Wet Weather

Heavy rains or melting snow will overwhelm a sewer system. The sudden flow from the excess water will cause sewage to back up into a home. These problems normally begin from outside on the street level. The water pours into the system after a heavy storm and raises the water table. The water surfaces at the lowest point of the basement. Of all the reasons this one is the less preventable. Urban development is also a problem for a sewer system. Natural draining areas become blocked by asphalt and other structures. The water is unable to drain properly and causes flooding in the sewer system.

Poor Home Maintenance

Cracks in a basement can allow water from sewers and ground moisture water to invade homes. Improperly cared for pipes can also burst and send sewage flooding into a home. This is why home upkeep is so important to property protection. Plumbing and basement conditions are not the only things that affect a flood situation. The state of the home owner’s property is just as important. Outside a home, one of the most common sewer blockage problems is tree roots. The invasion of tree roots in a sewer system falls to the property owner to fix. The root will block a pipe or sewer line and prevent wastewater to flow where it needs to go. The tree root problem should be fixed as soon as possible. If not, the homeowner could find themselves completely separated from the sewer system.

Too Many Users

The last cause of basement flooding is as simple as a population increase. The more homes on a sewer line, then the more possibility of sewer flooding. Residents who have trouble with sewer flooding should be mindful of what is flushed and wash down drains and toilets. One careless discard can lead to trouble for a whole system.

What Home Owners can do to Prevent Sewer Flooding:

Be aware of how much waste is washed down a drain.
Make sure all pipes and drains are repaired and in working order.
Install preventive plumbing aids like sump pumps and backwater valves to handle the water rushes that can’t be controlled.

Make Sure You’re Covered for Sewer Backups

If you’re a homeowner, here’s one of the worst nightmares you can experience. Torrential downpours deluge your property and neighborhood with rainwater, overwhelming your home’s sewer system or your sump pump’s ability to handle the water runoff. The next thing you know, you have raw sewage backing up into your home’s drains, overflowing toilets and tubs, or flooding your basement. A backed-up sewer can do a real number on your home, causing thousands of dollars in damage to floors, walls, furniture carpeting, and electrical systems, as well as pose a major health hazard. No problem. You’ve got insurance, right? Not so fast. According to the Insurance Information Institute, most sewer system backups are not covered under a typical homeowners insurance policy, nor are they covered by flood insurance. Uh-oh. For homes that have been severely damaged by sewer backups and are uninhabitable, your basic homeowners’ policy may include Loss of Use coverage, which provides reimbursement for lodging, food, and other living expenses you may incur if you have to vacate your home. Loss of Use coverage also reimburses you for the lost rental income if you rent out part of the house. but that’s about all you’re going to get with your average homeowner’s policy. For most consumers, coverage for sewer-related problems must be purchased either as a separate product or as an addition to a homeowners policy. Fortunately, sewer backup coverage is available from most insurance companies for a nominal cost. The sewer and drain professionals at Horizon Services recommend that most consumers in our rain-prone region of Delaware, Pennsylvania, and Maryland err on the side of caution and purchase this additional insurance. You can typically purchase sewer backup insurance for an additional premium of $40-$50 per year; a small price to pay for a significant piece of mind and protection. If you live in a flood plain or near a river or stream, you may be required to carry flood insurance, as well.

What Causes Sewer Backups

Most homeowners probably don’t realize that they are responsible for the maintenance and repair of their main sewer line the pipeline that runs between their house and the municipality’s sewer main, usually located underneath the street. The main sewer line is owned and maintained by the property owner, including any part of the line that extends into the street or public right of way. Over time, these main sewer lines can easily deteriorate, crack, collapse, or become obstructed. You may not have a clue that this kind of damage is occurring. But one severe rainstorm may be all it takes to bring the problem to ahead. Some of the more common causes of damaged sewer lines and sewer line backups are:

- Aging Sewer Systems: More than half of the nation’s sewer lines are 30+ years old or connected to aging municipal sewage systems. After decades of wear, tear, and obstruction, the sewer line and system no longer have the capability to withstand heavy demands and so they back up and overflow.

- Combined Pipelines: Some newer sewage and drainage systems combine stormwater and raw sewage into the same pipeline. During intense rainstorms, these combined systems are exposed to more volume and debris than they can handle. With nowhere else to go, the outgoing water and sewer back up into basements and other low-lying drains.

- Tree Root Infiltration: Shrubs and trees seeking moisture can make their way into cracks or through joints in your sewer line, causing extensive blockage and damage. Tree roots can travel a long way; the damage may occur from a tree on your property, a neighbor’s tree or a tree on public property. Samples of the tree roots can be obtained to identify which party is responsible for cleanup and repair.

- Blocked Municipal Lines: Many times the problem has nothing to do with your property, but with a blockage in your municipality’s sanitary main running under your street. If the blockage is not detected in time, sewage from the main can back up not only into your home but your neighbors, as well.

Usually, this kind of backup happens slowly, giving you plenty of time to call a licensed plumbing, drain or sewer company. If water and sewage are back into your basement at a rapid rate, don’t delay; call your municipality’s public works office or sewer department and report the problem immediately.

Causes of Basement Flooding and Basement Drain Backup

Flooding of basements can occur at any time. It can happen to anyone who has a basement, even if never flooded before. While most often flooding occurs during big rains or rapid snow melts in the spring, it can occur even during dry weather. There are a number of reasons why basements flood. Flooding can occur by seepage or flow through the walls or foundation floor, from surface water sources, or by a sanitary or storm sewer backup. Please remember: Basements are inherently prone to flooding. They are, by definition, the lowest level of a building, typically built partly or entirely below ground level. Groundwater is water that is naturally located below the ground’s surface. The groundwater level can be, at times, above the level of the basement floor. In some locations, groundwater can be above the level of the floor at all times. Sewers are also located in the ground. This includes all varieties – storm, sanitary, and combined. While in most cases, sewers are below the level of the basement, the water level in the sewers can be, at times, above the level of the basement floor. Gravity does its best to move water from high to low. If either the groundwater level or sewer level around your home is above the basement floor, gravity will try to move that water into your basement. A crack in the foundation floor, for example, provides gravity with a perfect path for water to be pushed into the basement. Sanitary sewers always have a path to the home, by design, and it is called the sanitary sewer lateral. While under normal conditions, the lateral allows water to flow from your home to the sewer, there is the potential for water to move from the sewer toward your home. The circumstances described are shown in Figures 2 and 3, which are discussed in more detail below. In order to understand why a basement might flood, it is important to show the more common pathways, intentional or not, that permit water to flow into or around your basement. Figure 1 indicates a typical home and how it is serviced during normal conditions. Not all homes have a storm sewer lateral (as shown in the figure), but most just have a single sanitary sewer lateral. Figure 1 highlights common problems (in red) that all might contribute to a higher risk of flooding. Most are on private property or are things that are within a homeowner’s ability to change -whether by regular maintenance or by specific projects to eliminate or reduce potential flooding sources. Some of these problems include:

Poor lot grading: the sloping of the land is promoting water flow toward the house.
Un maintained foundation: cracks have developed that allow water to seep in.
Problems with pipes: both the weeping tile and laterals have problems.

Flooding During Dry Weather

Most flood events do happen during wet weather, but it is quite possible for a flood to occur during dry weather too. Three of the most common reasons are as follows:

A blocked or failed sanitary lateral – The sanitary sewer lateral, just like the shingles on your roof, or your paved driveway, is a feature that will degrade over time. As a lateral degrades, several things can happen. For example, tree roots might penetrate and the lateral might collapse because of gradual deterioration. These scenarios can block the lateral, resulting in a sewage backup. In this case, it will be your own home’s domestic wastewater that floods your basement. The only way for the wastewater to drain becomes the lowest fixture in the home – usually the floor drain or a basement level shower stall, sink, or toilet. Your lateral, just like your roof, your driveway, or windows, needs maintenance, and ultimately needs to be replaced or rehabilitated. Consider having you’re lateral inspected every 5 to 10 years depending on the age and condition you find it in. Call a qualified and licensed plumber for this service. Another reason for the blockage of a sanitary sewer is simply due to what is being flushed down the toilet. Toilets are for human waste and toilet paper, and that is pretty much it!
Foundation drainage failure – Subdivisions are sometimes constructed in lower-lying areas that are generally wetter than others. In such cases, the foundation drainage system, whether by gravity or by pump, must work continuously to keep the groundwater level around the foundation lower than the basement floor. Just as with sewer laterals, gravity foundation systems, often called weeping tiles, may degrade over time or get plugged by fine sediments. As a result, the ground around the foundation will cease to drain itself by gravity. In other cases, sump holes in the foundation are constructed to accommodate a sump pump. These devices pump out the water around the foundation and either discharge it to the lawn, storm sewer or illegally to the sanitary sewer. Discharging a sump pump to the sanitary sewer is illegal. It is possible for these pumps to fail, or simply be unable to keep up with the incoming water, or get plugged. This flood type will be discussed further in the wet weather section.
Water supply-line break or hot-water tank failure – Sometimes, a flood is due to a break in the home’s internal water supply plumbing or failure of the hot-water tank. This can result from aging plumbing or equipment, a puncture of a pipe during construction, or freezing-induced splitting of a pipe.

Flooding During Wet Weather

Flooding during wet weather is far more common than flooding during dry weather. Rain, ground-thaw, and snowmelt put a heavy load on drainage systems, including the storm and sanitary sewers found underground. With the additional water on the surface and underground, there are a number of reasons why a basement might flood.

Surface inflow or overland flooding – During periods of heavy rain or rapid snowmelt, surface water may pool around the house, or accumulate in hard surface depressions such as driveways or roads adjacent to a home. During extreme weather events, this water can flow into the home. Close proximity to a natural stream or roadside ditch can also present a risk. Generally, proper grading on the property will reduce the risk of surface water getting into your home. This is illustrated in Figure 2.
Foundation drainage failure – Homes usually have some form of a drainage system built around them. This safeguard promotes the movement of water away from the basement and blocks the entry of water into the building. For the purposes of our discussion, the waterproofing aspects of a foundation are considered part of the foundation drainage system. Within this category, there are three main causes for basement flooding, all generally a result of excessive groundwater around the foundation, as illustrated in Figure 2:

Seepage – If the water table rises, water can enter the basement via cracks, holes, and other unintended flow paths. This is generally considered to be part of the aging process of the home and the materials used to build it. Regardless of the condition of the drainage materials and pipework around the foundation, if water can enter the foundation floor or walls via cracks and holes or other defects, it likely will do so during heavy rains, ground-thaw, or snow-melt periods, when there’s lots of water in the ground. Settlement of the lot grading around the building and downspouts discharging run-off water too close to the home can increase the quantity of water around the foundation and increase the risk of water entering via cracks.

Sump pump failure – If your basement is equipped with a sump and sump pump(s), it can mean that the foundation drainage system of your home requires some assistance to keep up with the groundwater around it, or it simply cannot drain adequately by gravity to the surrounding ground or storm sewer. New homes are required to have sump pumps in these situations. Sump pumps, when working properly and adequately maintained, can safely pump excess water above the foundation and away from it. Ideally, this water should be routed to the lawn or storm sewer. If the pumps cannot keep up or fail to operate (perhaps due to a power failure, or malfunction), the groundwater level around the foundation can rise to the point that it flows up and out of the sump onto the basement floor.

Weeping tile failure – Over time, the foundation drainage system can deteriorate. As a result, the weeping tile system can fail. This may be, due to a partially- or fully-collapsed pipe, or due to sediments plugging the pipes. If Sewers are full the weeping tile fails, and the drainage of water around the foundation is either impeded or blocked altogether. As a result, the groundwater level around the foundation gets too high and it may spill into the basement via the sump, if one exists, or via leaks in the foundation. In situations where there are leaks in the sewer lateral or plumbing beneath the foundation, groundwater can inundate the sanitary lateral and restrict the flow of sanitary waste water. This could result in both groundwater and/or waste water entering the basement by way of the floor drain or the lowest sanitary fixture.

Sewer backup – Most homes only have one connection to the sewer system, and that is the sanitary sewer lateral. However, newer homes built in the last 20 years, as well as some other older neighborhoods, have storm sewer laterals as well, for the purpose of foundation and downspout drainage (See Figure 1.) These laterals form either one or two intentional direct connections to the municipal storm and/or sanitary collection systems. The municipal storm and sanitary systems operate well and are maintained through a variety of municipal maintenance programs. However, when a blockage occurs, or when the systems are overloaded during heavy rains, a sewage backup can occur into a building, as per Figure 3. Here are a few reasons why:

Sewers are full – When the sewers are full, this is called a “surcharged condition”. It means the pipe system is full and the water level in the manholes may rise well above the top of the pipe. If the sewage level in the system exceeds that of your basement, flows can be blocked, or worse, sewage can flow towards your home (see Figure 3). When this occurs, the wastewater may enter your basement by way of the lowest fixture, which is usually a floor drain, shower drain, sink, washbasin, or toilet. The underlying cause of this is excess water in the sewer system, which ultimately overloads the sewer with more water than it was designed for. Excess water generally comes from leaks in sewer mains and sewer laterals, inflow from surface features as well as illegally connected, private-side sources including foundation drains, sump pumps, and downspouts. The technical term for this is “extraneous flow” or “inflow and infiltration”.

Flow Restriction – Any situation that puts additional flow into the sewer lateral may make the problems of a partially- or fully-blocked sewer lateral worse. If the flow is restricted, there is more chance a sewer backup can happen.

Sewer backup – More often than not, basement flooding is a result of overland flooding, infiltration flooding or sewer backup, or a combination of two or all three of these types of flooding. Sanitary sewage is generated by the use of toilets, sinks, drains and other home water uses. Because this type of sewage contains a high degree of contaminants and can pose a significant risk to human health and the environment, it requires treatment at sewage treatment facilities before it is released back into the environment. Sanitary sewage is collected through sanitary sewer laterals, which connect homes and buildings to underground sanitary sewer pipes. Storm sewage consists of excess surface water, resulting from rainfall or snowmelt that has collected in streets, sidewalks, roofs and parking lots in urban areas. Various methods are used to channel this water to underground storm sewer pipes, including swales and catch basins. Although storm sewage is significantly cleaner than sanitary sewage, it can be contaminated with pet waste, salt and other contaminants picked up from city streets and other urban surfaces. In most cases, your neighborhood is serviced by underground sewage pipes that are either combined, separated or partially separated. These pipes carry either sanitary sewage, storm sewage, or a combination of both to sanitary sewage treatment facilities and nearby lakes, streams, and rivers. Combined sewer systems convey a combination of sanitary sewage and storm sewage, which is conveyed to sewage treatment facilities before being released into local surface water, including lakes, streams and rivers. Combined sewers are designed to automatically bypass treatment facilities and re-route excess sewage to local surface water bodies when they become overwhelmed. This automatic bypass is called a combined sewer overflow (CSO), and it helps to protect sewage treatment facilities from damage and also helps to reduce the chances of sewer backup in buildings. However, as CSOs result in the release of raw, untreated sewage, they can have a significant negative impact on local surface water quality. Reduced water quality can have a negative impact on aquatic life, and can also reduce the recreational qualities of lakes and rivers. As homeowners’ weeping tile and downspout connections can contribute a substantial amount of water to the combined sewer, they can increase the chances that CSOs will occur. Separated sewer systems have two individual pipes that are designed to convey only sanitary sewage and only storm sewage. The separation of the different types of sewage allows municipal engineers to direct sanitary sewage to treatment facilities, while storm sewage is allowed to flow into nearby lakes, streams, and rivers with less intensive treatment. In some cases, neighborhoods are serviced by partially separated sewers, which include sections that are combined and sections that are separated. A sewer backup can happen when municipal sanitary, combined, or storm sewer systems receive more water than they can handle. Excess water can cause the sewers to “surcharge,” and push water backward through home sewer laterals and cause sewage to backup into the home through basement floor drains, toilets and sinks. Excessive surcharge in the municipal sewer can create high pressures around basement floors and the foundation, which can cause structural damage to the home. For example, excess pressure in pipes beneath the home can result in the heaving of basement floors, especially when improper backwater valves are used. When weeping tiles are connected to the municipal system through sanitary sewer laterals or storm sewer laterals, sewage can be forced back into the weeping tiles, resulting in possible structural damage to the home. If a home has a storm sewer lateral and the municipal storm sewer surcharges, water can be forced out of the storm sewer lateral and can enter the sanitary sewer lateral, resulting in a sewer backup in the home and can also contribute to sewer backup in the neighborhood.

What you need if your basement drain is backing up and flooding

So your basement floor drain is backing up and flooding. There’s water in the basement. First, you need to determine if it is local waste produced in your home that can’t get out due to a blockage in the main line leaving your home, or if it is waste from the sewer system coming back in (called a backflow). A blockage can occur if a portion of the line has broken, but generally, a blockage is caused by roots that have grown into the line, or by something flushed down a toilet that has lodged in the drain pipe. When this happens, you will see evidence of your basement drain backing up as the lowest point in the system (generally the basement drain overflows) is where the evidence is visible. Chemical products may work to open the drain, but running a snake through the line is generally necessary. In the case of roots invading the basement drain line, a power snake with sharp cutting blades must be used to cut through the roots. With your own local waste backing up its one thing, but when nasty, contaminated waste from hundreds of neighbors starts pouring into your home, it becomes a whole different issue. In this case, usually due to high levels of rainfall temporarily raising the water overall table, the system will be overwhelmed. If the lowest drain in your basement (or other shower drain or toilet) is lower than this temporarily raised water level, you will find your basement drain backing up. In some cases, the pressure created by the raised water level is so great that water raw sewage will be spewing several feet into the room from the basement drains.

There is only one way to prevent this particular condition of your basement drain backing up; the installation of a gate to keep the unwanted reverse flow out. Some of these gates are manual and must be manually inserted or manually turned closed. The best are automated solutions called “Backwater Valves“ or “Backflow Preventers” A Backwater Valve automatically senses a reverse flow (water flowing the wrong direction and back into your home) in your main line and completely closes it off from the sewer system outside. This prevents your basement drain from backing up. As many know, what’s at the stake is thousands of dollars of damage to the basement living space, not to mention the health hazards caused by the bacteria in the raw sewage produced by hundreds or even thousands of your neighbors. Some people simply insert a plug into their basement drain in an attempt to stop a basement drain backup, but in a case where groundwater comes in when there is not a mainline backup, the end result is also flooding. Additionally, the force of incoming water can simply push these plugs up and out of the way leaving you unprotected. A good automated backflow valve is the best solution to avoiding a basement drain overflow that lets water in the basement.

Basement Sewage Information

Having sewage back up into the home is an unpleasant and potentially unhealthy experience. The information contained here can help protect you from the hazards of raw sewage in your basement and give you practical methods for proper sanitation of your building should a backup occur. Sewers can back up into your basement from several paths during storms and it is the property owner’s responsibility to protect the building. Open floor drains are the major culprit, as are basement plumbing fixtures (toilets, sinks, shower drains, etc.). Floor drains are intended to allow water (from a broken water pipe, groundwater, etc.) out of your basement on (what should be) rare occasions. Otherwise, floor drains should always be capped off—a plumber can help you. If you must have plumbing fixtures in your basement, a licensed plumber can install devices that may protect you from backups (check valves, etc.) Open floor drains and basement plumbing fixtures put you and your property at risk during storms. Roots growing inside the lateral and blocking the pipe is the most common reason for sewer back-up not related to storms this, and any internal plumbing problem is the responsibility of the property owner a private plumbing contractor should be called. In rare cases, the main sewer line can break, become blocked or be overwhelmed with stormwater resulting in area-wide backups.

First Steps

If you have a backup, call a plumber. The plumber should be able to troubleshoot and fix almost all causes of a sewer backup. The county cannot recommend any plumber check your Yellow Pages. You may want to get more than one estimate and check references. Main sewer issues in other geographic areas in a county are handled by the local town/village.

Cleaning Up After Floods/Sewer Backups

Proper responses to sewer backups can greatly minimize negative health effects and property damage, destruction of your valuables, and the risk of electrocution. Prompt cleanup of affected property can help minimize the inconvenience and damage. Most homeowner-type insurance policies DO NOT cover sewer backup damage. Ask your insurance agent for details on an inexpensive policy rider that can save you considerable expense and effort.

Health and Safety Issues

Please be aware of the risk of potential health and safety problems when addressing the cleanup of your home. Sewage and floodwaters can contain bacteria, fecal material, viruses, and other hazardous microorganisms which can cause disease. These “germs” can be transmitted by touching contaminated items or by tracking them into uncontaminated areas on shoes. Children can be especially vulnerable. Odors from sewage backups are unpleasant but not harmful. The speedy removal and cleanup of sewer water are very important and necessary.

Protect yourself and your family during cleanup follow these guidelines:

To reduce the danger of electrocution do not enter your basement if it is flooded call your utility company.
Avoid skin contact with sewer water, if your cut while working in sewer water contact your physician.
Do not allow children to play in areas contaminated by sewage backup.
Do not eat or drink anything exposed to sewer water.
Keep contaminated objects, water, and hands away from the face.
Wash hands immediately following contact with sewer water or contaminated objects and surfaces.