This is a fascinating, clearly written and highly informative book on a very important topic, namely, how to deal with your poo if you are off mains drainage. It is very timely for Irish readers given that its publication coincides with the septic tank inspection process currently underway in the Republic of Ireland. Driven by EU legislation to protect surface water and groundwater this process is an attempt to deal retrospectively with the many failing systems that have been installed on unsuitable soils.
With about one-third of all houses (500,000 households) in Ireland relying on an individual domestic waste water treatment system to collect, treat and discharge their household waste water, and a further 800,000 households across the UK, there is a huge market for this book. It sets out, in a clear and concise way how to check that your septic tank set up is not failing, if it is to determine whether it can be repaired or improved – the book is clear that if suitable soil conditions exist on site then upgrading to a new septic tank and percolation is usually the best option, both environmentally and cost wise, even if a raised percolation bed is required – and if that is not possible to understand the options that are available for an upgrade.
Written by Feidhlim Harty, a man with over twenty years’ experience of designing natural, zero-energy sewage treatment systems, it covers standard septic tank and leachfield set-ups, mechanical treatment units/packaged sewage treatment plants, treatment wetlands (such as vertical flow or horizontal flow reed beds or constructed wetlands), packaged tertiary treatment reed beds, and willow treatment systems (where there is no effluent outflow and a ready source of firewood). All solutions are clearly set out encompassing what they are and how they work, the resources required (e.g. land area or electricity) and the pros and cons of each system. And as an added bonus there are sections on compost toilets and greywater recycling. So, with this book you can not only decide which system you want but, crucially, whether it would actually work on your site.
There are some interesting asides that I picked up during my reading of the manual; a retention pond is prone to excessive algal growth unless there is a high degree of pre-treatment within the wetland; problems with odours from your treatment wetland is usually exacerbated by bleach and other chemical based cleaning products, which reduce the effectiveness of the septic tank bacteria; if you don’t de-sludge your septic tank regularly and allow solids into a gravel reed bad you are likely to require full replacement of all gravel and plants; clay lined soil based constructed wetland systems are the most robust of all treatment types, being just four that particularly jumped out at me. And I was especially pleased that the importance of maintaining whatever sewage treatment solution chosen is kept at the forefront of the readers mind; each system type has notes on the amount of maintenance required as well as a final chapter dedicated to this important topic.
Priced at £14.95 hard copy or £5.99 on Kindle, anyone looking to build a house off-mains drainage would be well advised to spend a few quid now for a book that could potentially save a few thousand down the line and at the very least will ensure they install the optimum system for their site, whether their overriding concern is cost, sustainability, ease of use, or all three. At the same time, it should be in the required reading list of every architect or engineer who designs buildings that are off mains drainage.