Chris Laurence, Realtor in Front Royal
Key Move Properties, Front Royal, VA

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Front Royal, Linden, Warren County real estate
Chris Laurence, Realtor ® (540) 671-1367

Septics and Percing Q&A

Below is a Q & A covering the most common questions
about septic systems and percing lots.

View my current listings for land & building lots


There is a lot of misunderstanding about septic systems and "percing", what it is, when and why it needs to be done, and how much it will cost. So here is a Q & A covering some of the most common questions I hear.

Note that this is for informational purposes only, and you should talk to the local Health Department if you intend to rely upon the information.

Also, while many of the comments below should apply generally to the State of Virginia, they are based on my experiences with Warren County in particular. There can be local variations.


Q. What is "percing"?

A. Percing is the process of obtaining a septic approval for a lot. Perc is an abbreviation of "percolation", dating back to when tests were carried out by pouring water into a hole and seeing how long it took to seep away into the ground. It is a much more sophisticated process these days, involving measuring slope and soil depth, analysis of the soil itself, and setting out the septic layout on the ground.


Q. What is a Septic Permit?

A. An actual Septic Permit is the final approval to operate a septic system, following installation and final inspection. But to get to that point from undeveloped land, you need a septic approval, which will take one of the following forms:

  - a Certification Letter - no expiry date, usually recorded at the Court House and
    transferable with the land, granting approval in principle for a septic system but not
    guaranteeing the specific system to be installed

  - a Construction Permit - valid for 18 months, not transferable, granting permission to
     install a septic system to a specified design.

A Certification Letter has to be converted into a Construction Permit before installation of the septic system can begin. If an owner has no plans to build immediately, he will normally request a Certification Letter.


Q. What is meant by a 3 Bedroom Perc?

A. There are a couple of "rules of thumb" in operation - (1) that 2 people in a home use approx 150 gallons per day (gpd) of water; and (2) that maximum occupancy of a home will be 2 people per bedroom. Thus, a "regular" 3 BR septic approval assumes consumption of 450 gpd and maximum 6 person occupancy of the dwelling. A "regular" 4 BR approval assumes 600 gpd and maximum 8 person occupancy.

There can be variations on this, the most common of which would be, for instance, a conditional 3 BR approval. This may state that it is for a 3 BR home, but maximum 4 person occupancy - because the system is only designed to deal with 300 gpd of wastewater. It is understood that some jurisdictions will not grant conditional approvals


Q. What is the difference between a "conventional septic" and an "alternative system"?

A. A conventional septic is basically a good "old-fashioned" gravity system that your parents and your grandparents knew. Wastewater from the house goes into a large septic tank where bacterial action breaks it down. From there it passes through a distribution box into a gravity-fed drainfield, where it simply seeps into the ground. Nature itself is the filter. A variation is a pumped conventional system, where pumping is required to move the wastewater to the top of the drainfield above or alongside the house, but the drainfield still operates under gravity.

An alternative system can be one of several types, but is broadly designed to pre-treat the wastewater so that it is less of a pollutant by the time it gets into the ground. Early examples were the "sand mounds", but more modern systems include Puraflo (peat moss filter), AdvanTex (synthetic filter), Aquarobic and FAST (aeration systems). Dispersal into the ground may also be more "hi-tech", such as a low pressure drip (LPD) system. Whatever the system, some form of pumping is always involved.

These days, conventional systems are much more difficult to obtain, especially on smaller lots. On the west side of Warren County, for instance, new approval for a conventional system is almost unheard of.


Q. What decides the type and specification of the system?

A. The $64,000 question! There is a whole range of factors, including depth of soil, composition of soil, amount of slope, proximity of other drainfields and wells, proximity of streams, springs or drainage channels, and location of the drainfield relative to the house site. These factors also apply to the "reserve area" which is a backup area in case of future failure of the main drainfield. In most cases, this reserve area has to be the same size as the primary drainfield area and meet all the same criteria.


Q. Can I perc my lot myself?

A. You can, while coordinating with the Health Department, but unless you really know what you are doing and have the time and ability to attend site visits etc, it is not advised.

I only recommend employing an AOSE (Authorized Onsite Soil Evaluator), also sometimes referred to as a Soil Scientist, who is recognized and approved by the Health Department.


Q. What does the percing process entail?

A. First, the boundaries and corners of the lot need to be clearly marked (which may entail a fresh survey). Then the AOSE, accompanied by a backhoe and its driver, will dig "perc holes", take soil samples and other readings, and work out the optimum location and design of a septic system. He will stake this out on site, along with the proposed well location and likely house site. Next, a surveyor needs to "survey in" all the stakes, and produce a final plat. Finally, the AOSE will put together the application and submit it to the Health Department for approval.

If a Certification Letter is requested, it is recommended that it is recorded at the Court House once issued.


Q. How long does the percing process take?

A. Realistically you need to allow six to eight weeks, though it can depend on weather and ground conditions, etc.


Q. How much does the percing process cost?

A. For a Certification Letter, around $3,500 +/- in Warren County, but this will vary by jurisdiction (for instance Fauquier County has a much higher application fee, and costs will be around $1,000 more). Costs include the AOSE's time, surveying and plat, backhoe rental, and the application fee itself.

For a Construction Permit for a conventional (non-engineered) septic, there is no additional cost.

But for a Construction Permit for an alternative septic, the system first has to be "engineered", i.e technical plans drawn up for the installation. This is performed by a firm specializing in engineering septic systems, and the cost could be another $1,500 to $2,500, depending on the system and features of the location.


Q. If I want to sell my lot, do I have to get it perced?

A. Technically no, but in practice no one is going to buy your land at fair market value without knowing that it is perced, and the terms upon which the approval is granted. And it is rare to find a buyer who is prepared to spend his own money on the process prior to owning the land. So realistically, you need to get the land perced with a Certification Letter in order to sell, or at least to start the process at the same time as it is marketed.

I am generally only prepared to market an unperced lot if the owner is committed to having it perced as part of the process.


Q. My lot was perced back in the 1980's or 1990's. Can I revive the old permit?

A. Unfortunately, no. The rules changed in 2000/2001, and any older permits are now dead and gone. Basically, you will need to go through the complete process described above to perc your lot again, though sometimes the original soil analysis (if available) can be re-used.


Q. My lot has not been perced (or it has an old, expired permit), and I have no plans to sell it or build for the time being. Should I get it perced now?

A. My answer to that is an emphatic YES, especially if it is a smaller lot. If you do not do so, then you run the risk that other lots around it may be perced in such a way as to make it impossible to get a septic approval on your own lot in the future.

For example, all wells typically have to sit at least 100 ft from any drainfield, and smaller lots in particular can struggle to meet that requirement if neighboring lots have their well sites close to your boundary. This applies regardless of whether those approved septics and wells have actually been installed.

My strong advice is to perc the lot with a recorded Certification Letter to protect your investment, and to ensure that your land will remain buildable. Once you have that Certification Letter it is grandfathered in, and effectively forms part of the title to the land.


If you are looking to sell land, whether or not it is perced
please don't hesitate to call me or email me

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