Septic replacement issue... (1 Viewer)

[Jay H]

Does anybody know if $17,100 sounds high or not to replace a septic system? The house I am considering is going to have its septic system replaced before we close (if I decide to buy it). Currently, the house septic is not to standard as it has a septic tank, but also a drywell for greywater (laundry, dishwasher). That is not up to standard to the replacement would be to fill/cap the drywell and then replace the septic tank and just plumb all the outflow to the septic tank so all the greywater and sewage goes to the septic tank and drainfield.

The owner has an estimate of $17,100 for a 3br, 1 full bath ranch. I am currently inquiring what size tank he is going to put in because if I buy I am considering putting a half or full bath upstairs where 2 bedrooms are. I've never lived in a house with septic but would the addition of another bathroom severly affect the size of the septic tank I need? I want the owner to put in a tank that would be large enough to support an added bathroom sometime down the line. Should I be very concerned that the owner will put a septic tank too small, I figure, many homes these days have at least 2 full baths, especially in metropolitan NYC area where I live. I think most standard sizes should support 2 bathrooms since I'm not buying the 20,000sf mansion.

Jay

 

[Mort Corey]

I think I'd get my own estimate, addressing your future concerns, and have the owner discount the sales price accordingly (if possible). If he's selling the property, he really has no incentive to have a first class job done. JMHO

Mort (who believes the $17K figure is in the ballpark)

 

[Kirk Gunn]

Question: Sounds like the owner is not expanding the septic tank, but rather capping a greywater well and re-directing that plumbing to the exising septic. Is there any increase in "capacity" such as a bigger tank or extended drainfield ? If this is just digging up pipes and re-directing, 17k seems a little high (but I am not a plumbing professional).


An additional comment: He is selling a 1Bath house, so his reasonable burden is to bring the current septic up-to-date with one meeting the capacity of the existing 1Bath house. If you want to add another bath down the road, you should expect to pay for the difference in added capacity.

Can't imagine it would be much more....

 

[Jay H]

The septic tank is being replaced with one enough to handle 3 bedrooms, however, the old not to form drywell (or whatever the technical name for it) will be removed from the system. Now I'm not sure if they normally would physically remove it or just fill it in and cap it. Then the plumbing would have to be changed to send all the outwater to the new septic tank and the drainfield setup of course.

I gather that septic systems are sized by the number of bedrooms and not bathrooms. Of course, it is moot for me as I'm a single guy, but I'm looking for resale and possible expansion issues.

Jay

 

[Bryce]

Septic tank size is estimated based upon the number of bedrooms in a home. A value of 150 gal of water/day is used for an estimate for each bedroom. It is basically a safety factor value since it is counting 2 people per bedroom each using 75 gals/day which is probably significantly more water than most people use on a given day. The tanks are also designed for a 24-hour retention time so a 3 bedroom house will generally have a 1000 gal tank, which is usually the minimum size manufactured (they go up in 250 gal increments).

The real variables involved in the cost would be the geology and terrain of the area. The drain field has to be a certain size based upon the amount of water that will be discharged into it daily and the absorption rates of the soil it is built upon. There also must be at least three feet of suitable soil underneath the drain field so the contaminants in the untreated water can be broken down by bacteria before reaching the water table. The slope of the drain field also can't excede 4%.

I'm not sure of the actual cost of a system since I just had to plan out systems on a mock landscape for an environmental engineering course. If that property you are looking at does not have the correct soil requirements, they might be installing a mound septic system which is much more expensive since fill has to be brought in to create an "artificial" drain field.