An experienced soil scientist studies the soils on the property, usually to determine the suitability for a particular use. Soil parameters such as landscape position, slope, depth, horizonation, color, texture, structure, consistence, presence of limiting features such as rock and water table are evaluated and described. Some parameters such as permeability and depth to water table may be estimated based on soil texture, structure, or color. This is commonly referred to as a “perc test” when the evaluation is for determining the suitability of a site for a septic system but the process is basically the same regardless of the end use. A report detailing the results of the evaluation is prepared and recommendations regarding the proposed use are made.

It is a test to measure or estimate the amount of water a particular soil will absorb in a given amount of time.

In the old days a volume of water was poured into a hole in the ground and timed as it went out and suitability for a septic system was based on the result. The problem was even soils that really aren’t suitable will sometimes pass this kind of test. Soils that are really rocky will often pass water but not provide adequate treatment of sewage to protect the environment. Soils that have a water table present in wet seasons of the year will also often pass in the dry times.

Today soil morphological features (like depth, texture, and color) are most often used to to determine the suitability of a site for a septic system (see site and soil evaluation). The trained evaluator uses these features as reliable indicators of soil conditions over a broad time and uses them to determine site suitability. Sometimes we still put water in a hole and time it as it goes out but only to determine how much water the soil willl take, not to determine whether it’s an environmentally safe and sound place to put it.

Soil conditions can change drastically over short distances so you may have vastly different soil conditions on your lot than your neighbors have. also

The health department changes the regulations that govern where you can put a septic system from time to time and they only make it harder (or more expensive) not easier to get a permit. So if your neighbors houses have been there for awhile the regulations may have been different then. also

Traditionally the health department evaluators will not prepare a permit to install an alternative type system although one may be suitable for your lot. also

They just might not have had enough time to look at all the possibilities. also

They’re health experts- not soils experts. At SETEC all we do is soils.

You should always get a professional soil scientist (CPSS), who is also an AOSE or PE to evaluate your property. Using a comprehensive method of site and soil evaluation they are the most qualified to evaluate and describe the strengths and limitations of the soil condition on your property. Many AOSE’s and a very few PE’s are also CPSS’s. All AOSE’s (who are not CPSS’s) have recieved at least minimal specialized training and demonstrated skill in evaluating soils specifically for septic systems. Very few PE’s (who are not CPSS’s) have ever evaluated soils for septic systems, although many are excellent designers of septic systems.

Of course, I think you should contact Soil and Environmental Technology (setec@soilandenvironmentaltechnology.com) first. If we can’t help you we can point you to someone who can.

Although you can have a system designed using that paperwork, you should definitely have that looked at again. We will do a FREE in office review of the paperwork and our files to see if it looks like there are other potential alternatives available or wheter it would be worthwhile to reevaluate the lot. When we do a preliminary evaluation for subdivision lots there are alot of unknowns and contraints that sometimes lead to overkill in the recommendations we make at that stage. It’s only after the lots are finalized and house sites identified that a comprehensive evaluation specific to your plans can be performed. This is especially true on large lots with multiple potential house sites or sites in remote locations.

I’ll give you an example. A develpor puts a contract on a large undivided tract of land to develop into a large lot subdivision. He (or she) is signing up to spend a lot of money on surveys, roadbuilding, marketing, etc. But first they usually have to obtain local government approval, part of which is showing that all the proposed tracts in the subdivision will support some kind of septic system. The tract is wooded and remote with limited access to established roads and the subdivision roads won’t even get built until all the approvals are in place. So the developer hires SETEC to make sure all the proposed lots have a specific place where a septic system can be approved. (Usually, the developer has already had us go out and do a soils map of the property to make sure there are enough suitable soils to even consider the development.)

So here we go, hand auger in hand, to evaluate lots that often aren’t even flagged in the field yet. The lots are large and there are plenty of nice places to build a house once people can get back in there but the soils on a particular lot (or several) are stony and we can only auger a couple of feet deep. Although it’s a place where we could maybe get a conventional drainfield (if we could bring in more appropriate equipment) , we have to identify a site so the developer can move forward, so we recommend a system that will work for the level of evaluation were able to accomplish, a drip system.

A couple of years later, there are roads into the property, the lot lines are flagged, and a potential homebuilder has picked a site different than that we originally picked. You can see how that original evaluation, although still valid, may not be the best solution for your particular situation.

Now is the time for a comprehensive evaluation to tailor a solution that will work specifically for you. Often all it takes is using a backhoe to dig the holes to go from a $20,000 dollar system to a $5,000 conventional one. I can’t promise you still won’t need that drip system, but you won’t go away wondering either.

The minimum charge for the most basic site and soil evaluation for an individual lot is $250. Contact us to discuss the cost to perform a site and soil evaluation that fits your needs.