Question
QUESTION: I have a house in which my sup pump will work constantly up until 1 week after a rainfall. I have installed a good sump pump. My problem is with drainage. I have a pipe that exits out from the house and goes underground. It is connected to 4" corrugated pipe that goes underground. It runs along side of my house for 50 feet. At the end I have a 2 1/2 foot hole by 2 feet deep. This hole is a constant lake. Is running this underground a bad idea. The corrugated pipe that runs underground is at a downhill run. I don't know how to fill in the end of the sump pump run hole. Would I just be better off running it on top of the grass on out to the street? Who do I even call to help me with this.
Thanks for any response on this.
Ed

ANSWER: Hello,

Sounds like the water may be seeping back into the ground and then into your basement again.

A 2 feet deep hole is too small to handle discharge from a sump pump (5 feet deep by 5 feet wide is the minimum) and since it appears that this hole is located immediately next to your house wall,then the water will simply enter your basement again when the hole overflows.

I do not think any municipality would allow a sump pump to discharge into a public street. This can create nuisance conditions from standing water and freezing water in winter. Some municipalities allow a direct connection to a sanitary sewer but usually the connection must be made by a licensed plumber.

Draining the water onto your own property may be an option if the water can seep into the ground without creating flooding or some other nuisance or hazard.

There are plastic drywells (which may be installed in batteries if necessary) available for the purpose of discharging sump pump water.  Or a drywell can be constructed of concrete or masonry. A pit filled with stone for use as a drywell will contain less water.

The surrounding soil must be permeable enough to accept drainage from the drywell. The drywell should empty out in about 48 hours. You need to know what volume of water you are dealing with in order to size the drywell and to determine if the soil surrounding the drywell is adequate for drainage or if it would have to be modified in some way to improve its drainage characteristics.

Other options may include draining the water to a permeable detention basin that can also serve as a rain garden. However,sediment from the pump water will deposit in this area.

I suppose there are various types of outfits that do this type of work, such as landscape contractors,waterproofers and home improvement contractors but hiring someone who specializes in the construction of drainage systems would probably be the best option, if available. Good design of a drainage system is very important. Hiring an independent designer has advantages in that this designer does not come under the influence of a contractor who may or may not have an understanding of the importance of good design. A designer can act as a watch dog to protect you from wrongdoing on the part of the contractor. Good luck. Let me know if I can be of further help.

Mark Harshman
http://www.harshmandrafting.com



---------- FOLLOW-UP ----------

QUESTION: Thank you for all of the advice but I guess I wasn't as clear as I should have been. The corrugated tube runs along side of my house and then out into a clearing about 30 feet from the house. That is where the hole I have dug is at. I also appreciate who to contact because a regular plumber just doesn't know. You have been great and a big help. Thank you so much.

Answer
Hello,

A detention area for the sump discharge does not necessarily have to be on the ground surface. One can be constructed underground if you want to use the ground above for another purpose. You could lay down gravel fill,surrounded by filter fabric and then place a 1 to 2 feet deep layer of topsoil over that or place some type of permeable paving such as permeable concrete over the area. The water will seep through the concrete and into the detention area.  Other examples of permeable paving would be concrete pavers with grass in the joints between pavers,permeable asphalt,grass pavers (grass grown in a metal or plastic grid work,creating a traffic grade grass),interlocking concrete pavers (a concrete grid filled with grass or gravel) or simply an organic or gravel mulch cover. The grass paver grid work can also be used with concrete by filling the hexagonal voids in with concrete. Water then percolates down through the holes left where the voids join.

Large diameter corrugated pipe embedded in gravel fill and surrounded by fabric to filter out silt could also be used for a retention area.

The problem with ordinary black corrugated pipe is that the inside corrugations will slow down the speed of the water and will more easily allow silt to deposit inside the pipe. Ordinary pipe of this type is not really rated for burial although more and more I am not hearing of any problems with placing it underground. There is a type of black corrugated pipe specifically rated for burial.

Black corrugated pipe having a smooth inside wall is also available and a smooth insert can also be used to make ribbed inside walled pipe into smooth walled pipe.

Running the drainage pipe on the surface may be more convenient but it may take up space or be unsightly. There is not necessarily an advantage to running the pipe along the surface. Running it underground would put the pipe out of sight and not pose an obstruction to any other activity on the surface.

To prevent frost heave, embed the pipe in a gravel bed,providing about 6 inches of gravel underneath the pipe. Make the width of the pipe trench 2 feet wide. The depth will of course be determined by the elevation of the retention area in relation to your house. A minimum 1/4 inch per foot pitch should be maintained. Special drainage pipe tie downs,which will further prevent frost heave, are available or they can be improvised from landscape staples or rebar. They fit over the pipe in a U shape and aid in keeping the pipe in place during frost heave or when water is moving through the pipe. Leave a minimum 8 inches of topsoil over the top of the pipe gravel.
Good luck. Let me know if I can be of further help.


Mark Harshman
http://sites.google.com/site/harshmandrafting/
http://www.scribd.com/markscrib47
Email: [email protected]