Trench®, born in 1999 and created using Microsoft’s Excel, was designed loosely around Australian Standard 1547:1994 Disposal Systems for effluent from domestic premises. If you are assessing sites for domestic wastewater in Tasmania, you will know the software has become an industry standard here. It’s used in some mainland states, too – notably Queensland, where it is also a teaching tool – and in New Zealand.
AS1547, in conjunction with our New Zealand counterparts, has changed twice in the intervening years (in 2000 and 2012), and some regulators and wastewater practitioners ask me when Trench® is going to catch up.
There’s no need. It’s true the software could be massaged to better suit the newer versions of Excel, but its fundamentals remain as valid as they did 14 years ago. That’s because it was deliberately designed to be independent of any particular Standard or protocol, and in fact has global application. Its site capability and environmental sensitivity factors, coupled with the very flexible ranking system, means Trench® is as equally valuable sizing a wastewater system in Dubai as it is in Glasgow. The assessor in Dubai, and the assessor in Glasgow, separately tweak the ranks of each factor to suit his or her local Standard and protocols.
I may tinker with Trench® a bit, though……