Supply Chain - Wastewater Treatment
The existing Derrycrin WwTW located near the Ballinderry River - Courtesy of NI Water[/caption]
Derrycrin during construction (August 2023) - Courtesy of NI Water[/caption]
Temporary treatment plant used at Derrycrin - Courtesy of DLJ Water Ltd[/caption]
Derrycrin WwTW inlet works - Courtesy of DLJ Water Ltd[/caption]
The new rotating biological contactors - Courtesy of NI Water[/caption]
Flow split chamber - Courtesy of DLJ Water Ltd[/caption]
MCert chamber - Courtesy of DLJ Water Ltd[/caption]
Desludge valves - Courtesy of DLJ Water Ltd[/caption]
NI Water Capital Delivery and Operations personnel pictured with the contract team from DLJ Water and RPS - Courtesy of NI Water[/caption]
Close up view of the completed Actiflo® AS3 units - Courtesy of Thames Water[/caption]
View overlooking the completed East Shefford STW Actiflo® plant - Courtesy of Thames Water[/caption]
Inlet works screens - Courtesy of United Utilities[/caption]
Drone image over the MOBTM plant cells - Courtesy of C2V+[/caption]
(left) MOBTM briquettes, (top right) fully developed biofilm on MOBTM media and (bottom right) MOBTM media - Courtesy of Nuvoda[/caption]
Mecana tertiary pile cloth filters - Courtesy of United Utilities[/caption]
MOBTM plant - Courtesy of United Utilities[/caption]
MOBTM plant - Courtesy of United Utilities[/caption]
(left) Location of new sewage treatment works and tunnel route and (right) Slyfield Regeneration Project area - Courtesy of Adams Hendry[/caption]
RIC 1 and 2 pass areas - Courtesy of BAM Enpure Ltd JV[/caption]
This combined dataset is then used in Leapfrog 3D geological modelling software, which applies intelligent interpolations, and highlights anomalies that can be quickly assessed and removed. The resultant 3D model has then been used to enhance communication in the engineering AutoDesk BIM 360 federated models, and in the proprietary Arcadis SmartAtlas GIS viewer.
Rapid Impact Compaction (RIC) is a method of imparting energy to the ground using a repeated but relatively short drop-weight, where a base plate (or “puck”) is in constant contact with the ground. RIC is preferred over a larger drop-weight technique due to its more progressive and less disturbing impact on the ground it is being used on. The method is also faster and uses smaller scale setups. A challenge for the RIC method was whether the energy it imparts is sufficient to densify the ground, versus other higher energy drop-weight methods. A trial was deemed necessary to demonstrate the suitability of this method. RIC is proposed to be applied over the majority of the site with an expected densification of landfill down to approximately 4.5m. Areas where assets will not be supported on driven full depth piles will undertake a second pass of the RIC method, reducing the long-term settlement of the landfill material. The predicted reduced surface will be levelled as required by the infill of depressions with imported stone or other suitable material.
Improvement of the existing ground by reinforcement through installation of Vertical Rigid Inclusions (VRI) method across the site. Supporting of level sensitive and heavier elements will be on precast driven piles founded below the landfill material. The combination of methods will be designed to achieve Thames Water’s settlement performance values over 40 years, and remain within the allowable values of 50mm and 100mm. This will reduce the need for full depth driven piling which would otherwise be required.
Reduction of infiltration to the landfill materials by ensuring impermeable surfaces drain to the treatment works and are released at the outfall away from the site. Gas and leachate well monitoring is provided along the perimeter of the site to monitor any impact and provide leachate removal points if required.
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(left) Rapid impact compaction rig and (right) pile under test - Courtesy of BAM Enpure Ltd JV[/caption]
(left) inlet pumping station physical model and (right) inlet pump testing physical model - Courtesy of Hydrotec Consultants Ltd[/caption]
The pump design has been developed to fulfil the project brief load requirements (future peak IPS capacity 2585l/s) and some flexibility either side of the requirements is available due to the standard capacity equipment design offered from the supply chain.
The proposed arrangement now consists of a wet well 12.5m diameter, approximately 20m deep. A common inlet will be provided to dissipate any entrained air, and two selectable pumped sections with double isolation will be provided by wall mounted penstocks on full height walls.
The pumping well will be constructed in two halves, hydraulically connected in normal operational mode however each half will be able to be isolated (using motorised penstocks) in accordance with specification requirements surrounding double isolation, to allow person entry into half of the wet well at a time.
Each half of the wet well will have three pumps installed giving a capability to provide full flow to treatment from two pumps with a standby permanently installed.
The pumping station was first modelled by computational fluid dynamics (CFD) to demonstrate the assumed flow patterns that will occur. The pumping station was then physically modelled to comply with the specification and process design requirements particularly with respect to distribution, mixing, settlement, turbulence, dispersion, and freeboard for the full range of flows that each structure is expected to receive.
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Storm overflow physical models - Courtesy of Hydrotec Consultants Ltd[/caption]
Inlet works
The inlet works is being designed to receive all pumped flows from the inlet pumping station (including future peak IPS capacity 2585 l/s), inlet works drainage and screening liquor return flows. Flows will enter the inlet works and then separate across the four escalator screens inclined at an angle of 45°. Each screen will be provided with a local proprietary control panel. Each panel will incorporate a differential ultrasonic level control.
An emergency bypass will be provided upstream of the screens to accommodate all four screens blinding at the same time. Three 1200mm wide duty screens will be required to screen flows from low flow up to 2585 l/s, screening 6mm in two directions.
The inlet works and grit treatment plant will be covered with odour covers which will be connected to the inlet works and PST odour plant. The inlet works has been classified as a Zone 2 Area under the odour covers and all equipment beneath the odour covers will be ATEX rated.
Storm tanks
Storm flows from the inlet work storm separation chamber will flow into two storm tanks via a 1400mm above-ground pipe. Within the 1400mm pipe between the storm separation chamber and the storm tanks there will be a partial pipe MCERTs certified flow meter to measure the total flow into the storm tanks.
During normal operation the blind tank will fill first, then the spill tank will fill. In the event that both tanks are full to capacity (and still in storm flows) the spill tank will overflow via a weir and the storm tank will discharge to river.
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Elevated inlet works - Courtesy of BAM Enpure Ltd JV[/caption]
The storm tanks contents will automatically return to the inlet pumping station via 700mm gravity pipe when the flow being pumped to the inlet works drops below a predetermined set point. The return flows will be controlled to approximately 0.5 DWF via an automated valve controlled by an electromagnetic flow meter located in the gravity main, returning to the common inlet well of the inlet pumping station.
Storm tank cleaning will be a pumped system with the two pumps located external to the storm tanks. Storm tank cleaning will be initiated during the latter part of the storm tanks draining back to the inlet pumping station and will not operate when the tanks are filling. The pump discharge pipe work will include connections for flushing with washwater.
Ferric storage & dosing
Two 45m3 ferric storage tanks will be located in a concrete bund with the dosing skid packages and control system located within an adjacent kiosk. The bund will be capable of containing 110% of the one of the storage tanks plus 10% allowance for rainwater. A drive-in bunded area for chemical deliveries will be provided and an underground chemical interceptor will contain any local spillages, complete with a Castell interlocked 3-way valve to allow the bunded drainage area either to drain into the interceptor (during a chemical delivery) or to drain into the site drainage (normal operation).
Chemical dosing points will be provided upstream of the PSTs, on the common outlet channel of the ASP, and upstream of the tertiary treatment plant. The dosing points will utilise sparge systems to ensure adequate distribution of chemicals into the channels.
Odour control plant
The odour plant is a 2-stage system. Stage 2 filters will discharge into an 18-metre-high odour stack. The plant has been designed to achieve a minimum removal efficiency of 98% of H2S and 99% removal of odour, based upon a total system duty of 8432 m3/hr (of which 4813 m3/hr is from the inlet works and 3619 m3/hr from the primary settlement tanks).
Service water
A potable water main supplies a service water break tank via a ballcock (float valve). The service water break tank has a working volume of approximately 30m3 which gives a nominal retention of approximately three hours at average throughput. Service water booster pumps draw water from the tank and transfer it to the service water main network where it feeds the polymer make-up system for all thickeners and dewatering belt presses.
Primary settlement distribution chamber
The distribution chamber has been CFD modelled to calculate the flow split to each downstream primary settlement tank from first principles, and assess whether the proposed design would deliver an equal flow split (+/-5%) for seven future flow scenarios. This required the inlet bellmouth to be turned down to improve flow splitting.
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PST distribution chamber CFD models: (left) with four PSTs in service and (right) with six PSTs in service - Courtesy of The Fluid Group[/caption]
Primary settlement
Primary settlement consists of four 47.15m long by 10m wide tanks, with a depth ranging between 6.24m at the hopper end and 5.3m at the outlet length (equating to 1 in 50 floor slope). Each PST tank has three sludge hoppers at the inlet end. The outlet of the PST discharges into a common 1000mm wide outlet channel. From this outlet channel the 1000mm outlet pipe from the drop box combines with the 700mm RAS lines into an above-ground 1200mm pipe.
Retractable odour covers will be provided across the PST tanks to allow for future inspection, cleaning and maintenance. The odour covers will be connected via ducting to the inlet works/primary settlement tank odour plant. All mechanical equipment installed below the covers will be constructed from 316 stainless steel or high performance plastics. The primary settlement tanks have been classified as a Zone 2 Area, and all electrical equipment beneath the odour covers will be ATEX rated.
The design of the PST Tanks is based upon a maximum inflow of 3022m3/hr to all four in-service tanks, and a peak flow to each tank of 1007m3/hr with one PST out of service. In normal operation all four PST tanks will be in service.
Within each PST tank a chain and flight scraper system will be provided which will utilise high-tech non-metallic materials as the main materials of construction. Scum from the primary tanks will gravitate via a rotating surface skimmer pipe to the above-ground primary settlement scum tank. The primary scum return pumps are progressive cavity pumps, operating in a duty standby configuration. The pumps are fixed speed pumps operating between a high and low level in the scum tank.
The PST sludge hoppers will desludge based upon a SCADA-adjustable interval and duration. The primary desludge pumps are progressive cavity pumps, operating in a duty/standby configuration. The pumps are variable speed pumps operating to maintain a SCADA-adjustable flow set point.
Once the effluent has flowed through each PST it will enter into a common 1000mm wide outlet channel. From this outlet channel flows transfer to the ASP distribution chamber via a drop box and 1000mm above-ground pipe.
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ASP overview - Courtesy of BAM Enpure Ltd JV[/caption]
Activated sludge plant
The ASP plant will have a distribution chamber using the same general arrangement as the primary settlement distribution chamber.
The activated sludge treatment tank consists of four ASP lanes. Each ASP lane has a selector tank followed by an anoxic zone and then the three aerobic zones. The main aeration lane will be fitted with aeration pipework and fine bubble diffusers. The aeration vessel is 80m long and 6.1m wide with a water depth of 7.05m. The total instantaneous maximum air demand of the ASP is 10,438 m3/h.
The first third of the aerated fraction of each lane will contain 50% of the aeration capacity, the middle third 30%, and the final third 20%. Each aeration lane will have three passes, arranged as channels of 6.15m width. The air for the diffuser grids will be supplied from three ASP air blowers operating on a duty/assist/standby basis. The aeration system will be controlled by an ammonia based real time control (RTC) system utilising a feed forward ammonia load input and a feedback ammonia concentration.
Once the effluent has flowed through each ASP lane it enters into a common 1000mm wide outlet channel. From this outlet channel flows transfer to the FST distribution chamber via a drop box and 1200mm above-ground pipe.
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Anoxic and aeration zones flows - Courtesy of BAM Enpure Ltd JV[/caption]
Final settlement tanks
The FST plant will have a distribution chamber using the same general arrangement as the primary settlement distribution chamber. The four FSTs will consist of 32m diameter flat bottomed circular tanks with a side wall depth of 6.15m. The FST will separate solids from the flow via settlement, producing a clarified effluent which overflows a peripheral weir into a launder channel, before gravitating to the tertiary treatment distribution chamber via a 1000mm below-ground pipe.
The combined clarified outlet flow from the four tanks will be monitored by a common flow meter, as well as suspended solids and phosphorus monitoring instrumentation, all provided on the common line to tertiary treatment.
The design of the FSTs is based upon a maximum inflow to each tank of 1741m3/hr with one FST tank out of service. In normal operation all four FST tanks will be in service. Each tank will have a 700mm inlet pipe, which will flow into a central diffuser drum before entering the FST tank. Each tank features a 600mm outlet pipe fed via a peripheral launder channel, as well as a 400mm RAS gravity outlet pipe. Each of the four tanks features a full bridge rotating scraper system which will run continuously in normal operation.
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32m final settlement tanks & sludge return (RAS pumping station) - Courtesy of BAM Enpure Ltd JV[/caption]
Sludge return (RAS/SAS pumping station)
Sludge from each pair of FSTs will enter one of two RAS/SAS desludge chambers. The two chambers will be located side by side and will share a set of three duty/duty/standby RAS transfer pumps, which will recycle the settled sludge from both RAS/SAS desludge chambers to the activated sludge plant distribution chamber feed line.
The variable speed centrifugal RAS transfer pumps will be capable of pumping 2200m3/hr at a maximum head of 8.9mhd. The pumps will operate between high and low level in the duty RAS/SAS desludging chamber, with both chambers provisioned.
A pair of duty/standby SAS pumps is provided, which will facilitate wastage of surplus sludge, with each pump drawing from a single RAS/SAS desludge chamber. The fixed speed centrifugal pumps will transfer sludge to the SAS buffer tank. Control of the SAS pumps will be carried out either on a timer or based on the level in the SAS buffer tank, with the common discharge line featuring flow monitoring.
Tertiary treatment
Clarified effluent flow from the FSTs will pass to the tertiary ferric mixing and flocculation (post-precipitation) stage, where the option will exist to dose ferric sulphate solution into the flow in order to encourage flocculation of remaining solids. This stage will be split into two parallel streams, with flow from the FSTs initially entering via a single bellmouth inlet into a common inlet channel, before passing via twin overflow weirs into two rapid mix chambers, and subsequently overflowing into two flocculation chambers. The design of the rapid mixer chambers will ensure complete mixing (>95% CoV) of chemical in less than 4 seconds.
Flow from the flocculation chambers will weir into a common outlet channel leading to a flow distribution chamber feeding the tertiary treatment stage.
The distribution chamber has been CFD modelled to calculate the flow split to each downstream cloth pile filter from first principles, and assess whether the proposed design would deliver an equal flow split (+/-5%) for seven future flow scenarios.
The tertiary treatment stage will comprise six cloth pile filters, which will operate with all filters in service - however the peak flow will be able to be treated with only five filters in service. The filters will be sized to accommodate a peak flow of 840 l/s, producing a final effluent of 20 mg/l TSS (95%ile) and 0.2mg/l TP (average).
Bypass pipework is to be provided adjacent to the cloth pile filter structure, by which clarified effluent from the FSTs may bypass the tertiary ferric dosing/flocculation and cloth pile filter stage.
Each of the six cloth pile filters will feature a central rotor drum onto which filter discs are attached. The rotor and discs will be fully submerged within the tank, with the discs supporting the physical cloth filter media. Flow entering the filters will flow from outside the discs through the cloth into the discs’ interior, with solids collecting on the external surface of the cloth pile, creating a headloss. As this headloss increases, the water level in the tank will rise and at a pre-set water level (as detected by an ultrasonic level sensor) a cleaning cycle will be initiated.
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Tertiary treatment flocculation chambers: Eliquo Hydrok Mecana cloth pile filters - Courtesy of BAM Enpure Ltd JV[/caption]
Filtered final effluent (FFE) from the inside of the filter disc and rotor drum assembly will pass forward through the unit via a low-level aperture to an outlet chamber, from which flow will weir into the common final effluent outfall chamber. An emergency overflow weir is to be provided, allowing unfiltered effluent from the filter tank (external to the discs) to weir over into the outlet chamber.
Backwash liquors from the backwash pumps will exit the filters via a common manifold, draining by gravity to the grit plant liquor PS. Eight backwash pumps will be provided per machine, giving a total of 48 pumps across all six machines. The pumps will be submersible units placed within the tank, with each pump being dedicated to three filter discs. The backwash flow rate is rated for 10 l/s (subject to the installed pipework design/headloss).
Each of the six filter tanks will see some solids settlement occurring (and potential accumulation of other debris), which will create a build-up of sludge in the bottom of the tank. This sludge will be periodically removed by a set of two duty/standby sludge pumps per machine (i.e. 12 sludge pumps installed in total). The discharge from each sludge pump will be connected to the common backwash manifold, leading to the grit plant liquor pumping station.
Final effluent discharge
Flows leaving the cloth pile filters will pass out from the main filter chamber via a low level aperture into a small outlet chamber, from which flows will weir over into the common outfall channel. The final effluent (FE) will flow under gravity through an FE flow measurement flume, with an ultrasonic instrument for measurement of final effluent flows discharged to outfall.
The FE outfall channel will feature a pipe leading to the FE washwater system, with a further line branching off this pipe servings as the suction line for FE Meteorburst Analyser. On exiting the FE outfall channel, flows will enter a dedicated FE outfall main, which will drain by gravity, discharging to the river north of the STW site.
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New Guildford STW: 3D model night-time overview - Courtesy of BAM Enpure Ltd JV[/caption]
Thickened sludge blending tanks - Courtesy of BAM Enpure Ltd JV[/caption]
Each tank will feature separate inlet connections for the three types of sludge being received, with actuated valves and crossover lines allowing all sludges to be directed to either of the two tanks. The tanks will also feature outlet actuated valves, which will allow either tank to be isolated from the sludge belt press feed pumps downstream, thereby ensuring the pumps only draw from a single tank at any given time.
A set of three duty/duty/standby sludge belt press feed pumps will be provided, which will transfer blended thickened and imported sludge from the thickened sludge blending tanks to the sludge belt presses. The pumps will be variable speed progressive cavity units, with a peak capacity of 30m3/h (i.e. 15m3/h per pump) at a maximum head of 48.5m, based on sludge of up to 7.0%DS.
Dewatered cake leaving each belt press will enter a discharge cake hopper leading to the suction end of a sludge cake pump. Three pumps will be provided, with a single pump dedicated to a single machine; each pump will operate in conjunction with the associated belt press upstream.
The pumps will be variable speed progressive cavity units, with a peak capacity of 7.4m3/h of sludge (up to 30%DS). The pumps will transfer the cake via individual discharge lines to the sludge cake silos, with manual discharge crossover facilities allowing sludge from the pumps to be directed to either of the two silos as required.
Cake silo storage & discharge
Dewatered sludge cake will be pumped to two truck-loading cake silos, with a combined storage capacity of 600m3, sized to provide 7-days of storage at average cake production. Each silo will feature a discharge screw conveyor (with a sliding frame ‘anti-bridging’ device) which will discharge the cake through a hydraulically operated slide gate valve.
Odour control plant
The odour plant will be a 2-stage system. Stage 2 filters will discharge into an 18-metre-high odour stack.
The plant has been designed to achieve a minimum removal efficiency of 98% of H2S and 99% removal of odour, based upon a total system duty of 6629m3/hr, extracted from the various tanks and thickening/dewatering machines in the sludge plant area.
(left) Outfall route plan - Courtesy of Bam Enpure Ltd JV, and (right) outfall low flow scenario CFD model - Courtesy of Arcadis[/caption]
Outfall structure
The outfall structure will consist of a reinforced concrete headwall, set back from the river channel, to be founded in the river terrace deposits and flared to direct flows downstream and minimise the impact of upstream debris from collecting. The headwall will have duckbill valves on the discharging pipes, and erosion control products utilised in the surrounding area to tie the headwall into the natural riverbank and bed.
The erosion mattress employed following the headwall structure will provide a secondary point at which turbulent flows can dissipate energy without eroding the natural bed of the river.
Where the headwall ties into the natural riverbank, the hard/soft interaction between headwall and natural soil will be reduced by the installation of Rock Rolls erosion control and willow stakes at the base, and the installation of a natural hydro-seeded CocoBN blanket or equivalent (to be seeded with local seed varieties) which will retain the slope shape until vegetation establishes and provides an effective natural erosion control. This will also provide a gradual slope to access down to the river.
Google Earth image of Boherbue[/caption]
Inlet works preliminary treatment - Courtesy of Glanua[/caption]
Secondary aeration treatment - Courtesy of Glanua[/caption]
Cloth filter tertiary treatment - Courtesy of Glanua[/caption]
Sludge drying reed beds to process wastewater sludge naturally - Courtesy of Glanua[/caption]
Solar panels for clean, renewable energy - Courtesy of Glanua[/caption]
(left) Precast concrete aeration tanks reduced construction time and safety risks and (right) view of final clarifiers and cloth filters - Courtesy of Glanua[/caption]
Off-site fabrication of steel building, fully assembled as works have been completed (April 2024) - Courtesy of Glanua[/caption]
- FilterClear® (2024)
FilterClear® (2024)During AMP7 over 800 sites were required to meet tighter phosphorus permits under the National P Removal Programme. The majority of these sites adopted the solution of using tertiary solids removal (TSR) plant with ferric or aluminium dosing to meet the permit requirements. There are 6 major TSR plant suppliers in the UK, three of which use the same technology, each with its unique feature, competing in the P removal market. This has driven the TSR technologies to evolve and improve, addressing the needs to enhance reliability and to minimise the use of chemicals whilst meeting increasingly stringent standards.
FilterClear for phosphorus removal
FilterClear is a true depth filtration technology, with 900 mm of filtration bed depth. The influent is pumped to the top of the filter and flows through four layers of media: anthracite, silica, alumina and magnetite, which have decreasing particle size and increasing density. This configuration provides an equivalent of 4-stage filtration in a single vessel, allowing the filter to operate at a much higher filtration rate (up to 35m3/h) and achieve a better effluent quality than conventional sand filters; coupled with its much smaller footprint. FilterClear is a powerful tool in a designer’s armoury.
The key benefit of depth filtration is to enable the solids to be removed progressively through the entire depth of the 4-layer filter bed, extending the run-time and reducing backwash frequencies. The backwash can be controlled by timer or pressure. After backwash, the media will settle back to the original layers thanks to the carefully selected density and particle sizes of the four media types.
FilterClear has an average operating pressure of 0.4 bar, offering a low energy demand and a low operational carbon footprint.
Experience across the many FilterClear plants installed to date has highlighted the low cost of ownership, particularly with respect to operation and maintenance. The plants are fully automated and typically require just one annual service (less on sites with activated sludge upstream). There is no routine requirement for replacement parts or filtration cloths and the FilterClear plants require only a top-up of anthracite every few years.
Furthermore, all media layers are naturally-occurring minerals, thereby not introducing any microplastics or fibres into the treated effluent or dirty backwash water.
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FilterClear plant at Yeovil WRC - Courtesy of Bluewater Bio[/caption]
For chemical P removal, good coagulation and flocculation are critical. Many TSR technologies need purpose-built coagulation and flocculation tanks with mechanical mixing, and some will also require polymer dosing.
By comparison, FilterClear only requires coagulant dosing for P removal; no polymer or ballast material is required. This is because large flocs are not essential for depth filtration. Chemical dosing can be added directly upstream of the FilterClear plant via an inline static mixer, and flocculation will occur in the headspace inside the filter vessel, above the media bed, removing the need for mechanical mixing or a flocculation tank, thereby simplifying the asset and reducing associated costs.
The absence of a separate flocculation tank further minimises the FilterClear footprint, makes the solution simpler to build and operate and eliminates the associated operational and maintenance tasks. It also eliminates the need for an overflow from the flocculation tank which, having been dosed with coagulant, represents a compliance risk.
Design for manufacture and assembly (DfMA)
Increasingly, clients and their tier one partners are looking to minimise site construction activities and durations. FilterClear plants are designed to allow off-site assembly and testing, then delivery to site as a package plant. Where possible, the complete filter gallery, including backwash pumps, blowers, actuated valves, instruments and controls are skid-mounted and transported fully assembled. Site activities are then limited to coupling the filter vessels, adding the media and commissioning. This DfMA approach ensures both quality and safety are well controlled and ultimately delivers a better solution in a shorter time at a lower overall cost.
Health and safety is an integral part of the design process, ensuring that all equipment is safe to install, operate and maintain. Filtration and backwash of the FilterClear plant is fully automated, with minimum operational input. The filters are enclosed, with no moving parts or serviceable components within the vessels and need minimal operator intervention. Due to the enclosed, fully automated design, risk of operator exposure to wastewater or chemicals is minimised. Furthermore, all machinery is at ground level for easy access.
Proven performance
Most TSR plant suppliers prefer to offer an effluent total suspended solids (TSS) guarantee as a surrogate to a TP guarantee. However, water companies have realised that, at low concentrations, there is a very poor correlation between the TSS and TP concentrations thereby introducing compliance risk.
As the developer and owner of the technology, Bluewater Bio Ltd has a deep understanding of both the process and phosphorus removal, and accordingly are able to provide a TP guarantee. This offers the client and their contractor the simplest and clearest assurance of meeting the final effluent permit as well as being contractually most straightforward. FilterClear performance has been tested and proven at over 50 sites across most UK water companies, all reliably achieving the respective permit requirements for both TP and iron. Knowing that more stringent TP permits will be imposed in AMP8, Wessex Water carried out long-term trials to push the performance limits at several sites with impressive results.
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‘Site A’ performance graph: Blue line shows the Total P concentration of the TSR feed and the green line shows the Total P concentration of the final effluent after FilterClear treatment - Courtesy of Bluewater Bio[/caption]
‘Site A’ is a typical small trickling filter site. In AMP7, a FilterClear plant was installed to meet a new 0.5 mg/l TP permit. The trial demonstrated that the plant achieved an average TP below 0.07 mg/l, with a 95%ile iron concentration of 0.27 mg/l. This performance has been achieved with an overall ferric dose of just 15 mg/l (including 1st point and 2nd point dosing) with simple flow-proportional dosing control, and despite some unrelated control issues during the trial. The long-term trials have demonstrated that FilterClear plants can reliably achieve a TP permit of 0.1 mg/l, making the solution future-proof. This offers the client a means of reducing WLC whilst adding future certainty.
FilterClear: Key advantages
Proprietary stratified FilterClear media of up to four layers, specially developed and applied over 10 years for exceptional performance.- High loading rate (25-50 m3/m2/h, i.e. 2-5x flow rate of competing technologies).
- High solids retention (low pressure drop and long backwash interval).
- High quality filtrate in a single step (SDI <3 : NTU <0.1 : BOD concentration <6mg/l).
- Low CAPEX (2-5x less media, fewer vessels).
- Low OPEX (no chemical use, low electricity consumption).
- Low backwash volume (<6% of filtrate, small backwash tanks, better yield, less waste).
- Small footprint (2-5x smaller filter area, smaller plant).
- Low O&M (simple, reliable, easy to maintain).
- Modular systems up to 1200m3/h per vessel.
Case study: Wessex Water: Yeovil Pen Mill WRC
During AMP7, Wessex Water installed 14 FilterClear plants across its region for phosphorus removal, ranging from small sites less than 4,000 population to large sites over 75,000 population. Yeovil Pen Mill Wastewater Recycling Centre (WRC) is the largest site among these.
Yeovil WRC in Somerset is a large treatment works owned by Wessex Water, serving a population equivalent (PE) over 75,000 (including trade discharge). The existing treatment processes comprised:
- Primary settlement tanks.
- High-rate plastic media filters.
- Intermediate humus tanks.
- Trickling filters (slag media).
- Humus tanks.
To meet tightened consent requirements, a major upgrade was required during AMP7; comprising tertiary MBBR plant and a tertiary solids removal (TSR) plant.
The TSR plant with chemical dosing is required to achieve the total phosphorus (TP) consent of 0.5 mg/l. On a whole life cost basis, taking into account process reliability, delivery programme, power demands, chemical consumption and maintenance requirements, FilterClear from Bluewater Bio Ltd was identified as the preferred solution, and the contract was awarded in May 2022.
The key elements of the FilterClear plant at Yeovil WRC are:
- Number of filters (800mm diameter): 11
- Number of backwash pumps: 2 duty/2 standby
- Number of backwash blowers: 2 duty/2 standby
- Number of clean backwash tanks: 1
- Number of dirty backwash tanks: 1
(left) FilterClear plant at Yeovil Pen Mill WRC next to a trickling filter and tertiary MBBR plant at Yeovil WRC and (right) Skid design at Yeovil Pen Mill WRC for easy access and maintenance - Courtesy of Bluewater Bio[/caption]
The FilterClear plant design has taken into account the following:
- Treat the peak flow during filter backwashing.
- Ensure the solids holding capacity is adequate under the worst-case scenario.
- Manage the interfaces with tertiary pumping/ferric dosing.
- Minimise the whole life cost and footprint.
- Enable safe and easy access, lifting and maintenance (ALM).
Thanks to the high filtration rate, the FilterClear plant has a smaller footprint in comparison to conventional filters. The compact nature of the FilterClear plant makes it ideal for the very congested site at Yeovil. At the time of writing (July 2024), the FilterClear plant has been installed and is currently being commissioned.
Throughout the project, the design teams worked closely with Wessex Water on the ALM assessment to ensure that the plant is operator-friendly. Particular attention was paid to eliminating hazards during operation and maintenance.
Highest accolade - rising to the challenge in AMP8
Innovation plays a critical role in the water industry’s ability to adapt to climate change, population growth and new and emerging pollutants. Bluewater Bio Ltd continue to develop and enhance technologies so that they excel in performance, value, reliability and sustainability.
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FilterClear technology received a King’s Award for Enterprise (Innovation category) in 2024[/caption]
In 2024 Bluewater Bio Ltd received a King’s Award for Enterprise in the Innovation category for its FilterClear technology. The award was granted on a recommendation by the Prime Minister and approved by His Majesty The King and is the most prestigious award for a UK business. This award is further recognition that FilterClear has become the preferred choice for clients.
With AMP8 on the way, over 900 sites will be on the national P removal programme and FilterClear will play a major part in delivering a successful outcome.
Winchester House, 259-269 Old Marylebone Road, London NW1 5RA
| 020 7908 9500 | bluewaterbio.com |
- Silicon Carbide Ceramic Membranes (2024)
- AquaPyr (2024)
Cembrane SiC membranes, modules, stacks & towers - Courtesy of Enpure Ltd[/caption]
Applications of Cembrane SiC membranes - Courtesy of Enpure Ltd[/caption]
(left) Installation of Cembrane SiC stack, (top right) Cembrane SiC stack from above, and (bottom right) SiC membranes have sprinkler cleaning option - Courtesy of Enpure Ltd[/caption]
AquaPyr Model 440 - Courtesy of ACWA Services[/caption]
The AquaPyr Ultra Low Waste Filter product range - Courtesy of ACWA Services[/caption]
Silver Lake WwTP: Effluent TP before/after the installation of the ACWA AquaPyr Ultra Low Waste Filter - Courtesy of ACWA Services[/caption]
- Goscote STW: Mecana Installation
- Goscote STW: IFAS Installation
- Greenham Common STW
Greenham Common STWThames Water’s Greenham Common Sewage Treatment Works (STW) is situated in the shadow of a former US Air Force base in Bishops Green, Newbury, and alongside the River Enborne. The untreated wastewater that Greenham Common receives has a high rag content and repeated screening carry over was affecting the full treatment process, the overall performance of the site and risked that the site would go out of environmental compliance. Thames Water approached Hydro International’s UK Wastewater Services team, M&N, to evaluate the site and propose a robust solution. The team installed the MNSS Combined Screen, to capture larger influent materials at the front end of the wastewater treatment process, protecting and improving the efficiency of the downstream treatment system. Due to the site hydraulics/flows, there was no reliable wash water system for the MNSS Combined Screen, so the team found an innovative way to solve this. They created a bespoke system, including pumps, to use the effluent from the site’s primary settlement tank. The spray nozzles on the MNSS Combined Screen were also altered to accommodate the change. [caption id="" align="alignnone" width="1200"]
Greenham Common STW MNSS Combined Screen[/caption]
Simon Brum, Project Manager, Hydro International’s UK Wastewater Services Team, said:
"We needed to find a quick and effective solution for the Greenham Common STW to prevent any overflows, and designed and installed a robust, reliable inlet works system that combines screening, washing, transport, compaction and dewatering in a single cost-effective standalone solution.”
Henry Crompton, Lead Project Engineer at Thames Water Utilities Ltd, commented:“We needed a suitable solution that was effective and within budget, and the team delivered that. We are very happy with the work undertaken on this site and will be using it as an example to our other Thames Water teams who may encounter the same issues.”
Handling flows of up to 150 l/s, the MNSS Combined Screen is designed for smaller plants and those facilities that require a more cost-effective screening solution - helping engineers, operators, and site owners to maintain treatment effectiveness even at remote and budget - constrained sites. [caption id="" align="alignnone" width="1200"]
Greenham Common STW MNSS Combined Screen[/caption]
Optimised for reduced maintenance and extended component lifetimes by the UK Wastewater Services team, only the MNSS Combined Screen achieves a screenings capture ratio of 53%, the highest of any independently tested 6mm combined screen.
To learn more about how our inlet works specialists can help you with your wastewater needs
M&N Electrical & Mechanical Services Ltd | +44 (0)1305 821142 | www.hydro-int.com/ukwws
- Finham STW: IFAS Installation
- Ground-breaking project leads to advanced wastewater grit removal system
Ground-breaking project leads to adv...Suspended solids carried in water can cause a range of harmful effects in rivers, lakes and oceans, making the capture and removal of these solids critical for effective environmental protection. To address this problem, the project focused on optimising the stacked trays that remove high levels of suspended solids from wastewater. Combining optimisation methods and computational fluid dynamics (CFD), the project was able to derive new designs for hydrodynamic solids removal components that would have been difficult or impossible to achieve using traditional engineering methods. The research was part of a Knowledge Transfer Partnership (KTP), supported by the UK government’s innovation body Innovate UK, which began in July 2019 and ran until September 2021. It builds on years of collaboration between Hydro International and the University of Exeter in the field of CFD. The core of the project involved the optimisation of stacked trays that enable the removal of high levels of suspended solids in wastewater, with the primary objectives being to improve performance and reduce maintenance requirements. This was a complex, multi-objective, high-dimensional problem, so the team needed to adopt an unconventional approach in order to solve it. To tackle the problem the project team coupled Bayesian optimisation techniques and CFD modelling, using a Bayesian optimisation toolset originally developed by the world-renowned Machine Learning Group at the University of Exeter. Bayesian optimisation was selected as it can be an order of magnitude more efficient than alternative approaches, such as genetic algorithms, on such complex design problems. The Bayesian optimisation toolset was then connected to CFD simulations, allowing the team to use computing power to automate the design and evaluation process. The team ran the CFD simulations using supercomputers in Exeter and Bristol, with each optimisation run modelling some 300 designs at a time. This would have been impossible to achieve using other optimisation techniques. The team was one of the first in the world to use these techniques on new GW4 Isambard super-computing architectures. The team subsequently corroborated simulation results through physical testing of prototypes in Hydro International’s hydraulics laboratory in Clevedon. The outcome of the project was a new stacked tray design that improves grit removal performance and enables the production of more compact systems that can handle higher wastewater flows and requires less maintenance—an excellent example of combining academic research with commercial incentives to address real-world challenges. Although the project was focused on improving technologies that will be applied to future iterations of the HeadCell® advanced grit removal system, the findings are fundamental to Hydro International’s core technologies, and will be applicable to other products that rely on the same hydrodynamic principles such as Downstream Defender® and First Defense®. In addition, not only did the project apply methods for complex design optimisation already developed by the University of Exeter, but it also drove new developments in multi-objective optimisation and constraint handling, resulting in new advances in expertise and understanding. Following completion of the project, Innovate UK assessed the KTP and awarded it a Grade A, or “Outstanding”. Dan Jarman, Hydro International’s Group Technical Manager said:“We have a long history of investing in new science and new technologies to help our customers, and this project continues that tradition. This is the first time that Bayesian optimisation and CFD techniques have been applied in the water sector, which represents a significant step forward in product design excellence. In a sector that has been unfairly criticised for being slow to adopt new technologies and techniques, we’ve shown that there are teams out there willing to push boundaries in order to benefit utilities, consumers and the environment.”
Jonathan Fieldsend, Professor in Computational Intelligence at the University of Exeter said:“This project is an excellent example of what can be achieved when a KTP involves such a wide range of talent and experience. To achieve its outcome, it has needed academics from the Computer Science and Engineering departments, specialists from industry, and support from a highly-skilled impact and business team. It has delivered significant enhancements for an important Hydro International product - in the crucial area of wastewater management - and has also led to advances in applied optimisation techniques and algorithms which have use more broadly in CFD-driven design.”
About Hydro International
Hydro International is a global company that provides advanced products, services and expertise to help municipal, industrial and construction customers to improve their water management processes, increase operational performance and reduce environmental impact. With over 40 years of experience and a reputation for engineering excellence, businesses and public organisations all over the world rely on Hydro International products and services to reduce flood risk, improve water treatment and protect the environment from water pollution. Headquartered in Clevedon, UK, Hydro International has a network of over 80 distribution partners and serves customers in more than 40 countries.About the University of Exeter
The University of Exeter combines world-class research with excellent student satisfaction, ranking in the Top 150 of the THE and QS World University Rankings. We are one of the very few universities to be both a member of the Russell Group and have a Gold award from the Teaching Excellence Framework (TEF), evidencing our international reputation for excellence in teaching and research. Each year, the University of Exeter delivers over 1500 projects with industry and generates over £52m from this work. We believe impact is about making a difference, and our world-class researchers have an excellent track record in making valuable contributions to our society, economy and the environment. Our dedicated KTP team - based at the University’s Innovation, Impact and Business directorate - is the leading Knowledge Base partner in South West England and has successfully delivered over 100 KTP projects to date, with 85% of these rated good to outstanding.
To learn more about how our inlet works specialists can help you with your wastewater needs
M&N Electrical & mechanical Services Ltd | +44 (0)1305 821142 | www.hydro-int.com/ukwws
- Senior Civil Engineer - Water (6286)
Senior Civil Engineer - Water (6286)The opportunity
Across the entire business, Stantec are building on top of what’s already been a highly successful period of growth. Our strategy within the Water division for 2023 and beyond is creating a number of new exciting opportunities across the business. We partner with the top water clients across the UK, work on some of the largest, most iconic water projects in the industry and we promise to design with community in mind by reducing environmental impacts and improving social impacts. We enable the delivery of sustainable development and infrastructure projects that adapt to and mitigate the effects of climate change. Our Civil Engineers work across the project lifecycle in asset planning / strategy, concept design, outline design and detailed design. We work in a variety of project areas within the water sector, including clean water treatment and networks, wastewater treatment, wastewater networks, flooding, and urban drainage. You can find out more about our work in the water sector here: Stantec H2O+U - UK. You’ll be responsible for the project’s civil engineering design, the leadership of civil engineering teams and will work alongside our overall project design leads to ensure successful project delivery and outcomes for our clients. You will also have access to Stantec’s world-class expertise to help you deliver cutting edge design.About You
You’ll have experience working as a Civil Engineer on projects within sectors such as the water, environment or other related infrastructure sectors. Ideally you will hold Chartered or Incorporated member status with a relevant professional body such as ICE or CIWEM. You’ll have a passion for the water and environment sector and supporting our developing civil engineers. You’ll also be experienced in successful project delivery and working collaboratively with project teams to develop innovative solutions. Finally, you will have experience of working in a client facing role, leading client engagement and collaboration on a regular basis.
About Stantec
The Stantec community unites more than 31,000 employees working in over 450 locations across 6 continents. We have been working with our clients and communities in the UK for over 150 years. We plan, design, deliver and manage the development and infrastructure needed to support the creation of sustainable, healthy and prosperous communities. Our teams provide effective and relevant solutions, translating our clients’ vision into valued consents, deliverable plans for projects and programmes, and efficient designs for delivery, based on technical excellence and deep market insights. We deal with today’s challenges, but also keep a fairer, better tomorrow in sight, looking at how we deliver clean growth, support radical changes in our economy and meet the needs of future communities. Stantec provides equal employment opportunities to all qualified employees and applicants for future and current employment and prohibit discrimination on the grounds of race, colour, religion, sex, national origin, age, marital status, genetic information, disability, sexual orientation, gender identity or gender expression. We prohibit discrimination in decisions concerning recruitment, hiring, referral, promotion, compensation, fringe benefits, job training, terminations or any other condition of employment. Stantec is in compliance with laws and regulations and ensures equitable opportunities in all aspects of employment. Building an inspired, inclusive work environment that attracts, supports, and develops world-class talent is a crucial key to our success. If you are excited by this role but worry that your experience doesn’t exactly align, we encourage you to apply. - Civil Engineer - Water (6331)
Civil Engineer - Water (6331)
The opportunity
Do you have a passion for Civil Engineering ? Are you driven to create solutions for the unprecedented climate, environmental, and efficiency challenges facing our clients and the wider community? Then make a real difference and join us at Stantec! We are excited to continue our growth journey in Ireland and Northern Ireland and we have exciting plans for expansion in 2025 and beyond. We look forward to continuing our work with Uisce Eireann on the Engineering Design Services Framework and in Northern Ireland, we are proud to have been appointed to Northern Ireland Water’s IF182 Professional Services Framework. Taoiseach Simon Harris recently opened our new Dublin office, and we have now also moved to a new city center office in Belfast. This exciting pipeline of work, coupled with the scale of opportunity across the AMP8 cycle in the UK means that we seeking Civil Engineers at all levels with experience in the water/wastewater industry to join us. We are flexible with location so the position can be based in Dublin, Belfast or elsewhere. You will have the opportunity to join a dynamic team spread across the UK and Ireland, supporting the delivery of a variety of projects as part of a major capital investment programme.You will play an important role in the team, developing technical solutions & providing advice to our clients. You will provide technical expertise to ensure projects are delivered to cost, schedule & quality standards and work collaboratively amongst multi-disciplinary teams to ensure first class delivery of our projects. You will work closely with external stakeholders & clients to develop long term relationships.About You
You will be Degree qualified (or equivalent) in Civil Engineering or other relevant subject and have some experience of working within the regulated water industry.You will have knowledge of water and wastewater infrastructure/networks and treatment. Due to the nature of upcoming projects, ideally, you will also have experience in areas such as Clean Water and Wastewater Treatment, Trunk Mains and Large Diameter Pipeline Design.Ideally, you’ll have previous consultancy experience in a design role.Most importantly, you’ll embody our values and ethos of client focus and service excellence and have a passion for making a difference in the Water sector.Why Join us?
- Our People Culture: We're a close knit team and very proud of our friendly and collaborative environment
- Growth: We're on an exciting growth journey in Ireland and Northern Ireland - we want you to be part of it!
- Awards: Stantec were awarded the International Consulting Firm of the Year and Best place to work - Large Consulting Firms at the 2024 NCE awards as well as being consistently recognised in the top 10 Corporate Knights most sustainable companies in the world.
- Great Benefits: Competitive salary, pension plan, holidays, free private medical insurance, discounted gym membership and lots more.
- Flexible working arrangements
- Great Projects: We have secured positions on both the Uisce Eireann and NI Water Frameworks and are delivering a wide variety of projects that will make a real difference to our communities
- Industry leading training and development as well as paid for professional subscriptions
About Stantec
The Stantec community unites more than 31,000 employees working in over 450 locations across 6 continents. We have been working with our clients and communities in the UK for over 150 years. We plan, design, deliver and manage the development and infrastructure needed to support the creation of sustainable, healthy and prosperous communities. Our teams provide effective and relevant solutions, translating our clients’ vision into valued consents, deliverable plans for projects and programmes, and efficient designs for delivery, based on technical excellence and deep market insights. We deal with today’s challenges, but also keep a fairer, better tomorrow in sight, looking at how we deliver clean growth, support radical changes in our economy and meet the needs of future communities. Stantec provides equal employment opportunities to all qualified employees and applicants for future and current employment and prohibit discrimination on the grounds of race, colour, religion, sex, national origin, age, marital status, genetic information, disability, sexual orientation, gender identity or gender expression. We prohibit discrimination in decisions concerning recruitment, hiring, referral, promotion, compensation, fringe benefits, job training, terminations or any other condition of employment. Stantec is in compliance with laws and regulations and ensures equitable opportunities in all aspects of employment. Building an inspired, inclusive work environment that attracts, supports, and develops world-class talent is a crucial key to our success. If you are excited by this role but worry that your experience doesn’t exactly align, we encourage you to apply. - Senior Civil Engineer (6463)
Senior Civil Engineer (6463)
The Opportunity
Following a number of successful frameworks bids across the water industry, and in preparation for the most challenging AMP ever, we are expanding our high-performing engineering teams across the country. In Newcastle, we are excited to have been appointed as a Strategic Technical Partner by Northumbrian Water for the AMP8 period. Stantec provide a range of technical enabling, solution delivery and design services to support Northumbrian Water in achieving its vision to be the leading provider of sustainable water and wastewater services. As part of our long-standing relationship with Northumbrian Water, including the ongoing ESH-Stantec joint venture, we will continue to develop innovative solutions to support their delivery of capital investment across both infrastructure & non-infrastructure projects. In order to continue providing our clients with our expert service, we are looking to recruit a Senior Civil Engineer into our team Newcastle on the picturesque Quayside. You will become part of an international team, redefining our landscape with sustainability, the environment and the communities we serve at the heart of everything we do. As a Senior Civil Engineer, you will work across the entire project lifecycle in asset planning, strategy, concept design, outline design & detailed design. You’ll be responsible for delivering civil engineering solutions, guided by our Principal Engineers & Design Leads, whilst also supporting & mentoring our more junior engineers.You can find out more about our work in the water sector here: Stantec H2O+U - UK.
About You
We are interested in speaking with passionate engineers with design experience within the UK water industry. You’ll hold a degree in Civil Engineering and ideally have achieved Chartered status with a relevant professional body such as ICE or CIWEM. You will have gained experienced delivering community focused projects, whilst working collaboratively with multi-disciplinary teams to delivery innovative solutions. We will support your growth & development through training & project exposure, though prior experience within storm overflows, SUDS, surface water management & sewage treatment would be beneficial.
About Stantec
The Stantec community unites more than 31,000 employees working in over 450 locations across 6 continents. We have been working with our clients and communities in the UK for over 150 years. We plan, design, deliver and manage the development and infrastructure needed to support the creation of sustainable, healthy and prosperous communities. Our teams provide effective and relevant solutions, translating our clients’ vision into valued consents, deliverable plans for projects and programmes, and efficient designs for delivery, based on technical excellence and deep market insights. We deal with today’s challenges, but also keep a fairer, better tomorrow in sight, looking at how we deliver clean growth, support radical changes in our economy and meet the needs of future communities. Stantec provides equal employment opportunities to all qualified employees and applicants for future and current employment and prohibit discrimination on the grounds of race, colour, religion, sex, national origin, age, marital status, genetic information, disability, sexual orientation, gender identity or gender expression. We prohibit discrimination in decisions concerning recruitment, hiring, referral, promotion, compensation, fringe benefits, job training, terminations or any other condition of employment. Stantec is in compliance with laws and regulations and ensures equitable opportunities in all aspects of employment. Building an inspired, inclusive work environment that attracts, supports, and develops world-class talent is a crucial key to our success. If you are excited by this role but worry that your experience doesn’t exactly align, we encourage you to apply.