AboutRob Janus Expertise Recycling, solid and liquid waste management, social and environmental procurement,
transportation demand management, energy and resource conservation, green buildings and
corporate environmental management systems.
Experience 20 years working in the public and private sector waste management field.
Education/Credentials Bachelor of Arts in Economics.
Expert: Rob Janus Date: 5/2/2008 Subject: Septic Perc test
Question We just failed our perc test on our Arizona lot (not too surprised as there are many alternative systems in this high desert area) We were told clay was the main reason for the failure. Now that we are $1000 poorer.. is it worth having it tested again, somewhere else, or just save our money for the $$$ alt system to be designed?
Answer Hi Len,
Thank you for your question. I'm a little unclear on a couple of points about your question.
First, I'm not sure why you don't already have an indication from your original contractor as to the odds of finding a suitable site on your lot? Unless we're talking about a large acreage, they should have a handle on the geography and soil conditions of the site in general, the options for siting the field, and the chances that another site on the lot would differ from the results you already received (usually slim).
If "clay" was the reason for the failed test, what's really being said is that the soil is not draining quickly enough due to high levels of clay. Again, on a standard lot, this condition is not likely to be isolated. You may ask your neighbors what they found when testing their lots. This will you some indication as to whether the condition is widespread or more isolated.
As a final thought, an alternative that may be available in your area is to add fill to the area (usually up to 18") to aid in proper drainage. Sometimes excavation is required. Check with your local regulatory agency to see if this option is available and if any restrictions apply (such as having to wait a period of time to allow the fill material to settle before retesting for perculation).
