First off, this is my first post here, so I apologize in advance if this isn't the right place to ask this. Please feel free to move it around and/or re-tag it if you think it fits better somewhere else. Also, I can't imagine that nobody has ever run into this situation before, but after spending half a day searching the internet and StackExchange and finding nothing, I guess it has never been asked before:
My question is simple: Can a septic system leach field be installed over/within clean fill? Assume that the fill is about 4 to 8 feet deep and has been approved by the applicable regulatory agency in regards to compaction, setbacks, etc. Also assume that there is enough space to install such a leach field without encroaching into any setbacks, easements, etc. Furthermore, assume that the fill material will pass a perk test and is free of trash, large boulders, organic material, etc.
Some more background:
I am asking this question first and foremost from a theoretical standpoint. However, my specific situation is as follows: I own a vacant one acre lot in northern Arizona that has approximately 12 feet of elevation change between the highest corner and the lowest corner. While I have not done any excavation on the lot or conducted a perk test I have gathered a small soil sample and observed a nearby road cut. Thus, judging by these observations, I presume that the soil is approximately 2 to 3 feet thick and is very clayey, expansive, and rocky. Beneath this layer of rocky clay soil is lava bedrock. I would not say this bedrock is impermeable, as it seems to be broken up into large chunks judging by the road cut. Furthermore, I have used the county's GIS system to figure out what type of septic permits were taken out by by my nearest neighbors. This showed that most of them required an alternative system if they had one at all. I don't plan on building on this lot for many years. However, in the interim, I plan on clearing a space on the property and grading a flat area where I can park an RV and dry camp occasionally. In the future though, I may want to build a small house on the property and live there permanently. Thus, while I am grading the flat area, I am wondering if I can do the following: 1. Strip away all of the existing soil from approximately the lower quarter of my property. (It is expansive remember.) 2. Create or bring in a new soil that is more suitable to septic system leach fields and building foundations. 3. Use this new soil to create a flat area for my camping purposes and then at some point later on, use it for a leach field and perhaps a small house.
Thanks in advance for any alternative ideas/thoughts/answers.