Septic systems, when properly designed, installed, operated and maintained, provide effective treatment of household sewage at a very reasonable cost. Unfortunately because the septic system is buried "out of sight" in the backyard, it often becomes "out of mind." But, a septic system, just like a car, appliance, or tractor must be properly operated and maintained to ensure long-term, cost effective service.
Tools and fact sheets
Find online tools, forms, worksheets and printer-friendly fact sheets for septic system owners.
No matter the season, there are steps you can take to keep your septic system running well.
Even with attentive care and management, issues can arise. Learn how to identify some of the more common septic system issues and how to address, or even prevent them.
Management = Operation + Maintenance + Monitoring Systems
The goal of on-site sewage treatment is to protect human health and the environment by safely recycling wastewater back into the natural environment in a cost-effective manner. Effective on-site treatment of wastewater is dependent on proper design, installation, operation and maintenance of the system. A well-designed system will not properly treat sewage over its intended life without appropriate operation and timely maintenance! Good management of an on-site system will improve the performance and extend the life of the system resulting in reduced total cost to the owner with increased reliability and satisfaction.
Management = Operation + Maintenance + Monitoring
One of the 'hottest topics' in on-site sewage treatment today is the management of systems! Once a well-designed system — including provisions for management - has been properly installed (the responsibility of the designer, installer and inspector) it must be used, watched and taken care of to meet its owner's expectations. This is no different than any other piece of equipment we own.
"Standard" systems have been designed to require minimal management. Existing codes and rules have paid minimal attention to management and few if any enforcement agencies have provided significant encouragement for owners to follow good management practices. This lack of attention to good management has often proved costly to homeowners and the environment. We must now make a concerted effort to increase our attention to management of all systems — standard and 'alternative'.
'Operation' is the day-to-day use of the system by the residents. The 'users' of the system control the quality, quality and pattern of the wastewater entering the system. The performance of septic systems is greatly influenced by what enters it!
"Using" water does not mean it goes away forever but rather means that we are changing it from 'clean water' to 'dirty water' by adding human wastes, food particles, cleaners, soil, lint, and other materials. These additions contain pathogens, organic and inorganic solids, nutrients, and chemicals. We are counting on the system to clean it again for reuse later. Users determine the quantity of water used by the number of gallons per flush of the toilet, the length of showers, the number of loads of clothes washed, faucets running while brushing teeth or washing dishes, as well as the frequency of doing each of these things, and all other water use practices.
'Maintenance' is the work of doing periodic upkeep on the system. It includes the repair, replacement, and cleaning of existing components. It can also be the addition of new components to enhance performance.
Examples of maintenance are: the repair of leaking fixtures and appliances, the replacement of septic tank baffles or weak pumps, the cleaning of effluent screens or lint filters, the removal of solids from a septic tank or composting toilet, or the addition of an effluent screen to the outlet baffle.
The monitoring of a system is the frequent observation or testing of all on-site system components. It could even mean the testing of effluent or contents! An important aspect of monitoring is to know what needs to be watched, when it should be done and who's going to do it — a plan! The results of monitoring should be recorded and the information used by those doing 'operation' and 'maintenance'. The use of the information is what makes it valuable!
Examples of monitoring may include: knowing what goes down the drain; reading and recording the results of a flow meter; checking baffles, screens, pumps, and alarms for proper function; noting wet spots near the drainfield or mound; recording the date and condition of the septic tank when it is pumped; or sampling and testing effluent from a performance system and reporting the information to a local agency as required.
Management of alternative treatment systems
Specific operation, maintenance and monitoring procedures should be planned and followed to provide good management of all systems. 'Alternative' treatment systems (i.e. sand/peat filters, constructed wetlands, aerobic tanks, composting units, etc.) typically involve special mechanical components, living plants, or other devices, which require special knowledge, skill and attention to perform as designed. Owners may wish to or be required to hire professional management of an 'alternative' system. The complexity and costs of management must be an important criteria considered in the initial selection of an 'alternative' system.
Who, when and how
Total management of a system must involve the residents generating the sewage with varying levels of assistance from professionals. The individual owner will likely determine management responsibilities of a single household system. Traditional trench and mound systems requiring relatively simple management are typically managed by the owner using licensed pumpers and other professionals as needed. Homeowners are capable of handling typical management tasks if they are aware of what needs to be done and make a commitment to it. Owners of complex systems or those unwilling to make the commitment may feel the necessity or be required to hire outside professional management. More opportunities to 'contract out' some steps will likely be available in the future.
Multiple-household systems have another dimension to management — other users. Each homeowner is responsible for the content and quantity of the wastewater generated and must rely on co-users to do the same. All users collectively are responsible to each other and for the management of the commonly used portions of the system. Common components could include large 'community' septic tanks, pre-treatment units or the soil treatment/dispersal system (i.e. trench, mound, wetland, drip lines, etc.).
A good management plan will specify 'who will do what' and 'when and how' they will do it. Each system is unique. The plan must be for the specific system and must be followed to be effective! In some multi-household systems residents can do some management tasks, such as reading water meters, but most functions will require additional equipment, skill and commitment.
The amount and cost of management will vary considerably with the size, type, and complexity of the treatment system. Owners must be willing to pay for the necessary management to achieve effectiveness and efficiency of their investment.
The bottom line is that a responsible person or entity — resident, business or private/public organization, must be designated to know and carry out the specific management practices required for successful treatment of wastewater in any system including on-site systems. For individual or multi-household systems in Minnesota there are several management structure options to choose from:
- Environmental Subordinate Service Districts
- Sanitary Sewer Districts
- Homeowner Associations
- Municipal Utilities
- Homeowner Cooperatives
- Private Joint Ventures
Each option has strengths and weaknesses to be considered for any local application. These options will be discussed in detail in the August/September issue of Focus 10,000.
A properly designed, installed, operated, and maintained on-site system = safely recycled water!
Parameters to monitor septic system performance
Monitoring wastewater characteristics
There are many characteristics to monitor an on-site wastewater treatment system’s performance. They vary from something as simple as checking for sewage on the surface, to complicated laboratory analysis. All cost and required amount of sample vary from lab to lab, but estimates are given. Be sure to contact a lab prior to dropping off samples.
When choosing a lab to perform analysis of wastewater characteristics, a certified lab is always the best choice. These labs use standard procedures. The Minnesota Department of Health maintains a list of labs across Minnesota that are certified.
There are many locations where samples can be taken. It is best if the sample locations are determined when the system is being designed. These sample locations must be built into the design. Effluent chambers, pump tanks and designed sampling ports are suggested locations to obtain samples.
Some obvious locations where the wastewater characteristics are of interest are:
- Out of home
- After septic tank.
- Sampling at system’s "end-of-pipe"
- Sampling groundwater (lysimeter, sampling wells)
- Sampling soil (dry g/microgram fecal)
Piezometers can be used to determine the amount of separation. Lysimeter or soil access ports can be used to determine the amount of fecal under system.
Biochemical Oxygen Demand (BOD5) is the most widely used parameter applied to wastewater. It is a measurement of the dissolved oxygen used by microorganisms in the oxidation of organic matter in sewage in five days. Because of the timeliness of these results the samples for a BOD5 test must be run within 24 hours of taking the sample. An average cost for a BOD5 test is $12. A minimum of 500 milliliters is required to run the test. A typical BOD5 value for septic tank effluent is 100- 250 milligram per liter (mg/l).
Color is an indication of how ‘clean’ the wastewater is. A black sample represents wastewater that is anaerobic and still need significant treatment. A clear sample represents a sample where the BOD5 and TSS have been minimized. The amount of fecal coliform cannot be estimated with a visual inspection.
Dissolved Oxygen (DO) is a measure to determine how much oxygen is in wastewater. Septic tanks usually have very low values of DO because the microorganisms in the septic tank use up all oxygen initially present. A typical value for DO in a septic tank is less than 1 mg/L. This can be measure with a probe or kits are available which evaluate the DO by comparing the color of sample after a chemical is added. The DO must be measured when the sample is taken or soon after because the level will decrease over time.
Fecal Coliform is an indicator organism. There are many pathogenic organisms present in wastewater. They are difficult to isolate and identify. The intestinal tract of man contains countless coliform bacteria. The presence of fecal coliform organisms, which are easily tested for, is an indication that pathogenic organisms may be present. The number of fecal coliform organisms will change over time; therefore fecal coliform test must be run within 6 hours of taking the sample. An average cost for a fecal coliform test is $16. A 500-milliliter sample is sufficient. An average value for septic tank effluent is 100,000- 100,000,00 cells/100 milliliter.
Fats, Oils and Grease (FOG) are added to wastewater through the use of butter, lard, margarine, vegetable oil, and meat. A typical value for FOG from a septic tank is 10 — 50 mg/L. A restaurant can produce very high values, often greater than 100 mg/L. A quart of more of the effluent is required to run this test. An average cost of this test is $42. The cost is so high because of the chemicals required for this test.
Nitrogen is a nutrient essential to the growth of plants and microorganisms and in high levels can be toxic to humans. Wastewater naturally contains fairly high levels of nitrogen, typically in the range of 50-90 mgN/L. It is found in four different forms: organic nitrogen, ammonia, nitrite and nitrate. High nitrate (greater than 10 mg/L) and nitrite (greater than 1 mgN/L) in drinking water (greater than 10 mg/L) can cause blue baby syndrome in infants, which is potentially fatal blood disorder. At high concentrations of ammonium and if the pH gets about above 9, unionized ammonia may be formed which is toxic to fish and other aquatic animals. High ammonium also adds to the BOD load of the effluent when it is oxidized to nitrate. Typical ammonium levels in the septic tank effluent are 30-50 mgN/L. A 100-milliliter sample should be sufficient for a nitrogen test. An average cost for a nitrogen test is $10.
Phosphorus is a nutrient essential to the growth of plants and microorganisms. This nutrient may cause increased growth of aquatic vegetation and algae in surface waters that can result in eutrophication impacts. A typical value for septic tank effluent is 7- 20 mg/L of phosphorus. A 100-millilter sample is needed at a minimum. An average cost for a total phosphorus test is $10.
Total Suspended Solids (TSS) is a measure of the organic and inorganic solids, which remain in wastewater after separation occurs in the septic tank. Typical suspended solids values of septic tank effluent range from 20-140 mg/L. A 100-millilter sample is needed. An average cost for a TSS test is $4.
Temperature of wastewater is a very important parameter because of its effect on chemical reactions. Temperature of wastewater varies from 45-70 ° F depending on the season. Wastewater temperature is usually not a problem for individual residents, but very low or very high temperatures can be a problem from restaurants and infrequently used homes. The temperature of the wastewater must be done when the sample is being taken.
Turbidity is a measure of the light-transmitting properties of water. It is another test to easily measure the quality of waste with respect to suspended matter. Turbidity can be roughly measured in the field or a lab analysis can be performed. A 100-milliliter sample should be collected. An average cost of the lab test is $4.
Odor is often detected when a system is not performing properly. A properly functioning system will have little or no odor.
Flow Meters are used to measure the volume of wastewater going to an on-site system. They are usually located in the basement. This data, when collected on a regular basis can indicate how much water is being delivered to the on-site system. A typical flow for a 3-bedroom home is 450 gallons per day, but this is highly variable depending on the water conservation measures used by the residents.
Tchobanoglous, George and Franklin L. Burton. Wastewater Engineering: Treatment, Disposal and Reuse. Metcalf and Eddy, Inc. Boston, MA. 1991.
Abney, Jack, L. Selection of an Appropriate Wastewater Disposal System. Proceedings of the Seventh National NSF Conference 1980. Ann Arbor, MI. 1981.
Canter, Larry, W. and Robert C. Knox. Septic Tank System Effects on Ground Water Quality. Lewis Publishers, Chelsea, MI. 1986.
Crites, R and G. Tchobanoglous. Small and Decentralized Wastewater Management Systems. McGraw-Hill. Boston, MA. 1998.
Home maintenance summary
Septic system operation and maintenance
A septic system, just like a car, appliance, or tractor must be properly operated and maintained to ensure long-term, cost effective service. Many septic systems are installed and forgotten. After all, they're buried in the yard, "out of sight - out of mind." Licensed professionals design and install septic systems, but often uninformed homeowners are responsible for their operation and maintenance. Septic systems must treat all wastewater from our homes and prepare it for recycling back into nature while protecting human health and valuable water resources.
Septic systems are designed to properly treat wastewater while protecting human and environmental health in a cost effective manner. Onsite septic systems are a mini water recycling plant in the back yard. They clean our wastewater and return safe water to the groundwater system. If a septic system is not functioning properly, clean water is not returned to the groundwater. The tips below can help homeowners keep their systems operating properly.
Control water use
Repair all leaky faucets, fixtures and appliances immediately. Check toilet bowls for leaks: at night, put some food coloring in the toilet tank. In the morning, inspect the bowl. If colored, there is a leak between the tank and bowl.
- Install low water use fixtures and appliances (especially toilets and shower heads).
- Do not empty roof drains and sump pump water into the septic system; channel away.
- Wash only full loads of clothing and dishes.
- When replacing a washing machine, take a close look at the front loading, and water efficient top loading machines. These machines save a great deal of water over older washers.
- Reduce length of showers and number of toilet flushings.
- Reroute water softener and iron filter recharge water out of septic system.
- Spread water use as evenly as possible throughout the day and week, especially laundry.
Eliminate harmful products from system
Use liquid laundry detergents and gel dishwashing detergents. This minimizes the non-organic solids sent to the tank. Read labels carefully – many gel dishwashing detergents are high in phosphorus content; avoid these products.
- Reduce/eliminate use of harsh cleaners, disinfectants, detergents and bleach, including laundry detergents. Increase elbow grease, decrease cleaners.
- Avoid the use of anti-bacterial soaps. They are not necessary for cleanliness, and destroy good bacteria in the tank and soil treatment area.
- Dispose of solvents, paints, unwanted medications through other means such as hazardous waste disposals and exchanges. Return un-used medications to the pharmacy if possible.
- Keep grease, lint, food particles, cigarette butts, paper towels, disposable diapers, coffee grounds, plastic and other solid products out of the system.
- Install an effluent filter, preferably one with an alarm on the outlet pipe of your septic tank. This will catch washing machine lint, small particles that stay in suspension in the liquid and other matter. These must be maintained and cleaned regularly. One type is installed and maintained by your pumper. Another type is installed and maintained by the homeowner.
It is not necessary to use additives to enhance the performance of a properly operating septic system. If bacterial activity is low, it is because disinfectants and other products are killing the bacteria. Reducing or eliminating the use or disposal of these in the system will allow the bacteria to reestablish. Some additives cause solids to become suspended in the liquids. These solids will end up in the drain field, causing significant damage. Starters, feeders and particularly cleaners are unnecessary, and may be harmful to your system.
Cleaning/pumping the septic tank
The septic tank must be cleaned or pumped regularly to remove all solids. The recommended time is at least every 3 years. Refer to the Septic Owner's Guide for a chart to determine a pumping schedule based on number of people in the home, size of the system and water use habits.
- Always have the tank(s) cleaned through the manhole (20 to 24 inch opening). The inspection pipes are just that - for inspection. These are the white 3 - 4" pipes at the end of the tank and drain field.
- Flushing and back flushing is the most common method of agitating solids so they can all be removed.
- Inlet and outlet baffles should be inspected to be sure they are in place and functioning properly.
- If you have an effluent filter, inspect and clean regularly.
- The soil treatment area should be inspected at the time of pumping.
Pumps and filters
All pumps and motors should be routinely checked for proper operation.
- Replace weak or faulty pumps and motors.
- Effluent filters should be cleaned or replaced regularly.
- Alarms on pumps and filters must be attended to immediately.
Mow but do not fertilize or water plantings over the drain field/mound.
- Maintain stands of appropriate plants on constructed wetland sites
- Any shallow rooted grasses or flowers may be planted over a drainfield or mound. Avoid deep rooted plants, shrubs and vegetables over your system. If native prairie grasses are used, manage by mowing - do not burn over this area.
- Be sure water -seeking trees such as willows are located far away from the system.
- Stop cutting the grass over the soil treatment area a couple weeks before the rest of the lawn. The extra growth will help insulate the area, and will help prevent freezing.
Protect the soil treatment area
Keep all foot and vehicle traffic off the tank, pipes and soil treatment area (drainfield or mound). The only exception is the lawn mower. Mounds and drainfields are not 4-Wheeler jumps, walking paths, or for use by snowmobiles or cars.
Home maintenance tips
By controlling water use, selecting appropriate products, and making wise disposal decisions, homeowners can improve the performance of their septic system and avoid major problems.
- Reduce use of drain cleaners by minimizing the amount of hair that goes down the drain.
- Limit use of antibacterial soap.
- Reduce use of cleaners by doing more scrubbing with less cleaner.
- Take short to moderate length showers instead of tub baths. Showers use less water than tub baths.
- Do not flush facial tissues, paper towels, cigarette butts, or personal hygiene products down the toilet.
- Do not dispose of unwanted prescription or over the counter medications in the septic system.
- Use moderate amounts of toilet paper. Toilet paper should break up easily in water.
- Do no use "every flush" toilet bowl disinfectants that are placed in the tank or bowl.
- Shut off water while shaving and brushing teeth (save up to 5 gallons per minute).
- Fill basin to wash hands instead of washing under running water.
- Do not run the hot water in the shower to warm the bathroom.
- Shut off water in the shower while lathering and shampooing.
- Repair leaky faucets and toilets immediately.
- Install low-flow showerheads.
- Take shorter showers.
- Distribute wash loads evenly throughout the week to avoid overloading the system with large volumes of water in a short period of time.
- Use the minimum amount of detergent or bleach necessary to do the job. This is often less than suggested by manufacturers.
- Use liquid detergents (powdered detergents may add fine particles to the sludge accumulation in the tank.)
- Use a water/suds-saving, top-loading washing machine to reduce water and detergent useUse highly biodegradable powdered detergents if liquid detergents are undesirable.
- Select a front-loading washing machine which may use 40 to 65% less water.
- Use laundry detergents that do not contain phosphates or bleaches.
- Wash only full loads. Adjust load level settings for small loads.
- Install filter on washer to remove lint.
- When using drinking water treatment devices, be sure there is a shutoff valve so the system doesn't run continuously when the reservoir is full. Some units may reject up to 8 gallons for every gallon retained.
- Use minimal amounts of mild cleaners as needed only.
- Do not use a garbage disposal or dispose of vegetables, meat, fat, oil, coffee grounds, and other undigested food products in the septic system. (Use composting or garbage service.)
- Use the minimum amount of soap necessary to do the job, often less than suggested by manufacturers.
- Reduce the use of drain cleaners by minimizing the amount of grease and food that go down the drain.
- Keep a pitcher of drinking water in the refrigerator instead of running the tap every time to get cool water. Install low-water-use dishwasher, use liquid detergent in the dishwasher. Hand wash dishes in the basin instead of under running water. Use low-phosphate (0 to 5%) dishwasher soaps. Wash only full loads in the dishwasher. Limit use of antibacterial soap. Install low-flow faucets. Repair leaky faucets.
Basement and utility rooms
- Dispose of all solvents, paints, antifreeze, and chemicals through local recycling and hazardous waste channels.
- Consult local solid waste officials for proper methods. These materials kill valuable bacteria in the system and may pass through to contaminate drinking water.
- Install a water meter to monitor water usage.
- Reroute the water softener and iron filter recharge water outside the septic system. It does not need to be treated. Recharge the water softener as infrequently as possible to reduce water use.
- Route chlorine-treated water from swimming pools and hot tubs outside of septic system and away from drainfield.
- Never let wash water from latex paint on brushes or rollers go down the drain and into the septic system.
- Route water from condensation in high efficiency furnaces outside of septic system (to prevent freezing problems).
Management and ownership of multi-house systems
Septic systems--for homes not connected to municipal sewer-- treat household wastewater to protect family health and the environment. In most cases, septic systems are owned and managed by the individual homeowner. Management of a septic system includes the daily operation and the maintenance necessary to keep it functioning properly. Of course, daily operation (flushing the toilet, washing the clothes, etc.,) is the responsibility of all persons in the household.
In some situations where homes are located on small lots, such as a small rural town or around a lake, several homeowners may find it necessary or advantageous to join together with neighbors to treat their household wastewater. In this case everyone connected to the system must take personal responsibility for the day-to-day operation, although the group as a whole has special interest in the maintenance. Multiple- household systems can have individual or larger group septic tanks and any type of soil treatment system appropriate to the soil conditions and space available.
The drainfield, mound or other system may be located on property purchased or leased specifically for this purpose or on a property already owned jointly, as in a cluster housing development. The more people in the system and the more complicated the treatment technology, the more important proper management becomes. Management structure options fall into two primary categories: private and public.
Private management structure options include homeowners, associations, private joint ventures and water quality cooperatives. Homeowner associations, the most common entity, typically have by-laws that regulate the community property on which all or part of the treatment system is located. They may or may not have trouble recruiting and maintaining dedicated staff or qualified volunteers to deal with all management functions.
A "privatized joint venture" may be set up by a local unit of government to contract a private vendor to provide management services to homeowners for a user fee. The vendor may contract with several communities.
Water quality cooperatives are a new structure allowed by 1997 Minnesota legislation. This organization is like a rural electric cooperative that furnishes management expertise and levies a fee for its services. The legislation authorized two pilot cooperatives to be formed in Minnesota.
Public management structure options include municipal utilities, sanitary sewer districts, and subordinate service districts. Public utilities, formed by cities, townships, or counties, are the most common form. They are a separate government entity providing wastewater treatment services assessing the users of the service to cover the costs.
Sanitary sewer districts may be formed by cities, townships, and counties or by petition to the MPCA of 20 percent of the voters residing and owning land in the affected area. Special state legislation and district courts can also create such districts.
Environmental subordinate service districts are becoming popular in Minnesota. These are typically a three-way partnership between private citizens, a township (often with county cooperation), and a local vendor--often a local utility. The adaptation of these districts to multi-household septic systems began in Cass County in 1994.
To be effective, all management structures must work to educate homeowners about the importance of good day-to-day use of their septic system, provide continuous monitoring of the soil treatment system, and arrange for routine cleaning and maintenance of the individual or community septic tanks.
The impact of cleaners and additives
Antibacterial products in septic systems
An onsite sewage treatment system or "septic system" is a very effective way to safely recycle household wastewater back into the natural environment. A soil treatment based onsite system will remove all pathogens and most of the nutrients contained in wastewater if it is properly designed, installed, operated and maintained. "Operation" refers to everything we do or put into the system.
To achieve proper treatment, a septic system is very dependent on millions of naturally occurring bacteria throughout the system. We add many of these good bacteria through the wastes and materials typically found in wastewater. Anaerobic bacteria in the septic tank decompose organic materials in the wastewater and aerobic bacteria in the soil destroy disease-causing pathogens.
The use of antibacterial or 'disinfectant' products in the home can and do destroy good and bad bacteria in the treatment system. Normal use amounts of these products will destroy some beneficial bacteria but the population will remain sufficient and recover quickly enough to not cause significant treatment problems. Excessive use of these products in the home can cause significant and even total destruction of the population. Often the use of a single product or single application will not cause major problems but the accumulative affect of many products and many uses throughout the home may add up to an excessive total and cause problems.
More research is needed to determine 'what is excessive?' and which products are more or less harmful to systems. Recently many products are being marketed as "antibacterial". Consumers and on-site professionals working to diagnose treatment system problems have many questions about individual products. Questions like 'how antibacterial is antibacterial?' and 'which products are better or worse than others?' are a couple of them.
Several professionals have reported problems with low or no bacterial activity in systems and upon the removal of antibacterial products from the home, beneficial bacterial activity returns and desired treatment functions resume. These products affect all treatment systems but because of special attention being paid to new 'alternative' treatment technologies now being introduced into the on-site industry, it is possible that some systems may be more affected by fluctuating bacterial numbers due to antibacterial products than other systems. More research needs to be done on this as well.
What are these antibacterial products we are talking about? They include: 'antibacterial' hand soaps, tub, tile and shower cleaners, drain cleaners, toilet bowl cleaners, laundry bleach products, and others. Also included are 'antibiotics' that may be prescribed for medical treatment. These are products that are found in nearly all homes. They often carry a "safe for septic systems" statement printed on the label. The question may be "How Safe?"
The University of Minnesota Extension Service Septic System Owner's Guide suggests:
To improve septic system performance:
- Do not use 'every flush' toilet bowl cleaners
- Reduce use of drain cleaners by minimizing the amount of hair, grease, and food particles that goes down the drain
- Reduce use of cleaners by doing more scrubbing with less cleanser
- Use the minimum amount of soap, detergent and bleach necessary to do the job. Frequent use of detergents with bleach additives is excessive amounts of bleach.
- Use minimal amounts of mild cleaners, as needed only
- Route chlorine-treated water from swimming pools and hot-tubs outside of the septic system
- Dispose of all solvents, paints, antifreeze, and chemicals through local recycling and hazardous waste channels
- Do not flush unwanted prescription or over the counter medications down the toilet
All of the practices above work toward preventing the loss of beneficial bacteria throughout the system. Bacterial additives (enzymes, starters) are not necessary and will not compensate for excessive use of antibacterial products.
It might be that in an effort to be "super clean" and protective of the families health through the use of antibacterial products in our homes, we might compromise our health in another way – by damaging our on-site sewage treatment system.
Medications and your septic system
The problem with medications and septic systems
Medications are a part of daily life for many people connected to a wastewater treatment plant or a septic system. The human body does not completely metabolize medications, so they enter septic systems unavoidably through our body wastes. According to the Centers for Disease Control and Prevention:
- 48.9 percent of people used at least one prescription drug in the past 30 days.
- Approximately 23 percent of people used three or more prescription drugs in the past 30 days.
- Approximately 12 percent of people used five or more prescription drugs in the past 30 days.
Chemotherapy drugs are potent, lifesaving treatments for patients with many types of cancer. Chemo interrupts the cellular functions of fast-growing cells and, when possible, triggers cell death. In a cancer patient, fast-growing cells tend to be cancer cells, so these are the cell types most affected by these drugs. However, other fast-growing cells (e.g., hair) are also affected. The biologic pathways targeted by a major subgroup of cytotoxic chemotherapies include DNA replication and repair functions. In a cancer patient, many genotoxic drugs are given at near-lethal doses both singly and in combinations with other cytotoxic drugs to trigger overwhelming DNA mutations and thus trigger cell death. At lower levels, genotoxic drugs tend to trigger DNA mutations without death. OSHA states that the drugs (after injection into patients) are concentrated in the urine.
Many of these chemo drugs are completely broken down by the patient's body and are not a problem; however, some are excreted from the patient unchanged or as active metabolites. These drugs are fully functional even if they are in the patient’s sweat, vomit, urine and feces. As the patient and their family dispose of the patient’s biological waste, all are exposed to dangerous amounts of these DNA-mutating drugs. Most of the biological waste enters wastewater treatment plants or septic systems, where it is partially degraded and may harm the beneficial bacteria in systems. One example, cyclophosphamide, is known to survive standard wastewater treatment and may maintain its drug function for months or years.
Cytotoxic drugs are not cancer-specific. They can act against any growing cell with the amounts of damage increasing with increased rate of cell growth and the concentration of drug. This means that these drugs do not distinguish between the patient and anyone else and possibly the beneficial bacteria in our septic systems.
With wastewater treatment plants, the use of medication is less of an issue as they have the benefit of dilution due to the larger number of people using a system and additions from commercial sources of wastewater. Normal use of many medications, including over-the-counter drugs, will not harm your septic system. However, antibiotics and certain strong medications such as those used in chemotherapy can affect the operation of your system. The problem is that we do not know which chemotherapy drugs will be problematic, as they are not tested for their impacts to wastewater treatment.
High concentrations of antibiotics along with other pharmaceuticals and chemicals can kill or retard the growth of the anaerobic bacteria in the septic tank, pretreatment system and soil treatment area. These anaerobic bacteria are necessary for proper operation of the system because they digest some of the organic matter entering the septic tank. They reduce the amount of solids in the tank and reduce the biochemical oxygen demand of the effluent. If the septic tank bacteria are reduced, solids accumulate in the tank faster and can create problems in the soil treatment area. In pretreatment and soil treatment systems, aerobic bacteria are needed to continue the treatment process, and they can be negatively impacted as well.
Steps to take
If a member of the household is expected to be taking medications on a short-term basis (less than three months), the septic tank should recover after the treatment. If the tank is cleaned after the treatment, it will recover more quickly. If the medications, including chemo drugs, will be used long-term, here are some recommended steps for homeowners to consider to protect their septic systems.
- Unused medications should never be flushed. High concentrations of antibiotics will destroy the beneficial bacteria. Many more take-back programs have developed across the U.S., often associated with law enforcement, pharmacies, or hospitals that will dispose of the medication.
- Minimize the use of other products that kill bacteria such as antibacterial soap, drain cleaners, quaternary ammonia, cleaners and bleach, as these products further stress the bacteria in the system.
- After a new treatment program begins, the septic tank should be evaluated to determine if it is operating normally. It should have a septic odor from methane and hydrogen sulfide production along with the three distinct layers: sludge, scum and a clear zone. If there is no clear zone or if there are visible solids in the clear zone, this is an indication that the bacteria in the tank may be upset. If the septic tank has a chemical odor or is yellow in color, this can indicate a toxic tank as well.
- Increased maintenance of your system may be required with certain strong medications, such as chemotherapy drugs. The septic tank may have to be pumped more often to remove solids that are accumulating rapidly due to the loss of beneficial bacteria. A septic professional can monitor the system, take samples of BOD or TSS, and recommend a management plan, which may include the following steps.
- If the septic tank gets too toxic, it may be necessary to use the tank as a holding tank during a prescribed treatment.
- Fill the septic tank with clean water after pumping to dilute the concentrations of the medicines at the restart of the system.
- Certain design changes may be necessary to protect the pretreatment or soil treatment area. These changes could include adding an effluent screen, which is placed on the outlet of the septic tank to limit solids exiting the tank. The effluent screen will need to be cleaned frequently if the septic tank is upset. An alarm is a critical part of an effluent filter installation, as it will indicate when the filter needs to be cleaned.
- If hair loss is expected, an effluent screen is particularly helpful in preventing hair from being washed into the septic system. Hair can remain suspended in the wastewater and is carried to the drainfield, where it could plug the soil and cause drainfield failure.
- Adding additional septic tanks or a pretreatment device are other possible design changes to try to break down the contaminants with either more detention time or aeration.
Detergents, cleaners and garbage in septics
Many materials generated in daily living enter the wastewater system for disposal and treatment. Some are obvious and others much less obvious. The following are choices you can make to improve the performance of your septic system and protect your investment.
When washing clothes or dishes, use the minimum amount of soap, detergent or bleach necessary to get the job done. Also use liquid detergents and soaps. If liquid detergents are undesirable, use highly biodegradable powdered detergents.
Reuse laundry wash water with a suds-saver device on the automatic washer. The second load of clothes requires only a fraction of the soap and reuses the water.
Consider a front loading or low water use washer when purchasing a new washer.
Minimize the amount of hair, grease and food materials that go down your drains.
Use minimal amounts of mild cleaners and only use as often as needed.
Do not use "every flush" toilet bowl disinfectants. Reduce toilet bowl cleaner use by doing more scrubbing.
Garbage disposals shouldn't be used with septic systems. Vegetable, meat, fat, oil, and other food products add large amounts of sludge. A result is more frequent tank cleaning. These materials are difficult for bacteria in the septic tank to break down.
Hazardous waste products should not be disposed of in a septic system. This includes even small amounts of latex paint rinsed off rollers or brushes. Dispose of all solvents, paints and chemicals through local recycling and hazardous waste channels. Consult local solid waste officials for proper methods. These materials kill valuable bacteria in the system.
Unwanted medications should not be flushed down the toilet or poured down the drain. They will kill beneficial bacteria in the septic tank and drainfield.
Do not flush facial tissue, paper towels, cigarette butts, disposable diapers or personal hygiene products.
Septic system cleaners
The general rule of thumb about septic system starters, feeders, cleaners and other additives is: If they are safe to use, they are probably not effective; and if they are effective, they are probably not safe to use. There is no quick fix or good substitute for proper septic tank operation and regular maintenance.
A "starter" is not needed to start bacterial action in the septic tank. There are numerous bacteria present in wastewater. It is also not necessary to "feed" the system with additional bacteria, yeast preparations or other home remedies. We feed the system every time we use it.
Septic tank '"cleaners," intended to remove solids from the tank, will probably damage the soil treatment system. Many additives agitate the solids that should float to the top or settle to the bottom of the tank. This agitation suspends the solids. It allows them to be flushed into the drainfield. There they clog pipes and soil pores, leading to partial or complete failure of the system. This can result in the need for a costly replacement of the soil treatment system.
Other additives, particularly degreasers, may contain carcinogens. These cancer-causing agents flow directly into the groundwater with the treated sewage.
Minnesota Rules Chapter 7080, titled "Individual Sewage Treatment Systems Program," bans septic system additives which contain hazardous materials. In addition, it specifies additives must not be used to reduce the frequency of proper septic system maintenance.
EPA or USDA approval of additives means the product contains no hazardous materials. It does not mean the product is effective at what the manufacturer claims it will do.
Septic system additives
People selling additives for their septic systems often contact rural homeowners via phone or mail. There are many "sales pitches" used to encourage homeowners to buy the product. The main pitch is saving money on the cleaning of the septic tank. Homeowners often ask, "Should I buy these products?"
There are three primary types of products offered on the market: starters, feeders, and cleaners. Starters and feeders are intended to encourage the growth of beneficial bacteria in the septic tank. These beneficial bacteria work via 'enzyme action' and are essential to the break down of organic wastes in the septic tank.
Starters are products often advertised to be used in a new system or just after the septic tank has been pumped or cleaned to add bacteria to 'get it going'. The truth is that the sewage entering the system has plenty of bacteria in it to get the system working just fine. Are they necessary? No, but they won't do any harm. They do cost the homeowner money.
Products known as 'feeders' are advertised to furnish nutrients to the system so the bacteria are healthier or reproduce faster. It is not necessary to add nutrients because the sewage furnishes all of the nutrients necessary to 'feed' the bacteria. 'Feeders' that add bacteria are often advertised as producing "enzymes". Enzymes are how all bacteria work. If there is a low level of bacterial activity in the septic tank it is because the family living in the home is putting too many disinfectants and cleaning products down the drain which kill the bacteria. Addition of new bacteria will not solve this problem. By reducing the excessive use of these products, the bacterial activity will return by itself. Feeders will neither harm nor benefit the system. They will cost the homeowner money.
Septic tank cleaners are products that claim to clean the pipes and clean the septic tank. If they do this by bacterial 'enzyme action', they may just be a starter or feeder. If they cause the solids in the septic tank to become re-suspended in the liquid (effluent) they may be dangerous to the person using them or harmful to the environment as a 'chemical' or damage the soil treatment (drainfield) portion of the system. Solids entering the soil treatment unit will likely do irreparable damage. In attempting to save the cost of pumping the tank every one to three years ($60 to $150), the homeowner may need to replace the drainfield or mound ($1000 to $5000). These 'cleaners' could be very costly to the environment and the homeowner. There is no substitute for cleaning or pumping the tank on a regular basis.
Often the salesperson will site a stamp or certificate from the USDA, EPA or some state on the label implying that it is an endorsement of the product. This stamp or insignia only says that there is no dangerous product in the container. It does not constitute a recommendation, endorsement, or guarantee that the product will do as it claims.
Water use and septic systems
The most common cause of septic system failure is excessive water entering the system. Conserving water will help maintain good performance.
Consider your water use patterns. To achieve complete and uniform waste treatment, the system needs adequate time to work. Ideally, daily and weekly wastewater should enter the system as evenly as possible. Every time water is used, it enters the septic tank. An equal amount of water leaves the tank headed for the drainfield. Large amounts of water entering the system in short periods of time cause problems.
The average Minnesotan uses from 50 to over 100 gallons of water each day. Most of this water goes down the drain after bathing, washing clothes and dishes, and flushing the toilet. Here are some good water-saving ideas:
Conserve water in the bathroom (60% of water use)
- Install low-flow toilets and showerheads to cut water use by one-half to two-thirds.
- Take shorter showers.
- Shutting off the water while brushing teeth and shaving.
- Be sure leaks are repaired quickly.
Conserve water in the kitchen
- Always wash full loads in the dishwasher.
- Keep a pitcher of drinking water in the refrigerator.
- Do not allow water to run while washing and rinsing dishes and preparing vegetables.
- Shut off water to water treatment devices when the reservoir is full.
- Repair leaky faucets promptly.
Conserve water in the laundry room (20% of home water use)
- Wash full loads of clothes.
- If you wash a small load, use a partial-load water-level setting.
- Distribute wash loads throughout the week to reduce impact on your septic system.
- Use front-loading washers or water-saver features on top-loading washers.
Conserve water around the home
- Route water from swimming pools, hot tubs, and tile drains outside of your septic system.
- Water softener recharge water does not need to go in the septic system.
Landscaping septic systems
Section 12 "Soil Treatment Systems" of the Manual for septic professionals in Minnesota has landscaping information on pages 70-75.
- Introduction (12-70)
- Guidelines for planting on and near septic systems (12-71)
- Vegetation tables (12-72)
- Trees and shrubs (12-74)
Tree root behavior and their interactions with individual sewage treatment system (ISTS)
To ensure a properly functioning soil based septic system whether an in-ground system or mound, a suitable vegetative covers must be established. The purpose of this vegetation ranges from removing moisture and nutrients from the soil, preventing soil erosion, to acting as an insulating layer.
The University of Minnesota's Onsite Sewage Treatment Program (OSTP) recommends herbaceous plants such as turf grasses, wildflowers, and native grasses as suitable cover for septic systems in Minnesota. Turf grasses have fibrous root systems that hold soil in place, require maintenance similar to a lawn, and are available in numerous varieties including shade-tolerant to suit site conditions. Wildflowers and native grasses are an attractive alternative to turf grass, while providing many of the same benefits including fibrous roots, low maintenance (once established), and tolerant of dry soil conditions.
While it is true that no dedicated scientific research has contributed to our understanding of rooting and septic systems in Minnesota and beyond, this should not dismiss existing tree rooting research findings, informal surveys and anecdotal evidence via field observations recorded while troubleshooting septic systems.
Just the facts
The following are some of the facts regarding septic system functioning and tree rooting behaviors.
- Septic systems have oxygen: The fact is that compliant septic systems in Minnesota effectively treat septic tank effluent by utilizing oxygen-loving soil bacteria among other beneficiary aspects of oxygenated soil.
- Septic systems are shallow: Significant components of a septic system, distribution pipes and distribution media (rock, chambers, etc.), are installed within 6-12" from final grade.
- Septic systems require erosion protection: Septic systems require adequate erosion protection to ensure that the 6-12" of soil cover remains. Newly planted trees and deciduous trees provide minimal protection from raindrop impact and surface runoff, especially during early spring and late fall. If trees are selected as the vegetative cover, mulch, cover crops, or other soil conservation strategies must be established and maintained during tree dormancy over the entire life of the septic system (20+ years).
- Dense vegetative cover insulates: Vegetative cover is critical to insulating the system over the winter. Well-established vegetation helps hold snow close to the soil surface where it insulates the septic tank, piping, and soil treatment area. Snow helps keep the heat of the sewage and soil from escaping, keeping the frost depths shallow. In the absence of snow cover, a dense vegetative cover acts as an insulating layer helping prevent the septic system components from freezing.
- Tree rooting depth varies: Depending on site specific conditions and tree species, tree rooting depth can vary from 12 inches to depths of 48 inches. (See additional discussion under Tree Rooting Behaviors.)
Additional justification exists as to why establishment of trees and woody plants over a septic system are a significant concern. Careful consideration and understanding of existing research has aided in this understanding.
- Roots (i.e. structural roots) penetrate through the soil treatment area below the sewage effluent and create macro pores for effluent to travel without proper treatment.
- Tree throw or the blow down of trees in a storm, uprooting the tree and disrupting the soil which is protecting the system. Structural damage to the septic system infrastructure may also result from uprooting. Creating a clearing for the septic system's soil treatment area in a forested area may increase wind velocities in this clearing and enhance the likelihood of tree throw. Property owners and septic system designers should carefully consider prevailing winds directions, preponderance of the prevailing winds, shelterbelt establishment, etc. when siting a septic system.
- Disease or natural mortality of a tree that is planted on or around the septic system can cause erosion, structural disturbance to the ISTS, creation of macropores where partly treated septic tank effluent may travel to our water supplies, and may cause additional concerns.
Tree rooting behaviors
Although no direct research has been done looking at how tree and other plant roots affect septic systems, we can draw on scientific literature to tell us a bit about tree root growth behavior. Understanding these additional facts is critical when considering the types of vegetative cover established on and around a septic system.
Tree rooting characteristics: Tree rooting characteristics have been documented in several studies. Tree root growth is highly dependent upon the soil environment and species.
- Tree Root Depth: The University of Florida Extension (Gilman, 2003) has found that the majority of fine roots exist within the top 12 inches of the soil. However, this was not found to be true when soil textures are considered. In Colorado (Sillick and Jacobi, 2006), greater than 90% of tree roots, by mass, were found within the top 12" and top 36" in clay soils and sandy soils, respectively. In a Utah study of aspen trees, their root mass was found within the upper 48" in a sandy loam soil (Gifford, 1966).
- Lateral Root Spread: A University of Colorado Extension publication (Sillick and Jacobi, 2006) compared lateral root spreading in different textured soils and found that trees studied in sandy soils had lateral spread 2-3 times the drip line, while clay soils had lateral rooting up to five times the drip line. This is a more detailed analysis than a study in Florida that documents lateral rooting of trees beyond the drip line (Gilman, 2003).
- Taproot: The same University of Florida (Gilman, 2003) study revealed that many times a taproot does not exist. Taproot development depends on the trees species, tree age, soil, and if the tree has grown naturally or been transplanted from a nursery. Nursery trees commonly have their taproot cut to initiate lateral rooting growth. Once planted, nursery trees can form many taproots or none. This depends on the soil texture and soil compaction level.
- Sinker Root: Sinker root development is a rooting structure that develops from nursery trees. These roots have been documented to vertically penetrate into the soil until water is found, where a root mass will develop. Aspen trees in Utah were found to possess these sinker roots at depths exceeding 114" into the soil (Gifford, 1966).
- Species: Yet another factor that influencing tree root growth is genera. A paper in the Journal of Arboriculture (2003) looked at 4 different types of trees and their root growth activity. It was found that lilac and pear tress had longer root growth then serviceberry and crab apples. There was a direct correlation between the tree diameter at breast height of the tree and the width and depth of the spread of its roots.
Research is needed to know exactly how tree roots function when planted or exist around septic systems. Until that time we can utilize the current knowledge about tree roots and make well-informed assumptions on how these roots may affect a septic system.
Gerhold, H.D., and A.D. Johnson. 2003. Root dimensions of landscape tree cultivars. Journal of Arboriculture 29(6): 322-325.
Gifford, Gerald F. 1966. Aspen root studies on three sites in northern Utah. American Midland Naturalist 75(1): 132-141.
Gilman, Edward F. 2003. Where are tree roots? University of Florida. IFAS Extension. ENH137.
Olson, K., D. Gustafson, S. Christopherson, and B. Liukkonen. 2006. Septic system owner's guide. (verified 1/30/2007). University of Minnesota Extension Publication PC-06583-GO.
Silllick, J.M., and W.R. Jacobi. 2006. Healthy roots and healthy trees. Colorado State University Cooperative Extension. No. 2.926.
Finishing septic systems
The finishing of the onsite system is not something to consider only after it has been installed. Instead, think about the finishing early in the planning stages, when discussing the location of driveways, sidewalks, decks, and gardens. For example, the soil treatment system cannot be under a driveway, the piping carrying effluent to the system may freeze in winter if it passes under a sidewalk, and a deck built over the tank can cause some serious maintenance problems.
Involve the homeowner in planning discussions, so they understand how some of the decisions for the location of the septic system will affect their plans for developing the rest of their lot. Be sure to consider future development, such as the location of swimming pools or outbuildings, and talk about firewood piles and other backyard activities. All of this thought will help minimize problems in the future.
Once the system has been constructed, the first part of the finishing is backfilling around the piping. The pipes must be proper materials as specified by the Department of Health. They also need to be located with a proper slope to minimize standing water. The minimum slope is one inch in eight feet. Pipes carrying solids (raw sewage) have a maximum slope of one inch in four feet. Pipes carrying just water have no maximum slope.
These pipes should lie on natural soil. If the soil is not natural, use rock or sand bedding to fill spaces around the pipes. You may also need to compact the soil under the pipes to minimize settling.
The piping needs to be properly glued together to minimize any leakage in or out. Leakage often leads to problems with tree roots. Roots can't enter the pipes except by cracks or leaks already present. They can't create holes in pipes. But once roots "find" cracks, they will enlarge the cracks as they grow. Roots growing inside pipes can cause slow drainage and in extreme cases, completely plug the pipe.
After the pipe is properly bedded, it may need to be insulated. Any time piping goes under an area from which snow will be removed, it should be insulated to minimize any chances of freezing. Proper insulation can be done two ways. One method is to use an insulated pipe product manufactured to include both pipe and insulation in one. The benefits of this method are good R-value and ease of installation. Another method is to bury three-foot wide, flat Styrofoam insulation board on top of the pipe, with the pipe centered beneath the board. You need approximately three feet of buried depth with one inch of insulation, because one inch Styrofoam is equivalent to about twelve inches of soil. So, depending on the depth at which the system will be located, the amount of insulation necessary will change: two feet of soil plus two inches of Styrofoam, one foot of soil plus three inches of Styrofoam. If there is four feet of soil above the pipe, no insulation is necessary.
Soil used to backfill around the system components will settle over the course of a month or two. When you're backfilling over trenches or around tanks or drop boxes, you need to mound the soil to allow for settling. You can figure on settling of about three to four inches per foot, but for heavier soils, the amount of settling will be greater. Using sand as a backfill is an option for heavier soils, to minimize some of the settling. But you can never be certain just how much settling will occur, so plan on waiting four to eight weeks to allow settling to take place, before you actually finish the system.
Drainage of surface water
Drainage is critical in the soil treatment system area. No surface water should be allowed to run over, pond over, or drain into the system. All rainwater, including drainage from roofs and driveways and any sump pump water, has to be routed away from the soil treatment system. Make sure there are no areas where water could stand above the tank(s), as well as over any of the piping.
Make sure the surface water is moved around or down gradient of the system, using landscaping, ditches, and/or shallowly buried draintile. When using tile to deal with surface water, make sure that the rock above it comes very close to the ground surface. Along with surface water, underground flow can also affect the system. Over time, natural drainage patterns create flow patterns in the soil. If at all possible, keep all parts of the system outside these natural subsurface drainage ways. Drain tile can be used to redirect subsurface flow away from the system.
The vegetative cover for the soil treatment system has three functions. It needs to create a ground cover to hold snow in the wintertime and to minimize erosion. It should take up and transpire some of the water entering the system. (Unfortunately, many plant materials that are excellent at using excess water also have invasive root growth, and are not desirable for landscaping the system.)
The third concern is that the vegetative cover look nice. Many perennials, particularly native prairie species, would be good choices, as would grasses, both native prairie species and common turfgrass plants. A combination of native grasses and flowers would provide excellent erosion control and water uptake, due to the deep root system of the grasses, along with the desired ornamental qualities of the prairie flowers.
Note that the vegetative cover is a permanent planting. Annual flower beds that would be replanted each year are not appropriate. Vegetable gardens should not be located over the soil treatment system, primarily because, like annual flower beds, they are tilled and replanted each spring, potentially disturbing the system below them. A vegetable garden would be more harmful to the on-site system than the system would be to the garden. Woody plants, such as shrubs, vines, and trees, should not be planted over the system.
Establishing a groundcover over the system should be a first priority. Temporary seeding of annual grasses such as oats, rye, or ryegrass can provide quick cover if the intended permanent vegetative cover cannot be planted right away. Sod can be laid at almost any time that frost is out of the ground. Seeding turfgrass species is most successful when done between mid- August and mid-September, although April to mid-May seedings are possible. Perennials can be planted either spring or fall; summer plantings are likely to need too much irrigation to become established.
The maintenance of the vegetative cover depends on plant materials chosen. It's important that the plants chosen be somewhat drought tolerant, because it's not acceptable to water plants growing over the system. Although low maintenance of the vegetative cover is best, periodic mowing of grass, and weeding of other plantings may be necessary. Check the system at least annually to be sure gophers or other animals haven't taken up residence. For more information about plantings over the soil treatment system, see Landscaping Septic Systems, FO-6986.
The risers for inspection and maintenance access should be at an elevation that prevents the intrusion of water into the tank and treatment system. There's no reason, though, for the risers to stick up so much that they are a maintenance headache or an eyesore. One way to camouflage the risers is to paint them green. Children should not play on or around the risers.
Finally, check to make sure that all of the system components are operating properly, including the tank and pumps. Now is the time to go over the entire system, its components, function, and capacity, with the homeowner. Review the maintenance schedule for the system and for the landscaping.
Protecting your system from flooding
According to University of Minnesota Extension and the Onsite Sewage Treatment Program (OSTP) staff, if you have a septic system that is in the area affected by the recent flooding, there is potential for damage to the system. However, you can take action after the flooding to minimize the damage. When floodwaters cover your septic system it should not be used. If the drainfield or ground above your septic tank floods, your individual sewage treatment system is not working.
If your system was flooded
The OSTP staff recommends the following steps to help your system recover:
- Pump the tank(s) as soon as possible after the flood recedes and prior to resuming use of the system. Be sure to pump both the septic tank and the pump/lift station (if you have one). Silt and other debris may have collected in your septic tank while it was under water which could ultimately find its way to and damage the drainfield. Additionally, a variety of substances such as pesticides, petroleum products and other contaminants may have entered the tank. These contaminants could be detrimental to the beneficial bacteria in both the tank and the drainfield and therefore need to be removed. However, it is not advisable to leave the septic tank empty after pumping if the soil around the area of the tank(s) is saturated; this can cause the tank to "float" toward the ground's surface if the soil's water pressure remains high. If you have this concern, consult a licensed tank pumper/maintainer.
- Locate and protect the drainfield from compaction by keeping all traffic off the area. Often considerable traffic takes place around a flooded home as flood cleanup and home restoration occur. This traffic could include but not be limited to foot traffic, debris piles, dumpsters, and heavy equipment. Compaction reduces the capacity of your drainfield to treat wastewater and could lead to the early failure of your entire system.
- Check electrical connections for damage or wear before turning electricity back on.
- Check that the septic tank manhole cover is secure and that inspection ports have not been blocked or damaged. Check for animal damage or intrusion in the drainfield area.
- Check the vegetation over your septic tank and drainfield. Repair erosion damage; sod or reseed as necessary to provide a good plant cover. You may need to mulch the area to provide insulation if the grass has not become well established before winter.
- Inside your home, be sure to disinfect thoroughly if sewage backed up into the house or garage. Disease-causing organisms (pathogens) in wastewater can cause serious illness, such as dysentery, hepatitis, and other waterborne illnesses. However, avoid flushing these disinfectants into drains which empty into the septic system. The disinfectants could be detrimental to the beneficial bacteria in both the tank and the drainfield. If you need to chlorinate your well, follow the University of Minnesota instructions fully. Do not allow the bleach to enter your septic system.
- If after the floodwater has receded from the drainfield and the surrounding soil has had a chance to dry, but the drainfield still will not accept effluent from the septic tank, the drainfield pipes or soil might be "plugged". At this time the homeowner should consult a licensed septic system professional.
- If homeowners have additional concerns they should discuss them with a local septic system permitting authority or a licensed septic system professional.
- If you have a drainfield that has not been flooded, but is soggy due to heavy rain, minimize water use within the home. The additional water added due to household use can cause poorly treated sewage to surface in your yard or raw sewage to back up into your house. You can minimize water use within the house in a variety of ways, including taking shorter showers or baths and not doing laundry until the drainfield begins to dry out.
If portions of your system were destroyed
Often flood waters can cause components of septic system to be partially or completely washed away. The owner of such a system should not assume that soil or other "fill" can be added and new system components constructed. The homeowner should contact a licensed septic system professional or the local septic system permitting authority to discuss options that will meet state and local codes.
Heavy rains can cause slides to partially or completely cover septic system components with rock, mud, or silt. These slides can affect the operational integrity of the system, especially the drainfield. Care needs to be taken for slide debris removal from the area on or around a septic system in order to protect system components, taking special care to keep vehicle and equipment traffic off the drainfield to avoid compaction. Once again the homeowner should contact a licensed septic system professional or the local septic system permitting authority to discuss options that will meet state and local codes.
If your drainfield is saturated or has standing water not caused by flooding or heavy rain, you may have a long-term problem. Contact a licensed septic system professional or the local septic system permitting authority to discuss options that will meet state and local codes.
Staying safe around septic systems
Properly designed, installed, operated and maintained, septic systems provide economical and effective sewage treatment. When treating sewage, the tank contains very low levels of oxygen. Hydrogen sulfide, methane, carbon dioxide and other life-threatening gases are also present. Tanks have 'manholes' to be used only when cleaning and inspecting from the outside.
The following are safety issues with septic systems.
- Never use electrical lights, appliances or tools in or close to water or wet ground near the septic tank or drainfield. This can result in electrical shock or explosion.
- Do not smoke near septic tank openings. Combustible gases could be present and cause an explosion.
- Contact a plumber or other qualified person if you smell 'sewer gases'. They can identify the source and correct it immediately. If the gas is very strong, evacuate the building until the problem is corrected and the gases are removed.
- Never go down into a septic tank.
The sewage treatment process uses many beneficial microorganisms, like bacteria, in the treatment process. However, the tank also contains harmful bacteria, viruses, and disease causing organisms. Liquid and solid contents of the septic system are capable of causing infectious diseases.
After working on any part of the septic system:
- Wash hands thoroughly.
- Wash hands before eating, drinking or smoking.
- Change clothes before entering homes, food stores, restaurants, etc.
Because sewage is corrosive, always be very careful around the tank and its components. Keep vehicles and other heavy equipment away from the septic system and drainfield. Also, remember to keep children and other spectators away from the septic system when it is being worked on. Having a trained, licensed and bonded professional work on your septic system is the safest way of having repairs performed.
You should have your septic tank pumped and the system inspected every 3 years or more frequently.
For more information, call your local Extension office.
Septage: What happens after your tank is pumped?
Have you ever driven by an open field and noticed the land application of septage, believing there was cause for great concern? In reality, it's a safe practice that can produce environmental and economic benefits.
Septage is the material pumped from residential and small business septic tanks. In Minnesota, septage is either land-applied or transferred to a publicly owned treatment facility, such as a municipal wastewater treatment plant.
About 70 percent of Minnesota's septage is land-applied. In many parts of the state, municipal plants have limitations on how much septage they can accept. Therefore, the practical solution for most septic pumpers is to apply the septage to land.
Individual or onsite septic systems usually consist of a septic tank and a soil treatment area. The septic tank is designed to collect the wastewater from the home and separate the liquids from the solids – the septage. The liquids go to the soil treatment area where harmful bacteria and other pathogens are destroyed and some nutrients removed. When done properly, the soil treatment area and land-application of septage returns cleaned, safe water to the ground water.
Septic pumpers must follow guidelines developed by the Environmental Protection Agency and Minnesota Pollution Control Agency to protect public safety and water quality. These guidelines include specified distances from property lines, waterways, wells, surface waters and residential or commercial sites. The septic pumper must also document what crops are grown and how they are managed, meet guidelines for how much and how often septage is applied to each site, and keep complete records. Lime must be added to destroy harmful pathogens and help control odors.
The proper land-application of septage has many advantages. Farmers are able to utilize a natural fertilizer source, reducing the amount of commercial fertilizers they use, such as nitrogen. Applying septage locally and limiting travel distances helps control costs for pumpers and homeowners. As fuel prices rise, the cost of septage disposal rises.
According to Minnesota state codes, all rural property owners must have their septic tanks evaluated a minimum of every three years, and pumped if needed. It is the homeowner's responsibility to ensure their septic system is working properly as it recycles used water and replaces it in the groundwater.