Thanks Brian, maybe I should have been more clear. This is for rainwater only, not septic. ( I will be tied into the city sewer system).

I should also add that even if I tie my rainwater into the city's stormwater drain I will still need to install a stormwater system (just a little smaller) so I still have all the negatives and just added cost.

I guess my real question is how in the world could this civil engineer do the test in an area obviously made up of land fill.

Only one way to find out, ask the engineer.....

I don't understand why only one hole was dug. Rain is going to fall on the entire property, so don't you need to worry about all the land? Perhaps he had the hole dug in the backyard because the whole yard needs to pass and he had a feeling that area would not. I guess what I am asking is how do you plan to manage the stormwater from the section of the yard that was filled?

My guess is that the engineer purposely dug in a location that they knew would fail the perc. test, so that the City would have no choice but to let you tie into the storm sewer. Tying into the storm sewer is the best long term option, even though the upfront cost is higher.

It could also be that the required stormwater management system needs to be so large that it will not fit on the site and thus tying into the sewer allows the system to be much smaller (and much cheaper).

In my opinion (as a civil engineer) you should ask these questions to your engineer, many times there are reasons decisions are made that the owner does not realize.

Indiana_th, “My guess is that the engineer purposely dug in
a location that they knew would fail the perc. ” That is what I suspected. What annoys me is that he should have asked me if tying into the city
storm-water system is what I wanted to do.

I agree that it could be cheaper to tie-in if the drainage system
needs to be very big but he would have no way of knowing that without doing a
proper perc test. Based on my perc test in the front yard (8.5
min/inch) my drainage is actually very good and the stormwater system shouldn’t
be very big. I really think he did it to save himself some work.

Also he did the test pit in the back yard which is the
farthest point possible from the city drain.
If I tie into the city, the collection system would be best placed in
the front yard anyway to avoid a long drainage line running from the backyard.
To do this he will have to redo the test in the front yard anyway. I have
plenty of room in the front yard or even side yard for the system.

Millworkman, “Only one way to find out, ask the
engineer.....” normally I would agree but this guy is so slick (based on other
interactions) that he will most likely try to BS me into accepting whatever he
did. I think in this case my best bet is to forearm with Houzz expertise before
I make that call.

Dekeobee, the stormwater to be managed is just the rain from
impervious sections (the roof and the driveway). The backyard fill area just
needs to drain itself which it is capable on most days but does puddle up in
heavy storms. This will be handled with proper grading.

As for doing multiple holes I think he was supposed to do several
holes until he found a good spot and then do multiple test holes in the area of
the proposed Stormtech system. His whole
approach/method was so far from the proper EPA method of running a perc test.