As European legislation regarding effluent discharge tightens,  a company with a long tradition of designing and manufacturing benchmark wastewater treatment products has introduced a new range of small to medium-sized package treatment plants.
Designed by Balmoral Tanks for use in homes or developments housing up to 50 people, the CE-mark pending “Balmoral HydroClear” reliably and consistently provides pollutant removal levels of 97 per cent.

New process overcomes pitfalls
An aerated biological system, the HydroClear utilises a moving bed biological reactor, or MBBR, at its core. A new process in the package wastewater market, MBBR technology embraces the benefits of common fixed film media processes without suffering their common downfalls.
Overgrowth of bacteria leading to ‘channelling’ is an issue with common market process designs such as submerged aerated filters (SAF), rotating biological contactors (RBC) or trickling filter (TF) designs.
The MBBR process, widely adopted in larger-scale systems, is incapable of blockage as its media is constantly mobile. The sloughing effect of the media also removes excess growth promoting a continuing re-growth of healthy bacteria, vital to maintaining reliable treatment.
With an eye on the new BS EN 12566-3 European standards, Balmoral, in conjunction with the DTi and Cranfield University’s School of Water Science, designed the new system to address optimum effluent treatment and other key aspects that are important to the supply chain including product storage, transportation, installation and maintenance.
Phase 1 of the research programme involved an independent 17-week design evaluation programme at Cranfield University based on the procedures set out in BS EN 12566-3. This work allowed the new design to be fully verified in practise before committing the finished product to the CE accredited test house at PIA in Aachen, Germany.
For the Cranfield tests, a single household model was chosen as it is widely recognised that the most challenging situations are faced by small systems.
A full-size prototype plant was fed with genuine sewage from the university sewage works including washing machine effluent and bath water. The feed setup was designed to reflect the expected peaks and troughs typical of a single household. Extreme situations were also tested, including no feed, high loadings and power failure, typical of what the plant would face during CE-mark European testing. These tests provide a much more rigorous regime with a wider spread of measurements compared with previous approaches and ensure realistic simulations of real-life scenarios.
HydroClear significant step forward
The HydroClear represents Balmoral’s third generation of sewage treatment plants. Its predecessor, the continuous aeration plant  (CAP), proved very popular with trade professionals and end-users alike but the company’s commitment to providing best-in-class products led to the creation of this innovative solution.
Tim Mackley, wastewater product manager at Balmoral Tanks, said: “The design, performance and shape of the HydroClear offers substantial improvements on what is currently available. European regulations drive the market towards higher and consistent effluent quality and effective use of new technology was required to achieve this.
“Our successful CAP product was limited to 6 and 12 population sizes and we recognised that a broader product range was desirable. The new HydroClear is available in 6, 12, 20, 30, 40 and 50 population models.
“We are extremely proud of this product which is a pioneering application of the latest wastewater technology rather than a variation on what has gone before. Taking today’s challenging wastewater treatment environment into account, a broad range of requirements were addressed.
“We took the design right back to first principles. A three-year programme of research, design, engineering, testing and production ultimately enabled us to produce a system that far exceeds legislative demands through its reliability of performance.
“The HydroClear offers a build quality the industry has come to expect from Balmoral; a rotationally moulded one-piece high density polyethylene tank, providing robust on-site characteristics and a ruggedness not found in competitive products.”

Installation and maintenance eased
The air blowing compressor is housed in a cleverly designed sealed manway cover, meaning there are no electrics or moving parts within the vessel. Internal servicing is accessed from ground level providing easy, quick and safe maintenance.
Allan Joyce, Balmoral Tanks’ MD, said: “Although our previous range of wastewater treatment plants was doing extremely well, Balmoral recognised that to satisfy our clients, particularly installers, modifying the existing product wasn’t really an option.
“They wanted something that was more easily installed, with a low invert depth, while end-users demand high performance, low maintenance and reliability.
“I’m satisfied the HydroClear exceeds all the criteria called for. We are offering a host of improvements at a highly competitive price.
“Naturally, we are happy to advise specifiers, installers and end-users on the benefits of this all-new range through our RIBA-approved training modules.”
End-of-test results and industry feedback indicate that the HydroClear operates at the top end of the performance table. EC legislation now dictates that all sewage treatment plant must display effluent quality information on documentation provided with the product.
“The HydroClear is showing significant improvements and industry leading performance in terms of effluent quality, transportation, storage, installation and maintenance”, concluded Joyce.
Balmoral Tanks Ltd is a division of Aberdeen-based Balmoral Group Holdings Ltd which is a privately owned company headquartered in Aberdeen, UK. The group comprises a number of distinct business units and divisions including Balmoral Tanks Ltd, Balmoral Comtec Ltd and Balmoral Park Ltd.
Employing over 300 people the group has been providing solutions to the building, civil and environmental engineering, energy, marine, polymer engineering and processing sectors since 1980.