Assessing the Medium-Term Impact of Permeable Pond Covers on Pond Performance and Odour Management – Monitoring Phase

Abstract

This project was an agreed extension to the original APL project 1829, ‘Assessing the medium-term impact of permeable pond covers on pond performance and odour management’. The aim of this extension was to undertake a further study into the ongoing performance of the pond cover at Piggery C, in terms of its ability to continue to reduce odour emissions as well as its ongoing durability and integrity.
The key findings from this extension support the original findings of project 1829, in that permeable pond covers are an effective tool in reducing odour emission rates from anaerobic ponds. Tensile tests undertaking on the cover material during this extension project demonstrate that the polypropylene material has degraded. Results indicate that the material would be more likely to tear, and that tears would be easier to propagate once started. This aspect has particular relevance in situations where the cover requires handling, such as has for pond maintenance or desludging. This extension trial found that using shadecloth only as a pond cover has significant potential to reduce odour emission rates, demonstrating it to be a lightweight, cost effective material for deployment on anaerobic ponds to act as an odour reduction tool, as odour reduction rates were similar to polypropylene covers.
This extension trial initially had a duration of three years, however APL requested reduction of the monitoring phase to 18 months.