Frequently Asked Questions
A – The septic system is more properly called an on-site wastewater treatment system. It is an extension of your home plumbing system that is designed to collect and treat wastewater from the home. It accomplishes this by separating the wastewater into solid and liquid components and sending the liquid portion to a soil absorption field or drain field where soil bacteria treat the liquid. The solids are retained in a septic tank and must be periodically pumped and taken to a wastewater treatment plant for final treatment. A system is working properly only if it is treating the wastewater, not merely disposing it.
A – A gray water system is a plumbing system that collects wastewater which does not contain human waste, such as washing machine water or the water from a sink or shower, and treats it separately from the “black water” which does contain human waste. The gray water must still go into a holding tank and allowed to settle for a minimum of three days. After settling the water from gray water systems may be recycled for toilet use or used to irrigate non-food crops such as a lawn.
A – This specialized septic system, sometimes called a No-Dak System, relies on a raised mound of engineered fill to elevate the bottom of the system to the required four feet above a limiting soil layer such as a seasonal high groundwater table, groundwater table, rock formation, gravel layer or an impervious layer of soil. The mound system must be designed by a registered professional engineer or licensed plumber and the design must be submitted to the South Dakota Department of Environment and Natural Resources (DENR) for approval.
A – A holding tank is, as the name suggests, a tank that holds the wastewater until it can be properly disposed. The wastewater from a holding tank must be pumped and taken to a treatment plant for proper treatment. The holding tank must have a float system that lets the property owner know when it is time to have the tank pumped.
A – Permits are required for all installation or repair of septic systems in rural Minnehaha County. Certified installers can obtain permits at the Minnehaha County Planning Department, 415 N. Dakota Avenue, Sioux Falls, South Dakota. Permits can only be issued to certified septic installers.
A – All systems must be installed and repaired by state-certified installers. Persons who wish to become certified should contact the South Dakota Department of Environment and Natural Resources (DENR) at (605) 773-3351 or 1-800-438-3367.
A – The list can be found at http://denr.sd.gov/des/sw/SepticInstallers.aspx on the internet or by calling the South Dakota Department of Environment and Natural Resources (DENR) at 1-800-438-3367.
A – The installer will need to know the total number of potential bedrooms that could be placed in the home, the total size of the home (square feet), the types of high-water-use appliances that may be included in the home and whether a garbage disposal will be installed in the home. The installer will also have to perform tests on the soils in the area where the system will be installed. A soil investigation (deep hole, 8-foot hole, soils hole, soil boring) will dictate the depth to which the system may be placed and a percolation (perc) test will help determine how large of a system will be required.
A – The purpose of the tank is to remove the solids from the wastewater so they do not reach the drain field and plug it. Therefore, a larger tank is required because more solids are being introduced into the system. A garbage disposal also chops up the solids resulting in finer solids that tend to float in the solution longer and thus have a greater potential of reaching the drain field.
A – The cost of a system can vary widely depending on the types of soils on the site, the amount of water use in the home and the physical features of the lot such as the depth to a seasonal water table or the location of a stream or wetland. Costs could range upward from $3000 for a standard system serving a small home to as much as $15,000, or more, for a mound system for a larger residence.
A – A minimum separation of 10 feet must be maintained between the septic tank and any building. The minimum distance which must be maintained between the drain field and a building is 20 feet.
A – South Dakota regulations require that septic tanks be at least 50 feet from a lake or stream, 50 feet from a well deeper than 100 feet and 75 feet from a well less than 100 feet in depth. The absorption area, or drain field, must be at least 100 feet from a lake, stream or well deeper than 100 feet and at least 150 feet from a well shallower than 100 feet.
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A – It is not recommended that trees or shrubs be allowed over the drain field. The roots can reach into the drain field lines and plug the pipes. The area above the absorption area should be maintained in a grass cover.
A – South Dakota regulations state that any system existing prior to February 28, 1975 can continue to be operated as long as the system does not allow groundwater to become polluted or allow wastewater to reach the surface of the ground. If either of these situations exists, or if an older system is repaired, the system must be brought into full compliance with the state septic regulations. Any system installed after Feb. 28, 1975 must meet all requirements of the state regulations.
A – No, South Dakota regulations prohibit untreated wastewater from being emptied onto the surface of the ground. Surfacing untreated wastewater constitutes a serious health threat.
A – Outhouses, or pit privies are prohibited by South Dakota regulations.
A – Cess pools and similar disposal methods are prohibited by South Dakota regulations.
A – If there are foul odors around the system, slow or backed up drains, algae growths, wet spongy ground or lush plant growth in the area of the drain field or near the tank, you should have a certified installer check the system.
A – Ongoing homeowner maintenance is an essential step in ensuring that your system continues to properly treat wastewater. Make sure that you do not overuse household cleansers, cut back on water use, and have your septic tank periodically pumped by a septic pumper and the waste taken to a treatment plant for proper treatment.
You must also ensure that there is no vehicle traffic or parking over the drain field. Vehicles could compact the soil in the drain field and prevent the proper absorption of liquids in the area. The pressure of vehicular traffic could also force frost deeper in the winter months and could result in frozen pipes within the absorption area.
A – You should have your septic tank pumped a minimum of once every 3-5 years if you do not have a garbage disposal. If you do have a garbage disposal in the home, have the tank pumped at least once per year and take care with the types and amounts of materials you run through the garbage disposal. Keep a record of any repairs, pumping or other maintenance.
A – No, the waste pumped from a septic tank must be taken to a wastewater treatment plant for final treatment. South Dakota regulations prohibit the placement of non-treated wastewater on the surface of the ground.
A – There are two types of system additives: biologicals (bacteria, enzymes and yeasts) and chemicals. Most septic tank additives are either ineffectual or are so strong that they should not be introduced into the environment where they could contribute to pollution. Some additives can actually damage the septic system and prevent it from properly treating the waste which could result in costly system repairs. A properly operated and maintained system should not require any additives.
Some people claim that a “starter” must be used in a new system or after a tank has been pumped. This is not necessary. The system has ample bacteria provided that nothing is introduced into the system that kills the bacteria.
A – A general rule of thumb is to not place anything into the system that could just as easily be placed in the trash. Materials that will not readily break down in the waste water should not be introduced into the system. Limit washing food scraps, coffee grounds or similar materials down the drain. Do not flush items such as plastics, paper towels, facial tissues, sanitary napkins and tampons, cigarette butts, dental floss, disposable diapers, condoms, or kitty litter.
Use cleansers such as bleaches, disinfectants, drain cleaners and toilet bowl cleaners only in moderation. Exclude all toxic, hazardous or highly antibacterial chemicals from the system. Items to exclude include anti-bacterial soaps, anti-freeze, gasoline, paints, pesticides, pharmaceuticals, photographic chemicals, oils, thinners, and waste oils. Such materials should be taken to a household hazardous waste collection center or recycling facility.
A – Both aerobic (with oxygen) and anaerobic bacteria (without oxygen) play a critical role in properly treating the wastewater. Care must be taken to not introduce anything into the system which will damage the bacteria levels in the system. Some of these items could also pose an environmental problem if introduced into the septic system.
A – Opening the tank will not kill the bacteria. At times it may be necessary to open the tank to perform certain types of maintenance on the tank. This should be done, however, only by a qualified professional since the gases (such as methane) in the tank can be both toxic and explosive.
A – Stay out of the tank at all times! The gases within the tank can be highly toxic. Only a qualified professional should enter the tank when necessary, and then only with the proper safety
A – Yes, if an excessive amount of water is applied to the lawn, it could saturate the ground and reduce the soil’s ability to absorb wastewater. This can result in system failure and allowing wastewater to surface on the ground or back into the house. This is also the reason that the drain field must be located away from areas where there may be concentrated storm water flows. Downspouts also cannot be emptied into the septic system and the flow from downspouts must be directed away from the system.
A – The tank is located where a series of pipes extend out of the ground. There should be a larger (approx. 6-inch pipe above where the manhole is located and a 4-inch pipe above both the inlet and outlet of the tank. The drainfield (or leach field) may be more difficult to locate of you do not have a record of its location. Look for areas where the soil may have settled along the trenches and left a slight depression, for areas which may be damp when the rest of the yard is dry, or for areas where the grass is growing differently than that of the surround site, either greener (increased water and nutrients), or grass isn’t growing as well (possible overload of nutrients). Once you have located the drainfield, be sure to keep a sketch of the area for future reference.
A – It is not recommended that trees or shrubs be allowed over the drain field. The roots can reach into the drain field lines and plug the pipes. The area above the absorption area should be maintained in a grass cover.
