Transportable & Relocatable Wastewater Treatment Plants

A recent addition to OHW range of wastewater treatment options is the engineer designed purpose built transportable & reusable STP. Fully approved construction by Lloyds of London, these Plants are housed in 20’ and 40’ containers to facilitate sea borne and road transport options.
Each unit is ‘double skin’ constructed, comprising the container walls to which is bonded a tubular steel reinforcing cage lined with 4mm fibreglass sheeting for watertight status and longevity. All exposed metal surfaces are then sprayed with a corrosion protective coating. Unique to this OHW design is the full use of the vessel’s entire volume , which enables a gain in capacity & efficiency of up to 40% over those plants of the “plastic tanks fitted into a container” variety. This advantage ultimately relates to a smaller footprint and less transportation costs/litre of treatment capacity supplied.

Treatment Capacities

The treatment capacity of the Plant will vary from project to project depending upon the constituent load contained in the wastewater stream. Given that many mining and construction applications are often located in areas with very high daily temperatures, it is not uncommon to have a per capita water consumption of 300 litre in some instances. In other areas of a more temperate nature, water consumption of 150 litres per capita is more the norm. However, as a general rule, given a ‘domestic strength’ wastewater quality, the following treatment capacities could be used as guidelines:-

20’ version …….. up to 10,000 litres/day or 50EP
40’ version ……...up to 20,000 litres/day or 100 EP

Combinations of multiple units to suit any flow volume Plants that are required to treat very large volumes of influent could be coupled with an up-front primary treatment tank fabricated from zincalume or fiberglass for example, in order to lessen the overall cost. However, this is only one of many mix and match options that are available to create outcomes most suited to the purpose and the location.

Effluent Quality

The standard configuration of the transportable unit is designed to produce a B class effluent quality that in most instances will satisfy the on-site disposal requirements of the local and State authorities.

• BOD5
• TSS
  
• Faecal coliform
  

<20mg/litre
<30mg/litre
<30cfu/100ml

If however the requirement is for class A effluent to be used, for example for toilet flushing, dust suppression and the like, where human contact is probable/possible, then a superior quality of effluent is demanded, which will require additional Plant capacity to facilitate tertiary polishing.

Disinfection

All transportable Plants can be fitted with either Chlorine or UV or both for the disinfection/sterilization of Pathogens. Ultimately, the chosen option will be based upon customer and regulatory preferences or requirements.

Commissioning & Decommissioning

Transportable Plants arrive on site set-up and ready to connect to the power supply and the incoming drainage line, and are ready to receive wastewater immediately. The pumps, MCC and associated equipment arrive at the same time, all mounted in a 6’ container (pump shed) ready for connection, or alternatively, these components can be incorporated within the structure of the Plant itself. However, commissioning of the Plant with an OHW staff member present is preferred where possible as on the spot training of the Customer’s representative can take place. Once the project has been completed, the Plant can be quickly decommissioned either by OHW staff or the Customer’s staff and is then ready to be collected and moved to the next project or placed in storage. Snap on/ snap off connections make commissioning and decommissioning the Plant a quick and simple task. Residual effluent can be removed by tanker if available, and if not, the use of a ‘Geotube’ or similar is recommended.

Storage & Handling

The Plants are fully stackable and come with the usual lifting eyes, stacking lugs and forklift slots.

Delivery Time

Approximately 3-4 weeks from time of order.