions of finished units are within a tolerance of +/-2.5%.


    Marsh Civils product portfolio and specifications


    Installation/technical manual


    CE Certificate