The Dedicated Ophthalmology Referral Practice

Water Gardening Magazine September 2003

The following article appeared in Water Gardening Magazine in September 2003. It described the reed bed system installed at the hospital in place of a conventional septic tank or mains drainage. This article is reproduced by kind permission of Wincey Willis and Water Gardening Magazine.

Click below to download the entire article as a pdf file

A POND WITH A PURPOSE

Wincey Willis visits an environmentally friendly veterinary practice with a rather special wildlife pond

Regular readers may remember my little dog Pixie ­ she has been a pinup on my pages on more than one occasion. She is quite an old girl now and recently she was diagnosed as being totally blind. Very sad news but she’s coping amazingly well, as long as we remember not to move anything, she retains her mental picture of the house and garden, and keeping her feisty terrier attitude she will not be beaten. To get this diagnosis we travelled to the Veterinary Eye Hospital at Marlbrook, just outside of Leominster.

As always, I am on the look out for wildlife and I was delighted to discover a fantastic pond in the grounds. The hospital was officially opened in June this year but the whole site has been under construction since 2001. What I didn’t realise at the time was that it was much more than a pond. In conversation with the owner and chief veterinarian, Paul Evans, I discovered this was a pond with a purpose.

When he had initially applied for planning permission, on what was arable land, he was turned down. After much discussion he decided to develop an environmentally aware scheme, to allay the planners’ fears. He would landscape the site in such a way that all the waste water from the hospital and therun off from the hard standing areas would be utilised to create an attractive wildlife habitat. This was where Dr Rick Hudson of Cresswater came into the picture; as an expert in creating reed bed filtration systems, he came up with a superb plan.

THE EARTH-MOVING

Starting with a flat field, it was no mean task. I find it incredible that it only took two weeks to do the actual construction work. After the earth-moving on a grand scale, it was necessary to create high points and low points, the massive liner was manoeuvredinto position. There are three reed beds, into which the waste water from the the hospital is pumped. The lavatory waste first passes through a septic tank and the liquids are then pumped into the reed beds.

The common river reed Phragmites australis is used in all three beds. It is the same reed that the Norfolk thatchers use. The 9cm pot-grown reeds are planted at a rate of four per square metre. Their initial planting was devastated by rabbits; the whole site is now rabbit-proofed. This reed is particularly effective ­ it has a large rhizome with thick hollow roots that conduct oxygen into the substrate. The reed movements create funnels at the point were they enter the ground, keeping the gravel surface open which aids the oxygen gathering properties. The reeds will be cut after the second year, around the end of December, and will regrow in April.

THE WILDLIFE

Sandi Everett had been ‘site manger for much of the building project. I asked her about the wildlife and how soon found the pond. The dragonflies soon discovered the site and on the day I was there, magnificent emperor dragonflies gave us a fantastic ariel display. Tiny newts with gills still attached could easily be spotted on the rocks around the water’s edge. She explained the first birds to take advantage of the site were a pair of pied wagtails, who nested in a pile of stones that were about to be used around the pond. This year they have nested in the operating theatre’s air extraction unit, right in front of a fast whirling fan!

With such a scant regard for safety it is a miracle that they haveraised the four babies, who can now be seen strutting around the pond’s perimeter. Mr Evans delighted in the swifts and swallows which swoop down to drink “Using the runway from the east or west, depending on wind direction.”

In the beginning the two-metre deep pond was allowed to fill naturally with rainwater and any run-off is now channelled through gravel and planted beds. The beds becoming progressively drier with plants which suit the substrate. The water from the car park and surrounds flows into a lined and planted ditch dug out of the grassy surroundings. The plants aid the cleaning of the run-off and the water tops up the pond.

This whole system is working for people and for wildlife. It will only improve with age, attracting more and more new species with each passing season. I left the site wishing that many more newbuilds could incorporate such a wonderful wildlife attraction. It should be part of planning law. As Mr Evans said, the cost of doing it this way or installing a mechanical digester powered by electricity would work out the same. WhatI want to know is, why would anyone choose the digester?

HOW DO REED BEDS WORK?

It is the bacteria which do the purifying work, complemented by the reeds creating the oxygen rich environment, in which bacteria function best. The gravel substrate creates a huge surface area to which the one vertical flow reed bed and two horizontal flow beds. The vertical flow takes out the ammonia and the horizontal flow reduces the suspended solids. The pumps which enable this to occur are fitted with alarms in case of breakdown. They do not need to be cleaned or serviced in any way, the sealed units are used for a couple of years and then replaced. I was relieved to note that there are no unpleasant smells, even on one of the hottest days of the year.

The final inspection chamber was opened with gusto, by Dr Hudson, eager to show me the crystal clear water, about to be added to the pond. The pond is a showcase of artful planting, with wildlife in mind. The waterfall enhances the oxygen content and the many surface area plants, such as the magnificent Nymphaea alba, keep the light levels low enough to discourage algae bloom.