What’s a septic system cost if the land doesn’t perc?

VortecJeep

VortecJeep

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Concord, NC
I own the wooded lot next door to us. I want a detached garage. Wife talks about including a guest suite in detached garage that our daughter could rent. If we do that, it would have to go on the other lot because our septic and well couldn’t support it.

When I bought that lot, I was told it didn’t perc. That was ok with me, I bought it so nobody else would try to build there. So if one was to want to build, what’s a ballpark for a septic system on land that doesn’t perc?
 
@braxton357 has experience here I think.
If it truly doesnt perk - I think you'd have to build a lift/pump station and send it to the county sewer. $$$$$.

But I have 2x in my life bought land that "didn't perc"...only for it to perc just fine a couple hundred feet away from where they said it didnt/
 
Your first step is to call the county and tell them you want to install a new septic system for a 1 bd studio, they should be able to do a site plan and let you know your best options locally. If you have sewer nearby then yeah a lift station will be your best and cheapest option. There are a lot of different systems that are used on land that won't perc that start with just bringing in dirt and doing a standard chamber system to really crazy shit that is $$$.
 
Only the front section of our lot perked. A septic field was cleared in the front and we have a pumped system. Septic field is probably 300ft from the tanks. There are two tanks.
 
VortecJeep said:
I own the wooded lot next door to us. I want a detached garage. Wife talks about including a guest suite in detached garage that our daughter could rent. If we do that, it would have to go on the other lot because our septic and well couldn’t support it.

When I bought that lot, I was told it didn’t perc. That was ok with me, I bought it so nobody else would try to build there. So if one was to want to build, what’s a ballpark for a septic system on land that doesn’t perc?
Click to expand...
Just wondering, why won't your well/septic support it? I can understand the permitting behind the septic, but what's up with the well? FWIW, if you build a suite but don't include a closet in it, you can permit it as a bonus room and a bathroom and be fine with the size of your septic per code. At least in Wake County. When we finished our upstairs the inspector (who was a major pain in my ass) told me I could add a bathroom to the upstairs without having to resize my septic because they go by bedrooms. He told me that rooms without closets get classified as other rooms and not bedrooms and are ok. Don't know if that is true, but seeing how big of a hardass he was about failing me on stupid shit, I feel like he is right.
 
2 of these
Some of this
And one of these

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How big is the lot?

Don't depend on the county to tell you what you can and can't do. When I bought this place (mostly clay dirt and brownstone), I hired a 'soil scientist' to locate and design a septic system that would work. He hand-drilled test holes all over, and mapped out the best area, etc. Then it was just having the county guys sign off on it. Few hundred bucks (five, iirc), but well worth it. Search for an 'environmental soil scientist'.

The only thing they went back and forth on (and the county won) was that the county insisted I bring in about 15 truck loads of fill. It came from my neighbor that did the grading and septic....same type soil, same rocks, dug up from 1600' away (his place) from my field. But it was "approved fill".
 
Blaze said:
Just wondering, why won't your well/septic support it? I can understand the permitting behind the septic, but what's up with the well? FWIW, if you build a suite but don't include a closet in it, you can permit it as a bonus room and a bathroom and be fine with the size of your septic per code. At least in Wake County. When we finished our upstairs the inspector (who was a major pain in my ass) told me I could add a bathroom to the upstairs without having to resize my septic because they go by bedrooms. He told me that rooms without closets get classified as other rooms and not bedrooms and are ok. Don't know if that is true, but seeing how big of a hardass he was about failing me on stupid shit, I feel like he is right.
Click to expand...
It’s an assumption on my part. Just looking at worst case scenario. And if I wanted to rent it out later to someone who isn’t family, I can think of a lot of good reasons for it being totally separate.

We are nowhere near sewer, so a pumping station to the sewer is not possible.

If it were connected to our septic, it would have to have a pumping station to get there as it would need to travel uphill.

I’m at least two years away from doing any of this, but starting to think about things.
 
kaiser715 said:
How big is the lot?

Don't depend on the county to tell you what you can and can't do. When I bought this place (mostly clay dirt and brownstone), I hired a 'soil scientist' to locate and design a septic system that would work. He hand-drilled test holes all over, and mapped out the best area, etc. Then it was just having the county guys sign off on it. Few hundred bucks (five, iirc), but well worth it. Search for an 'environmental soil scientist'.

The only thing they went back and forth on (and the county won) was that the county insisted I bring in about 15 truck loads of fill. It came from my neighbor that did the grading and septic....same type soil, same rocks, dug up from 1600' away (his place) from my field. But it was "approved fill".
Click to expand...
1 acre.
Good info on the environmental soil scientist, thanks!
 
Zoning might prevent you from having an unoccupied building on its own lot. Make it a barndominium with full apartment and it's a 1BR house with a big ass garage.

Similarly, might not be able to have two active septic systems on the same lot.
 
I went through this about 10 years ago.... Hired a soil scientist, and ended up with an Advantex AX20 system,, This is probably the most expensive route there is, but I went into it expecting and wanting an onsite sewage treatment system, so figure this is your worst case... Cost me about $32,000, I'm guessing it would be at least 20% more than that by now, But it lets you have a relatively tiny septic field, it only required 400sqft and an 800sqft reserve (If I remember the numbers correctly) to support a 4 Bedroom 2 bath House, That's all under VA laws, might be different in NC...
 
shawn said:
Zoning might prevent you from having an unoccupied building on its own lot. Make it a barndominium with full apartment and it's a 1BR house with a big ass garage.
Click to expand...
This

From my experience.....Forsyth/Davidson won't permit a "single bedroom"... For some reason 🙄
They have a min of 2 bedroom, and septic tank sizing is based on BEDROOMS with closets.
And neither will grant a building permit on a "lot" that is not a primary residence. So you Must
braxton357 said:
call a surveyor to combine the lots and make this an accessory structure to make things simpler
Click to expand...

Honestly, you can save yourself some headache and speak to either:
1) Your inspections dept (even though septic is health dept... They can be very helpful or break your heart before you spend a dime)
2) a contractor you trust that's done plenty of work in your area.
 
CasterTroy said:
This

From my experience.....Forsyth/Davidson won't permit a "single bedroom"... For some reason 🙄
They have a min of 2 bedroom, and septic tank sizing is based on BEDROOMS with closets.
And neither will grant a building permit on a "lot" that is not a primary residence. So you Must
Click to expand...
are they doing this to prevent tiny houses?
 
I rarely post but this is my daily... And I see some very questionable posts.

Unfortunately you have to start with the Health Department and tell them what you "were told" that the lot doesn't perk. And ask for them to come out and confirm with their own perk test just in case they find it does indeed perk if they have no record of doing it in the past. You basically need to question or figure out "who said that it doesn't?" It's usually a free service if it's a single lot by most health departments to come out and do a perk test. In Wake, Durham and Orange it is free. Any more than 1 lot (or above a certain acreage) and they will recommend a soil scientist. (or)

If they "recommend" for you to contact the State Department being NCDEQ "because it's a free service for them to come out". Do keep in mind that nothing in life is free in NC... I would recommend a private soil scientist for a private single residential lot. Or you better have all your existing "shit in order"! Even down to where your dog poops...

If no perk - next is Municipality. No 2 municipalities in NC are the same. Un-perk-able lots are not fixable in Orange or Durham counties possibly other NC municipalities. And the entire state of TN forget it. For the most part bringing in dirt is now considered "disturbed land" and will only get you barred from ever even working with them to install a non-conventional system if they will even approve one from the get-go for any disturbed areas. It must be un-disturbed. And anyone who argues that you can't tell, you can simply plug the ground down 3' min. and you will see the difference night and day...

But simply ask Municipality your options after telling them exactly what you want to do and see what they say. If they shoot you down with a final answer then they now have permanent record in case you try to do it without them. Most municipalities only communicate by email now days to have record. Durham will tell you that "since Covid they only do email". LOL - It's only for "record"...

Any non-conventional septic system will eventually go to NCDEQ-DWQ to be approved after the municipality signs off that you can even construct one. Depending on what system you use, they may also "own it" as well so an easement to and around it must be recorded. Before contacting your municipality you better read up on NCDWQ's website and do your homework before even starting.

NC Dept. of Environmental Quality

www.deq.nc.gov www.deq.nc.gov

Private "state approved" soil scientists will run anywhere between $300-$whatever depending on lot size.
Soil scientists "usually" require an up-to-date surveyed site plan before they will map it. So add another $500+.
A non-conventional system runs between 30k-60k depending on the regulations / requirements.
A non-conventional system will belong to and be monitored by NCDEQ-DWQ either by you sending in a yearly discharge sample or yearly on-site inspections. In NC that's typically $150-$250 depending on which.

Disclaimer: I do not work for the state or any municipality. I work for a Civil Engineer for Private Development. And I have over 30 years experience dealing with "them"...
Disclaimer: I've sold parts to individuals on this site who work for the state. So you better be nice on here!
Disclaimer: What one doesn't see, one doesn't know...
 
To save a bit of time on their akward website, here's a link to the DWQ info you would need to understand for a non conventional discharge septic system to see if you qualify. It would be best to be up on it even before contacting your municipality. Quite in depth, but simply spelled out once you understand and dive in. I have no references nor experiences for Concord area so my info above is basically an educated guess to what you may encounter.


I forgot to mention that there's literally thousands of existing non-conventional systems in NC. Most in the Triassic basins of Durham and Chatham counties but also in low lying areas. We've helped to permit several in Durham county.

Also if a system is installed and fails, it may cost a bit of money but DWQ will typically bend over backwards to help you "remedy" it.

Also here's a descent website to look up your soils. If link doesn't work search "NC USGS Soil maps".

Experience

experience.arcgis.com experience.arcgis.com

Hope that helps.
 
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