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3.2.13 Disinfection & Polishing

This section details the microfiltration, UV disinfection, and chlorine dosing systems that polish treated effluent to Class A recycled water standards. Based on the LBC OWMS O&M Manual V1.1.

Distinct from Bore Chlorine System

This chlorine dosing system is part of the WWTP and is separate from the 3.1.3 Chlorine Dosing used for potable water treatment.

Treatment Sequence

Treated effluent from the discharge tank passes through the control room in this order:

  1. Microfiltration — polishes remaining suspended solids
  2. UV disinfection — primary disinfection
  3. Chlorine dosing — secondary disinfection
  4. Distribution — to RWS tanks or LAA irrigation areas

Microfiltration

Item Detail
Housing Harmsco HUR 90 HP (Orenco)
Filters HC/90-5 cartridge filters (Orenco)
Purpose Achieve TSS target of <10 mg/L; ensure lowest turbidity for optimum UV disinfection
Position Upstream of UV disinfection system
Isolation Red-handled ball valves on the inlet/outlet PVC
Flush Blue-handled valve on the black drain from the base of the housing

Harmsco stainless-steel microfilter in the WWTP control room, with isolation and blue flush valves

Maintenance

Task Frequency Responsible
Remove and clean filter cartridge Quarterly ENVR

UV Disinfection

Item Detail
Model Sanitron S5000C (Orenco)
Quantity 2 units
Power 220 V 1Ø, 0.64 A each
Control Independent enable/disable points on T-COM panel
Fault behaviour UV fault does not disable any pump
Mounting Two Sanitron canisters stacked on the control-room wall; lamp-status indicators on each unit

Twin Sanitron UV disinfection units on the WWTP control-room wall

Maintenance

Task Frequency Responsible
Clean UV glass sleeves via internal wiper mechanism Quarterly ENVR
Replace UV lamps Annually ENVR

Chlorine Dosing

Item Detail
System Grundfos Dosing Station DDA 7.5-16 AR (1 L02 P1 02)
Supplier Thinkwater NT
Location Climate-controlled WWTP control room (20 ft container)
Pump Grundfos SMART Digital DDA, mounted on the inner tank lid
Inner Tank White plastic reservoir with black screw-top lid
Containment Blue square bund around the inner tank; floor drain immediately in front of the station

Chlorine dosing provides secondary disinfection after UV treatment. Ample chlorine supply must always be available on site.

Grundfos SMART Digital chlorine dosing pump and tank in the WWTP control room

Injection Point

Chlorine solution is injected into the treated-effluent line on the control-room wall, downstream of the dosing station.

Item Detail
Injection Chemical-rated tube into a PVC T on the vertical effluent pipe
Fittings Brass adapter and grey compression fittings on the side-feed
Manifold Same wall assembly as the distribution manifold; Netafim Aquative Plus solenoids below the T

Chlorine injection T on the treated-effluent line in the WWTP control room

Chlorine Storage Safety

Chemical Storage

Chlorine and all chemicals must be stored in appropriately bunded and signed areas with relevant safety information and MSDS sheets readily available.

See 3.2.15 Safety Guidelines for full PPE and hazard requirements. Outdoor emergency rinse at the plant: Decontamination Shower (fed via the RPZ).

Class A Discharge Targets

Parameter Target
E. coli ≤ 10 CFU/100 mL (max)
BOD ≤ 30 mg/L (max)
TSS ≤ 20 mg/L (max)
TN ≤ 60 mg/L (avg)
TP ≤ 20 mg/L (avg)
pH 6–9

Contingency — Declining Disinfection Performance

E. Coli Failure

Control
Ensure ample chlorine supply on site
Confirm chlorine doser operation
Maintain chlorine dosing per manufacturer requirements
Confirm UV disinfection system operation
Clean UV glass sleeves using manual wiper
Replace UV bulbs annually

TSS Failure

Control
Clean out microfiltration cartridge
Ensure AdvanTex ventilation assembly operational
Review and adjust recirculation ratios
Ensure primary tank effluent filters in place and functional
Manage sludge/scum in septic tanks to prevent carryover

See 3.2.15 Contingency Plans for full declining water quality response procedures.

Control Room

The microfiltration unit, UV system, chlorine dosing, alkalinity mixer/dosing tank, flow meter, and T-COM control panel are installed inside a secure, climate-controlled 20 ft shipping container (repurposed MAC Water Treatment Plant container, fitted out by SCF Containers Berrimah).

Orenco T-COM control panel with LCD touchscreen (HMI1) in the WWTP control room

T-COM panel operation: 3.2.16 · 3.2.19 Local HMI.

The control room includes:

  • Potable water supply with backflow prevention (RPZ below)
  • Outdoor decontamination shower and hose tap (isolated at the RPZ)
  • Sample collection tap (see below)
  • Distribution manifold to LAA and RWS (see below)
  • Mechanical flow meter (see below)
  • Alkalinity dosing tank and mixer — see 3.2.11 Primary Treatment
  • WiFi router and outdoor transmitter for T-COM and contractor internet (see below)
  • Power distribution board (see below)
  • Electrical pit behind the control room (see below)
  • Air conditioning indoor unit (see below)
  • Floodlight and security camera on the container (see below)
  • Work bench

Potable Water Valve Boxes

Two in-ground valve boxes in the gravel beside the control-room container.

Item Detail
Purple box Valve allowing potable water into Absorption Area 1 (the field at the bottom of the hill) — used for low-occupancy / turf makeup watering; see 3.2.8 Irrigation Area 1
Green box Isolation valve for potable water to the control room

Purple and green valve boxes in the gravel beside the WWTP control room

RPZ and Isolation Valves

Outdoor reduced-pressure zone (RPZ) backflow preventer on the copper potable supply along the control-room container wall. Two blue-handled ball valves (one either side of the RPZ) isolate this branch.

Item Detail
Device RPZ backflow preventer (wall-mounted on copper)
Isolation Blue-handled ball valve upstream and downstream of the RPZ
Serves Outdoor decontamination shower (safety shower / eyewash), and the hose tap
Use Close both blue valves to shut off the shower and hose tap for maintenance or isolation

Distinct from Bore Chlorine Shed

The potable-water decontamination shower and RPZ at the bore chlorination shed are separate — see 3.1.3 RPZ and Decontamination Shower.

WWTP RPZ with upstream and downstream blue isolation valves — serves decontamination shower and hose tap (2026-10-31)

Decontamination Shower

Outdoor emergency safety shower and eyewash on a concrete pad beside the WWTP control-room container (grey corrugated wall). Stainless vertical unit with yellow pull handle (shower) and yellow push handle (eyewash).

Item Detail
Location Outside the WWTP control room, on the gravel / concrete pad
Type Combined safety shower and eyewash
Supply Potable water via the RPZ and isolation valves on the container wall
Also on this branch Hose tap (same RPZ isolation)
Use Immediate rinse for chemical splash / eye or body exposure when handling chlorine or other plant chemicals

Know This Location

Before handling chlorine or other chemicals in the control room, confirm the path to this shower is clear. Use it at once for any splash to eyes or skin, then seek medical advice.

WWTP decontamination shower and eyewash beside the control-room container (2026-10-31)

Show on Map

Sample Collection Tap

Item Detail
Type Brass quarter-turn tap with blue handle, on a PVC T in the wall manifold
Purpose Draw treated-effluent / recycled-water samples inside the control room
Isolation Red-handled ball valves on the parallel vertical PVC lines beside the tap

Sampling tap on the treated-effluent manifold in the WWTP control room

Distribution Manifold

Wall-mounted PVC manifold after disinfection. It splits treated effluent to the land application areas (absorption / irrigation) and to the recycled water storage tanks.

Item Detail
Manual Valves Red-handled ball valves — isolate or shut individual absorption (LAA) legs
Automatic Solenoids Netafim Aquative Plus — turn absorption areas on or off, and divert flow to the RWS tanks
Daily Limit Logic When the programmed daily discharge volume is reached, the N/O irrigation solenoid closes and the N/C solenoid opens to the RWS tanks (resets at midnight) — see 3.2.14 Recycled Water Storage

Distribution manifold in the WWTP control room — manual LAA valves and Netafim solenoids

Field layout of the irrigation zones: 3.2.8 Effluent Disposal.

Flow Meter

Item Detail
Type Mechanical, 50 mm, flanged in the treated-effluent PVC line
Pulse Output One pulse per 1,000 L
Mounting Horizontal, Unistrut-supported on the control-room wall

The pulse output is the volume signal used for discharge-limit and irrigation logic (see 3.2.12 AdvanTex Secondary daily discharge limit).

50 mm mechanical flow meter in the WWTP control room (one pulse per 1,000 L)

Communications

Item Detail
Router MikroTik RouterBOARD, wall-mounted in the control room
Outdoor transmitter MikroTik panel, J-mast mounted on the control-room container wall
T-COM Network path for Orenco T-COM telemetry — 3.2.16 · Web · Viewer · HMI
Contractor access WiFi for contractors working in the control room

MikroTik WiFi router in the WWTP control room (T-COM and contractor internet)

MikroTik WiFi transmitter on the mast outside the WWTP control room

Power Distribution Board

Wall-mounted Legrand enclosure labelled WWTP DB. Estate grid connection and other boards: 3.3.1 Grid.

Circuit Breaker
Main Clipsal 63 A isolator (red toggle)
Control Panel Schneider Electric Acti9 iC60N C32
Aircon Clipsal MAX4 16 A
Power Clipsal MAX4 16 A
Lights Clipsal MAX4 10 A

WWTP DB circuit breakers in the treatment plant control room

Electrical Pit

In-ground electrical pit immediately behind the control-room container. The lid is labelled ELECTRICAL.

Item Detail
Cover Noremak, Class A, AS 3996:2019, 30 kg
Lid marking P5 Cover model marking — not the estate Pit 5 Distribution Box

Electrical pit cover behind the WWTP control room

Air Conditioning

The control room is climate-controlled by a Panasonic split system, fed from the Aircon 16 A circuit on the WWTP DB.

Item Detail
Indoor Wall-mounted Panasonic inverter inside the control room
Outdoor Panasonic condenser, bracket-mounted on the container wall

Panasonic indoor air-conditioning unit in the WWTP control room

Panasonic outdoor air-conditioning unit on the WWTP control-room container

Floodlight and Security Camera

Mounted on an exterior corner of the control-room container.

Item Detail
Camera White bullet camera at the top of the corner, aimed down and out
Floodlight LED floodlight on a bracket below the camera
Cabling Flexible conduit from a wall junction box to the floodlight

Floodlight and security camera on the WWTP control-room container

Version Control
Version Date Description
2.0 2026-06-22 Rewritten for AdvanTex WWTP per O&M Manual V1.1
2.1 2026-08-30 Photo of Grundfos chlorine dosing pump and tank in the WWTP control room
2.2 2026-08-30 Photo of chlorine injection point in the WWTP control room
2.3 2026-08-30 Photo of sampling tap in the WWTP control room
2.4 2026-08-30 Photos of microfilter, distribution manifold, and 50 mm flow meter (1 pulse per 1,000 L)
2.5 2026-08-30 Photo of twin Sanitron UV units in the WWTP control room
2.6 2026-08-30 Photo of MikroTik WiFi router for T-COM and contractor internet
2.7 2026-08-30 Photo of WWTP DB circuit breakers in the control room
2.8 2026-08-30 Photo of Panasonic indoor air-conditioning unit
2.9 2026-08-30 Photo of Panasonic outdoor air-conditioning unit on the container
2.10 2026-08-30 Photo of electrical pit behind the control room
2.11 2026-08-30 Photo of MikroTik WiFi transmitter on the control-room mast
2.12 2026-08-30 Photo of floodlight and security camera on the control room
2.13 2026-08-30 Photo of purple and green potable-water valve boxes beside the control room
2.14 2026-10-18 T-COM communications link points to 3.2.16
2.15 2026-10-20 Photo of Orenco T-COM panel door with LCD Main Menu
2.16 2026-11-01 WWTP RPZ + isolation valves; outdoor decontamination shower / eyewash
2.17 2026-11-01 Show on Map for WWTP decontamination shower
2.18 2026-11-01 Cross-link to chlorination shed RPZ (3.1.3)

Next Review Date: 2026-12-22