If you’re buying property in an urban or suburban setting, chances are good that the home is connected to a municipal sewage system. If, however, you’re looking at purchasing a home on acreage or in a rural setting, waste may be handled through a septic tank. Proper care and maintenance is key to keeping your household sewage disposal system running properly, and with a bit of knowledge, you can avoid the expense and hassle of a poorly functioning septic system.
Septic Systems: A Common Waste Handling Strategy
Septic systems rely on bacteria to digest organic solid waste while fluid waste is gradually leached into porous surrounding soil. Homeowners who use septic tanks are completely responsible for the upkeep and maintenance of these sewage systems, and most states have laws requiring that the systems be maintained in order to protect human and environmental health.
Septic systems include a pipe that connects the home plumbing to a septic tank. In the septic tank, wastes are separated by gravity. Solids (also called sludge) settle to the bottom of the tank. Oils and grease float to the top. The remaining wastewater exits into a drain field where microbes in the soil remove most remaining contaminants.
Types of Septic Systems
There are a variety of septic systems for a range of soil types, and they vary widely in terms of cost, complexity, and maintenance requirements. All systems start with a tank for holding solid waste and grease and end with some sort of drainfield for liquid effluent, but these drainfields can look very different depending on soil composition and depth. A percolation test, which determines how much water the soil can filter, will probably be needed by property owners wishing to install a new septic system.
According to King County in Washington state, there are four common septic system types:
- Gravity drainfields. These rely on gravity to carry liquid waste through a series of pipes, situated below the tank, where it is allowed to leach into permeable soil. When the pipes are located above the tank, a pump is required to move waste uphill.
- Pressure distribution drainfields. These include a pump, which puts fluid waste into the system intermittently, using pressure to fill all sections of piping evenly. This type of system is better for systems where the soil depth and quality is insufficient to handle gravity-fed waste.
- Sand filter systems. These use added sand, usually held in a box of concrete or plastic, as a pre-soil filtering step and are useful when soil is not of the right depth or type for absorbing unfiltered fluid waste. These systems include a pump and pipes, laid in gravel above the sand, to distribute the waste across the length and breadth of the filter.
- Mound systems. These are another option for sites with insufficient topsoil, and include a mound of sand, gravel, and pressurized piping above or, occasionally, beneath the ground surface. Sewage is filtered through this man-made hill before it enters the soil below.
Septic System Inspections
Many states require septic system inspections whenever a property is sold. If you’re shopping for a rural home in a state that doesn’t require this step, you should have an inspection performed for your own safety. A faulty septic system can be an expensive and troublesome problem, so hire a professional to evaluate the system before you buy.
Once you own a home, the septic system should continue to be professionally inspected on a regular basis. Some local health departments require annual inspections, while others rely on homeowners to decide when an inspection is warranted. Your state or county environmental health department can help you plan an inspection schedule for your own septic system.
Septic System Maintenance
Septic systems can work very effectively, provided they are regularly maintained. Sludge should be pumped out by a professional every three to five years, on average. These pump-outs, which need to take place before the tank is over 50 percent capacity, are important and would be impossible without the right equipment, so leave this dirty job to a licensed professional. Observing the process is a good way to learn more about your septic system’s maintenance needs.
Septic System Dos and Don’ts
Homes using septic systems should follow certain guidelines to keep the septic tank working properly. Failure to do so can cause waste to seep up through the drainfield or back up into the home. The EPA publishes a guide to septic systems for homeowners, which includes a lot of information about looking after your tank and drainfield.
To help maintain septic systems, homeowners should:
- Avoid pouring household cleaners and chemicals down drains. These can damage microbial activity in the septic tank.
- Flush only bodily wastes and toilet paper. Things like sanitary napkins will not break down and can cause harm to your septic system.
- Only use plants with shallow roots over their septic drain field, as shrub and tree roots can damage the system. Contact your own local agricultural extension office for information that’s specific to your growing conditions.
- Practice proactive water conservation. Dripping taps and leaky toilets can overwhelm a septic system, which relies on a normal balance between solid and liquid matter to function.
Important Questions for Homebuyers
If you’re considering a home that is not connected to a municipal sewage treatment system, ask a lot of questions before you buy. First, find out whether your state or county requires regular inspections or time-of-transfer inspections. If it doesn’t, have the system inspected anyway. The Connecticut Department of Health recommends asking the following questions:
- “What does the existing septic system consist of?”
- “Is it working properly?”
- “How long will it last?”
- “If it fails, how much will a replacement system cost?”
It is also important to know exactly where the parts of the septic system are located, when the system was last inspected or pumped, and whether the homeowner has ever had any trouble with the septic system’s performance. By learning more about these common sewage-treatment systems, you can make septic system ownership a simple, headache-free experience.