A septic system is an underground system put in place to treat and dispose of wastewater in locations where a typical central sewer system is not the most feasible option. Septic systems are often preferred when the homes or other buildings are close together and in rural regions. It is contained on-site, making it a very efficient method of wastewater disposal.


Your septic system will utilize two main components, the septic tank and the drain field, to treat and dispose of wastewater.

First, wastewater leaves the home and enters the septic tank. Since wastewater is comprised of many types of matter, from solid waste to oil and other liquids, the water separates into a “sludge layer” in the bottom of the tank and a “scum layer” floating on the surface. The sludge layer will decompose as much as possible before removal in this tank.

From here, “clarified liquid” or “effluent” that has separated between the two layers of lighter and heavier waste leaves the septic tank through a perforated outlet pipe and disperses in the drain field. In some cases, the drain field includes features that help filter the effluent, such as sand or plant matter.


Septic system issues are often caused by a user error or an installation error. Here is a list of common issues related to a poorly maintained, selected, or placed septic system:

Overfilled Septic Tank – An overfilled tank could be due to a few different factors:

  • Inefficient water use in the home or building can fill the tank too quickly. A typical septic tank requires time to break down solid material and convert other waste into gas. Filling the tank too quickly reduces the total amount of time during which this process can take place. The water level rises over the outlet pipe level and solid material lodges in the pipe before it has a chance to decompose, effectively blocking the effluent passage into the drain field and over-filling the tank.
  • Failing to pump sludge out of the tank on a regular basis can cause too much heavy, solid material to build up and similarly raise water levels. The material will then clog the outlet pipes and cause further damage as the tank continues to fill without an outlet.
  • Dumping non-organic waste can similarly overfill the septic tank. Many soaps, detergents, oils, grease, and personal hygiene items are non-biodegradable, once again causing too much solid material in the tank that then becomes lodged in the perforated outlet pipes when the water level rises. It is important to be careful even with items such as paper towels, used cigarettes, and kitchen scraps.
  • Using detergents and soaps rich in phosphates encourage algae growth, which can then clog the perforated outlet pipes. Be sure to use the manufacturer directed amounts of these products to reduce the risk of algae in your system.

Contaminated Soil Surrounding a Septic Tank – Septic systems typically allow waste to separate into layers based on weight, then disperse the remaining water into the surrounding soil through outlet pipes. Because most solid waste naturally settles in the tank, very little waste should leave through the outlet pipes with the water. However, dumping cleaning chemicals, fuels, and other toxic liquids disrupts this process. What cannot be converted into gas and released through vents flows out of the tank with the effluent, directly into the surrounding soil. Even some products that claim to clean septic systems can enter the drain field this way and damage the land and water surrounding the tank.

Broken Septic System Components – Many issues involving broken septic system components are a result of rusted elements or damage from sulphuric acid. This could be a sign that it’s time to update an aging septic system or upgrade to materials like fiberglass rather than concrete or steel, so be sure to discuss options with a professional.

Tree Roots Compromising the Drain Field or Septic Tank – Tree roots can cause significant damage to a septic system. Ensuring that trees are planted a safe distance from the system can help, but there is always a chance that a stray root or unplanned sapling can cause damage down the road. If you are concerned about tree roots compromising your system, seek professional help to remove the risk or existing problem. A trained septic system professional will know the proper environmentally-safe chemicals or other methods to use in removing the roots, and how to fix root damage.

Issues from Topographical Features – Septic systems rely on gravity and must be placed at a specific depth, so it is important to consider the lay of the land around your home or other building before installing a septic tank. A septic professional will be able to tell you whether or not there is too much slope for the gravitational system to work, if the soil type or rockiness of the ground is appropriate, and if the water tables are at a suitable level for the tank and drain field to function properly. Homes with basements have special considerations as well as homes built on hills, in low areas, or on other rugged terrain.


If you are experiencing an immediate issue with your septic system such as water or waste backed up into your home, contact Hills Septic and Portable Toilets immediately. It is important to keep a safe distance from the waste material to avoid exposure to chemicals or toxins that were disposed of previously. Any clothing and other materials, including cleanup equipment, that comes in contact with overflow should be disposed of or disinfected with a 9:1 ratio mixture of water to bleach. After cleanup is completed, the area must be completely dry for a full day and night before normal room use can resume. It is also helpful to contact a local administrative office involved in septic health and regulations to ensure that proper cleanup procedures take place.


There are several types of maintenance and general use considerations that should be employed with any septic system:

  • Make sure you know where your system is and how to check on it regularly. Monitoring your system is an easy way to prevent issues from sneaking up.
  • Keep track of all maintenance that is performed on the system. This is a good idea for when you sell your home or if a professional has a question about the life of your septic system.
  • Schedule regular tank cleanings and inspections, about every two years. Smaller systems should be inspected and pumped more frequently than larger systems.
  • Try to use a more moderate amount of water. Using a large amount of water on a daily basis can overfill the system and cause issues.


If your home is not connected to the public sewer system, all the wastewater your home generates is treated by an “individual wastewater treatment system”, commonly called a septic system.

The importance of maintaining your system can be compared to the importance of maintaining your car’s engine. While changing your oil is the most important aspect of maintaining your automobile, pumping your septic tank is the most important aspect of maintaining your septic system. Every septic tank must be pumped out at least every 2 to 5 years. The size of the tank and the number of people using the system are important factors used to determine how often the septic tank should be pumped. No septic tank should go longer than 5 years between pumpings. In situations where a large number of people are using a small septic tank, it is not uncommon to have the tank pumped annually or even more frequently. If the septic tank is neglected, solids will overflow from the tank and into the leaching system. This will result in clogged leach lines, contaminated soil and ultimately leach field failure.


  1. MONEY: The cost and effort to get your tank pumped every 2 to 5 years is minimal. By pumping your tank regularly you can avoid costly expenditures of $3000 to $10,000 or more when a leaching system needs to be replaced.
  2. THE HEALTH OF YOUR FAMILY AND COMMUNITY: Inadequately treated wastewater can pose significant human health risks and can contaminate wells, groundwater and surface water sources.
  3. PROPERTY VALUE: A failing or improperly maintained septic system will result in a decline in the value of your property. When the time comes to sell your property, it will be critical that your septic system has been maintained properly and that it is working properly.


If you are like most people, you know very little about your septic tank system. This is understandable because there have been many myths and misconceptions surrounding septic tank systems and the way they work. Here, we will try to give you a clear understanding of what happens to your household waste after it goes down the drain. As the diagram illustrates, waste water generated in your household travels outside into the septic system. The most common type of septic system consists of two parts.

  1. The septic tank.
  2. The leaching system.

Some more complicated systems may include aerators, pumping stations, dosing chambers, drop boxes, raised fill leaching systems or other alternate systems.

The septic tank is a large box that is most commonly made out of precast concrete. Some septic tanks are made of metal, plastic or fiberglass. The size of a residential septic tank depends upon the age of the house, number of bedrooms in the home and the regulations in the county in which it is installed. Typically, a newer three to five bedroom home will have a 1500 to 2050 gallon septic tank. Smaller homes and older homes may have a 1000 gallon septic, or even a smaller tank. While older tanks consist of a single compartment, newer tanks often have 2 compartments. Some homes have more than one tank. When household wastes enter the tank several things occur:

  1. Everything flows into the tank through the inlet baffle and into the middle section of the tank. Here, the bacteria that live in the tank break down the wastes and it separates.
  2. Three layers form in the middle section of the tank. Organic solids form a crusty layer of “scum” at the surface of the tank. Inorganic solids form a layer of “sludge” at the bottom of the tank. The middle layer is relatively clear liquid called “effluent”.

The main purpose of the septic tank is to provide a place for all the solid wastes that leave your house to accumulate. Here the solid wastes can be dealt with by pumping them out of your system. Solids overflowing beyond the tank and into the leaching system should be avoided at all times. Solids overflow from the septic tank when the system is neglected by the homeowner and the tank is not cleaned out frequently enough by your local septic tank pumper. As time passes, solids continually accumulate in the tank. As the scum and sludge layers thicken, the clear water middle layer of effluent eventually gets “squeezed out”. As this happens, solids will overflow into the leaching system every time water is run in the house.

The leaching system distributes the treated effluent that overflows from the septic tank into the ground. Every time water goes down a household drain, some water (effluent) flows into the leaching system. There are several different types of leaching system. The most common type of leaching system is a conventional leach field with a distribution box. Other types of leaching systems include raised leach beds, modified raised beds, above ground mounds and leach fields on drop boxes rather than a distribution box. When a septic system is designed for an individual home, many factors need to be taken into consideration. Some of these factors include separation distances from the home, wells, neighboring wells, water lines and other utilities, property lines, trees, streams, bodies of water and groundwater. “Percolation test” results reveal how well the soil on the particular site accepts water (different types of soil leach at different rates). “Profile hole test” results reveal the soil conditions of the site and the depth to groundwater, seasonal groundwater, bedrock or other barriers to drainage in the soil.

Leach Fields consist of a series of trenches that usually stem out from a distribution box. These trenches are sometimes filled with stone with a perforated pipe running through the stone. Gravelless leaching chambers may also be used in place of the pipe and stone leach lines. Different homes and site conditions require varying amounts of leach lines (measured in linear feet). The number of bedrooms in the home and the percolation rate of the soil are used to determine the number of feet of leach line necessary. As the “clear” effluent flows out of the septic tank, it drains into the leach lines and into the soil.

Mound System is an alternative to the traditional leach field. The mound is an engineered drain field in areas where septic systems are more prone to failure due to having extremely permeable or impermeable soils, soil with shallow cover over porous bedrock, and soils that have a high seasonal water table. The mound system includes a septic tank, a dosing chamber and a mound. Waste from homes is sent to the septic tank where the solid fraction settles to the bottom of the tank. The effluent is sent to a second tank called a dosing chamber. In the dosing chamber, the effluent is evenly distributed in doses into the mound. Wastewater is partially treated as it moves through the mound sand. Final treatment and disposal occurs in the soil underneath the mound. The mound system can also better handle the effluent because it doesn’t all come into the mound at once allowing the effluent to be better cleaned and helping to keep the mound system from failing.

Evapotranspiration (ET) Beds are wastewater treatment and disposal that offers an alternative to conventional soil absorption systems for sites where protection of the surface water and groundwater is essential. An ET system is unique in its ability to dispose of wastewater into the atmosphere through evaporation from the soil surface and/or transpiration by plants, without necessarily discharging it to the surface water or groundwater reservoir. However, in certain cases, the ET concept also offers flexibility by combining seepage with evaporation as an alternative option.

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Have more questions? Need to schedule a service? Call us at (605) 348-3293 or fill out the contact card linked below!

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  • (605)-348-3293
  • 7481 Stagestop Rd. Black Hawk, SD 57718
  • Service areas: Pennington, Meade, Custer, Lawrence, and Butte Counties