AUGUST 1 2024 – AT THIS RATE OF INSANITY, IFIELD BROOK WILL BE ECOLOGICALLY DEAD WITHIN THREE YEARS” – RICHARD W. SYMONDS [THE IFIELD SOCIETY]

A focus on one tributary: Leigh Brook is essentially “dead”

We recently conducted a focussed high resolution study with the help of our partners at River Mole Catchment Partnership testing a variety of parameters along the entire Leigh Brook. Our tests reveal this stream to be essentially “dead” from excessively high pollution. Elevated levels of phosphate were as high as 15ppm. It also contained toxic ammonia levels as high as 5.66ppm NH4+ -N mg/l (ammoniacal nitrogen) and low BOD. Our Ammonia Hanna kits tested 3ppm. We tested downstream of the Holmwood sewage treatment plant outfall, a known treatment works with serious failings. Unfortunately this sewage treatment works provides almost the entire discharge of the brook during low summer flow. Downstream of this outfall the toxic levels of ammonia and phosphate we recorded were almost certainly above permit levels.. we are in the process of confirming this.

Our full test results will be published in due course but this stream, like too many tributaries in the Mole catchment, are fed by failing sewage works that release treated effluent damaging to aquatic life and river ecosystems. Rivers are subjected to discharges of poor quality treated effluent that are a slow death for our streams. The discharge of treated effluent which occurs all day everyday is in many ways far more important than the occasional, but too frequent, release of untreated sewage in storm overflows.