Cress Water Solutions are working with Landscaping Architects called Terravita, in Ibiza.

We are currently working with Landscaping Architects called Terravita, in Ibiza, on 5 projects for treating sewage effluent to a high quality so that the water can be recycled for garden irrigation.

Oxford Motorway Services

Early In 1998 Cress Water Solutions was contracted to design and install a modified waste stabilisation pond and reed-bed system in conjunction with a basic SAF sewage treatment plant to treat the wastewater from the new Welcome Break Oxford Motorway Services Area being built at the time just off Junction 8A on the M40. Discharge of the final treated effluent was to be, and still is, to a minor tributary of the River Tame. We continued to be involved with the system for some 5 years following its commissioning providing maintenance to ensure it worked to its fullest potential. In that time it became apparent that the original design figures under-estimated the loadings expected. A number of modifications, such as the addition of floating aerators, and another SAF Plant beside Pond 2, were made and some extra plant was added by others, especially to deal with the high ammonia levels.

Then, in 2015, we were re-engaged by Welcome Break to urgently bring ammonia levels into compliance with Environment Agency regulatory requirements and look at a full refurbishment and upgrade of the whole system. With the addition of a Starbucks Drive-Thru and the then imminent construction of a Pizza Express and a large extension to the Ramada Hotel there was going to be a big increase in the amount of wastewater produced on the site. To cope with the higher loadings the existing system needed to be upgraded and refurbished. Our first actions were to specify and install a SAF Plant on the side of Pond 4 and restore the SAF on the side of Pond 2 to full working order to bring the ammonia levels down and into compliance.

In the intervening years it had become apparent that the pond system had a huge buffering capacity and resilience and had been vitally important in keeping the final discharge well within compliance at least as far as BOD and SS were concerned. It was, however, nearing a critical state in its ability to handle the larger loadings it was receiving. In particular the addition of raw untreated sewage into the first pond could not be allowed to continue following the failure of the original SAF Plant.

Over the last three years, working with David Setford, from Setfords Consultants, we have upgraded the system with the installation of a Masko-zoll Pre-screening Plant, an enlarged modern SAF Plant with two parallel streams incorporating settlement tanks at the start and end, and cleaning out the reed-beds at the end of each of the four large ponds. As soon as the SAF Plants were brought into action the colour of the ponds changed from a dirty unpleasant brown to clear dark water, most of the unpleasant sewage smells disappeared, and the quality of the final discharge improved dramatically. Since commissioning in May 2018, the system has been sampled regularly every month. A typical set of results is given in Table 1 below:

Table 1. Sample Results for final discharge from Oxford Motorway Services on-site SAF and Pond Sewage Treatment System.

We can confidently say, with a year’s regular maintenance and experience of its operation under our belts, that the upgraded plant is exceeding expectations, producing a high quality final effluent, and should be more than adequate to cope with increased loadings over the next 25 years.

A side benefit of the system is that the site has become a wild-life haven and sanctuary. Last year more than 10 pairs of mallards raised broods of 8-10 chicks, a pair of Canada Geese raised a brood of 8 chicks and numerous coots and moorhens also raised broods. At one point there were over 40 ducklings on the 4 ponds. Numerous pairs of tufted ducks were seen but no chicks were ever sighted. A wide range of insects including butterflies and dragon flies, and smaller birds are abundant. Pigeons, red-kites, snipe, herons, pheasants, partridges and woodpeckers are frequent visitors. Deer frequent the site as evidenced by their footprints.

Two awards for Cress Water Solutions in 2016

This year, 2016, we have received two further awards:

In the BUILD Construction & Engineering Awards Scheme 2016  we have been named “Best for Rainwater Harvesting & Water Recycling Solutions – UK & BUILD Excellence Award for Water Garden Landscaping”,  and

In the 2016 BUILD Sustainable Building Awards Scheme 2016 we have been named “Best Natural Wastewater Management Company 2016 – UK”

For more information about BUILD and the awards click here >>

Oxford Motorway Services, Junction 8A, M40

In 1998 we designed and installed a modified waste stabilisation pond and wetland treatment system for Welcome Break at their then new flagship Motorway Services Area on the M40, just east of Oxford. With some changes this system is still very much in operation today. The process pathway involves pumping raw macerated washed screen filtered sewage for initial treatment to a SAF Plant. The partially treated effluent from this plant is discharged, after settlement, into the first of a series of 4 large treatment ponds. Each pond has a sub-surface flow horizontal flow reed-bed at its end. The final pond discharges into a large balancing pond that takes all the surface water run-off from the site and discharges all wastewater off-site into a nearby stream.

Since 2003 we have had nothing to do with the system; maintenance, repairs and modifications being carried out (or not!) by others. At the back-end of last year (2015) we were contacted again and invited to become involved once more to bring the system back into full and proper operation. It had been badly neglected for years and it was clear that any modifications made to simply keep the system going were going to be hugely detrimental in the long run. In addition, whilst the final discharge was meeting the environmental limits that had been approved for BOD and SS, the system was failing to meet the permitted ammonia consent levels. Throughout this time the pond system has shown itself to be extremely rugged.

Whilst the whole system needs upgrading, in response to the immediate and urgent need to control and reduce ammonia levels in the final outlet, Welcome Break agreed for us to go ahead initially with the installation of a new SAF Plant on Pond 4. This is designed to continuously recycle the water in Pond 4 and reduce ammonia to below the permitted levels. Fortunately there was space on the banks of the pond system for the installation to take place. This has just recently been completed. We have installed the new plant on a permanent basis with the intention that it becomes an integral part of the final solution for upgrading the performance of the whole system. Our next task is to select the best available technology for upgrading and providing the initial treatment at the top end of the Pond System which also allows us to take advantage of all the benefits provided by the pond system.

“Best for Bespoke Reed Bed Solutions in UK”

We have just been informed that in the BUILD 2015 Construction and Engineering Awards Scheme we have been named: “Best for Bespoke Reed Bed Solutions in UK”.

Naturally we are delighted.