Richard writes: My lot will not accommodate a conventional leach field. What alternatives can you suggest and who would you recommend to design alternative septic systems?
Steve Bliss, of BuildingAdvisor.com, responds: What is acceptable in your area after a failed perc test is determined by local building codes and health department regulations, so you should first check with them. A face-to-face meeting is usually the most productive. In my experience, these people are eager to help and like being consulted early in a project. An early meeting can prevent a lot of headaches later on.
That said, there are a wide variety of alternative systems from low-tech “mound system” to more technical systems with synthetic prefilters that treat effluent coming out of the septic tank and other synthetic or natural filtering media to replace traditional gravel or stone trenches.
Nearly all alternative systems rely on an electrical pump that operates on a schedule, with an alarm to alert the owner of a failure. Because alternative systems are generally less resilient than conventional systems, most municipalities want assurances that a system will work properly and be maintained properly before approving it.
Because of the higher level of maintenance required, some areas may only approve these systems for use by multiple homes in larger developments that typically contract with an outside company to manage the system – essentially becoming a mini sewage-treatment plant.
Most septic system designers are familiar with alternative systems such as mounds and should be able to provide information about options and costs in your area.
If you want something truly innovative, you may need to do additional research and may need special permission to install the system. Of course, you want something with a proven track record as the cost of tearing up and repairing or replacing a failed system can easily exceed the cost of the original system.
See Also:
Are Alternative Systems Allowed?
Chamber System Failure
How Much Slope For Septic Line?
Inspecting a Septic System
Lifespan of Septic System’
Minimum Lot Size For Septic System
Perc Test Cost
Perc Test: Best Time of Year?
Replacing Failed Drain Field in Same Location
Retesting a Site That Failed to Perc
Sand Filter for Existing System
Testing an Existing Septic System
Testing for a New Septic System
Wet Sites, Septic Systems For
Who Performs Perc Test?
View all SEPTIC SYSTEM articles
Joe says
What Does “Failing” A Perc Test Mean?
If the test results indicate that only an alternative septic system, such as a sand filters, can be installed, does that mean the test failed?
How is a contingency clause that requires “passing the PERC test” usually interpreted? Does passing a perc test mean a homeowner can install a standard, conventional septic system?
buildingadvisor says
Yes, in most cases, “passing the perc test” means what you say – that you can install a conventional septic system, assuming you have the necessary space for the drain field. The test results will dictate how large the drain field needs to be and the maximum number of bedrooms (also a function of zoning).
If the test fails, you may still be allowed to install an alternative system such as a mound.
To avoid any disputes over the meaning of this or any contingency in your offer, it is best to clearly spell out the conditions of our offer. For example, your perc test contingency may state, “perc test and soil analysis must indicate that a conventional septic system for a three-bedroom home can be installed on this building site.”
If the results show that only an alternative system is permissible, then you can negotiate with the owner for a reduced price.
Jeff says
Can I Replace Poor Soil That Won’t Perc?
I’m thinking of buying a lot that has only 6 inches of poor soil ( over hard pan ). I can already see it will not perc. However, I still wish to buy it and build a good size house. Other houses in area passed the perc test after sandy loam was trucked in. I’m thinking I will have to do the same, unless there is a better septic system that can work without rehabilitation of the soil. Any ideas?
buildingadvisor says
I have heard about people “rehabbing” soil that won’t perc by bringing in a few feet of better draining (more sandy) soil and waiting 4-5 years for the soil to settle and then doing a new perc test – hopefully with better results. Some areas apparently allow this and some folks do it under the radar. I am not aware of any regulated areas in the Northeast where this practice is allowed.
If this approach is allowed in your area, it is an option, but still carries risks. The site may still not pass the perc test, which could be more stringent five years from now. So you still may need to install an alternative system after spending a lot of money on fill. If the practice is not allowed…we you know the risks there.
As for other options, the cheapest alternative system is usually a mound, which can double the cost of your system. Sand filters and drip irrigation are other options, but costs are even higher. All alternative systems carry higher costs for monitoring and maintenance. Which option is best depends on site conditions and local regulations.
Septic system regulations and what type of alternative systems are allowed vary considerably from one town/county to the next. So I strongly urge you to talk to the health department and/or a licensed septic system designer in your area to find out what your options are. To guess at what is allowable or base your decision on hearsay about what the neighbors did x number of years ago is a very risky approach.
Better to move on and find a site that percs – or price the cost of an acceptable alternative system into your bid.