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Have a very difficult lot the govt regulations that will not allow me to use closed loop horizontal. Do not want to use pump and dump open loop but the vertical closed is very expensive.
Since the septic tanks are in, but not the field it was suggested to dig the field a few feet deeper laying in as many loops as possible. These could be connected to the vertical loops, but would reduce the number of vertical loops required.
Ever heard of doing this? Pros and cons appreciated.
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Replies
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I dont think - from the research that I have done building my house - that you even even want to sneeze on the drain field or the sanitation officials will fail the field. It is my impression that the drain field has to be virgin - untouched. If you go and dig it up I think you will be asking for trouble.
I am sure other people will correct me if I am wrong
sam
*As Sam mentions, disturbing the septic leach field can cause problems. Almost anything you do with heavy equipment will REDUCE the permeability of the soil. So water will percolate less well and air exchange in the soil will be worse. Therefore you'd need a bigger leach field to do the same task. Whether you local officials would identify and react to those issues would vary with location and the individuals involved. Something to clarify before proceeding for sure.The is a tendency and sometimes regulations to keep pee, poop, and their breakdown products the heck away from everything else. Even though the geothermal loop will be under pressure (so stuff could leak out but not in). And no one is going to be drinking the fluids from the geothermal loop. Still, you might encounter resistence to the design for that reason. -David
*Bick,What govt regulations preclude horizontal closed loop? I know many states ban open loop systems, but why not horizontal closed loop?I think if you dig a "few feet deeper" you could be opening yourself up for trouble. Our GSHP loops have methanol mixed with the water to prevent them from freezing. The unit is rated for loop temps down into the 20's F. Unless you really get good separation between the loops and septic you may have some septic problems in the winter? On the plus side, if you really bury the loops deep you'll get a more efficient system!What kind of septic field did you plan? What kind of soils do you have? If you're going with some type of trench system I'd agree with prior posts. Around here we have "boulder clay" that forced us to go with a 24'x50'x5' thick sand filter. All the treatment is done in the filter so it really doesn't matter what the native soils are.
*What govt regulations preclude horizontal closed loop? No regulations regarding the loops at all. I'm located in the sand dunes of western michigan, on the lake. Because the dept of envir quality has categorized my lot as both "critical Dunes" and "High risk erosion" I cannot alter any slopes with a grade of over 33%. I've used every inch that is below 33% grade as the building envelope. The driveway is 200' long and would have been an excellent location for horiz closed loop but because the entire lot is sand, the excavator said going down 4 or 5' would cause the sides to fall in past the edge of the drive. Again because of the slopes, I couldn't alter anything outside of the approved driveway location. What kind of septic field did you plan? Was planning Infiltrator, but got a much more competitive bid from a reputable, longstanding septic excavtor for a traditional field. What kind of soils do you have? 100% sand
*When I put my Geo-thermal in two years ago I asked this question to my installer. To me the septic would warm up the hor. loop even more. However, my installer highly recomended against it stating that he knew of installation like that and it had to be removed because the Geo-thermal in extreme cold conditions was taking so much heat from the ground the septic would freeze. I don't know if that is true or not but the guy did a great job and certainly knew what he was doing.
*Bick,Must be a beautiful site for your home. Also sounds like you've got some almost insurmountable obstacles. Good luck!
*It is the most spectatular lot you could imagine. For that reason there is nothing that is insurmountable, as long as you consider the cousel of experts as you go forward. The insights gained over the last 3 months (here) have helped me learn exactly where I need to spend the limited amount of money available. This problem can be resolved by using a vertical closed loop. It was my plan all along, knowing what I know about my lot, but when someone offered up the septic field solution, I thought I'd run it by the pros. After doing so, closed loop vertical seems to be the only rock solid solution. Your comment about the obstacles gives me a sense of accomplishment. The lot was for sale for many years (at a premium price because of it's beautiful location) but no one would buy because of all of the challenges. My circular design was able to absorb every buildable inch giving me 3300 square feet where no-one else could fit 1500-2000 using conventional methods. At this point I'm really struggling with the HVAC with no local contractors. I may end up doing it myself with radiantec (SP?) if something doesn't break for me soon. Since the beginning of this project I've gone from "what ever made me think I could do this" to "it's working" and back again. Thanks for the support.Bick
*How much insulation are you including in the building? If you build like the swedish you might not need the heating unit and cooling will be cheap.
*Got pictures?
*We put in 2,000 feet of horizontal loop two years ago. Backfilled, tamped, and graded all surfaces level. Within the first year all of the fill settled an additional foot. Regraded. As spring approaches we have visable settling in 75-100 feet of trench. I would not want the soil under my septic system to settle a foot or so after it was put in. Now that would be a mess. Lots of good information about these systems at http://www.hydro-temp.com. They built and installed our system and we are very happy with it.