I am under contract on a 5 bed/4 bath home built in 1995. During the inspection, I found out it is a 1,000 gal septic tank. There has only been 2-3 people living there for the last 10+ years and they have “had no problems”. From what I have read, 1,000 gal should be for 3 bedrooms or less. I will have 5 people there constantly, which I think would call for a 1,500 gal tank. Should I be concerned? If so, would I need to replace the tank and the drain field or just the tank? Can I somehow leave the original tank and add a second 1,000 gal tank to add capacity? --208.104.xxx.xxx

Just for added context, the home was originally a 3 bed and they added an addition on, but did not apparently adjust the septic. --208.104.xxx.xxx

What are you buying a 5 bedroom for? --70.44.xxx.xx

I typically dont buy more than 3 bedrooms, but I am trying something a bit new on this one. It is a SFH that I am going to split into a tri-plex of sorts. It has a garage apartment that will become a 1/1. The main floor of main house is a 3/3 and try and rent it by the room - each room with a private bath. If that fails, I will rent it as a 3/3 altogether. Finally, I am going to add a full bath to the walk out basement which has a private entrance and use it for AirBnB. --208.104.xxx.xxx

So technically, you are not adding any bedrooms, so the septic system should be sufficient. --70.44.xxx.xx

--99.203.xx.xxx

The laundry is a maybe, because if it was built based on the # of bedrooms, the tank and drain field should be sufficient. That's what you need to verify. Is the system sufficient for the number of bedrooms. Because it doesn't matter if you have the whole house rented as one or split up into two, three, four units. It's still the same number of bedrooms. --70.44.xxx.xx

Thanks for the replies. There are 2 sets of w/d currently on the property. It was built as a 3 bedroom in 1995. They added 2 bedrooms in 2003, but made no changes to the septic. The addition looks to be permitted, but I am going to call the county and ask about septic sizing. --208.104.xxx.xxx

@NE, no worry on the splitting part. I only shared that detail because you asked why I would buy a 5bed. For the purpose of my question, I agree it makes no difference how it is split. I just did some quick googling and it looks like the average person uses between 80 and 100 gals a day. That would put 5 people at between 400 and 500 gals a day, well above the 360gal the permit states. If I was to need a larger drain field, can the existing one be extended “easily” or does it require digging up the field that is already there? --208.104.xxx.xxx

I know what I would do, but I won't say that on a public forum. LOL --69.80.xx.xx

I'll say it Gevans! Haha. I'd go for it with a back up plan if I couldn't accomplish my original goal or put an extra one in on a weekend if I needed it. --70.44.xxx.xx

Oh boy, now I am curious! Do you have a forum appropriate version you can post? I would only consider 1 room to be a B&B and I was thinking if I get 20% occupancy the water usage might actually be less than a full timer. The 3/3 that I am going to try and rent individually will be to longer term tenants - in theory. It is on several acres, so in terms of adding a new tank/field, it is possible. Would I basically be diverting the drainage from a few of the bathrooms and sending that to the new system or would I be daisy chaining the old to the new in some way? --208.104.xxx.xxx

You could always put 1 unit on a new system and the washers could go into a big hole dug and filled with stones --72.231.xxx.xxx

@Ken, is that a thing? How deep/big of a hole would you generally need? --208.104.xxx.xxx

James it is called a drywell,not legal in some areas but perfectly legal in other areas,it will help to keep a lot of water out of the septic lines --72.231.xxx.xxx

--47.155.xx.xxx

I lived with myself and 2 kids in one of my rentals on septic and we managed not to over load the failing sysytem. But i managed our water flowing into it. When it was rainy we didn't do laundry. Some baths at night, some morning. Dishwasher ran midday. After we moved out a single lady moved in, one person, total wetland in the yard, she was renting didnt care about water managing to stretch the life, she was just living her life. The tank failed in 2 months! She would not be trained to live there. Away with her, new system and no more issues. I currently will not buy any property with or on septic for rentals. Renters use the property not care for it. Perhaps your county will advise you on permits and restrictions on how to correct the issue. I like the add another tank, what are the land restrictions on that, in my county we need acres of land nowadays for septic. Pethaps ad additional tank and leech field would work? The county should be your partner in the solution. Hopeful the property comes with done acres or the best would be to hook on to public sewers if near by. --172.58.xx.xxx

Any renter will use more water and short terms will use it faster. It's the frequency there is no thought given to the septic especially if they come from living in areas with public sewers. No forethought is given. The system will not handle the flood of usage. Good that you are exploring options now! --172.58.xx.xxx

You may want to re read KEN NY post. --99.197.xxx.xxx

I have one property with a dry well for the washer and dryer. Big boulders in the ground with a pipe that just drops into there. I also have a gray water tank that I put into another property that takes the kitchen sink, bathroom vanity and shower. It's a 55 gallon drum with a bunch of holes drilled in it and it has an outlet that goes to about a 50 foot trench full of gravel. These are frowned upon, but if you plan on holding the property for a number of years, sometimes you just do what you have to do. --70.44.xxx.xx

--65.188.xxx.xxx

If proper permits were pulled and the extra two bedrooms were built to code, why would it not be a five bedroom. Chances are the assessment at the courthouse changed it to a five bedroom. --70.44.xxx.xx

With your tank size-- if at all possible put in a dry well for your dishwasher and washing machine. Those two applicances have only GRAY water. A dry well (i put in many while I lived on LI NY) is a hole that a 55 gal drum can fit into. Dig your hole and put plenty of crush and run-- aka blue stone. Punchture the bottom of the barrel and slice the side wall of the drum in 20 places. Put the drum in the ground and back fill with blue stone. Run your dishwasher and washing machine drain in to the top. Back fill. If your neighbors have water wells-- do NOT put your dry well within 100 ft of their well points. --99.103.xxx.xxx

James, there is nothing worse than ongoing septic issues. I've lived it, some of our renters have lived it. We've had to deal with it at 5 different houses at least. All nightmares until fixed, then no issues. You need to upgrade that tiny system if you are going to do everything you are proposing to do. --50.82.xxx.xxx

Advertising – When a septic system permit is available and indicates a capacity of three bedrooms, the broker may only advertise the property as a three bedroom home. To knowingly advertise more bedrooms than permitted would be a willful misrepresentation. --65.188.xxx.xxx

If James can uncover these issues, he may be able to negotiate a steal. --70.44.xxx.xx

@Bonanza: Do you happen to have anything like that for SC? --208.104.xxx.xxx

$5-6k not $20k. If someone quotes $20, run. --50.82.xxx.xxx

$20k issue --99.203.xx.xxx

Look into an infiltrator system. They are not accepted in some places but they can drastically reduce the actual length of the drain field. And yes the drain field is probably more important than the tank. Pumping the tank on a regular basis 2 - 4 years depending on how much usage is also very important. You don't want those solids to build up to the point they are pushed into the drain field and clog that. --108.4.xxx.xxx

James, I don't know anything about how SC does things. call a SC Realtor or SC lawyer or both. --65.188.xxx.xxx

I can get one done for $5000-$6000 you want to call someone who operates his equipment himself,that will be your best deal,not a big company with salesman and operators etc --72.231.xxx.xxx

I’m thinking a single 1500 with the old removed might be best, as I wouldn’t have buried trash in the yard and I would have only 1 tank to maintain. Thoughts? --208.104.xxx.xxx

--69.80.xx.xx

The half clamshell that gevans suggests is the infiltrator system. This system allows you to have shorter fields and disturb less area and still handle the capacity. Although not approved for new systems in our area, almost everyone replacing a field uses them here. --108.4.xxx.xxx