A perc test is a soil test that measures water absorption. “The tests are required in order to properly design an adequate septic system for the building being planned,” says Ray Brosnan of Brosnan Property Solutions. Experts then measure the amount of time it takes for the water to absorb into the soil.
- What You’ll Need A perc test, or percolation test, is a soil test that is performed before installing a septic system tank. The perc test is extremely important because it measures the level of liquid absorption of the soil where the proposed septic tank will be located.
How is a perk test performed?
A perc test tests the rate at which water drains through the soil. A perc test is conducted by drilling or digging a hole (or multiple holes) in the ground, pouring water into the hole, and then observing the rate at which water percolates, or is absorbed in the soil.
What is a perk test and how is it done?
A perc test is conducted by drilling or digging a hole in the ground, pouring water into the hole and then observing the rate at which the water is absorbed into the soil. Most of the world’s septic systems are designed in a way that requires a septic drain field or “leach field” to drain away any excess water.
Why is a perk test done?
Perc tests determine the right and wrong locations for a septic system, and they’re often required by local jurisdictions before a new one can be built or an old one replaced. That’s because septic tanks work by holding wastewater long enough to naturally separate liquids and solids.
What happens if you fail a percolation test?
Failing the percolation test If you still fail after that, you’d either have to discharge very well treated water to a watercourse (only an option in NI) or avail of a ‘zero discharge’ system (constructed wetlands that do not require emptying).
What happens if my land doesn’t perk?
NO PERC, NO HOUSE On rural sites without municipal sewage systems, a failed perc test means that no house can be built – which is why you should make any offer to purchase land contingent on the site passing the soil and perc tests.
Can you do your own perk test?
If you’re planning to install a new septic system, local ordinances will require you to conduct a soil percolation test. In some jurisdictions, you can do the test yourself, but in others, including some parts of California, you need a qualified professional to do it.
How do you know if land will perk?
Suitability can be determined through a perc or perk test, formally known as a Percolation Test. This test determines the rate at which water drains through the soil. If the property does not pass the perk test, than a standard septic system cannot by installed. There are alternatives, but they can be very expensive.
Do perc tests expire?
Also, perc test results expire after 2-5 years in most locations, so you may need to retest or pay a fee to update the results when you are ready to build.
How much does a mound system cost?
Mound Septic System Cost A mound septic system costs $10,000 to $20,000 to install. It’s the most expensive system to install but often necessary in areas with high water tables, shallow soil depth or shallow bedrock.
How expensive is a perk test?
Perc testing typically costs between $750 and $1,850, according to HomeAdvisor. However, that is just one portion of the testing cost. You may need to conduct additional tests before building, such as a deep hole test or a seasonal high water table test, which will add to the total soil testing cost.
How long does it take to get a perk test back?
A perc test takes anywhere from 1 to 6 hours, depending on the size of the land and soil composition.
How do I get land perked?
In most jurisdictions, a perc test is performed when an official from the county health department meets with the owner of the property and/or a licensed excavator to dig a hole and test the drainage rate of the soil on-site (they literally pour water in a hole and time how long it takes to drain through).
What does PERC mean in real estate?
Does the land perc? Short for soil percolation rate, what this means is: can the land absorb water from a septic system? You will need to have a perc test done in order to find out. Usually performed by a soil scientist, the perc test analyzes the topography, the types of soil, and their ability to absorb water.
What is a mound septic system?
A mound septic system is an alternative to other septic tank systems. It rests near the top of the ground and does not use a container for the waste. This type of septic system disposes the waste through sand, and the ground will absorb the waste.
What is an engineered septic system?
What is an engineered septic system? An engineered septic system is often used in cases where a conventional septic system cannot be installed. The basic three limiting factors on the placement of the septic system are the ground water table, bedrock, and local health ordinances.
What Is a Perc Test?
Real estate has traditionally been the preferred investment for people seeking to accumulate long-term wealth for their families and future generations. By subscribing to our complete real estate investment guide, you will receive assistance in navigating this asset class. A perc test is essentially a measurement of the capacity of a piece of ground to drain – or percolate – water into the surrounding soil. A perc test, on the other hand, is not a perk of ownership for those who are developing land for residential and commercial purposes: it is almost always a necessity.
As previously stated by Fixr: “A septic tank, in contrast to municipal or town sewer systems, necessitates the installation of a drain or leach field.
Why do you need one?
Septic tanks should not be installed in soil that is incapable of adequately draining. The results can be unpleasant and expensive. When it comes to septic system placement, perc tests can tell you where you should put your system and where you shouldn’t. They’re generally needed by local authorities before a new system is created or an existing one is rebuilt. This is because septic tanks function by retaining wastewater for an extended period of time, allowing the liquids and solids to naturally separate.
There, they leak into the surrounding soil and into the ocean.
The greater the amount of sand and gravel, the better.
Eyeing rural property? Make sure it passes this test.
When it comes to rural sites without municipal sewer systems, a failed perc test implies that a house cannot be built. As a result, BuildingAdvisor.com recommends that any property purchase offer be contingent on the site passing both soil and perc tests before proceeding with the purchase. That’s becoming increasingly difficult to do as prime building sites become increasingly scarce and/or expensive in many regions of the country, and failed perc tests become more prevalent on what’s left.
What do they involve, and who does them?
The procedure is quite straightforward: drilling holes and measuring the amount of time it takes for water to drain through them. The percolation rate is simply the product of the amount of water that was poured into the holes divided by the amount of time it took for the water to drain. For example, if it takes two hours for water to drain two inches, it equates to a perc rate of one inch per hour. However, it is not quite that straightforward. While there are home test kits available, who digs the holes, where they are dug, and how the findings are interpreted are all essential considerations, which means that for anything more than lawn and garden usage, this is not a do-it-yourself task.
There are additional regulations governing how frequently the perc tests must be done, which are normally every two to five years.
How much do they cost?
According to Fixr, the national average is $750, with lows as low as $150 and highs as high as $1,500. If a survey is required, expect to pay an additional $575 on average. Discussion with an engineer about your intentions for the land, followed by the labor-intensive process of digging at least two holes 40 feet apart and returning to examine how everything drains are all part of the package. Engineers and professionals may also assist with challenges such as solutions for decreasing high water tables, among other things.
Perc Testing and Soil Testing – What You Need to Know
This Article Discusses If you don’t have a perc, you don’t have a house. Test with a Deep Hole Testing with Percs SetbacksClearances Alternatives in the Event of a Site Failure View and post commentsQuestions Septic System Frequently Asked Questions SEPTIC SYSTEM articles can be found here. Traditional septic systems can only function well if the soil in the leach field region is sufficiently porous to allow the liquid effluent flowing into it to be readily absorbed by the soil. A failure to do so will result in untreated wastewater backing up and pooling on the surface.
- It is in this soil layer that the majority of the treatment takes place.
- This happens less frequently.
- Depending on the municipality, particular criteria may differ, however any of these qualities may exclude the installation of a basic gravity-fed septic system.
- A percolation test (often referred to as a “perc test” or “perk test”) is necessary to assess if a construction site is appropriate for a septic system installation.
NO PERC, NO HOUSE
A failed perc test on a rural site without municipal sewage services implies that no home may be built, which is why you should make any offer to acquire property contingent on the site passing both the soil and the perc tests before proceeding with the purchase. Percolation or perc tests are becoming increasingly popular in rural areas as prime building sites become increasingly uncommon (or prohibitively costly) in many sections of the country. Rural sites that do not pass the percolation or perc test are becoming increasingly common.
- Soils are often classified as either coarse sand and gravel particles or microscopic silt particles, with minuscule clay particles — the tiniest – making up the majority of their composition.
- Before investing time and money in testing, dig down to the lighter soil beneath the first few inches of topsoil (loam) and get a handful of it to have a good notion of what you’re dealing with.
- It shows that the soil has a high clay content and that it may fail a typical perc test if you are able to construct a ribbon of dirt 2 inches or longer in the ribbon test.
- Testing requirements differ significantly from state to state and frequently from town to town, since most governments let small municipalities to develop their own laws within the framework of state regulations.
a. Though not all of these tests require the services of a certified professional, it’s a good idea to engage a seasoned expert with extensive local knowledge because many of these tests have some wiggle space.
DEEP HOLE TEST
The majority of studies begin with a deep hole test that is excavated by machine to a depth that is considerably below the bottom of the planned leach field – often 7 to 10 feet deep or more. High water tables, as well as the presence of rock ledges or impermeable soil that will prevent water from being absorbed, are sought for by the testers. In certain regions, testers are also looking for drainage features in the soil. It may not be necessary to carry soil samples back to the lab; instead, visual observations of the soil strata may be adequate.
- It requires a trained eye to spot soil mottling, which is a sign of a seasonal high water table – at a depth of about 2 feet here, the water table is around 2 feet deep.
- Actual observations are utilized to determine the “limiting zone,” which is the area of soil where the soil is unsuitable for sewage treatment.
- The existence of a seasonal high water table may be visually determined by checking for “mottling,” which are splotches or streaks of color in the soil that indicate the presence of water on occasion.
- For situations when the limiting zone is too close to the surface to be accommodated by a normal leach field, a mound or other alternate septic system may be necessary.
- However, while the vast majority of soil specialists think that soil observation may offer sufficient information for the design of a functional septic system, most states now mandate perc testing to directly quantify the rate at which water percolates through the soil (perc testing).
- The results indicate whether or not a septic system can be implemented in a given community, and the results are used by system designers to calculate the size of the leach field.
SEASONAL HIGH WATER TABLE
Under specific situations, certain towns may additionally require direct testing of the seasonal high water table to be performed. For example, this may be necessary for some types of alternative energy systems or in places where the water table is known to be high. The most common method is to dig tiny monitoring wells, which are also known as piezometers. The monitoring wells are simply plastic pipes that are screwed into holes that have been dug into the earth.
Water is monitored in the pipes during the wettest time of the year, which is between June and September. It is necessary to have appropriate clearance between the bottom of the drain field trenches and groundwater in order for a system to be certified by the city.
PERC TESTING
To conduct a perc test, first consult with a representative from the local health department. Requirements can differ significantly from town to town in terms of who can conduct the test, the minimum number of holes, the depth of the holes, the required absorption rates, and the time period during which the tests can be conducted. In general, tests cannot be performed in frozen or disturbed soil, and some regions only allow tests to be performed during specific months of the year – so prepare ahead of time.
- If the test fails, you may be forced to invest in a more expensive alternative technology, or the site may be deemed unusable.
- A typical perc test consists of two or more holes drilled around 30 to 40 feet apart in the planned drain field region, with the holes being approximately 30 to 40 feet apart (see illustration).
- After that, either you or the technician should fill the bottom of the hole with 2 inches of clean gravel.
- Remove any loose soil from the bottom of the hole with a sharp tool as well.
- Continue to add water until there is approximately 12 inches of water in the hole for at least 4 hours.
- The next day, carefully wipe away any loose dirt that has fallen to the bottom of the holes and gently fill each hole with water to a depth of 6 inches over the level of the gravel in each hole.
- The timings are then meticulously recorded and used to compute the percolation rate, which is the amount of time it takes for one inch of water to descend into the ground.
- When using a normal gravity-flow septic system, a 60-minutes per inch (MPI) rate is commonly used as the cutoff point, indicating that the water dropped one inch in 60 minutes.
- Some municipalities demand extra “hydraulic” soil testing for locations that test higher than 30 minutes per inch in some instances.
- Water absorbs too quickly below that level to be efficiently treated before it reaches the groundwater table.
The hole with the weakest performance is the one that matters. The presence of a town official to witness the test is required in certain communities. Perc test regulations differ significantly from one municipality to the next. The following are some general ranges for soil permeability:
- Lower than 5 MPI: Extremely porous soil. Alternative systems, such as pre-treatment of effluent, pressured dosing, or the addition of denser soil surrounding trenches, may be permitted. A conventional leach field with a flow rate of 5 to 60 MPI is authorized. 60 – 120 MPI: Soil with a low water-holding capacity. Alternative systems, such as pre-treatment of effluent, pressurized dosing, improved treatment, mound systems, and other alternative systems, may be permitted. When the MPI is more than 120, the soil is said to be very low-permeable. It may be possible to use alternative technologies that provide improved wastewater treatment under certain situations.
In most circumstances, test findings are valid for two to five years, and in some cases they can be extended. However, like with all things perc, rules vary significantly from town to town, so don’t make any assumptions about what to expect. Always check with the local health department before embarking on a project.
OTHER SITE CONDITIONS
Septic system rules vary greatly from municipality to municipality, although the majority of municipalities demand that the leach field satisfy specified specifications in addition to passing the perc test. Some of the most typical stumbling blocks are as follows:
- Slope with a lot of incline. Typically, the maximum permitted slope for a conventional system varies between 20 and 30 percent
- Filled land Most of the time, native soils are necessary, while manufactured fill may be acceptable in rare instances. Wetlands and floodplains are two terms that are used to describe the same thing. This is not suitable for the leach field. Site drainage is important. During rain storms, the leach field should not be in the path of runoff, which might result in system erosion or flooding.
SETBACKSCLEARANCES
It is necessary to maintain a minimum distance between the septic tank and leach field and any structures, property lines, water pipelines, wells, or bodies of open water. In the case of tiny locations, a variance may be necessary in order to provide adequate space. It is possible that you will be required to find adequate area for both the current leach field and a replacement field, which will be used in 20 or 30 years after the original field has been depleted of its capacity. The number of clearances varies from one town to the next.
SEPTIC SYSTEM MIN. CLEARANCES (typ.) | ||
Distance to | Septic Tank | Leach Field |
House | 10 ft. | 10-20 ft. |
Property line | 10 ft. | 10 ft. |
Private well | 50 ft. | 50-100 ft. |
Potable water piping | 10-25 ft. | 25 ft. |
Open water(stream,pond, wetland, etc.) | 50-100 ft. | 100 ft. |
Dry gulch/stream bed | 10 ft. | 25 ft. |
Subsoil drains | 10 ft. | 25 ft. |
Note:Always check with local codes |
OPTIONS IF SITE FAILS
Even if your site fails a perc or deep-hole test, it is not always doomed to failure. It may be possible to “de-water” the drain-field area on sites with high water tables by strategically constructing gravel-filled trenches and subsurface drain pipes to divert water away from the drain-field region. To complete this project, you’ll need the services of a highly skilled earthwork contractor, as well as the assistance of a civil engineer or geotechnical engineer. Additionally, in recent years, a diverse range of alternative septic systems have been created for use on a variety of different types of sites.
- In general, these systems are more expensive, and many of them require additional components such as pumps, alarms, and other devices that necessitate more monitoring and maintenance than a normal sewage system.
- Building lots that were formerly considered unbuildable may become authorized building lots when alternative solutions become more prevalent and broadly recognized.
- Look for a contractor that has previous expertise installing the precise system you are considering as a second option.
- A clogged septic system is not a pleasant sight or scent to see.
- In order to do a perc test, who should I hire?
- Is It Possible for Septic Systems to Last a Lifetime?
How Much Slope Do You Need for a Septic Line? Performing an Inspection on a Septic System When Is the Best Time to Take a Perc Test? Should I use a Sand Filter with my existing septic system? Examining the condition of the wellSEPTIC SYSTEMView all articles
What Is A Perc Test? 14 Things You Should Know in 2022
When conducting due diligence before to purchasing a property, a perc test is an essential part of the procedure that must be completed (also known as a percolation test). The soil’s water absorption rate is determined by doing a perc test (or the percolation rate). Understanding whether or not an aseptic system can be implemented is critical to the process. In brief, if a piece of land is located in a rural area and a municipal sewer system is not accessible, a septic system can assist in making the site “livable.” A perc test is required for anybody purchasing land with the intention of constructing a home or living on it.
1. A perc test tests the rate at which water drains through the soil
It is necessary to do a perc test by first drilling or excavating a hole (or numerous holes) in the ground, then pouring water into the hole and watching to see how quickly the water percolates through the soil. This test is generally carried out by a licensed excavator or engineer, but it is closely monitored by your local health agency to ensure its accuracy. Depending on the type of soil on your land, it may or may not be able to pass this test with relative ease. In the sixth section, we’ll go through the soil criteria that will offer your property the best chance of passing the test.
2. A perc test is only necessary if a property doesn’t have access to a municipal sewer system
A perc test, which allows you to install a septic system on your land if your property does not already have access to a municipal sewage system, is only required if your property does not already have access to one. Keep this in mind while conducting your due diligence since it may obviate the necessity for a perc test entirely. You’ll want to check to see if the unoccupied site is within walking distance of a sewage line that’s already in place. If this is the case, there is no need for a septic system to be installed.
The results of the perc test will be required by the majority of county health authorities in order to decide whether or not the property is fit for the system.
If you want to avoid having to perform a perc test completely, seek for properties that already have sewage hookups while you’re looking for land to purchase.
3. Be sure to check with the county’s health department
To get the phone number of your county’s health department, all you have to do is Google the name of your county and “health department” to obtain their contact information. You’ll want to contact the health department ahead of time to verify that you understand the procedure and requirements and that there are no bumps along the way. Also keep in mind that, regardless of what you learn on the internet, each county has its own set of criteria that might differ from one location to the next.
Make careful you follow the instructions of your local health agency. You will almost always require a health department official to be present for your perc test, so make sure to arrange for this before the excavator comes out to do the job.
4. A failed perc test will complicate your plans to build
Okay, so you already know that a perc test is required in order to establish a septic system, and you also know that most landowners will not install a septic system if a municipal sewage system is available as an alternative. However, what happens if you fail the perc test and are unable to have a septic system installed? Several landowners are confronted with this issue. When looking for property, it is important to remember that if it does not pass the soil and perc tests needed by county health authorities, it will be impossible to construct a home on it.
Even while it may be tempting to acquire the land anyhow and attempt to make anything work, it is necessary to consider the worst-case situation before proceeding.
5. Don’t panic if your land fails a perc test
You make the decision to acquire land that has failed a perc test. You are aware that this indicates that it is not constructible. What are you going to do? Do you intend to put it on the market? Do you just let it go to waste? Is it too late to save the situation? What are you going to do? Don’t panic is the first step to taking action. Just though your property failed a perc test does not rule out the possibility of constructing something on it. If you’re ready to spend additional money on an engineered system or a raised sand bed to assist fix the drainage issue, you may be able to get around this problem.
- If your perc test fails, here are some alternate paths you might try.
- Other perc tests may have been performed previously, so check with the health department.
- While you may have had a perc test performed in one section of the property, it is possible that a former owner performed one in another.
- In contrast, if you aren’t testing that particular portion, you will continue to fail.
- The fact that you have one failed perc test does not necessarily imply that you have failed completely, or that the land is a lost cause.
- People generally consider this to be a long shot, but you’ll never know unless you give it a go.
- This will bring you closer to knowing if the answer is a definitive “no” or whether you can take certain changes on your land to make it more constructible.
If the water table is low, you have a better chance of passing a perc test, and in many regions, the water table is more likely to be low during particular seasons.
Find out when the failed perc test was done, and if it occurred during a time when the water level in your region would have been high, you may have a second opportunity at success on your hands.
In addition to being fairly priced (depending on your property’s circumstances and local standards), there are ecologically acceptable alternatives to traditional septic systems.
In the case of making an otherwise unbuildable property buildable again, it may be well worth the effort to invest in.
If your property has varied topography, it may make a significant impact in the different types of soil that can be found on your property.
Allow your excavator to test a few different locations on your property to ensure that you are not giving up too soon.
Occasionally, if you wait long enough, municipal water and sewer service will become accessible in your neighborhood. It might be a tedious and time-consuming waiting game, but it may be worth your while in the end. You should just wait it out if it’s the right piece of property for you.
6. The type of soil your property has plays a large role in whether or not it passes
When soil has significant percentages of sand and gravel, it is more likely to pass the perc test. This is due to the fact that sandy soil absorbs water at a far higher rate than clay, silt, or solid rock. When the land is located in a region with a low water table, it also does a better job of absorbing water than when it is not. Generally speaking, soil will fall somewhere in the center of any of the following. The granules of sand and gravel Silt particles of a small size Clay particles of minuscule size (the smallest)
7. You can do a few tests on your own soil to see what you have
A basic notion of the texture of your soil may be obtained without having to invest the time and money in a perc test. Here are a few examples of how you can go about it. Using a shovel, dig down to the lighter soil beneath the first few inches of topsoil, also known as loam. Take a handful of them. Clay texture is present in substantial amounts in soil that is sticky and moist in texture and may be formed into a long, thin ribbon or worm that retains its shape. The ribbon test is used to determine whether or not you are able to construct a ribbon of dirt that is 2 inches or more in length.
You may also use this Home Soil Percolation Test to determine soil percolation.
8. The perc test procedure varies based on the municipality
In the end, the perc test technique differs depending on where you are in the world. A perc test, on the other hand, will almost always be done by a licensed excavator in most countries. In addition to the owner, a representative from the county health department will be present during the test. The excavator will normally dig two deep holes to evaluate the drainage rate of the soil on the job site, and the results will be recorded. Using simple equipment, kids pour water down the hole they dug and measure how long it takes for the water to drain in minutes per inch.
As a result, you must normally have an official present to ensure that the exam is properly observed.
9. A perc test does not last forever
In most cases, perc tests are valid for 2-5 years, while the actual length of time varies depending on the local regulatory authority. As a result, it is critical to know when the most recent perc test was performed. It is necessary to commission a new test if you wish to construct on the lot if the existing test is older than 10 years old.
10. There are some common limiting factors for septic systems beyond a perc test
If you pass the perc test, it is possible that you may not be free of trouble. Is it true that most towns demand that a septic tank drain field (also known as an aleach field) fulfill particular specifications that go above and beyond simply passing a percolation test? We bet you didn’t realize how tough it may be to prepare property for construction! Consider the following points to be aware of even before you get down to the nitty-gritty of septic system rules. Slope with a lot of incline: The highest permissible slope for a typical system is between 20 and 30 percent, depending on the system.
The use of engineered fill may be appropriate in particular situations.
Wetlands and floodplains are two types of floodplains.
It is not permitted to construct a septic tank drain field in wetlands or flood zones. Drainage on the job site: During storms, it is important that your septic tank drain field is not in the route of runoff. This has the potential to produce erosion or floods in the system.
11. There is a minimum distance required for a septic tank
There are minimum distances that must be maintained between a septic tank and its drain field, as well as between the tank and other structures, property lines, water pipelines, wells, and open water. Even though the actual lengths will differ from one region to another, the most essential criteria to bear in mind is the minimum distance between the planned leach field and any privately owned wells (which is usually around 100 feet). You’ll need to be aware of these distances in order to comply with local regulations, and you may be required to select a new field to utilize in 20-30 years after the original field is depleted.
12. A perc test costs between $150 to $1,500
Performing a perc test will cost you something, just like anything else in life, and the cost might vary greatly depending on who you employ and how much work is necessary. Keep in mind that $1,500 is on the higher end of the spectrum, so you shouldn’t be overly overwhelmed by the figure itself.
13. You can use context clues if you want to avoid a perc test
Again, while it’s frequently advised to have a perc test performed before to purchasing a house, we understand if you’re attempting to keep under a specific spending limit. In most cases, there are several plainly visible criteria that can assist you in determining whether or not your property is likely to pass a perc test. You don’t want to pay anything? Make use of the clues provided by the context! Take a look at your immediate surroundings. Do they have any structures on their land? Is it clear that they passed the perc test on the surface?
- While there is no assurance, if you are ready to take the risk, there is a good probability that you will succeed.
- A nearby body of water might indicate a number of different things, including water that is close to the surface, wetlands, or a flood zone, among others.
- The expense of a perc test may be justified in this situation.
- Can you describe the geography of your land in more detail?
- Is there an incline to it?
- Taking these considerations into account may assist you in deciding whether or not to have one – in either direction.
14. There are options for a non-buildable property
That is to say, you failed your perc test and were unsuccessful with any of the other options. Never be concerned! We have some options for those of you who will not be able to establish a septic system on your land due to financial constraints.
- Storage facilities, pole barns, horse stables, grazing areas, crops, orchards, camping, hunting, lumber, mining, and drilling are some of the possibilities.
Even if your perc test did not turn out the way you had hoped, don’t give up on the possibility of putting your property to good use.
Final thoughts
A perc test is a basic test that is done to determine how well water drains on your land and if it is appropriate for a septic system installation. If a property does not already have water or sewer hookups, a septic system might be installed to assist make it habitable. When landowners receive a failed perc exam, they are frequently stressed. If this occurs to you, take a deep breath and regroup. You have two options: either repeat the steps in 5 and attempt to get a different result, or choose one of the alternate uses for your property in 14.
Don’t give up hope!
Additional Resources
If you are seeking for inexpensive land to purchase, you may find it on our Listings page. Before you acquire property, be sure to review the Gokce Land Due Diligence Program to ensure that it meets your needs. If you are wanting to sell land, please see our article on How to Sell Your Land for more information.
Would you like to receive an email with our latest blog/properties every Thursday?
Now is the time to subscribe. I hope you have found this content to be interesting. If you are interested in purchasing or selling land, you should look into the following: Disclaimer: We are not attorneys, accountants, or financial advisors, and the information contained in this article is provided solely for informative reasons. Our own research and experience have informed this post, and while we strive to keep it accurate and up to date, it is possible that some inaccuracies have occurred.
- Erika is a former Director of Affordable Housing for the City of New York who has transitioned into a full-time land investor.
- She graduated with honors from the University of Southern California with a Bachelor of Architecture and with a Master of Urban Policy from Columbia University before establishing Gokce Capital.
- Erika presently resides in the New York Metropolitan area with her husband, daughter, and cat.
- She is originally from Chicago and still considers herself to be a midwesterner at heart, despite her current location.
- ), Erika has a lot of interests.
- Erika’s most recent blog entries (see all)
Perc Testing and What to Do If The Site Fails
It is only if the soil in the leach area is sufficiently porous that it can quickly absorb the liquid effluent flowing into it that traditional septic systems will function properly. There must also be at least a few feet of decent soil between the bottom of the leach pipes and the rock or impermeable hardpan below, or between the bottom of the leach pipes and the water table. A site can also fail because the soil is excessively porous, enabling the effluent to reach the groundwater before it has had a chance to be thoroughly treated.
Slopes that are too steep for a typical leach field are likewise inappropriate for them.
In rare instances, an alternate septic system that is more expensive may be permitted. A percolation test (often referred to as a “perc test” or “perk test”) is necessary to assess if a construction site is appropriate for a septic system installation.
NO PERC, NO HOUSE
A failed perc test on a rural site without municipal sewage services implies that no home may be built, which is why you should make any offer to acquire property contingent on the site passing both the soil and the perc tests before proceeding with the purchase. Percolation or perc tests are becoming increasingly popular in rural areas as prime building sites become increasingly uncommon (or prohibitively costly) in many sections of the country. Rural sites that do not pass the percolation or perc test are becoming increasingly common.
Soils are often classified as either coarse sand and gravel particles or microscopic silt particles, with minuscule clay particles — the tiniest – making up the majority of their composition.
The other major test is visual examination of the soil in a test pit, which is also known as a deep hole test.
Check with your town’s health officer to find out what tests are required, when they may be performed, and who should be responsible for doing them.
DEEP HOLE TEST
The majority of studies begin with a deep hole test that is excavated by machine to a depth that is considerably below the bottom of the planned leach field – often 7 to 10 feet deep or more. It may not be necessary to carry soil samples back to the lab; instead, visual observations of the soil strata may be adequate. In order to determine the drainage properties of the soil, the presence of a seasonal high water table, and the depth of the “limiting zone,” which is the area where the soil is unsuitable for sewage treatment, soil tests or observations are conducted.
The higher layer of the water table, as well as impermeable rock or soil, form the limiting zone of a body of water.
Typically, the water table or impermeable soil in the leach field must be at least 3 feet below the bottom of the trenches in order for the leach field to be effective.
The speed at which water drains into a standard-sized hole in the ground is measured by this test. The results indicate whether or not a septic system can be implemented in a given community, and the results are used by system designers to calculate the size of the leach field.
PERC TESTING
To conduct a perc test, first consult with a representative from the local health department. Requirements can differ significantly from town to town in terms of who can conduct the test, the minimum number of holes, the depth of the holes, the required absorption rates, and the time period during which the tests can be conducted. In general, tests cannot be performed in frozen or disturbed soil, and some regions only allow tests to be performed during specific months of the year – so prepare ahead of time.
However, like with all things perc, rules vary significantly from town to town, so don’t make any assumptions about what to expect.
OTHER SITE CONDITIONS
Septic system rules vary greatly from municipality to municipality, although the majority of municipalities demand that the leach field satisfy specified specifications in addition to passing the perc test. Some of the most typical stumbling blocks are as follows:
- Slope with a lot of incline. Typically, the maximum permitted slope for a conventional system varies between 20 and 30 percent
- Filled land Most of the time, native soils are necessary, while manufactured fill may be acceptable in rare instances. Wetlands and floodplains are two terms that are used to describe the same thing. This is not suitable for the leach field. Site drainage is important. During rain storms, the leach field should not be in the path of runoff, which might result in system erosion or flooding.
SETBACKSCLEARANCES
It is necessary to maintain a minimum distance between the septic tank and leach field and any structures, property lines, water pipelines, wells, or bodies of open water. In the case of tiny locations, a variance may be necessary in order to provide adequate space. It is possible that you will be required to find adequate area for both the current leach field and a replacement field, which will be used in 20 or 30 years after the original field has been depleted of its capacity. Clearances differ from one municipality to the next, so always verify with local codes.
OPTIONS IF SITE FAILS
Even if your site fails a perc or deep-hole test, it is not always doomed to failure. It may be possible to “de-water” the leaching region on locations with high water tables by strategically constructing gravel-filled trenches and subsurface drain pipe to direct water away from the leaching area. To complete this project, you’ll need the services of a highly skilled earthwork contractor, as well as the assistance of a civil engineer or geotechnical engineer. A broad variety of alternative septic systems have also been created in recent years for usage on a wide variety of different types of land.
In general, these systems are more expensive, and many of them require additional components such as pumps, alarms, and other devices that necessitate more monitoring and maintenance than a normal septic system.
When it comes to modern building technology, though, it’s important to seek for items and systems that have a proven track record on the job. Morse Engineering and Construction can be contacted for additional information. Source:buildingadvisor.com
All About the Percolation Test Required for a New Septic Tank
Septic systems enable you to construct a house or business on even the most distant of lands that are not already served by a sewer system. A septic tank’s suitability for a particular property, on the other hand, requires more than simply the owner’s willingness to spend the money to install one. Prior to granting approval for a permit for the installation of the system, your county will need that you do a percolation test, which is also known as a perc test. Learn everything you can about this test before it is conducted so that you are well prepared for the procedure.
- A percolation test determines how well the earth drains in a specific area of a building’s foundation.
- It may be necessary to conduct a number of percolation tests before determining the best site for a septic tank.
- What is the procedure for testing percolation?
- It is necessary to dig a hole of specific depth and fill it with water before measuring how long it takes for the water to completely drain into the surrounding soil in each test.
- The soil’s water absorption rate will not be reliably measured if the holes are too small.
- Contractors often dig at least two pits at opposing ends of the intended drainage system to ensure that the entire region drains at an appropriate rate during the project.
- The majority of percolation tests are performed prior to the construction of a new septic tank.
In certain situations, relocating a system necessitates the performance of a percolation test as well, as the new location may have different soil drainage characteristics.
If you want to save money and learn more about your property’s drainage system before paying for any expert maintenance, you may dig your own percolation test pit.
If you decide to dig your own pit, make sure to slope all of the sides to both prevent the surrounding earth from collapsing and to allow you to escape if you do fall into the pit.
It is safer to slope all four sides of the task while doing it by hand with a shovel rather than using a machine.
If you fail a percolation test, you will be unable to construct a typical septic tank in the region where the test was conducted.
We at Walters Environmental Services invite you to schedule a professional percolation test with us now to determine whether your site is suitable for the installation of a septic system.
How to Do a Perk Test for Septic Tanks
Performing a soil percolation test will be required if you’re going to build a new septic system in accordance with local regulations. Depending on your jurisdiction, you may be able to do the exam yourself, but in certain cases (including some sections of California), you may need to hire a certified professional to perform the test. The percolation rate of the soil is determined in minutes per inch, and as long as it is within the limitations set by the local health authority, the test may be used to establish the size of the drain field that is necessary.
- It is possible for groundwater to get contaminated if the soil is sandy and drains too rapidly.
- However, if the soil contains a high concentration of clay and drains too slowly, raw sewage water will linger near the top and may pool there.
- The majority of the time, it takes two days to complete a perk test.
- Furthermore, you should never do a perk test on soil that is frozen or frosty.
The Basic Idea Behind a Soil Percolation Test
The length of time it takes for water to drain is measured by a perk test. Pouring water over the earth would not be sufficient to determine this; thus, holes must be dug to collect the water. The majority of countries need more than one hole, with a minimum amount of space between each one. Keep in mind that the greater the number of holes you dig, the more accurate the test will be. This is especially true if the soil qualities vary greatly over the region of the planned drain field. After the holes have been excavated, scrape the sidewalls of the holes to remove any soil that has been compacted by the digging tool; then, pour gravel into the bottom of the hole to fill it.
Some governments in locations with damp soil demand deeper holes to be dug using a backhoe, which must be done by hand.
If you live in an area where smaller holes are needed, the size and number of holes you dig, how deep you cover the bottom of the hole with gravel, and how long you let the soil to absorb water are all limited by local regulation.
A General Procedure for Conducting a Perk Test
When digging the holes by hand, you’ll need a post-hole digger, a source of water, a timer, and a mechanism for properly measuring the depth of water in each hole starting at the top of each hole.
In addition to using a long ruler to measure with, you may also tie a little hollow ball to a rope and use it as a float to be more precise. You may attach the string to a pulley system and move the string up and down the length of a ruler while following a marking on the string.
- Excavate the test holes – Most jurisdictions require the test holes to be 4 to 6 inches in diameter and sunk to a depth ranging from 18 to 36 inches. It is necessary to have at least two holes, but it is preferable to have more. When evaluating a plot for a prospective drain field, you should position the holes at a distance of more than 50 feet apart.
- Make the test holes in advance– Scrape down the sidewalls of the holes with a knife or other pointed tool to create a natural interface for the water to seep through to the bottoms. Remove any debris from the hole and then fill it with 2 to 6 inches of gravel to form the bottom. If possible, line each hole with mesh to prevent soil from sliding down the edges of the hole and into the bottom of the hole. A perforated drainpipe is recommended by some contractors to be inserted into each hole to prevent dirt from falling through.
- Prepare the soil by filling each hole with water and covering it with a lid, and then keeping it full for four hours. After you have completed this step, you must wait 18 hours before conducting the real test. That means you’ll have to wait until the next day, so make sure you cover the holes overnight.
- Carry out the real examination – Water should be filled into the hole to a level 12 inches above the gravel. Then, you should time how long it takes for the water level to drop to a level 6 inches above the gravel. Some authorities require you to repeat this test three times on each hole, and even if yours does not, it’s a good idea to do so as a precautionary measure anyway. Because of this, outcomes are more dependable.
- It is a good idea to keep track of your results in a table with headers for the hole number, the depth of water when you started, and the depth of water when you finished your round. For each row of the table, the reading is represented by a different letter.
Interpreting the Test Results
You’ll need to translate each result to minutes per inch, which you can accomplish by dividing the number of minutes it took for the water level to drop 6 inches by the number of minutes it took for the water level to drop 6 inches. Please keep in mind that if it takes more than 6 hours for the water level to drop by this amount in any hole, the location is not ideal for a septic drain field, and you should terminate the test right then. If you dig less than five test holes, the percolation rate with the slowest percolation is the one you state on the septic permit application, even if you dig more.
Consider the following percolation rates, which you would want to keep track of:
- 24.7 minutes per inch
- 20.5 minutes per inch
- 32.4 minutes per inch
- 31.3 minutes per inch
- 40.5 minutes per inch
There is an average percolation rate of 30 minutes per inch of depth, which is substantially greater than the lowest rate, which would be required to be reported if you just dug two holes. A higher percolation rate may allow for the installation of a bigger septic system.
Is the Site Suitable for a Septic Drain Field?
It is only one of the parameters that determines whether a site is appropriate for a drain field that soil percolation is measured. It is necessary to consider the height of the site, its placement relative to rivers, and the slope of the ground while calculating the equations.
- Sites that are higher in elevation than the septic tank are typically inappropriate unless there is a significant amount of separation between the site and the tank itself. Choosing such a location will need the installation of a transfer pump in the tank.
- It is not permitted to site drain fields in close proximity to wells, streams, or other waterways, although the exact distance between them is usually decided by the local health inspector.
- In addition to the danger of roots infiltrating the leach field pipes, densely wooded locations are undesirable for this use.
- Rocky terrain, as well as low-lying marshy places, are clearly inappropriate for this purpose.
- Septic fields should not be built on steeply sloping terrain, especially if the area slopes toward a canal or an adjacent property
- Instead, they should be built on flat land.
There are options available if your building site does not have a plot of ground appropriate for use as a septic drain field, including having a drainage system designed. You may also think about installing a sewage lagoon, in which the outflow from the septic tank is held above ground and cycled and aerated by a pump to keep the water clean. The use of this method may be appropriate in a rural, wooded environment with a high concentration of steep gradients and streams.