D R A F T R E G U L AT I O N S / O N S I T E
Missed opportunity ROI’s draft wastewater Code of Practice (COP) for one-off houses falls short of providing solutions for all soil types. Words: Astrid Madsen
S
elf-builders in counties with poor drainage such as Leitrim and Wexford will continue to struggle to get planning permission in areas where a mains connection isn’t possible, the draft Code of Practice published by the Environmental Protection Agency (EPA) suggests. Even though the draft COP is making it easier to pass the percolation test, increasing the T-value from 90 to 120, it provides no alternative for sites with very low permeability. “The draft COP offers another technical option and that will apply in areas that previously would have failed,” Stephen McCarthy of the EPA told Selfbuild at the Irish Onsite Wastewater Association (IOWA) conference in December. “It can be used in low permeability sites. But there’s still an upper limit so it’s potentially there as a new option for certain circumstances. We’ll wait to see how many cases that might apply to.” There was some degree of optimism that the changes would help self-builders on sites that currently can’t secure planning permission because they fail the percolation test parameters. “I hope the changes to the COP will mean more sites will become available to build on, but the T-value change does not represent a huge increase especially for difficult areas like Leitrim which may need more flexibility. Only time will tell how many more sites will come on stream as a result of this, but I am very optimistic it will help many more sites to be developed,” IOWA Secretary Joe Walsh told Selfbuild at the conference.
Added technologies
The EPA is updating the 2009 COP for Wastewater Treatment and Disposal Systems Serving Single Houses. That 2009 COP currently focuses on how to specify septic tanks and packaged 110 / SELFBUILD / SPRING 2019
treatment systems. Drip dispersal (DD) is the new technology the COP is focusing on, in addition to low pressure pipes (LPP). The EPA currently only foresees using DD as tertiary treatment (third stage filtration) for sites with a T-value between 90 and 120. McCarthy told Selfbuild DD would be used for effluent from a septic tank and filtration system or packaged treatment system. DD would be used as a means to discharge the effluent to the ground. A site assessor told Selfbuild at the conference that in his experience, local authorities want the onsite wastewater system that’s specified for a house to be detailed in the COP. Even though the COP allows for alternative systems, including DD and LPP, in his experience the planners end up sending out requests for further
information if alternatives are specified, which in turn delays the process. This has led to the practice of specifiers opting for what’s fully specified in the COP. This issue has been identified in the update to the COP which states the code is not a specifier’s manual, instead it now refers to specific standards applicable to the technologies it discusses.
No solution for sites with very poor drainage
There was hope amongst site assessors that the draft COP would include an option for soils that would fail any percolation test. According to Laurence Gill of Trinity College Dublin, who also spoke at the IOWA conference, evapotranspiration (ET) systems in the form of willow beds could