What kind of sump pump for outside pit?

[journey]

I would appreciate any information or recommendations as to what type of sump pump to install in the outside pit of my 1600 square foot residential home in Ohio. This pit was installed when the house was built 11 years ago. I have never installed a pump as I have a pedestal pump in the basement pit but would like to install one in this pit as well. The outside pit is approximately 8 feet deep in the ground. Any information would be appreciated. Thanks

[Wgoodrich]

Subsurface soil texture and layer levels would dictate the size pump you need. Example an 8' deep basement pump serving a soil type that has sand texture down to say 7' deep and clay hard pan massive at 7' deep would take as much as 150 to 300 gallon per minute pump/pumps with a minimum of 8' of head on the pump rating. Then again the same 8' deep basement with a subsurface soil type of sand only 2' deep and then a clay massive hard pan would only take about a 50 gallon a minute pump with the same 8' of head. These pump sizes in those type soil makeup would only be needed when you need it most during a flood emergency. That may happen next year in your area but may not happen for 20 years or even a 100 years in your area. Just remember your house is designed to last 100 years or more when you size that pump that must be capable of handling. Then again if you have a class one soil with gravel 10' deep or more no pump is required at all allowing the water to drain below the finished floor of the basement not requiring pumps at all. All depends on the layering and type texture of the soil your trying to artificially lower the water table.

To explain when it rains a lot the surface water then perks quickly down through the fast perk sand but then can't perk down any more once it hits the clay massive being a perk barrier. Now in the first discription of 7' deep sand to clay massive you just experienced a 7' deep underground pool of water that can't perk down and must perk horizontal directly at your basement or crawl. This perk can produce from 100 to 300 gallons per minute attack to your basement.

However the second discription of 2' of fast perk then a massive only has a 2' deep underground pool water to attack your basement or crawl space even being 7' deep basement. The rain can only perk 2' deep to the hard pan then horizontal to your basement only requiring 35 to 50 gallon per minute attack to your basement.

Ask a soil scientist to test your soil around your basement and give you are report the soil texture and horizon giving you information needed to size your pump. In this area boring tests cost about 100 dollars per boring with report.

Be aware soil horizon and texture changes many times even wihin one normal yard area get borings on each side of your basement about 10' out from the basement in my opinion then you are not guessing.

Hope this helps

Wg

[journey]

Wg, thanks so much for your quick response. Your information was very helpful and gave me some other things to consider that I had not taken into consideration. I appreciate the information and it will help me to determine which pump will be the best for my soil and other needs. Thanks again for sharing your knowledge.

Journey