Sewage Treatment System

Aquatic waste water and sewage treatment system

Originally the Community used septic tanks to treat waste water and sewage but there was always a problem with effluent polluting the waterways, a small stream discharging into the Owenreagh River. We were faced by the problems, typical of rural communities, of having no access to mains sewage and heavy land with a very high water table.

With the increase of population and buildings a better solution was needed and, being aware of the existence of environmentally friendly options, we approached Iris Water and Design to submit a feasibility study for a system capable of treating waste water for a population of 100 people.

A system of three ponds, cascade and wetland area was chosen from the proposals submitted. After sourcing funding and obtaining the required consent for construction and discharge, the main work was started in September 1993 (one of the few dry periods during that year).
One of the logistical problems was disposal of excavated material without radically changing the landscape or incurring high costs.

The upper two ponds are both lined with 500 micron Polytarp between two layers of Fibertex Polyfelt. The whole area was finally covered with aggregate. The third pond is basically lined with puddled clay, with no artificial liner.

The problem of groundwater under the second pond (which was severe) was solved by piping to a well-head situated between the second and third ponds, appearing as a small feeder stream.

From autumn 1993 to spring 1994 the whole estate was connected by an extensive network of pipes into the pond system.
Finally the planting of the wetland and marginal areas took place in June 1994.

The system is relatively low on maintenance input. De-sludging on such systems is normally not necessary for a period of 10-20 years. The marginal vegetation needs to be cut back in autumn.

The flow through the cascade and reed bed needs a weekly check and flowforms need to be kept free of algal growth.

Now, after more than 16 years, the system continues to function well with only minor problems such as an occasional build up of weed or odour, but these things right themselves or can be managed. The waste from over 80 people is treated effectively and tests of the water at the end of the process show virtually no contaminants.

The whole system has developed into an attractive wild life and recreational area with many species of plants, insects and birds including moorhens, herons and occasionally swans.

Members of the Community and friends and neighbours regularly walk there picking wildflowers, exercising dogs and enjoying the beautiful landscape, which now looks very natural and is a feature of pride for Clanabogan.

For further information on flowforms please visit www.iriswater.co.uk.