Anglo American's Australian Coal division engaged Dowdens Pumping & Water Treatment [Mackay] to deliver 8 specialised underground pumping PODs used for various dewatering applications at their Grosvenor Coal Mine, located 190km southwest of Mackay in Moranbah, Central Queensland.

The Grosvenor mine is a developing underground longwall operation that makes up part of Anglo American's plan to triple hard coking coal production at their Moranbah mine sites. Located next to their existing Moranbah North coal mine, Grosvenor is set to produce up to 5 million tonnes of hard coking coal per annum for export. The Grosvenor mine utilises a 10km overland conveyor to transport high-quality metallurgical coal to the Moranbah North Coal Handling & Preparation Plant.

Construction on Anglo American's $1.95 billion Grosvenor longwall project began back in January 2013, with the development celebrating a number of industry firsts including being the first underground coal mine in Queensland to use a tunnel boring machine to develop the drifts, or access tunnels, in coal mine development. Anglo American aimed to have the Grosvenor mine raise the bar for onsite system and production efficiency - making the supply of unique underground POD pumping systems a perfect match for Dowdens Pumping & Water Treatment's experienced Engineering Department.

Dowdens Engineering Department's comprehensive abilities have been on the radar of many Central Queensland/Bowen Basin mines for some time through direct contact and working with industry leading consulting engineering firms. Dowdens ability to expertly design/manufacture/install and commission unique equipment built to specific client needs, together with a history of successful installations over the past 15 years in the Bowen Basin has positioned the business as Queensland's premier pumping & water treatment organisation.

Underground Pumping PODs are used in mines as part of the site water management process. Mine water is collected from sumps and wet areas by Wilden air operated diaphragm pumps and delivered to PODs where water level sensors then activate the pump and transfer the collected mine water to a mains pump station, underground storage dam or directly out of the mine portal. Mine water is typically dirty with coal fine, rocks and dirt; therefore slurry pumps are needed to handle such water. PODs can be located in hazardous areas and can be fitted with Flame proof motors and motor controllers with PLC (Programmable Logic Controllers) and SCADA (Supervisory Control and Data Acquisition).

The Grosvenor mine site requirements meant each POD needed to have a 200kW power rating. With the site's physical constraints (i.e. the underground mined roof height and width, as well as the site lifting equipment for transporting) meant careful consideration was required for the overhung load whilst transporting this equipment. Capacity of a standard Dowdens POD is 4m3 with a 110kW motor, however with the larger flow rate required to and from the POD meant a 6m3 capacity working volume was needed. Bigger capacity and higher duty equated to a larger size motor and pump, more robust steel framework and additional accessibility for scheduled servicing.

Dowdens standard POD design incorporates a dirty water receiving area. This area, integral to the main hopper (container for collection of bulk material such as rock or soil), ensures particles that are too large for the pump to digest and transport are separated and manually removed periodically ensuring trouble free pumping.

Pumps selected by Dowdens for this harsh duty were Stalker 400SHD model with mechanical seals, seal lubrication and cooling. Motors selected were WEG brand Flameproof mine spec motors. The control for the pumps is a flameproof 200kW model with PLC and HMI (Human Machine Interface) screens. The controller starts and stops the pump, whilst also monitoring for faults and relaying important information to the mine surface via SCADA. Dowdens PODs built for the Grosvenor mine have the ability of easily interchanging the motors/pumps for differing duties. These will be identified as 200kW and 132kW cassettes. To accommodate this change the Main Control Unit (MCU) has the capacity to operate at either 200kW or 132kW with only slight changes to load controls.

The larger size and the flexibility to change the duty, together with Dowdens strategic POD site placement advice has enabled Anglo American less manoeuvring of the POD through development, saving costly underground labour and downtime. Without reliable pumping the mine's production slows/halts causing delays and safety issues which cost the mine many thousands of dollars each day. It was imperative the system worked and was extremely reliable. This project was delivered on time and within budget. Key project system components are listed below:

Unique features specific to the 8x Underground Dewatering Grosvenor PODs included:

• Fold out access platforms for operators to access the instruments and simplify servicing
• Direct fill points to prevent foaming of the mine water
• Overflow points for PODs operation on a steep slope
• Forklift access to both the pump and motor cassette

Key Project Features:

• PODs for this mine have the ability of interchangeable motors/pumps for differing duties
• PODs larger size, flexibility to change their duty together with Dowdens strategic POD placement advice enabled Anglo American to save on costly underground labour & pump downtime
• Safety & Design workshop hosted by Dowdens Mackay enabled project stakeholders to table all development & maintenance requirements ensuring seamless system delivery
• Project was delivered on time and within budget

A Rockhampton regional cattle grazier (located in Kalapa, QLD) employed Dowdens Pumping & Water Treatment [Rockhampton] to design, install and commission an economical yet efficient pumping solution to supply water for 50 head of cattle in a remote paddock.

The paddock in question has no access to mains electricity or town water so Dowdens needed to find a way to efficiently pump the water drawn from a 12m deep well into a newly installed poly water tank, eliminating the need to use the old onsite windmill. A solar powered pump and controller unit needed to be used.

Dowdens contacted local business Nu-Tank to float the idea of establishing an ongoing Rockhampton-based partnership to manufacture and deliver Dowdens dedicated solar pumping solutions in unison with their locally manufactured reliable one piece water tanks to farmers, graziers and local industry alike.

Working in partnership with Stephen Trail [Manager] from Nu-Tank Rockhampton the Dowdens Pumping & Water Treatment Rockhampton branch were able to co-design, test and develop specialised poly lugs that can be welded to the top of each tank. This has allowed Dowdens wide range of solar panels to be fitted safely and securely to the top of Nu-Tank's dedicated solar pumping water tanks.

The solar pumping system was designed to keep overall costs down whilst still delivering a regular supply of water to the cattle with negligible ongoing service or labour required.

A 3HRSS Waterboy submersible solar pump was installed in the onsite well at a depth of approximately 12m. The solar pump then transfers artesian bore water via metric poly pipe to the nearby specially adapted Nu-Tank poly water tank. The tank then gravity feeds a series of troughs throughout the paddock sufficiently watering the 50 head of cattle.

The Nu-Tank PWT3300 15,000L poly water tank was fitted with a PC500 Waterboy pump controller allowing the pumps flow rate and pressure to be easily managed via the easy-to-use electronic interface. The daily flow into the water tank is now approximately 6,000L - which is more than enough to properly water the 50 head of cattle in the paddock.

The top of Nu-Tank poly water tanks are rated to hold a much greater weight than the installed solar panels - meaning the environmental footprint of the entire solar setup was minimised and the grazier saved money on the total project costs.

Key Project Features:

• 3HRSS Waterboy submersible solar pump allows the system to draw and pump well over 6,000L/day
• PC500 Waterboy controller has many built in systems that are beneficial to the grazier which include (but not limited too): low water level cut out feature; pump speed control; operating lights telling you when the pump is running and what it doing; a dedicated restart timer used in the event the a low water level is reached the pump restarts automatically
• System is both affordable and easy to maintain with negligible ongoing service or labour required
• Total solar pumping systems environmental footprint was minimised using combined Dowdens / Nu-Tank technologies
• Dowdens Pumping & Water Treatment [Rockhampton] together with Nu-Tank aim to continue to strengthen their business partnership, delivering affordable solar pump and tank solutions to local farmers, graziers and Rockhampton based industry

Wilmar Sugar Australia Limited employed Dowdens Pumping & Water Treatment [Mackay] to deliver a broad acre irrigation system at their Gibson Creek sugarcane farm. Wilmar Sugar Australia Limited is Australia's largest raw sugar producer and one of the top 10 producers in the world.

The Gibson Creek sugarcane farm has a total area of 2,000ha, with works completed by Dowdens to date delivering irrigation to over 750ha of sugarcane - this project is still ongoing with the aim to irrigate the full 2,000ha upon completion. The broad acre irrigation system was designed, sourced, installed and commissioned by the Dowdens Pumping & Water Treatment Agricultural Sales Team, which has over 125 years combined agriculture irrigation experience.

The system is required to pump water stored in Wilmar's onsite dam (which when completed will hold a total of 2,000ML) to various irrigation devices watering 2,000ha of sugarcane.

To date the project has seen the team at Dowdens construct, install and commission six Valley Center Pivot Irrigators, with spans ranging from 520m down to 410m, and three hard hose poly line traveling irrigators.

Water for the irrigation system (sourced from Wilmar's 2,000ML onsite dam) required Dowdens to lay an extensive network of poly and PVC mains pipework ranging from 500mm to 150mm in diameter. In total over 12kms of mains pipe has been laid so far.

The entire system is gravity fed from the large onsite dam with a 6-cylinder John Deere diesel engine centrifugal pump feeding the six pivots, and three IVECO-Caprari multistage diesel booster pumps [pictured below] kicking in to raise mains pressure when water is required at the three hard hose poly line travelling irrigators.

The entire project was overseen and managed by Glenn Agnew from the Dowdens Pumping & Water Treatment [Mackay] Agricultural Sales Team.

Key Project Features:

• Six Valley Center Pivot Irrigators installed with spans ranging from 520m to 410m
• The Valley Center Pivots were fitted with auto-start generator sets - eliminating the need for farmers to travel to each individual Center Pivot to activate once feed pumps are on
• To date over 12kms of mains poly and PVC pipe has been trenched, welded and commissioned
• Dowdens sourced, delivered and commissioned three hard hose poly line traveling irrigators [2x Idrofoglia & 1x Trailco]
• 1x 6-cylinder John Deere diesel engine centrifugal pump feeds the six Valley Center Pivot Irrigators
• 3x IVECO-Caprari multistage diesel booster pumps transfer water to the three hard hose poly line traveling irrigators when required

BHP Billiton Mitsubishi Alliance (BMA) engaged Dowdens Pumping & Water Treatment [Brisbane] to design, manufacture, install & commission a 200kL / day Sewage Treatment Plant (STP) which included three pump stations and a specialised central control room at their Saraji Coal Mine, located 60km southeast of Moranbah and 200km southwest of Mackay in the Bowen Basin, Central Queensland.

Saraji Coal Mine has coal reserves amounting to 648 million tonnes of coking coal, one of the largest coal reserves in Asia and the world. The mine has an annual production capacity of 5 million tonnes, utilising open-cast extraction methods with a total of 11 coal seams.

Saraji Coal Mine required a new STP due to the existing onsite plant failing to meet release limits and becoming unsafe to operate. Dowdens Brisbane designed a new STP that incorporated the innovative MIRACELL™ Rotating Biological Contactors (RBC). RBC technology is a type of sewage treatment process in which disks that are connected to a shaft are rotated at a very low speed (3.7 rpm) by means of a motor which is equipped with a reduction gear. The MIRACELL™ RBCs are designed such that 40% of the disks remain in the wastewater.

As the discs rotate contact with the wastewater causes turbulence and consequently aeration. As a result of this repetitive process, organisms accumulate on the discs. The organisms receive the necessary oxygen from the air during the rotation of the discs and consume the pollutants existing in the wastewater, converting them to carbon dioxide and water in a totally natural way. The treated water discharged from any MIRACELL™ STP is guaranteed to meet the most stringent discharge standards and may be used for dust suppression, irrigation or directly discharged to a waterway subject to Environmental Authority approval.

MIRACELL™ Sewage Treatment Plants are fully automatic, utilising modular designed RBCs specifically designed for sewage treatment applications in capacities ranging from 50 to 20,000 Equivalent People (treatment of between 10m³ up to 4000m³ per day). Representing the ultimate in sewage treatment systems, a MIRACELL™ STP consumes as little as one fifth of the electricity and requires as little as one third of the space of its competitors based on the activated sludge technology.

Dowdens Pumping & Water Treatment are proud to hold Australia-wide exclusive distribution rights for MIRACELL™ STPs - these systems are most preferred by customers who clearly understand the economic value in purchasing an expertly designed and professionally built system. Offering a comprehensive range of innovative MIRACELL™ STPs, Dowdens provide an all-in-one service approach to each project. From project inception through to final commissioning, our team of industry trained engineers, draftsmen, project managers, sales staff and tradespeople including electricians, fitters, polywelders and plumbers will have you covered!

Dowdens Pumping & Water Treatment [Brisbane] were successful in the initial tendering process as we could deliver a complete turnkey Sewage Treatment Plant solution within the limited project budget, whilst also meeting all of BMA's specifications.

The standalone Sewage Treatment Plant Dowdens Brisbane supplied BMA provided an expertly-designed system that allowed them to meet their regulatory requirements, whilst providing a reliable, easily operated and maintained system. The new Saraji MIRACELL™ STP needed to accommodate the total mine site workforce of 645 Equivalent Persons (EP). Dowdens have designed the Saraji MIRACELL™ STP to treat up to five times the Average Dry Weather Flow rate of 40 kL/day - meaning the STP has the capacity to easily process and treat up to 200kL/day.

The Saraji MIRACELL™ STP and three fibreglass pump stations have been designed to capture and treat all waste influent (both Sewage & Grey Water) from the entire mine site and deliver it to the STP for processing. The system's design had to not only deliver the desired treated effluent quality but also incorporate strict safety requirements while adhering to the Queensland Government's Department of Environment and Heritage Protection stringent environmental conditions.

The Saraji MIRACELL™ STP includes a pH correction system to allow for pH correction. The pH correction dosing system comprises a pH correction chemical storage tank and a dosing pump. An Electromagnetic flow meter installed on the inlet of the chlorine contact tank automatically adjusts the chemical dosing rate based on the incoming treated effluent volume. This ensures the pH on the outlet of chlorine contact tank is always within the range of pH 6-9.

The Saraji MIRACELL™ STP is also equipped with a remote monitoring feature that enables the Saraji Mine operators to check the status of the STP from anywhere in Australia via portable devices such as smartphones or tablets.

Dowdens Pumping & Water Treatment [Brisbane] design philosophy for this project was: Cost Effectiveness - Current Best Practice - Ease of Installation - Simple Plant Operation - Plant Reliability & Reduced Maintenance.

Beginning in June, running through to October 2015 the Saraji Mine MIRACELL™ STP was delivered on time and within budget. Extensive onsite works were undertaken by Dowdens Pumping & Water Treatment to enable the new system to be properly housed and connected to existing site, power and pipework infrastructure. The STPs construction works involved (but was not limited to) civil, electrical, mechanical, hydraulic and structural works utilising Dowdens Infield Service / Installation Crew, Supervisors, Engineers and Project Management.

Key Project Milestones & System Components are listed below:

• Concrete foundations and bund
• 3x Fibreglass Pump Stations Installed (two in ground & one above ground)
• 1x 47kL Equalisation Tank
• 2x 22kL Primary Settling Tanks
• 4x MIRACELL™ Rotating Biological Contactors (RBC)
• 1x MIRACELL™ Lamella Plate Clarifier
• 1x Recycled Activated Sludge System
• 1x Chlorine Contact Tank
• Chlorine Dosing Equipment
• pH Correction Dosing Equipment

• 1x Central Control Room
• 1x Control Panel including Human Machine Interface (HMI) Touch Screen
• Safety Shower & Hazchem Storage Equipment
• Installation of roof over STP
• Construction of onsite car park
• External Lighting
• Security Fencing
• Earth bund around the perimeter of STP
• Manufacture of Platforms & Staircases

Longreach Regional Council recently engaged Dowdens Pumping & Water Treatment's Mackay & Rockhampton branches to manufacture and install a specialised pool water treatment system for the Yaraka Community Pool in Yaraka (a small town in Central West Queensland located 220 kilometres south of Longreach).

This project began with Longreach Regional Council asking for tender submissions to fully upgrade the Yaraka's Pool onsite filtration & treatment systems. Dowdens Pumping & Water Treatment was successful in winning the tender thanks to our price competitiveness, delivery times and unique in-house fabrication capabilities. On hearing about the tender a representative from the Dowdens Rockhampton branch immediately attended the pool to properly assess and quote the job. It quickly became apparent that a specialised filtration system was needed due in part to the pools remote location (limiting the possibility of regular system servicing), and the extreme weather patterns (high temperatures, dust storms & limited / sporadic rainfall) experienced in Central QLD.

Dowdens then set about designing the new filtration system utilising inhouse Engineering, Workshop Fabrication & Mobile Pool Servicing Departments. The end result was a unique twin-filtration systems that was mounted onto a fabricated galvanised skid to aid in maneuverability, ease of installation & transportation. The skid base was fabricated specifically to fit the existing shed onsite.

Having all the system components plumbed up on a single sturdy base made installation easy as only the Pump Inlet, Pool Water Return and Wastewater Pipes needed to be connected and the system was ready to go. The skid comprised 2x Pool Glass Media Filters, 2x Pool Pumps and 2x Salt Water Chlorinators. The Salt Water Chlorinators are fully automated allowing for round the clock (controlled via sensors) pH and chlorine / acid dosing together with chlorine generation. This has drastically reduced the need for regular onsite water testing and manual chemical dosing at the community pool. On Dowdens recommendation Longreach Regional Council also purchased a Dolphin Robotic Pool Cleaner which has noticeably improved the pools cleanliness.

All design, manufacture, delivery and installation / commissioning was successfully completed by Dowdens well within Longreach Regional Council's delivery deadline of six weeks.

The Yaraka Community Pool is now clean and ready for summer. The new equipment Dowdens supplied has reduced the need for costly regular maintenance whilst improving the automation of the pools chlorine levels - keeping the pool sanitised and chemically balanced at all times is extremely important for any community pool. Dowdens Pumping & Water Treatment's design philosophy for this project was simple: Cost Effectiveness - Ease of Installation - Simple & Effective System Operation - System Reliability & Delivering Greatly Reduced Ongoing Maintenance Requirements.

Yaraka Community Pool Filtration System ~ Key System Features & Components:

Following on from the successful construction and commissioning of the Coppabella Water Treatment Plant Aurizon Holdings Limited engaged Dowdens Pumping & Water Treatment [Mackay & Brisbane Branches] to deliver a much needed Sewage Treatment Plant (STP) Upgrade at their Coppabella Township, located on the Goonyella Rail Corridor (the world's largest metallurgical coal rail system) - 159 kilometres South West of Mackay, QLD. The Coppabella STP Upgrade project entailed the addition of an Ultra-Filtration (UF) 'Polishing' Plant onto the existing STP. Dowdens new UF 'Polishing' Plant can produce up to 180 kL/day of treated Class A effluent.

The township of Coppabella was primarily designed and built to service the junction of two railway lines (one from Goonyella Coal Mine and one from Saraji Coal Mine) and to provide accommodation to the regions coal mine workers in work depots. The town is wholly owned and operated by Aurizon Holdings Limited and contains: stations, residences, single-quarters, work depots, hotel, a shop, swimming pool, football oval, caravan park, school, ambulance, fire brigade, the recently completed Dowdens whole-of-town Water Treatment Plant and of course the upgraded Sewage Treatment Plant which is now capable of producing 180kL of treated Class A effluent per day for above ground irrigation applications. The local Coppabella Golf Course is one area where this treated effluent is used for irrigation.

After successfully completing various projects for Aurizon Holdings Limited, Dowdens won the tender to provide the process design together with equipment supply, civil construction, installation, commissioning and training for the STP plant operators. The construction phase of the project began with extensive civil works being undertaken to raise the ground level for the new STP components. The pre-existing STP has historically been subject to flooding during heavy rainfall events due to the sites proximity to the local creek. Upon surveying the sites substrate a water table was discovered 1m below ground level.

Working with local Civil Engineers Cardno a substantial foundation was designed / laid to ensure the new buildings, plant components and 4,000 tonne water tank would be stable and remain above the flood plain even during heavy rainfall. Once foundations were laid Dowdens began construction of the 400,000L lined stainless steel water tank, new building to properly house the STP process equipment, an operators office, laboratory facilities and a back-up generator used to power the entire STP in the event of power loss.

After extensive effluent testing and thorough examination of the existing STP process a UF 'Polishing' Plant was designed by Dowdens inhouse Water Treatment Engineering Dept. capable of processing up to 180kL of partially treated sewage effluent per day. The partially treated sewage effluent was rated as Class C and needed to be treated to an acceptable level (Class A) to then be used for above ground irrigation. This treatment process consists of three stages of filtration and sterilisation, including UF. This three-stage process runs as follows:

• Primary treated effluent from the existing STP (Class C quality) is transferred to a 45,000L Glass Media Filtration (GMF) feed tank via duty / stand-by submersible pumps on demand.
• In Stage 1 the clarified effluent from the existing STP process is first dosed with sodium hypochlorite as primary disinfection, to reduce biofouling of the Glass Media. It is then passed through the duty/stand-by Glass Media Filters which reduce particulates, suspended solids and turbidity from the GMF filtrate stream. This ensures no large particles damage the UF membranes in Stage 2.
• In Stage 2 the GMF filtrate is then passed through UF treatment process which incorporates 5% 'cross-flow' to maximise the filtration run-time between back flushes (triggered by high trans-membrane pressure). The systems consists of 8 individual outside-in PVDF membranes which reduce turbidity to less than 1 NTU (Nephelometric Turbidity Units) whilst removing any particles greater than 0.0002mm from the permeate stream. The UF feed is again dosed with sodium hypochlorite to assist with cleaning the UF membranes from biological and organic fouling between the backwash and Chemical Enhanced Back Flush (CEBF) cycles.
• In Stage 3 the UF filtrate is passed through duty/stand-by Activated Carbon Filters (ACF) on demand to reduce colour and odour (by removing aromatic compounds) as a final 'polish' before being fed to the treated effluent tank. The ACF filtrate is then dosed with sodium hypochlorite as a final disinfection of the treated effluent prior to it entering the treated effluent storage tank for dispersal via above ground irrigation systems. Dowdens provided a centralised, custom designed / fabricated, packaged chemical dosing system for this UF 'Polishing' Plant which included a 1000L Chemical Storage tank, a splash-proof racking area housing 5 individual Chemical Dosing pumps - complete with an internal bund and double containment dosing line connections.

When the treated effluent arrives in the 400kL stainless steel tank a recirculation system pumps it through a chlorine analyser and back to the treated effluent tank. The chlorine analyser then controls the residual free chlorine level in the treated water and will start / stop a chemical dosing pump as required to maintain the pre-set residual free chlorine level.

Each of the GMF, UF and ACF processes are periodically backwashed and cleaned, with residual waste being fed to a nearby buffer dam where chlorine is allowed to dissipate. Based on the level in the buffer dam and the level in the treated effluent tank, the water may then be returned to the pump station at the front of the STP for reprocessing.

With a history of successful installations over the past 20 years throughout the Queensland Mining Sector Dowdens Pumping & Water Treatment have the ability to expertly design / manufacture / install and commission specialised pumping and water treatment solutions that are built primarily in-house & onsite to client's specific unique requirements. The Coppabella STP Upgrade project is yet another example of Dowdens unparallelled capability to deliver specialised long-term engineered fluid handling solutions from project inception through to final commissioning / handover.