Thanks for the questions.
We do indeed have solution for above ground sewage treatment in the form of the BMS Blivet Package Sewage Treatment Plant.
One of the main features of our Blivet package sewage treatment system is that it can be placed above ground free standing with no extra supports.  It is also extremely compact, all units can fit in a standard 20/40 foot container.  Installation is as easy as lifting it onto hard standing and then connecting the inlet/outlet pipes & electricity.  The plant can be fully functioning in a few hours.  It also allows the easy addition of extra units if a population increases as it is a complete self contained modular system.  This type of installation is especially suited where temporary sewage treatment is required, where the inlet is via a pumped feed, where there is bad ground or a lot of rock close to the surface.  To move it to another site is only a matter of emptying it fully and disconnecting the inlet/outlet pipes & electricity.  BMS offer a free sewage treatment design service, so please contact us if you require an above ground package sewage treatment system.
BMS is a quality manufacturer of package products for wastewater and stormwater treatment. BMS started in 1986 and has exported products to over 50 countries around the world.  It is a third generation family business with huge expertise in wastewater and stormwater.
BMS also manufacture a full range of products for surface water and wastewater treatment including our pioneering next generation RBC system the Aerotor, which forms part of our 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 & vortex silt/oil/debris separators, fully fitted pumping stations, our plug & play vehicle wash water recycling system; the Recyclone and much more.  Please see our enclosed Company & Product Profile for a full summary or View our full product/services catalogue at this link
BMS also can provide a Free Design Service for Sewage Treatment, Pump Stations or Surface Water and a full O&M, Repair, Advice and Testing service for existing installations.  We also can do free CPD Presentations on Sewage Treatment/Surface Water Management at any location.  Let us know when suits.
We would be delighted to discuss any requirements you might have, and we are available to meet you at your convenience.  Please do not hesitate to contact us.
Tommy Butler