Perc Tests for Vacant Land Properties

I’m wondering if perc tests are a required part of due diligence for most vacant land properties? I read @retipsterseth article on the blog, which provided a lot of insight, and wanted to see how others are implementing this in their due diligence process. Are their certain rules or guidelines anyone has that define when they have a perc test performed?

Also, is this a contingency that anyone regularly uses in their purchase contracts? I currently have a simple one-page contract that doesn’t include contingencies, since I know these can sometimes scare off potential sellers. However, from a legal perspective I would think there would have to be some language in the contract about perc testing, in order to legally go onsite and have the property tested, prior to the purchase actually being finalized. Any insight or thoughts are greatly appreciated.

@hholladay I think some of this can be determined just by looking at the area and surrounding properties. If there are bodies of water nearby, if there’s a lot if clay soil in the area and/or if you don’t see any other dwellings on surrounding properties, it could be worth asking some questions. It also depends on how much the property is worth, and whether it has any other alternative uses if a dwelling can’t be built.

I don’t include this test as a contingency in my contract, but if I see anything that causes concern (and if the cost of investigation actually makes economic sense with the property), then I’ll consider some deeper exploration before buying.

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Most likely depends on soil type and price point. I try to buy and sell at a bellw market price and leave perc test up to end buyer.

However, higher priced property buyers may require it. You can always ask the seller you buy from if they have had it perc'ed, often timew they have.

Thanks for the responses @retipsterseth and @jawollbrink . Those are all good considerations I'll keep in mind. I can see how the SoilWeb overlay for Google Earth that Seth shared will provide a lot more detail about the soil characteristics of a given property, so that should be a big help moving forward.

Part 1:
With the regards to the SoilWeb overlay, I went down that rabbit hole and eventually clicked on the link on the drainage classification, which was broken. (SoilWeb looks to be circa 2011). Here's the NRCS's response with a new web-based interface (My Google Earth Pro install worked just fine just now, so still viable) and corrected links to look up the various drainage classifications et al:

"Geoffrey: we do not maintain the ge lib website and it contains numerous old / outdated links. The links provided within the GE interface to SoilWeb are now quite old—I apologize for that. We are working a way to bridge the older interface with the new interface:


I've removed the old links from the GE interface until we have an update.

Please see this link for an explanation of "drainage class":"

Cool, done and done.

Only I went back to my GE Pro and lo and behold the link he killed was the red soil name that led to the page in the video that had the drainage classes (with the broken links). I just killed the golden goose!

I wrote back saying thanks for the fast work (if only title companies fixed issues in 3 minutes like he did) but can he reverse it?

His response:

"I removed the old links while we work on something better. Have a look at the modern interface, all of the links / descriptions are current:

It may take a little while to bring this functionality back to Google Earth. For now, you can click on the soil profile sketch, that will take you to the OSD which includes drainage class."

The soil profile sketch is this:

Part 2:
Clicking on the sketch takes you to a very much more detailed page with the following right at the top.

Not as pretty as before, but if you have a soil-curious buyer, look at you now. :)

On a related note, I wonder if it's just the state where I live or if an increasing amount of states are allowing alternative septic systems by this point. A house I bought 15 years ago came with a system from a different manufacturer that I can't find at the moment, but kind of looked like this one:

Unbeknownst to me, until a guy with the County called me about a year later to ask how my septic was working out, it was apparently the first alternative septic that the County had allowed (again, 15 years ago). Over the years since then, I've seen systems like this in a bunch of different places.

I imagine that even if these are technically allowed, the impact on one's land flip would likely come down to the overall economics of the deal, as well, in that these might be cost-prohibitive for someone thinking of building a tiny house or inexpensive cabin on a cheap dirt parcel, but for a higher price-point property and buyer, these are probably an increasingly viable option that would allow someone to build despite a bad perc.