Percolation question regarding overground tank

Frog Song

We had a percolation test done on our site last week. The water didn't go down and the guy doing it (also doing our house plans) said we will have to have an overground septic tank instead of the usual underground one. He said the cost of this would be around 10 grand. And that he would be involved in doing it if we wanted him to instead of getting someone else.

If we have to get one put in then we have no choice but to do it. However just a couple of concerns that we have:
The time of year the test was done. My brother who owns the site and knows the land said that the water table is high at this time of year and that if we waited a few months it could go down. He by no means guarantees this but said if it was him he would wait and see. He is also wary that our guy seems in a big rush to get this done, suggested that he would arrange it and that he said the time of year will make no difference. As we are completely new to this and have no experience or knowledge of building we are putting our trust in our man to do the right thing for us. But there is that nagging feeling that this would mean more money for him and that he wants to get it done asap. But if it was in our best interests to wait a few months and see if the water table goes down we would rather wait and see. We are not looking for shortcuts by any means and want to do everything right but 10 grand that we may not need to spend is a concern for us if it is avoidable without any problems or implications.

I would welcome any advice if anyone has any experience or knowledge of this. As I said if it has to be done that's fine but if waiting until the summer to do it might mean a different result we would rather wait. Many thanks for any help.

sydthebeat

The Time of year makes no difference as the ground conditions will show the highest point of the water table any way, it's called mottling.
It's a false economy to think that by doing the test when the water table is low that somehow means you don't have to put in a proper percolation area. Its pointless if the water table rises as it has done, and you have a tank Submerged in water, a percolation area that floods and sewerage pipes that back up into the house. .... do you want that?

Every piece of land is not suitable for the safe disposal of effluent therefore that's why we have these tests, to determine the design of the system to ensure safe disposal. The parameters of these designs are quite detailed and prescribed so there's very little wiggle room on the assessor.

If you want a second opinion I'm sure you can pay another assessor to do another percolation test, but like i say, the highest point of the water table will be recorded anyway.

Frog Song

sydthebeat wrote: »

The Time of year makes no difference as the ground conditions will show the highest point of the water table any way, it's called mottling.
It's a false economy to think that by doing the test when the water table is low that somehow means you don't have to put in a proper percolation area. Its pointless if the water table rises as it has done, and you have a tank Submerged in water, a percolation area that floods and sewerage pipes that back up into the house. .... do you want that?

Every piece of land is not suitable for the safe disposal of effluent therefore that's why we have these tests, to determine the design of the system to ensure safe disposal. The parameters of these designs are quite detailed and prescribed so there's very little wiggle room on the assessor.

If you want a second opinion I'm sure you can pay another assessor to do another percolation test, but like i say, the highest point of the water table will be recorded anyway.

Perfect, it's really to get our facts straight more than anything else as we are getting mixed opinions on it. We don't want any problems down the line of course so if it has to be done that's fine. It was the difference in the water table that was the main question, if the time of year would make a difference or not. Appreciate your post, thank you.

sydthebeat

Frog Song wrote: »

Perfect, it's really to get our facts straight more than anything else as we are getting mixed opinions on it. We don't want any problems down the line of course so if it has to be done that's fine. It was the difference in the water table that was the main question, if the time of year would make a difference or not. Appreciate your post, thank you.

Your brother may have been thinking about the previous standard test called sr6 1991 which didn't record this 'mottling' level and their the time of year could be used to gain a more 'favorable' result but as i said this was a false economy. If the water table is going to be high in winter the system should be design for this high water table.

The new EPA tests have been standard in most counties for at least Five yeasr at this stage.

henryporter

Never heard of an overground septic tank - overground percolation area maybe: this would entail importing suitable soil to the site to build up the percolation area to a specific height above the existing water table to filter the effluent before it hits the water table - no point waiting for the summer for the water table to go down as has already been pointed out the signs are there all year round, plus if you did get away with it, you won't get any treatment when the water table is high.
You might be able to reduce the water table by improving drainage in the site (around the perimeter etc).

Frog Song

sydthebeat wrote: »

Your brother may have been thinking about the previous standard test called sr6 1991 which didn't record this 'mottling' level and their the time of year could be used to gain a more 'favorable' result but as i said this was a false economy. If the water table is going to be high in winter the system should be design for this high water table.

The new EPA tests have been standard in most counties for at least Five yeasr at this stage.

I understand. Good to know, I googled etc but wasn't really finding what I was looking for. Many thanks for making us aware of that.

Frog Song

Just to ask. Is the ten grand mark for this pretty average?

sydthebeat

Frog Song wrote: »

Just to ask. Is the ten grand mark for this pretty average?

i would have said "up to 10k" myself.. the more of these raised percolation areas that are being constructed the more contractors become more competitive.