Size of Septic System Question

[cover]

So here's my question and dilemma. I'm looking at an advertised 6 bedroom home. When I went to check the county appraisal, it shows as a 4 bedroom so I'm guessing that they didn't pull a permit when they finished the basement and added 2 bedrooms to the basement.

It has a 1500 gallon septic tank and the information I have is a 30' long x 20' wide drain field. Since they size septic systems to bedrooms, it stands to reason that PERHAPS the drain field isn't big enough for the 6 bedroom house (where it likely was for a 4 bedroom house).

A friend of mine thought I might have liability IF the drain field isn't sized properly for a 6 bedroom house on that day that I might go to sell years from now. The house was built in 1995.

I'm about to make an offer on this house but wanted to get some information as to liability and also, whether the size above is indeed adequate for a 6 bedroom house. Currently, all bedrooms are full (7 in current owners family) and the owners have lived there 4 years (which is the last time the septic tank was pumped).

Thanks for any thoughts and ideas on this matter...
cov

 

[phishfood]

Soil type plays a large part on required septic field size. I am not experienced enough in this area of plumbing to offer an opinion on your situation. I would contact a reputable septic company in your area, they should be able to offer an informed opinion, well worth whatever small fee they may charge.

 

[johnjh2o]

My first concern would be the added rooms. I would be asking to see the certificate of occupancy for the added rooms. (C.O.) Keep in mind that could prevent you from being able to sell the home in the future. Having an unpermited addiction can open up a real can of worms.

 

[Zanne]

Cover, if you contact your local Department of Healthy they can give you information on what size septic tank is needed for however many rooms because they are the ones who set the regulations and check up on things.

Now, the reason they go by rooms is that they assume those rooms will be occupied and what they really are looking for is how many gallons of sewage will be produced by the household on a daily basis. The tank must be sufficient to process that and get it out into the drainfield.

According to some sources, a 6 bedroom house would require about a 1,315gallon tank (so rounding up to 1,500 is pretty good. Some sources just recommend 1,500 anyway. (That is with the expectation of using about 900gpd).

As for the field line, that too is regulated by the Department of Health and I'm not sure if it is the same in every state.

http://inspectapedia.com/septic/fieldsize.htm has some information on drain fields.

I recently had to have my septic tank and field lines replaced.

Do you know what sort of field lines the house has? I had the perforated PVC pipe sans gravel-- about a 300 foot length of it (which defies code- each line must not exceed 100 feet). So if you need 300 feet it has to be split up. Although if you get something like Infiltrator systems it has a 40% reduction of length requirement.

You may ask to have a percolation test done on the soil to find out how well it drains. The test varies from place to place, but here we had to dig 4 holes at least 24" deep and 12 to 18" in diameter and then fill them with 5 gallons buckets of water and have the inspector come out the next day to check the levels. Then the inspector filled the holes again and came back an hour later to see how much had drained.

Have you ever lived in a home with a septic tank before? There are certain drawbacks-- such as, it is not recommended to do too much laundry in one day, you can't use certain chemical cleaners in toilets and sinks and such, garbage disposals in sinks is not recommended, sanitary wipes or flushable wipes are not all that flushable since they don't dissolve in the tank and they can clog things up. Sometimes tissues may even gum things up. Use bleach sparingly (and never mix bleach with acetone).

One of the nice things is that you don't have to pay the city a fee for sewage though. And, depending on the size of your tank and the usage, you only have to have the tank drained every few years. Make sure that the person who does it drains it completely though.