How To Run Sewer Pipe Pitch To Septic Tank? (Solution)

  • Slope the pipe 1/4 inch per foot (1/8 inch per foot minimum) toward the tank. Similarly, you may ask, how do you run a sewer line to a septic tank? A typical septic tank has a 4-inch inlet located at the top. The pipe that connects to it must maintain a 1/4-inch-per-foot slope toward it from the house.

How do you pitch a sewer line?

It is generally accepted that 1/4″ per foot of pipe run is the minimum for proper pitch on a sewer line. Larger lines such as 8″ pipe actually require less pitch due to the larger circumference of the pipe.

What is the minimum fall for a sewer pipe?

For 4-inch PVC piping and a building sewer less than 50 feet long, the minimum slope is 1 inch in 8 feet, or 1/8-inch per foot, and the maximum is 1/4-inch per foot. For sewers longer than 50 feet, the slope should be 1/4-inch per foot.

How steep can a sewer line be?

What is the proper slope or pitch for a drain waste pipe? Plumbing codes and wastewater piping guides commonly specify that building drains should be pitched at 1/8″ to 1/4″ of slope per foot of linear run or distance.

What size pipe goes into septic tank?

Four-inch pipe is standard, and it should extend far enough under the house to connect with the main soil stack, which is a 3-inch pipe that extends vertically past the main bathroom and through the roof.

What kind of pipe goes from house to septic?

The septic tank should be positioned at least 50 feet from the house proper. ABS or PVC plastic or cast iron pipe can be used to connect the tank to the house drainage system. [We do not recommend using clay pipe nor “orangeburg” pipe.]

Can you put a 90 in a sewer line?

You should design your wastewater pipes in a similar manner, for the most part. It’s a bad plumbing practice to have a hard 90-degree bend in a horizontal drain line that’s buried in a slab or otherwise hidden. All drain lines should have a minimum fall of an eighth of an inch per foot of horizontal run.

What is the fall of a 4 inch sewer pipe?

The minimum slope for a 4-inch PVC gravity flow sewer pipe is 1/8 inch per foot.

How much pitch does a toilet drain need?

The plumbing code requires drain pipe to be sloped at a minimum of 1/2 inch per foot and a maximum of three inches per foot or vertical. A slope of less than a quarter-inch per foot will cause a lot of drain clogs and a slope of more than three inches will allow the water to drain.

Can you install septic on a slope?

Why Drainfield Effluent lines need to be properly sloped If you have to install a conventional perforated pipe and gravel trench drainfield on a steep slope you’ll need to run the trenches along the slope or parallel to the fall line, stepping down the slope from trench to trench.

How to Run a Septic Tank Line From Your House

A septic system is made up of two lengths of pipe that are connected together. Initially, it runs from the house, where the system services are located, to a tank, where the waste is separated and solids settle out. The second section runs from the tank to the drainage field, where fluids from the tank are dispersed into the earth underneath the tank. The process of installing the first run of pipe is quite similar to that of installing a traditional sewage line. It is necessary to maintain a downhill slope to the storage tank.

Locating the Septic Tank

The tank serves as the nerve center of the septic system. It is required to be situated between the residence and the drainage field. Each and every septic installation must begin with a soil test, and depending on the results, soil conditions may necessitate the placement of the tank in a less-than-ideal site for digging sewer lines. Also required are minimum setback distances from property borders, functioning wells, surface water and other obstructions to provide a safe working environment.

Tank Depth

A standard septic tank has a 4-inch intake at the top, which is positioned towards the bottom. Ideally, a 1/4-inch-per-foot slope toward the pipe from the house should be maintained by the pipe connecting to it. To put it another way, for every 10 feet of distance between a tank and a home, the inlet must be 2 1/2 inches lower than where the pipe departs the house at its lowest point. The pipe usually exits at ground level, although it may need to pass beneath a foundation footing or concrete pad in rare cases.

Digging the Trench

The trench for the septic pipe should be dug before the hole for the tank since you will need a backhoe to complete the work and the tank will get in your way if it is already in the ground. To allow rainfall to drain properly, the pipe should be placed on a 2- or 3-inch bed of drain rock, so remember to account for this extra depth when digging. It is normal to use a four-inch pipe, and it should be installed far enough down to link with the main soil stack, which is a three-inch pipe that runs vertically past the main bathroom and through the roof of the home.


Local building and health agencies will demand permits for a septic tank installation. You will also be required to submit a design plan before the permits will be provided, so prepare ahead of time. This layout should be developed in collaboration with a local builder who is familiar with the unique characteristics of the topography in your neighborhood. Stay away from planting trees or plants near the tank, drainage field, or any of the pipe systems.

They will be drawn to the pipes in their hunt for nutrition, and their roots will be able to successfully block them. You will be unable to use your septic system until the roots have been removed from the pipe. Removal may be both expensive and time-consuming.

installing drain piping on steep slopes

  • In this section, you can ask questions and express your opinions regarding sewage or septic pipe lines on steeply sloping premises.

InspectAPedia does not allow any form of conflict of interest. The sponsors, goods, and services described on this website are not affiliated with us in any way. Installing or replacing sewer lines on steep hills is a challenging task. This article discusses the construction of drain lines on steep slopes between a house and a septic tank, as well as the maintenance of drain lines. For this topic, we also have anARTICLE INDEX available, or you may check the top or bottom of the page. Use the SEARCH BOX to discover the information you’re looking for quickly.

Guide to installing the replacement sewer pipe line at Steep Sites

Using real-world examples and photographs, we demonstrate how to diagnose and replace a clogged sewage line in an actual case study. Septic or sewage line blockage and backups may be prevented by having the proper drain line slope installed. In this section, we will talk about

  • Septic pipe installed in a zig-zag pattern on steep hillsides
  • Septic pipes with a U-turn on steep hillsides
  • Septic pipework running parallel to the fall line of a slope Designing steep septic systems for sewer or septic pipe repair or new installations

When it comes to a drain waste pipe, what is the right slope or pitch to use? When wastewater travels at the proper pace via a drainpipe, the water transports solid waste, such as feces and toilet paper, as well as water, to a septic tank or sewage mains for disposal. Generally speaking, plumbing rules and wastewater piping guidelines state that building drains should be pitched at a rate of 1/8” to 1/4” of slope for every foot of linear length or distance. Problems associated with steep dips between the home and the septic tank include: A steep building site, such as the one depicted in our page top photograph, can result in a significant drop in elevation between a building main drain and the septic tank inlet opening (or sewer main connection), resulting in waste piping slopes that exceed the recommended limits for slope in the waste piping.

If waste passes through the sewage line at a rate more than 2 fps, there is a possibility that water will leave sediments behind in the pipe, resulting in recurring obstructions.

ZigZagging Drain Line Piping Down a Slope

zigzagging the pipe down a steep slope, making multiple bends, would be one method of reaching the required wastewater flow rate in a drain line down a steep slope. However, in my opinion, the increased number of turns and length of this approach may increase the likelihood of future sewer line blockages. Additionally, the zigzag drain line approach will make it more difficult to clean out blockages, and therefore you will need to include sewer line cleanout access points at every run and turn in the installation.

Straight-run Drain Line Piping Down a Steep Drop Slope between House and Septic Tank or Sewer Main

According to my observations, many waste line contractors simply establish a straight sewer line from the home to the septic tank or from the house to the sewage main, regardless of the building slope, as long as we have at least 1/8″ per foot, ideally 1/4″ per foot, or more, of water pressure.

Drain lines with a lower slope or those are practically flat are more likely to clog. On a related note, if you’re building a drain line that may be too steeply sloped and you won’t be able to readily correct the problem, make sure to include extra cleanout access ports.

Experience in Installing Steep Sewer Drain Line Piping

It is my opinion that if the whole pipe run is steeper than what is generally specified, it is possible that you will never see a clog occur. The sewage line dips on a slope between 2″ and 3″ per foot over a 40-foot run between the home exit line and the septic tank entrance baffle at the property depicted in these images and in the other photos in this series on sewer line replacement, as seen in the other photos in this series. In order to avoid leaving particles behind while flushing the toilet, this house-to-septic tank drain pipe should be placed in the “risk zone.” However, after managing this property for more than two decades, we can confidently state that we have never had an issue with too-rapid drainage clogging the waste line.

Since we replaced the old clay plumbing with plastic piping, we have not experienced any sewage obstructions.

The black line on the right-hand pipe portion indicates to the installer when the pipe sections have been completely connected together.

The only issue we experienced with the line was when the previous clay line was smashed and subsequently became clogged with mud and other debris.

Other Steps to Avoid Problems with Septic or Sewer Drain Lines on Steep Sites

  • Cleanouts of septic tanks or sewer drain lines: I’d put external cleanout access ports on the sewage line every 20 feet or so for the sake of ease. Proper septic pipe hookups include the following: Ensure that the new pipe connections are made correctly, that they are lubricated, and that they are completely seated during the assembly process. The following are the proper sewage pipe directions: The receiving pipe hub, often known as the “female” end of the pipe, is located at the bottom of the following downhill segment. Make sure you don’t do this in reverse or you’ll attract leaks and blockage in your sewage system.
  • Smooth drain line connections should be employed: the hub-less drain pipe connector shown in our photo was used to connect the new plastic waste line (which runs downhill to the septic tank) to the old cast iron waste line at the point where it exited the structure. These pipes needed to be correctly aligned (to avoid leaks at the connector) and their connections and pipe ends needed to be filed smooth in order to reduce the likelihood of waste line clogs at this point in the system.

Installing SepticDrainfieldPiping on Steep Slopes is a Different Matter Entirely

Please understand that we have examined the installation of solid plumbing between a building and its septic tank or sewage main in this articleand that higher slopes may be acceptable in some circumstances. However, the possibility of a “OK” for steep drain pipe does not apply in any manner to the perforated piping put in a septic drainfield gravel trench, which is a different story. Those looking for help on installing a septic system on a steeply sloping or rolling site should check out the following articles:

  • For further information, see AEROBIC SEPTIC SYSTEMS, ATUs, and HOME – some of these systems can be used on steep slope locations. Or SeeHOOT Aerobic Systems Drip Disposal Design and Installation Guide for more information. Alternatively, see “Guidance for the Design, Installation, and Operation of Subsurface Drip Distribution Systems as a Replacement for Conventional Title 5 Soil Absorption Systems for the Disposal of Septic Tank Effluent,” published by the Massachusetts Department of Environmental Protection in 2006 and refining Massachusetts regulations 310 CMR 15.240, 15.242, 15.247, and 15.280-15.289
  • Or “Guidance for the Design, Installation, and Operation of Subsurface Drip Distribution Systems as SYSTEMS DE DOSAGE For hilly sites where the drainfield must be located either uphill or downhill from a septic tank or structure, PRESSURE is a term that refers to pressure dosing systems that may be beneficial for disposing of sewage. GRAVELLESS SEPTIC SYSTEMS – Other gravelless systems are capable of handling mild bends required to follow rolling slope lines
  • However, some gravelless systems are not. A system that will be required when the elevation of a structure or a septic tank is lower than the elevation of the drainfield or sewer main is Septic pumps, sewage ejector pumps, grinder pumps, effluent pumps, sump pumps, septic pumping stations, and septic pump alarms Installation of septic drainfields on steep or rolling terrain is described in STEEP SLOPE SEPTIC DESIGNS, which is part of the SEPTIC DESIGNS section.
See also:  Septic Tank How Often Should You Service? (Solution found)

Reader Q A – also see the FAQs series linked-to below

@hello there, dude. Sweep turns with a wider radius (e.g., 2 45s) will often flow better than sharper turns. On a corner where the toilet waste flow is present. If trenching provides for 4″ deeper depth, is it preferable to construct the 90° corner with a 1° drop rate as normal, or is it preferable to make the corner with two 45° corners while lowering the 4″? Thanks@Ted, Start by consulting with your local building or health department to see what type of design would be considered suitable in your nation and neighborhood.

  • We have a shortage of service personnel for upkeep, and I believe that a sprinkler system would be more beneficial to our grounds.
  • Thanks@Ted That doesn’t appear to be a concern in my opinion.
  •, Yes, without a doubt, that is not hygienic.
  • Thanks@Ted, In a situation when you are just transferring a cleared fluid, there should be no particulates left behind in the wastewater stream.
  • That is a very other issue.
  • What if it’s been sitting in a septic tank for a while, breaking down as if it were going to a leach field instead?
  • That would be the material that would be sent to the aerobic tank.

You may be required to utilize a grinder sewage pump and force main; we are in the process of establishing a traditional tank close to our home.

What is the maximum percent drop per foot for the effluent line in terms of percent drop?


Thank you very much.

It goes without saying that such lines must have the proper pitch in order to reach the final position of the septic tank.

You should verify with your local building authority to find out exactly what is required to be placed at a 4 foot depth in your area.

My issue is, can I dig a smaller trench and then descend vertically to the requisite four-foot depth before finishing?

Thank you for the information, it was really useful.

What would be the best configuration for the septic tank and pipes when the designated drain field area is 500 feet away from the house?

The slope before and after the hill is rather level, descending very gradually in the direction of the drain field before becoming steeper.

A construction site located in a swale below the city sewer lateral service point has been identified as a potential concern.

(Let’s pretend it’s 8 feet below the surface) Is there an alternative to the brute force strategy of bringing in hundreds of cubit yards of fill and compacting it to raise the elevation of the construction site?

A septic tank is just 18 inches away from the building foundation, which is a little near.

Solids dropping vertically have the potential to adhere to and clog the pipe; however, employing 45-degree elbows instead of 90-degree elbows can help to mitigate this danger.

I would begin by having the tank examined to identify which items are most important in this order of significance.

A sound septic tank, as opposed to one built of brick or rusted steel; how well the baffles and protection from groundwater leaks are maintained; and how well the baffles and protection from groundwater leaks are maintained.

The quality and capacity of the drainfield are important considerations.

Is this a reasonable drop?

This is an ancient septic tank that I was allowed to utilize because of a grandfather clause.

What is the length of the pipe drop when the septic tank is 120 feet away?

How steep do the pipes have to be from one drop box to the next?

Does the length of the pipe, in addition to its angle of incline, have a limit in terms of length?

Please let us know if this is the case!

Verne, you have an issue with a septic or wastewater system that has too much downslope.

The difficulty with longer segments of excessive slope sewer plumbing is that the liquid waste will occasionally overtake the solid waste in the line, causing the system to back up.

One of the most valuable aphorisms I can share, at least in the context of the building construction and mechanicals fields, is that it is extremely uncommon to come into a situation that has never been experienced before.

According to one of the solutions described on this page, the sewage line is made even longer by zig-zagging across the steeply inclined areas of the land.

I’ll leave the graphic specifics to your imagination, so go ahead and go creative.

Let’s put the question to your septic installer and see what she has to say about it.

STATIONS FOR PULLING OUT SEWAGE Hello, I have a question concerning the installation of a toilet in a cabin that is around 300 feet from the main home, septic tank, and field.

Is too much slope a problem in this situation, given the long distance that the effluent must travel to reach the tank?

Do you think that building a sewage pump would make any difference in this circumstance, considering that the septic tank is located downhill from the toilet?

There should be a thorough inspection of the whole sewage line (perhaps using a sewer camera), and any slope issues should be addressed.

It’s always filled, no matter how long you wait.

Is it necessary to have the angle coming out of the home re-done?

What type of valve is used to connect the pump to the drain field?

Alternatively, seeSEWER / SEPTIC LINES for STEEP SITES FAQs- questions and answers that were originally placed at the bottom of this page. Alternatively, consider the following:

Steep Slope Septic System Articles


Suggested citation for this web page

INSPECTION OF SEWER AND SEPTIC LINES AT STEEP SITES An online encyclopedia of building environmental inspection, testing, diagnosis, repair, and issue preventive information is available at Alternatively, have a look at this.


Alternatives include asking a question or searching InspectApedia using the SEARCH BOXfound below.

Ask a Question or Search InspectApedia

We encourage you to use the search box just below, or if you prefer, you may make a question or remark in theCommentsbox below and we will get back to you as soon as possible. InspectApedia is a website that allows you to search for things. Please keep in mind that the publication of your remark below may be delayed if it contains an image, a web link, or text that seems to the program to be a web link. Your submission will appear when it has been reviewed by a moderator. We sincerely apologize for the inconvenience.

Technical ReviewersReferences

Citations can be shown or hidden by selecting Show or Hide Citations. is a publisher that provides references. Daniel Friedman is an American journalist and author.

How Much Slope for Septic Line?

This page contains information on sitework, including how much slop for a septic line to have. Peter inquires: My builder has recently completed the installation of our septic system, and I’m afraid that he did something incorrectly. The drain field looks to be at a greater height than the tank’s exit, which is consistent with this. My brain doesn’t comprehend how the tank may empty upwards. Is there something I’m overlooking? Answer: Except if you have a mound system, or another pumping system with a dosing chamber and lift pump, you are accurate in assuming that you will require a downhill slope in your sewage pipes, which is not the case.

  1. The leach lines themselves, on the other hand, should be leveled out.
  2. Sewage lines should be sloped downhill to the septic tank and drain field at a rate of at least 1/4 inch per foot of length.
  3. To avoid clogging, steer clear of sags and sudden curves.
  4. The fear is that the water would flow too quickly and leave sediments behind, causing the pipe to clog.
  5. In situations when it is important to carry wastewater uphill, there are several different pumping system types that may be employed.
  6. I would consider getting in touch with the person who created your system to discuss the problem and, if feasible, have them come out and assess the location.
  7. It’s ideal if you can put your complaints in writing and send them to the contractor.
  8. An upward line such as the one you describe will never function effectively.
  9. Also read this article.

When Is the Best Time to Take a Perc Test? How much does a perc test cost? Who Should Be Hired for the Perc Test? After a failed perc test, should you retest? Should I use a Sand Filter with my existing septic system? Examining the condition of the wellSEPTIC SYSTEMView all articles Q and A Index

Reader Interactions

Many individuals appear to be uncertain about the correct pitch to utilize when installing a sewage line or a home drain. It is also common to hear the phrase “slope,” which has the same meaning as “pitch.” It is widely agreed that a minimum pitch of 1/4 inch per foot of pipe run is required for proper operation of a sewage line. Because of the wider circle of the pipe, bigger lines such as 8′′ pipe actually require less pitch than smaller lines. However, there are also additional considerations to bear in mind when it comes to pitch.

Pitch on a sewer line for a building or home

In Queens, Brooklyn, the Bronx, and Staten Island, most residential sewage lines are 6 inches in diameter, unless they are for very big structures or for enormous quantities of rainwater disposal. In the case of a 6′′ sewer line, the minimum required pitch is 1/4′′ per foot, which is about one foot for a fifty-foot run of sewer line. It is possible that field circumstances, such as utility impediments or a lack of usable pitch, will prevent this from taking place. Generally speaking, as long as the run of pipe is built without any dips (back-pitched pipe), the sewage line should continue to work well and without the need for any substantial maintenance to be performed on it.

  • What many people are not aware of is that there is a limit to the maximum quantity of pitch that may be used in a sewage line that is permitted by law.
  • Limiting the pitch is intended to prevent waste water from entering the public sewage at a very high flow rate and interfering with the flow of waste water in the public sewer, which would be harmful.
  • The installation of a riser connection on the public sewage is required in some rare cases in order to reduce the quantity of pitch.
  • Learn more about the connections between a house’s sewage line.

Pitch on a house drain

It is quite similar to the proper pitch on a home drain as it is on a house sewer line. The usual guideline is that one quarter inch of pitch is required for every foot of run. However, there are also more considerations to consider. When there is an excessive amount of pitch in the drain, the waste water inside the drain might flow exceedingly quickly. In some circumstances, such as when the water is running exceptionally rapidly through the house trap or the trap for a specific plumbing fixture, it is conceivable that water from the bottom of the house trap can siphon out, leaving the trap completely dry.

See also:  How Put Back On Septic Tank Cover? (Correct answer)

In order to reduce the excessive pitch of a pipe entering a sewage trap, it is recommended to utilize permissible bends.

It is also possible, and in many cases preferable, to run the drain line with less pitch in order to avoid making needless bends. A level aids in the establishment of proper pitch. When laying drain pipe within a structure, there are three extra considerations to bear in mind:

  1. Having the correct pitch on a house drain is quite similar to having the proper pitch on a house sewer line. The usual guideline is that one quarter inch of pitch should be used for every foot of run distance. There are, however, certain other considerations. Pitch concentrations that are too high might cause waste water to flow too quickly via the drain. At some circumstances, such as when the water is running exceptionally fast through the house trap or the trap for a specific plumbing fixture, it is conceivable that water in the bottom of the house trap can siphon out, leaving the trap completely dry. A trap that does not have a water barrier in the belly of the trap might allow sewage gases to leak into the home. In order to reduce the excessive pitch of a pipe entering a sewage trap, it is recommended that authorized bends be used. In order to avoid making needless bends, it is preferable to run the drain line at a lower pitch than the other options. An accurate level aids in the establishment of proper pitching. When installing drain pipe within a structure, there are three extra considerations to bear in mind.

Sewer and drain installations

Everyone enjoys saving money, and even more so when they can do so by doing part of the labor themselves. Keep in mind, however, the following things as well. Sewer pipes and plumbing drains are designed to survive much longer than the average person’s lifespan! When installed properly, they require little to no maintenance and do not require the usage of any mechanical equipment to function. We don’t pay much care to plumbing systems since they are normally trouble-free and reliable. Despite this, individuals continue to believe that having a basic understanding of plumbing will enable them to build plumbing systems, including sewage and drain systems.

In addition, there are safety and health concerns throughout the course of such an installation, as well as potential ramifications thereafter.

Our educational postings are not intended to be a how-to guide, but rather to serve as helpful tools for understanding fundamental plumbing principles.

Today is the day to get FREE professional guidance!

Placing the PVC

Everyone enjoys saving money, and even more so when they can do it by completing part of the job on their own time. Take note, however, of certain important considerations: Most individuals may not realize that sewer pipes and plumbing drains are intended to last far longer than they do. When correctly installed, they require little to no maintenance and do not require the use of any mechanical equipment to function. Generally speaking, we don’t pay attention to plumbing systems since they run so smoothly.

Task is typically re-done as a consequence, which results in a higher cost than completing the work correctly the first time.

Filtering system for drainage lines Having a plumbing system that does not perform correctly or that permits sewage gas or other toxic smells to enter our houses is not worth any possible savings, in my opinion.

For a plumbing system to last as long as possible while still meeting code standards, it is essential that the work is carried out by licensed and insured plumbing specialists. Today is the day to get FREE professional guidance!


You should examine the sewer cleanout on the exterior of the home if you are hearing gurgling and all of the house fixtures are clogged. This is often a black 3-4 in color “inch ABS pipe with a threaded cap is available. Remove the cap (WARNING: BE CAREFUL! (WARNING: IT MAY CONTAIN SOME PRESSURE!) : Assuming the sewage line is completely dry, you will have a clog inside the home plumbing, directly in front of the cleanout valve. Make a phone call to a plumber and have them rooter the line. Sewer line cameras are available from several rooter/plumbing businesses.

  1. You have two options at this point: call your preferred septic provider or pull up the tank lids yourself and check the water level and solids content in the tank yourself.
  2. Most tanks erected after January 2001 include a filter that has to be cleaned at least once a year (we clean filters—please call us).
  3. We’ll even notify you once a year when it’s time to clean your filters!).
  4. It’s likely that you have a blockage in your sewage system.


Whenever you flush the toilet, the water gurgles, the toilet takes an unusually long time to flush, or the water in the shower turns brownish after you have done the laundry, you are receiving a subtle indication that trouble is brewing. In order to determine when the tank was last pumped, look through your records and then contact your preferred septic provider for assistance.


If you are experiencing unpleasant odors within your home, such as rotten eggs, it is likely that a trap or vent inside your home is not venting correctly. Call your plumber right away since these gases are harmful to both people and animals!


At times, the smells emanating from the roof vents will seep into the yard due to meteorological conditions. Make use of a plumber to elevate the roof vents and/or to place a charcoal filter in the vents, as needed. It’s important to remember that your septic tank is vented via the roof.


If you notice effluent appearing in your yard, contact your septic service provider immediately. If you see this, it indicates that your leach line has failed and you should get help right away.


Contrary to common perception, you DO need to have your septic tank pumped on a regular basis. Pumping maintenance should be performed on a regular basis, otherwise your system will get overwhelmed with solid waste and eventually cause damage to your leach lines.

DON’T MAKE THIS HAPPEN TO YOU! This is an extreme example of a tank that is overflowing. There is sewage flowing from the tank access holes and into the yard!

grease build up in sewer pipes

Fats and grease should never be flushed down the toilet or sink. They have the potential to harden the lines and cause failure; they have the potential to generate an excessive buildup of the floating scum layer in the septic tank; and they have the potential to go into the disposal regions and adjacent soils and completely block the system off. A shattered lid can pose a serious threat to both animals and children. It is conceivable that they will fall through the cracked or broken lids and will not be noticed until it is too late to save themselves.

crushed or settled pipe

This is the second most prevalent problem we notice in septic systems that are less than 10 years old. In addition to blocking flow, loose fill soil surrounding the tank is causing a backup into the house since it is pulling the pipe with it as it settles. We have even observed instances when contractors installing new systems do not correctly pack the fill earth below the pipe, resulting in pipe settlement on systems that have not been utilized or have only been used for a short length of time (see below for an example).


When it comes to modern septic systems, this is the most typical issue we encounter. Take note of the fact that the unsupported outlet pipe is being driven down by settling dirt. Watch as the water level in the tank rises, forcing the flow of water in the inflow sewage line to slow. This will eventually result in a clog in the inflow sewer line at some point. The solids flowing down from the house will not be able to enter the tank correctly because of the high water level.

examples of settled sewer pipes:

INSTALLATION OF A TANK AND/OR REPAIR OF SEWER PIPESTHE “POLY” PIPEIMAGES BELOW PROVIDE AN EXAMPLE OF WHAT PIPENOTTO USES WHEN INSTALLING A TANK AND/OR REPAIR OF SEWER PIPES However, despite the fact that this grade of sewer pipe is less expensive at the time of purchase, it might end up costing you a lot of money in the long run!

settled inlet sewer pipe on unused system:

Even if the septic system has not been utilized in some time, it is conceivable that problems will be discovered during the inspection process. Pipes might settle on unoccupied ground and in yards as a result of faulty installation and/or automobiles and/or ATVs running over the pipes without realizing they are there. It may be beneficial to all parties to have a skilled inspector take a look at the system and diagnose any concerns, even though the County does not require an examination on an underused system before transferring ownership.

Roots growing in and around the septic tank:

In addition to disrupting the system by clogging or destroying drainage and distribution lines, tree roots can also enter the tank, causing it to leak. Foul odors, poor drainage, and patches of vegetation in the leach field are just a few of the signs that you may have a root problem.


Solids are kept in the septic tank and away from the disposal area with the use of concrete baffles. Using baffles to reduce agitation of wastewater entering the septic tank and prevent particles from escaping the tank and entering the drainfield, baffles can assist avoid drainfield damage and extend the life of the drainfield.

If the baffles are broken, missing, or have never been placed, the drainfield’s life expectancy will be reduced significantly. Baffle repair normally entails the placement of a plastic tee at the end of the sewer pipes to prevent them from clogging.

orangeburg sewer pipes

Orangeburg pipe was made in Orangeburg, New York, from 1860 to 1970, and was utilized to plumb numerous septic and wastewater systems throughout Yavapai County during that time period. Orangeburg pipe is produced from rolled tar paper (wood pulp that has been sealed with hot pitch) and was considered a low-cost alternative to metal, particularly after World War II, because of its flexibility and durability. In fact, the pipe itself is so soft that professionals might cut it with a knife during the installation process!

Orangeburg, on the other hand, is known for degrading over time (it has a 50-year lifespan at the most) and deforming when subjected to pressure.

If the septic system is approved, Orangeburg will normally be stated on the permits as the material for the inlet and/or outflow pipe material, respectively.

Drainage and Sewer Pipe Slope

Gravity drainage and sewer pipes must have a proper slope in order for liquids to flow easily and solids to be transported away without being clogged with debris. An excessively flat pipe will obstruct the passage of waste away from the pipe. Pipes that are overly steep, it is also frequently believed, will allow liquids to flow through them so fast that particulates will not be transported away with them. Drainage pipes are often laid at the smallest feasible slope in order to allow ceilings to be kept as high as they possibly may be.

Standard Horizontal Drainage Pipe Slope

Drainage pipes should be run with a constant slope at the following minimum pitches, according to the International Plumbing Code:

2 1/2″ or smaller 1/4″ per foot
3″ to 6″ 1/8″ per foot
8″ or larger 1/16″ per foot

Large Diameter Sewer Pipe Slopes

Calculations are required for large sewage lines in order to establish the right pitch. As a general rule, sewage mains should be built to have a flow rate of 2 feet per second during periods of peak dry weather. Most of the time, flow rates are kept below 10 feet per second. It is recommended that pipes be built with anchors or other ways of keeping the pipe from moving for flow rates greater than 10 feet per second. Article was last updated on May 23, 2021. Contribute to making Archtoolbox a better experience for everyone.

See also:  How Common Is A Cesspool Collapse On Unused Septic Tank? (Solved)

How to Install a Home Sewer Lateral

Photograph by William Taufic / Getty Images The first slope estimates are based on the elevations and the length of the pipe run that have been determined. The total decline in height is calculated by subtracting the finishing elevation from the beginning elevation and multiplying the result by 100. The slope may be calculated by dividing the drop by the whole run (length) of the pipe. Example: If the pipe terminates at a depth of 6 feet and the pipe starts its journey to the house at a depth of 4 feet, the total drop is 2 feet.

In most locations, the required minimum slope for laterals is 2 percent, which translates to 2 feet of drop every 100 feet of running distance.

An excessively steep slope will cause liquids to flow more quickly than solids, resulting in blockages in the drain system. When a slope is too shallow, it does not generate enough velocity to allow for adequate drainage.

Dig the Trench and Lay the Bedding

courtesy of Wicki58 / Getty Images Trenching for a sewer lateral must be done with care to avoid causing undue disturbance to the ground. Every inch of disturbed soil must be adequately compacted in order to reduce settling. Generally, it is preferable to keep the trench as narrow as possible (to reduce soil disturbance), but doing so needs exact knowledge of the location of the pipe’s end. It may be essential to dig a deeper trench at times. The bottom of the trench must be flat and compacted, and it must be shaped to match the slope that is wanted.

Moreover, sand is considerably simpler to slope than dirt, allowing for more precise control over the slope prior to the pipe’s installation.

Install the Pipe

Victoria Snowber is a Getty Images contributor. Typically, the sewer pipe is placed in sections, beginning at the lower end of the pipe run and progressing upward to the higher elevation. Modern sewage pipe is composed of polyvinyl chloride (PVC), and it is connected together either with gaskets or with solvent adhesive. The standard pipe size for residential lines is 4 inches in circumference. The material and dimensions of the pipe required by the municipal code are specified. The bell (female) end of each pipe segment should be oriented uphill in order to reduce the possibility of leaks at the pipe junctions.

Most building codes require one or two cleanouts at the home end to provide for simple access to the pipe for scoping or cleaning with a sewage auger, depending on the requirement.

Backfill the Trench

Dan Bannister / Getty Images courtesy of Tetra Images The trench is backfilled to complete the job once the sewer lateral has been entirely installed and passed final inspection. In many cases, the backfilling procedure begins with a coating of sand to protect the pipe and fill in any cavities that may exist around the pipe. The ditch is then filled with dirt that has been put in layers. Each layer of dirt is meticulously compacted to ensure that it does not settle in the future. Installing a caution tape over the top of the initial layer of compacted earth is always a good idea—and in many cases, it is necessary.

How far can you run a sewer line to a septic tank?

Dan Bannister / Getty Images courtesy of Tetra Images. After the sewer lateral has been entirely installed and has passed final inspection, the trench is backfilled to conclude the construction process. The backfilling operation is frequently started with a coating of sand to protect the pipe and fill in any cavities that may exist in the surrounding area. Next, earth is put to the trench in stages, filling it up completely. In order to avoid future settling, each layer of dirt is properly compacted.

Installing a caution tape over the initial layer of compacted dirt is always a good idea—and in many cases, it is necessary. Because of this, any excavation in the vicinity of the pipe will be prevented from causing unintended harm to it.

What is the proper pitch for a sewer line?

1/4 inch per foot is the standard. Drain pipe must be sloped at a minimum of 1/4 inch per foot and a maximum of three inches per foot, or it must be vertical, according to plumbing code requirements. Having a slope of less than 1/4 inch per foot will result in frequent drain clogging, while having a slope of more than three inches will allow the water to flow without clogging. Also Do you know how steep the slope is for septic lines? A standard septic tank has a 4-inch intake at the top, which is positioned towards the bottom.

  • To put it another way, for every 10 feet of distance between a tank and a home, the inlet must be 2 1/2 inches lower than where the pipe departs the house at its lowest point.
  • In general, the optimal slope of a drain line is 14 inches per foot of pipe length.
  • Manydrainseither have too little or too much slope, depending on the situation.
  • Additionally, the 90-degree bends make it difficult to pass through with draincleaning equipment.
  • The use of two 45 degree angle fittings separated by a 12 or 18 inch length of straight pipe is recommended if you need to turn 90 degrees.

How to Replace Sewer Line Under the House

Although toilets and plumbing applications have existed since the time of the ancient Egyptians, the indoor plumbing that we are familiar with today has only been in existence for a very short period of time. Families may enjoy the comfort and convenience of indoor plumbing, as well as the safety and cleanliness of their drinking and bathing water. However, despite the fact that they utilize their house drain lines on a daily basis, many homeowners are unaware of how they operate or what they are doing with them.

  • Pitch and angles are used by residential drainage systems to transport trash and wastewater from the drain pipes into the main sewer line and eventually into the city’s wastewater collection systems.
  • It is the 4-inch pipe into which all other home drain lines empties that is known as the sewage line.
  • Traps and cleanouts are also included in the plumbing system, which prevent drain odours from staying in the house with the vent lines installed.
  • Kitchen drain lines are frequently linked to laundry drain lines, and bathroom drains and toilets might be located back to back or side by side, but every property is different.

It is important to employ a professional drain expert on a consistent basis because no two homes are exactly same in this regard. To effectively clean, repair, and diagnose drain pipe problems, it is necessary to have a thorough understanding of their operation.

What is a Sewer Line?

All 2-inch drains eventually connect to the main sewage line by tie-ins on each individual line, regardless of whether the house is many stories or a single story. In the case of residences built on raised foundations, the main sewage line can be buried under the slab foundation and run below the yard, or it can be laid directly underneath the house. In most cases, major sewage lines will include at least two cleanouts, one at the end of the line and one at the beginning of the line. It is critical to have adequate cleanouts in order to eliminate mainline obstructions and prevent sewage backups from occurring.

The installation of cleanouts is beneficial for homeowners who are continuously experiencing sewage line difficulties as a result of blockages.

Many homeowners are unaware that the city of San Diego is not liable for any section of the main sewer line that runs from the boundary of the public sidewalk to the perimeter of their property.

It has the potential to save time and money.

When Does a Sewer Line Need to be Replaced?

A sewage line can be constructed of a variety of materials, the choice of which will be determined by the time and location of the home’s construction. An underground sewer line made of cast iron or clay will be found in older residences that have been in existence for more than 30 or 40 years; if the sewer line is beneath a raised foundation, it will be made of cast iron or ABS plastic. ABS plastic is being used in the construction of many contemporary residences. It is estimated that cast iron has a lifetime of 50 to 80 years.

  • Outside elements, on the other hand, will deteriorate cast iron and clay in particular, and this will not be prevented by any measures of maintenance.
  • Cast iron can degrade as a result of exposure to the elements.
  • Due to the fact that clay sewage lines are placed in five-foot pieces, there are hubs that keep them all together.
  • Roots are drawn to the main sewage line because of the nutrient-dense materials and moisture it contains.
  • Occasionally, when roots do break through the line, hydro jetting can be used to clean them out and return the pipe to its original state.
  • When there are big breaks or holes in the main sewer line, or when entire portions are missing, it is common for the line to need to be replaced.
  • The main sewer lines under the home are not immune to difficulties or breakage, which may necessitate the repair of the drain pipe.

When sewer lines that are exposed in a crawl space suffer problems, homeowners may observe sewer fumes from leaks or breaks, discover sewage overflows beneath the property, or face other drain troubles as a result of the situation.

How is the Sewer Line Replaced?

Depending on when and where the house was built, the sewage line might be constructed of a variety of materials. Cast iron or clay sewage lines will be discovered underground in older properties that have been in existence for more than 30 or 40 years. Cast iron or ABS plastic sewer lines will be found underground in older residences that have been in existence for more than 30 or 40 years. ABS plastic is used in the construction of many contemporary dwellings. An average lifespan of 50 to 80 years is achieved by using cast iron construction materials.

  1. However, this does not ensure that faults will only surface beyond its lifespan.
  2. In many cases of failed sewage pipes underground, root incursion is a possible cause.
  3. In addition, shifts in the earth can cause all sorts of drain lines to get out of alignment.
  4. As a result of the failure of those hubs or the occurrence of a breach in any of the lines, tree roots might infiltrate into the line and quickly take control.
  5. Essentially, it is the ideal habitat for root development.
  6. Before anything else, a plumbing professional will use a pipeline camera to check the line, determine the extent of root incursion or the source of the obstruction, and ensure that there are no cracks or breaks in the pipe.
  7. This can be caused by a large number of roots, old age, degradation, or shifting ground.
  8. Drain pipe replacement may be necessary if the main sewer pipes under the home experience issues or break down.

Is There an Alternative to Sewer Line Replacement?

Excellent news for homes with a lot of concrete and expensive landscaping, or if their sanitary sewage line goes beneath an existing city sidewalk or street: there is an alternative to replacing the entire line, or even a piece of the line, with new pipe. In order to repair a broken sewage line, eliminate root incursion permanently, or perform modest repairs in areas where a plumber cannot dig, epoxy relining solutions are an excellent option. It is a method that involves inserting an epoxy resin solution into a sewage line, inflating it to conform to the interior of the pipe, and then allowing it to cure for several days.

However, the first step in replacing a sewage line is to have a video examination performed and a precise diagnosis made by a drain professional.

We provide both epoxy relining options and traditional dig-ups and sewer line replacements through our team of professionals. Call 1 (800) BILL HOWE (245-5469), visit us on live chat, or schedule a service online today to get an estimate to diagnose and cure your sewage line problems for good.

Leave a Comment

Your email address will not be published. Required fields are marked *