Residential Septic System Cost
Residential Septic System Cost
(OP)
I have a friend whose septic system failed and has to be replaced entirely - apparently is forced to replace it by the county, for whatever reason. It is going to be placed on a different area of the lot.
Question: For a 2500 square foot three bedroom house, for the engineering design, materials and installation of the septic system (not a sand filter), does $22,000 US seem reasonable?
Question: For a 2500 square foot three bedroom house, for the engineering design, materials and installation of the septic system (not a sand filter), does $22,000 US seem reasonable?
Mike McCann
MMC Engineering





RE: Residential Septic System Cost
sounds extremely extreme, unless there is more to the story.
RE: Residential Septic System Cost
RE: Residential Septic System Cost
The house I used to live in (SW Ohio) had a failed septic system - the leachfield had become overgrown by brush and trees - also the septic tank was too small. It was an old farmhouse with a homemade (~700 gallon) tank. We were a family of five.
The County health department was requiring a new tank and modified mound system be put in. They would not allow us to use a leachfield again - didn't have enough property. For a leachfield, they wanted a back up area which would have required about 0.75 acres. We had slightly less than a single acre.
The lowest estimate was ~$20,000.
That was about 5 years ago.
RE: Residential Septic System Cost
Plus, there are always site-specific contraints to consider. At my own house, we added some bedrooms on, which necessitated an upgraded septic system, and the existing leech field was old, so we decided to go with a whole new system. However, in order for the leech field to work in the one area that made sense on the lot, we had to pay for rock blasting, which increased our costs by $8k-$9k. Cool thing was, because we blasted hard granite almost 20' below the leech field, I basically have 20' of sand/gravel below the leech field, so the leech field should last a LONG time. Too bad this doesn't correlate to increased building value...
RE: Residential Septic System Cost
For soils with fast water movement the cost might be as low as $10,000.
Maine does things different than the other states, and I think better, and the cost in that state might be more in line with $5000-10,000. In Maine though, the criteria to become a Site Evaluator, necessary to design systems, is pretty tough and you really need to know your soils. Because of that they're a bit more liberal on sizing systems, but apparently with a failure rate that's as good or better than the neighboring states.
Pete
RE: Residential Septic System Cost
I see that you are in Colorado. My system has been approved by CDPHE as an advanced treatment system and, I can say that after having worked on a number of large projects in Colorado for the last decade, you have some of the highest septic system costs I have seen anywhere. What I have found is that contractors will generally triple the parts price for a total price. I requested bids for a subdivision I was designing and one contractor quoted $51/ft to install 4" dia. building sewer 4' in the ground. The soil was like flour, no rock. I called him and told him I thought he had his numbers transposed (51 instead of 15)....Nope...51 bucks a foot he said.
I have a system going in where a competing system had been specified but the cost exceeded the cost of the owners manufactured home. The engineer told me that the cost of my system was not much more than a conventional septic tank and drainfield.
Tom
RE: Residential Septic System Cost
Mike McCann
MMC Engineering
RE: Residential Septic System Cost
FWIW