Septic System Mound

[Corben Briggs]

Hey all!

So I am looking into purchasing a new single family investment opportunity in a nice area of MA. One thing about the property is that it needs a new septic system in place however it will need to be an elevated system meaning there will be able a 4ft mound above grade from the rest of the backyard that covers a large portion of the yard

The thing about this is that it won’t get done until after closing since the seller doesn’t have the cash to pay for it and wants to do a 1.5x price hold back on it so I’m not able to see what it will look like aside from the blue print that the contractor gave us it until after closing.

Has anyone had an experience or stories with these elevated septic systems being a big issue or something that would prevent the house from selling? I know there’s some cool ways of dressing one up however haven’t had experience with that in the past.

Anything helps!

[George W.]

The only big issue with raised mounds is price. They're alot more expensive then a conventional septic system. Make sure that your pump tank has a high water alarm for if the pump fails. 

[Jay M.]

It sounds like the property is near the water?  I'm familiar with the Cape and the south coast of MA and there are an abundance of septic systems like this with a high water table.  Google street view the neighborhood and you'll probably see some raised systems.

If you're not familiar with interpreting the septic design find someone that is.  The final grade over the system may be worse than they're letting on.

[Account Closed]

@Corben Briggs

30 to 50k....just to be safe

[Account Closed]

@Corben Briggs

Then willow trees and maybe a fence. It will require annual maintenance and will always be an eyesore...however it will also be reliable and environmentally pretty sound..i wouldn’t want one by choice but they are very common and often overshadowed but the beautiful properties that house them.

[David Burkholder]

verify with the contractor what the angle on the sides of the mound will be.  If you are going with the cheapest price for the mound the si is es will be pretty steep.  Some higher priced contractors will bring in an extra truckload or two of dirt to make the slope less steep, particularly on the side facing the house.  (I wouldn't waste money feathering the slope on the side or the back side)

Also,  do not plant trees within. 15-20 feet of the mound,  the roots will travel to the water and cause maintenance problems down the road.

The sand mounds that I have owned or rented do not require any special maintenance, other than septic tank pumping every 3 years.

[John Teachout]

Do mound systems require more frequent septic pumping? 3 years seems like an extremely short interval between pumpings.

[Bryan Devitt]

@Corben Briggs they're very common in MA, no need to worry about it hurting the sale. As stated by others, spend the extra money and have them truck in some extra soil to make it not look like a box in the middle of the property. 

@John Teachout in MA most companies try to tell people to pump every 1-2 years if the house is at capacity or close. We just pumped for the first time at 12 years and the driver told us it looked great and was barely anything in there, but still suggested to do it every 6 just in case. It all has to do with how many people are living there, what they're dumping into the system, what TP is being used, etc 

[Brent Paul]

I have a mound system and I haven't had many problems.

As others have said you should expect the septic to cost at least 20k at least that's what my septic guy told me.

The city or county bylaws will dictate when it needs to be pumped.  In my area it was 300 bucks to get pumped.

The main thing with septics is people flushing down things that shouldn't be flushed.  It can damage the system or severely clog it.  When mine was pumped they found tampons, condoms, paper towels among many other things.  It totally plugged the pipe going to the tank.  Cost me 700 bucks to get it pumped so they could clean out the pipe and push a water jet through to clear the block.  Responsible tenants will be mindful, but someone not caring could really do some damage.  Tree roots can really cause some damage definitely don't plant anything near it.

[Sharon Rosendahl]

Keep trees far away. There was mention of willows? Those are horrible since their roots will seek more water no matter how much they have.

The only thing you should plant on a mound is grass. Same with a sand filter. Even standard gravity systems you should only plant grass over the drain field. 

My parents have a pressurized mound. They are expensive to install. With tenants, I like to pump annually due to them not being as careful. I do have a clause in my lease that they are expected to treat the septic appropriately and include a booklet on it. If I pump and find stuff I shouldn't then I can include that in the damages.

Light foot traffic is fine so the grass at my parents' place gets played on. It is a vacation home though so it isn't daily, heavy foot traffic. Don't put the drain field or other parts of the system in a high traffic area including driveways (if it is just a pipe, I put them into a second protective enclosure like a culvert style pipe), under something you are going to build or livestock area.

It is best to not have a disposal in your kitchen when you are on a septic. Too much stuff going down can cause problems, especially if it is greasy. It can cause problems including clogging due to hair and other waste turning into a clump and clogging your pipe going into or out of your tank.

Around here, a sand filter system is running about 25k. Not sure what a mound costs but probably similar.