Large Housing Estate Temporary Sewage Treatment Plant using the BMS Blivet Case Study
Many housing or construction projects are being held up or prevented due to the local municipal sewage treatment plant not being able to accept any further organic load. A solution to this is to treat the sewage on the housing development site, so that the organic load from the houses is reduced to a level comparable with the discharge standard required from the municipal sewage treatment plant. This means that there will not be any increase in the organic load sent to the overloaded municipal plant, enabling a development that would otherwise be postponed, or completely cancelled, to go ahead. The temporary treatment of the sewage will take place until increased capacity in the municipal plant is available. For such a temporary sewage treatment project, a completely self-contained, very compact, modular and portable system that does not require a concrete surround is a necessity. A system that also allows the flexibility of above/below ground installation is a big advantage. A package sewage treatment system that can accomplish all of the above and more is the BMS Blivet ‘all in one’ Package Sewage Treatment system. This case study focuses on how the BMS Blivet enabled a housing development to proceed, which would have otherwise been postponed/cancelled due to the local municipal sewage treatment plant being overloaded.
The development of enough housing to meet the needs of growing populations is a challenge that many countries face. The need for extra housing is often most pronounced in urban areas adjacent to big economic zones such as in the greater Dublin region in Ireland. Increases in population often outstrip the municipal authorities ability to provide adequate infrastructure to deal with this new housing stock, especially in the provision of adequate sewage treatment. The extension of, or development of new, municipal scale sewage treatment plants often takes years and sometimes longer, due to budget constraints. This means that the municipal sewage treatment plant does not have adequate extra capacity to allow the connection of new housing stock or business premises, even though there is an urgent need for the housing or premises. A solution to this is treat the sewage on the housing development site, so that the organic load from the houses is reduced to a level comparable with the discharge standard required from the municipal sewage treatment plant. This means that there will not be any increase in the organic load sent to the overloaded municipal plant, enabling a development that would otherwise be postponed or completely cancelled to go ahead. This can be done by the installation of a suitable temporary package sewage treatment system on the site of the development until the extension of an existing or a new municipal sewage treatment plant is commissioned.
However, a very specific type of package sewage treatment system is required, some of the necessities are:
- A completely self-contained ‘all in one’ ‘plug&play’ system that does not require extra tanks to work and that can be easily installed/commissioned with minimal civil works.
- A very compact system, as the area available for temporary plants is always at a premium, so the more compact a system is the better.
- A system that can be installed without a concrete surround so that it can be easily decommissioned and removed with the ability to be redeployed to another site.
- The flexibility that the system can be installed in phases as the population for a development increases.
- A system that is very quiet and generates minimal odour.
- A system that requires minimal power and maintenance.
- A system that can be installed above, below or partially below ground.
- A system that was installed successfully for similar temporary projects.
- A proven system manufactured to an approved quality system such as ISO 9001, which has a long track record in Ireland and worldwide.
The above tough set of requirements have been achieved on a repeated basis by the BMS Blivet ‘all in one’ Package Sewage Treatment System.
In 2018 BMS was contacted by AECOM Consulting Engineers regarding a new housing project that they were working on in Arklow, Ireland. The estate would be built in three phases and ultimately cater for approximately 200 houses and 800 residents. However, the Arklow Municipal WWTP was currently organically overloaded and could not accept any extra organic load. Conversely, the local authority had consented to the estate being allowed to connect to the municipal sewer, if the sewage from the estate was pre-treated to an adequate discharge standard, as there was a big demand for new housing in the area, especially being less than one hour from Dublin. Other stipulations for that the sewage treatment system were that a modular complete ‘all in one’ ‘plug&play’ solution was required, which could be easily installed/expanded in phases and ultimately could be decommissioned and removed, with the potential to move to another site, when the upgraded Arklow Municipal WWTP was commissioned. BMS worked with AECOM on producing a suitable design/layout/proposal for submittal to the local authority/Irish Water for approval, which ultimately was approved and enabled the development to go ahead.
Phase 2 of the Installation
Sewage Treatment Plant Design & Design Calculations
1 Population Equivalent (PE) = 60 g of BOD/person/day, 60 g of SS/person/day, 180 g of COD/person/day & 200 l of flow/person/day.
Average occupancy per house: 4
Outlet Effluent Standard: BOD 20 mg/l, SS 30 mg/l & COD 125 mg/l.
Phase 1; 34 Houses
34 x 4 PE = 136 PE
BOD: 136 PE x 60 g = 8160 g/day
Flow: 136 PE x 200 l = 27,200 l/day
COD: 136 PE x 180 g = 24,480 g/day
Phase 2; 26 Houses
26 x 4 PE = 104 PE
BOD: 104 PE x 60 g = 6240 g/day
Flow: 104 PE x 200 l = 20,800 l/day
COD: 104 PE x 180 g = 18,720 g/day
Phase 3; 137 Houses
137 x 4 PE = 548 PE
BOD: 548 PE x 60 g = 32,880 g/day
Flow: 548 PE x 200 l = 109,600 l/day
COD: 548 PE x 180 g = 98640 g/day
Phase 1: 34 Houses = 136 PE
Phase 2: 60 Houses = 240 PE (136 PE + 104 PE)
Phase 3: 197 Houses = 788 PE (136 PE + 104 PE + 548 PE)
Phase 1: 1 No. BMS BL2000 Blivet.
Phase 2: 2 No. BMS BL2000 Blivet’s.
Phase 3: 4 No. BMS BL2000 Blivet’s.
- The inlet works were designed to evenly split the flow into four by gravity. This allowed for phased addition of Blivet’s as the organic load increased with the four Blivet’s eventually operating in parallel. All the Blivet units were the same size to allow for easy flow splitting by gravity, without the additional upfront and OPEX cost of extra pumping.
- The installation of 4 No. BL2000 Blivet’s on a phased basis were the best economic way to allow phased development and to spread the cost over the three development phases.
- Civil works for a BMS Blivet are extremely easy and consist only of 1 No. 20N reinforced concrete slab 3.0 m (w) x 0.15 m (d) x length of the unit (8.3 m (l) for the BL2000), the placing of the Blivet on the slab and then connecting the power to the integral panel and connecting the inlet/outlet pipes.
- The Blivet can be placed above or below ground without a concrete surround. In this case it was decided to bury the Blivet’s to lid level. This eliminated the need for pumping in/out as the Blivet uniquely generates net hydraulic lift from inlet to outlet enabling gravity flow in/out.
- The area around the Blivet’s was backfilled with selected excavated material, as the steel reinforced GRP/FRP structure of the Blivet means it does not require a concrete surround. Therefore, decommissioning only will involve emptying the Blivet’s, disconnecting the pipework and electricity and removing the excavated material around the Blivet. The Blivet’s, which are completely self-contained package systems, can then simply be lifted onto the back of a truck and the ground reinstated. It can then be easily redeployed at another site.
- The BMS Blivet was ideal for the development because;
- It is a completely self-contained modular package system, that includes primary/final settlement via lamellae plates and Aerobic Treatment via the BMS Aerotor. Capacity could be expanded simply by installing subsequent units in parallel and adjusting the pre-installed flow splitting system. To allow for rapid commissioning of subsequent units, 4 slabs should be laid during the initial construction phase.
- It is the most compact ‘all in one’ system available.
- It is a completely covered system that emits minimal odour and is very quiet.
- The maintenance on each Blivet is the equivalent of only ½ an unskilled man hour per week. Each unit comes with a flashing beacon and can be fitted with GSM dial out system to automatically alert of any issues. The BL2000 only uses 10.9 kW/h/day.
- The Blivet provides at least 3 months sludge storage. This is market leading for a unit of its size.
- It has been installed at 100’s of locations in Ireland & 40+ countries worldwide including on a temporary basis in Lusk, Ireland for up to 5000 Population Equivalents (PE).
BMS BL2000 Blivet installed below ground
BMS Construction/Installation Details
BMS manufactured, supplied and commissioned 4 No. BL2000’s Package Sewage Treatment Plants in 3 Phases between 2019 and 2021 as the development progressed. All Civil works were by the Main Contractor, Noonan Construction. The civil works are extremely easy for a BMS Blivet, install a slab 3.0 m wide x 0.15 m deep x the length of the Blivet, excavate if being placing below/partially below ground, connect the inlet/outlet pipe and finally connect power to the integral control panel, simple as that. The Blivet can then accept sewage for treatment. In phased projects many contractors will often do all the civil works up front, which makes phased installation very easy later.
In this project to allow gravity flow in/out of the Blivet, the Blivet’s were buried up to deck level. However, some unique features of the Blivet particularly lent itself to this temporary project. As already alluded to it is a complete ‘plug&play’ steel reinforced ‘all in one’ solution, that contains everything required for sewage treatment; primary settlement, final settlement, aerobic treatment via the BMS Aerotor Next Generation RBC, and 3+ months sludge storage. The BL2000 Blivet is extremely compact, only 7.6 m in length by 2.3 m wide by 2.25 height to deck level, this means that excavation is minimised as much as possible. Furthermore, the Blivet does not require a concrete surround, even when buried. It can be backfilled with selected excavated material. This not only means placing of the Blivet is very easy but also is extremely important for a temporary plant, as a concrete surround would make for a very difficult and costly excavation to remove a sewage treatment plant. However, the Blivet can be easily removed due to not requiring a concrete surround. At present it is envisaged that new upgraded Arklow WWTP will be operating in 2024-2025 so the Blivet’s will be in place until then.
BMS Blivet Technology
The BMS Blivet is the most compact ‘all in one’ package sewage treatment plant available worldwide. It has been installed in 40+ countries all around the world in every possible climate extreme over 30+ years. The BMS Blivet was developed, designed and patented by BMS, Ireland. The Blivet offers simplicity in an age of complication, while able to achieve virtually any standard of effluent including low BOD, SS, NH4, TN & P. It is also extremely robust and built to last in an ISO 9001 certified factory in Ireland. You can see how the Blivet works at the following link; https://youtu.be/i0paRj7pew4
Maintenance is simple; ½ of man hour per week, see how to do it on our detailed maintenance video.
Overall, the Blivet is chosen by discerning customers who want a product that is easy to operate, built to last and who understand the upfront cost is only a small element in the overall cost of running a sewage treatment plant for 20+ years.
BMS Operation/Maintenance Details:
BMS provide a complete O&M service at the plant including sampling on the BMS Blivet when required. As part of the installation BMS supplied and commissioned a flow meter and an outlet composite sampler. The standard of effluent being produced to date has been very good.
Final Effluent Standard: BOD 20 mg/L, SS 30 mg/L & COD 125 mg/l
Other Temporary Sewage Treatment Projects
BMS have manufactured and supplied BMS Blivet’s to 50+ countries worldwide. BMS have vast experience of providing temporary sewage treatment solutions, some reference projects are:
- All US Army bases in Iraq exclusively used the BMS Blivet for temporary sewage treatment.
- The Bechtel ‘In Sallah’ Gas Pipeline project exclusively used the BMS Blivet to treat the sewage generated at all work camps in Algeria.
- The BMS Blivet treated up to 5000 PE in Lusk, Co. Dublin before the Portrane Municipal Plant was commissioned.
- The BMS Blivet UV is being used at 10+ sites in Ireland, UK and Europe to treat the sewage generated by workers on site to a full disinfected standard suitable for reuse on site. It offers a compelling payback compared to tankering away untreated sewage.
BMS have other temporary sewage treatment projects currently pending in multiple sites in Ireland, France and Africa.
Multiple BMS Blivets installed above ground on a temporary basis
BMS Design Service
BMS have over 30 years’ experience in sewage, wastewater and surface water design. If you have a project requiring sewage treatment, BMS can prepare a customised proposal and drawings. BMS can also design your surface water management system and have invested in specialist software to provide cutting edge project design.
Design Services offered by BMS
- BMS offer a free service to size and select the correct sewage treatment plant for each project. This involves calculating the incoming biological load & flow to determine a design population. BMS will then produce a customised proposal including design calculations and drawings to achieve a set final effluent standard.
- You can download our Free Sewage Treatment Plant Sizing and Selection Guide, which distils our 30+ years of worldwide experience into an easy to use guide which allows you to select the correct sewage treatment plant for varying incoming loads and outlet standards. It also contains terminology, worked examples, calculations, FAQ, Troubleshooting and more.
- BMS can provide full mechanical assessments of existing sewage treatment systems and make recommendations on upgrades if required.
- BMS can advise as regards planning applications, discharge licences & system optimisation for sewage treatment plants.
- BMS can design your full surface water management or SuDS system from first principles. We have invested in specialist software, which produces comprehensive design data. The design will include a full proposal, drawings and design calculations.
- BMS can offer advice on sizing/selecting the correct attenuation/infiltration system, petrol/oil interceptor (separator), vortex silt/oil/debris defender, outlet flow controls & storage tanks. BMS uniquely offer a ‘one stop shop’ from design to installation for our surface water management products.
- BMS offer free Continuing Professional Development (CPD) Seminars on Surface Water Management and Sewage Treatment at your premises.
- BMS can design a custom pump station solution for your requirements in GRP/FRP. This can include emergency storage and valve chambers. BMS Pump Stations are normally delivered ‘ready to go’.
- BMS can design a vehicle wash water recycling system for you with 100% Recycle and Zero Discharge.
What BMS Does
Butler Manufacturing Services is a family owned specialist manufacturer of package (all in one) products for sewage treatment and surface water treatment established in 1986 with exports to 38+ countries worldwide including the world leading Blivet package sewage treatment plant, a ‘one stop shop’ for all surface water products from design to installation including attenuation, interceptors, holding tanks (incl. chemical resistant), hydrobrakes, rainwater harvesting tanks/filters & vortex silt separators, chlorine contact tanks, fully fitted pump stations and pumps, our ‘all in one’ vehicle wash water recycling system with zero discharge and much more.
If there is a requirement for any of the above on any project that you are working on, we would welcome the opportunity to work on a solution with you.
Email: [email protected]
Phone: +353 43 3326100
Address: Butler Manufacturing Services Ltd., Strokestown Road, Longford, Ireland, N39 VY43.