Recently, we changed some of our household drainage lines, diverting the kitchen sink line from the septic tank and out the other way, all through PVC pipe and eventually underground. My husband said he needs to build in a grease trap before he covers the pipe so that he can clean out the grease that will inevitably collect and eventually clog the drain. He says these used to be used a lot in older homes. Does anyone know the best way to do this? Thanks!

-- Janie Dye (jdye_24088@yahoo.com), March 05, 2000

Answers

Our home is one of those "older" ones, and yes, we have our grey water routed out to the ditch that runs along side our property. The drain pipe passes through a small concrete tank that is about 18" x 18" by about 12" deep (it has a metal lid on it about 3" above the ground level). I'm not really sure that it needs to be cleaned out because we haven't looked inside of it, in about 4 years. We built an addition over it. Before that time, we had live here 7 years and only looked inside it once in awhile. I'm not sure why, but we never had any grease build up inside of it. My thinking is that either we don't have enough grease in our diet (ha), or we have a lot of grease in our diet and we're eating every bit of it and not letting any of it go down the drain, or (more than likely) we have our hotwater tank set at boiling and the grease is still too hot to stick in the grease trap as it passes through that cold concrete.

I would put one in though. Our kids were always lifting the lid to show off the spiders and such inside. Having one will give you the pleasure of saying "hey, you kids, don't be playing in there!" or "put that lid back on there, before someone falls in and breaks their neck!" :-)

-- Peggy (adkinsonthefarm@hotmail.com), March 05, 2000.

Janie: My friend has a 100+ year old house and we found, in the attic, 5 huge metal containers that held lard. Rose's 1906 brand! Boy did they use grease in them days. My grandma poured hot grease down the kitchen sink and said," don't fret honey we trap it". Anyway I used to own a dental lab and we had a plaster trap that may work. We washed our plaster bowls in the sink and the trap kept the pipes from clogging up. Set up right under the sink. Dental supply companies sell them. Kirk

-- Kirk Davis (kirkay@yahoo.com), March 05, 2000.

We have them a lot in Australia. Peggy's description is about right, although ours are a bit bigger - more like 18" wide x 24" deep x 30" long - maybe her's needed to be bigger to work. They retain a fair amount of water in them - a bit like a small septic tank - pipes enter and leave about two thirds or three quarters of the way up. However, the way they work is that the hot greasy water hits the cold water in the grease trap, cools down, the grease comes out of solution, coagulates, floats to the surface, and you get - guess what - grease trapped in the grease trap. If it's working properly, you definitely have to clean it out regularly, and it's not pleasant, because all the food scraps have settled to the bottom of the tank, which is acting like a small septic tank under its grease seal - anaerobic - STINKS!!! Better than grease-coating everything which should be breaking down in your septic system, though. Or keeping it separate but letting the grease make up its own mind about which parts of your drain its going to block up.

I worked in an office once which had been converted from an old hotel, and then done duty as a restaurant. They had a grease trap - legally required for food preparaton places feeding waste water to the sewer - which was half the size of a septic tank.

-- Don Armstrong (darmst@yahoo.com.au), March 06, 2000.

I would check with a septic contractor. You can still buy those concrete grease traps. In fact, in Texas many places require them, including the Farm Home Administration. I suspect they are available where you live. If you didn't want to buy one, you could probably make one from a plastic barrel. HOWEVER, I have lived in the country for 40+ years, in some 14 or so different houses. There was only one house with a grease trap. The land lady said the house had been in their family for 50 years, and she didn't remember anyone ever cleaning the grease trap. The drain worked just fine. Everywhere else the entire kitchen sink flow drained out into the pasture, except at one house we owned. My former husband and his brother installed the pipe about 6 feet below ground, with the end of the 4" perforated sewer pipe emerging about 110' from the house. We kept a tin can over the end. We never had a problem with that drain in the 6 years I lived there after the installation.

-- A.C. Green (ratdogs10@yahoo.com), March 06, 2000.

Janie: We have such a system in our house. In the original design, all greywater was collected in a 450 gallon underground tank and used as lawn fertilzer when it got full. Problem was, the impeller on the pump used to water the lawn kept getting clogged up with hair, grease and small food scraps which made it through the sink traps. We installed a blue plastic drum in the line before it empties into the 450 gallon tank. You actually need two drums 'cause you cut the top off the one which gets buried in the ground and use the top 1/4 of the other one as a lid. The greywater line in diverted into the buried tank just below it's rim. The outflow line exits the the barrel at the same level. The secret to happiness is to install a 90 degree elbow on the outflow turned down toward the bottom of the barrel and put just enough pipe on the end of the elbow to install a tubular screen to keep the trash in the barrel and out of the outflow pipe. Initially I used window screen but this proved too fine. The screen clogged up and required weekly cleaning. I changed to 1/4" hardware cloth and and now clean the screen every 3-4 months. About every 6-9 months you will have to clean out the barrel (yechhhhh!) but I can't figure any other way to make the settlin's go away. A dipper made from a deep cooking pot with the handle extended with an aluminum tube works fine for this task. Good luck, John and Pat

-- John and Pat James (jjames@n-jcenter.com), March 06, 2000.