CASE STUDIES

This scheme was made up of nine (9) no existing Borehole treatment plants which pumped into a combined trunk main supplying Fleete and / or Deal reservoir systems. Previous investigation had confirmed that the output of individual sources is affected by the switching in and out of other sources supplying into the common trunk main. Under conditions of high groundwater level and low demand there is a risk of excessive abstraction rates whereas at high demand and low groundwater level the site output is constrained by the higher head on the system. 

One of the Purestream Industries founders was  leading the project from a feasibility and then design and engineering perspective. It was proposed to install Variable Speed pump Drives (VSDs) to some or all of the borehole abstractions to ensure the full deployable output of all sources could be met under conditions of simultaneous pumping of all sites at peak output, yet to ensure that at times of reduced demand the individual sources do not exceed the licence and/or ‘safe’ abstraction rates. It was further proposed that a source management control system is introduced to enable continuous pumping of all sources as much as was practicable to minimise the number of pump stop-start events and so minimise potential turbidity events and to afford improved operation of disinfection systems.

The projects required all or some of the following requirements

• Feasibility study of      installing VSDs at selected sites, to include a review of existing site      installations, adequacy of power supply, main incomer and MCC condition      and building adequacy for VSD installation 
• Provide individual pump      duties with a range of flow, together with system, power and efficiency      curves.
• Estimates of any change in      operating costs from present.
• Phase 2 included the      detailed design of the pumping systems and pump selection for the      boreholes with a FDS for the wider system.

 KRG requested a review of the Dukan II water treatment system, in order to improve the water situation for Sulaimani City and the surrounding areas. The Dukan II system is one of three strategic Dukan Water Projects (DWP), with infrastructure spread across 41.5 km and providing treated water to population centres over three separate districts, with a predicted urban population in 2030 of 1,367,847and geographically located approximately 50 km from IPS2. The Dukan II water production facility and pumping system (Dukan II System) were originally constructed in 2008 to provide 8,000 m3/h, and further extended in 2012 to provide a design inflow of 12,000 m3/h, but the Dukan II system has been unable to reach its nominal design capacity since the 2012 extension according to discussions with plant operating staff. 

One of the Founders of Purestream Industries was working for the main contractor and 

lead the project with a brief to conduct diagnosis analysis and assessment of the Dukan II system and propose suitable solutions to allow the system to achieve the 12,000 m3/h design capacity. Numerous challenges were identified across the water treatment sites and the associated booster pumping stations, which were identified through a detailed site assessment, temporary monitoring equipment to confirm pump performance after their 15 years in service and the existing instrumentation across the sites. The report put forward numerous solutions in an optioneering format, to allow the client to manage their risk profile from the sites and their capital budget. 

 A 700 MLD wastewater recycling scheme which pumped final effluent from the outlet lagoons of the Eastern Wastewater Treatment Plant,  serving Southern Melbourne, and pumped the recycled effluent to an impound reservoir for indirect potable reuse. The recycle process stream included intake pumps and associated surge, Ozonation (Pre & Post), RGF, UV, final chlorination disinfection and solids thickening system. 

One of the Founders of Purestream Industries was working for the one of the main consultants, within an alliance format with the client and various contractors. He led the detail design aspect for the Balance of Plant. The project was conducted in the highly regulated Australian Water industry on a greenfield site located adjusted the the existing works, however the project required a detailed understanding of the interfaces between the old and new plants in order construct the works with the minimum disruption to the exiting works. This role also included the development of the scheme general specifications, the associated design management systems and after the design phase, a quality assurance role as part of the Alliance team. The total scheme value was in excess of > $350 million, highlighting Purestream Industries personnel's ability to be able to take responsibility for providing design services of a section of a larger scheme. 

This scheme included various upgrade projects to a large (180 MLD) Wastewater Treatment Works (Woodman Point) which serves the Southern region of Perth. Upgrade works at the site included: 

• New Sludge thickening area –      incorporating new DAFT (for Activated Sludge thickening), relocation      Rotating Screw Thickeners – RST’s (for primary sludge thickening) during      continued plant operation, thickened sludge storage and conveyance and the      associated chemical dosing plants,
• Alterations to the existing      anaerobic digester system, utilising the excess heat from the CHP system      for a heated water circuit, 
• The retrofit and      refurbishment of a large Sequence Batch Reactor (SBR) system while      maintaining plant operation and 
• Upgrades to the ‘waste      tanker’ receival facility. 

One of the Founders of Purestream Industries was working as the Lead engineer for the above upgrade works for the one of the main contractors, in a JV with a local construction partner, within an alliance format with the client and various consultants. These projects were running concurrently so there was an element of multi-site/multiple project delivery requirements, with the key focus of managing the staffing requirements across the numerous project needs, supply chain management and staff retention and training. The projects were all conducted in the highly regulated Australian Water industry and related to wastewater treatment in a brown-field environment, which required a detailed understanding of the project interfaces in order to maintain effluent compliance during the upgrade works. 

 
Total value of the works was approximately $35 million AUD, with the largest package ~$20m and the smallest ~$1m. The split of Civil works to MEICA works for the above projects was~ 70% MEICA / 30% Civils. All of the projects included physical or biological processing elements and associated pumping and EICA elements, with interlinking control systems to existing infrastructure.

One of the founders of Purestream Industries was the Engineering Manager for a package wastewater treatment plant manufacturer that had secured the framework to supply fixed film aerated biological treatment units to a Southern Water during AMP5. The framework included the supply and M&E installation of various process equipment to sites across the Southern Water region including  denitrification plants where both pre-anoxic and post-anoxic fixed film biological units were proposed and installed for the first time.

Gaining invaluable experience of working on SW sites, understanding and incorporating SW asset standards, specifications and requirements into projects has provided Purestream Industries with a strong working knowledge and background to SWS engineering and construction approach. The framework involved all elements of a multisite competitive tendering process from enquiry, proposal, detail design, manufacture, factory acceptance testing, shipping, logistics, installation supervision, commissioning, snagging and site acceptance tests. Full Operation & Maintenance manuals were provided along with all necessary CAD drawings, data sheets and P&IDs to SW standards. Our point of contact for much of the framework was through the 4 Delivery (4D) capital delivery program where the principal designer was MWH.

Approximately 20 projects were delivered over the AMP5 period with a range of capacity and complexity in terms of both construction and process perspectives. The products and equipment supplied was part of a much larger program of works on each site where capacity increases, consent tightening and plant refurbishments were undertaken with schemes total contract value ranging from £50k to £3.3 million and thus sits ideally within the scope and range of projects to which Purestream Industries is focused on. The projects required all or some of the following requirements

• Working alongside principal contractor to SWS H&S standards
• Integration of M&E works on existing plants – brownfield upgrades
• Discipline interfaces for piping, civils, electrical work
• All deliverables and communication through SWS Business Collaborator interface

Brownfield construction works to upgrade the Cirencester Sewage Treatment Works to provide additional treatment capacity to allow compliance with the current quality consent to 2021 design horizon. Areas of upgrade included refurbishment of existing Inlet area, provide new PST’s, convert existing PFT’s for re-use, new MCC’s, associated process pipework, installation of Ferric dosing system, refurbishment of FST distribution chamber, liquid polymer system and upgrade of the storm water overflow system. 

One of the founders of Purestream industries was responsible as the Lead Engineer for the project, managing a team to produce the upgrade design for the scheme, procurement support and then construction and commissioning supervision and support as the project progressed to sectional handover. Close working relationship with the civil construction team, the client (Thames Water) and external stakeholders. 

Project Value range ~ £5m. 

This project required all or some of the following requirements

• Stakeholder engagement throughout the project life cycle
• Ensuring designs complied with HSE requirements and were constructible and operable
• Multi-discipline team covering civil, MECIA and environmental works

 A company based in the South-East of England that manufactures toiletries and cosmetic products was able to reduce their trade effluent tariff thanks to a design, supply, install, operation and service contract developed by one of the founders.

The company was approached with an innovative proposal of lowering their trade effluent bills and improving their environmental credentials at their manufacturing plant. It was estimated that around 50m3of effluent was generated and discharged every day down the local sewer by the manufacturer and their trade effluent bill, based on the Mogden Formula totalled ~ £10,000 a month (~2007) with COD and Suspended Solids averaging approximately 8500 mg/l and 800 mg/l respectively. The characteristics of the effluent were high in natural oils, surfactants and emulsions resulting from the washing of the vessels, product lines and chemical cleans; there was a significant proportion of lost product in the effluent consisting of lotions, gels, shampoos and scrubs resulting in composition that was frequently high in viscosity.

The company was facing regular adjustments in their trade effluent bills amounting to 10% annual increases and recognized that without intervention, their effluent bills could double in less than 5 years, significantly impacting their operating profit.

After initial discussions with the company the primary proposal was to install a treatment plant on site and remove the resulting sludge generated by tanker. However, during this period site trials and jar testing were completed and a chemical agent was identified with the characteristic qualities of facilitating coagulation and flocculation of the emulsified effluent. This had the resulting benefit of reducing COD to below 2000mg/l with the consequential effect of only a modest increase in suspended solids in the effluent. At meetings with the water company trade effluent officer, agreement was reached such that, as long as the COD were reduced by the levels attained in the trials, the suspended solids would not require separation and removal and could continue to discharge to the sewerage network. The cosmetic manufacturer saw their trade effluent bill reduce immediately as a result of this compositional change in effluent recalculated by the Mogden formula. 

Due to increased growth and production at one of the largest salmon and trout processors in Europe, effluent discharged from the facility to the foul sewer was at increasing risk of failure to comply with the trade effluent consent. Working at the time for the supplier of industrial package treatment plants, one of our founders was involved from the initial enquiry through process design, jar test and sampling, proposal development, procurement, installation and commissioning of the effluent treatment plant that would ultimately reduce the company effluent characteristics comfortably back within its discharge consent and lower its trade effluent bills. The energy efficient design, featuring an element of odour mitigation, was housed within a purpose built prefabricated building in keeping with the design of the main facilities and consisted of the following elements

• a below ground buffer tank providing >6 hours retention and mixed by Flygt Jet Aerators to reverse anaerobic conditions. 
• submersible pumps to a rotary drum screen and 
• re-pumped through a coil pipe flocculator where ferric chloride and caustic were injected to facilitate the coagulation and flocculation of the influent prior to 
• release within a Dissolved Air Flotation tank. 

After installation, further work continued with the client aimed at reducing the volume of sludge skimmed from the DAF cell and collected in a below ground storage tank by the initiation of site trials with a plate press and polymer system. 

 A leading motorway service operators in the UK required to expanding the capacity of the existing sewage treatment plants due to increasing traffic and visitor numbers, which resulted in increased flows and loads and the EA imposing a tighter effluent discharge standard of 20:30:10 (BOD:TSS:NH4-N) from the site. A consulting engineer was appointed by the client to oversee a tender process to replace or upgrade the existing plant (sequence batch reactor) with a plant suitable of achieving the discharge standard. The winning contractor appointed the process equipment supplier that one of our founders was working for as the Engineering Manager and was responsible for developing a construction phase plan alongside the principal contractor. 

One of the immediate and obvious constraints from the outset was the extremely confined footprint within which to complete the works. Thus a key challenge for the contractor was to remove the existing SBR tanks, equipment and controls and replace with primary conical tank, temporary biological units and lamella humus tank whilst maintaining full operation of the motorway service station and compliance with the EA discharge consent permit. 

A solution was put forward by the founder for this transition, was to utilise temporary hire plant (comprising lamella separators, transportable biological units and a tertiary drum filter) and effectively bring the temporary plant up to maturity (biofilm establishment and full nitrification) by progressively increasing flows through these hire assets (utilising a branched tee off the existing SBR feed pumps) and thus reducing loads to the existing SBR. Once the temporary biological units were achieving full flow and compliance (through a sampling program of continuous monitoring), the SBR tanks and associated equipment could be decommissioned and removed, freeing up space to install the new permanent treatment plant 

The complexity of this operation, involving a small site, deep excavations, operating plant and construction equipment required a detailed and comprehensive health and safety plan, risk assessments and method statements for the assurance of the process and safety of both construction workers and operators of the treatment plants. Once the new and permanent plant was fixed in place and the MECIA installation had been completed, flows were gradually diverted to the new plant in order to ‘seed the process unit’ until it became fully operational and meeting its new consent limits in 2010. All of the construction and operation activities were undertaken without any disruption to the client or customers of the motorway service station.