BLOG: How Much Do You Know About On-Site Wastewater Treatment Systems?

On-site wastewater treatment systems are an effective method of disposing of sewage in the United States, especially in rural areas that do not have readily available sewer lines. About 25% of the US population owns an on-site wastewater treatment system. If you are the owner of an on-site wastewater treatment system, you must take steps to ensure you are not causing damage to your property, your family, the environment, and the property and families of those around you.

A septic system has two main components: the septic tank and the drainfield.

Septic Tank
The size of the septic tank varies based on the number of bedrooms in the home, the number of wastewater contributing fixtures and appliances (i.e. whirlpool bath, garbage disposal, dish/clothes washer, etc.), and/or state and local regulations. Waste enters the tank from household plumbing through a pipe and enters the septic tank, which is a buried watertight container made of materials such as concrete, fiberglass, or plastic. The tank holds the waste long enough to allow solids and liquids to separate and form three layers:

• Scum layer – solids lighter than water, such as greases or oils, float to the top
• Liquid layer – partially clarified wastewater
• Sludge – solids heavier than water settle at the bottom of the tank

The tank also contains baffles and tees, which slow the wastewater entering the tank to allow solids to easily settle out.

Treatment of the wastewater begins in the septic tank as naturally-occurring bacteria in the sewage work to break down the organic matter in the tank. Sludge and scum that cannot be broken down remain in the tank until it is pumped. The partially clarified liquid layer then flows through an effluent filter out of the tank and into the drainfield for final treatment.

Drainfield
The wastewater (effluent) entering the drainfield may contain many potentially harmful microorganisms and pollutants, many of which can be effectively removed through soil treatment. The drainfield, also referred to as a leachfield, disposal field, or soil absorption system, consists of perforated pipes or chambers within a series of trenches or mounds lined with gravel and buried one to three feet below the surface. Water flows through the perforated pipes or chambers and slowly trickles through the gravel and into the surrounding soil, where the natural processes in the soil complete the sewage treatment process.

Maintenance is a Must!
Installing an on-site wastewater treatment system on your property can be much more beneficial to the environment than running miles of sewer lines to your property. Unfortunately, in many cases, once an on-site wastewater treatment system is installed, it is often forgotten until it malfunctions. When the system is installed on your property, you are the one responsible for it. About 10-20% of on-site wastewater treatment systems malfunction each year. More often than not, system malfunction or failure is the result of improper maintenance by the owner. How should it be maintained?

System Failure
An on-site wastewater treatment system can fail for a number of reasons, but usually point to improper maintenance by the owner. Not having your system inspected often enough can cause the owner to miss key factors contributing to a wastewater treatment system failure.

Photo courtesy of Seattle-King County Public Health

What Can I Do?
Properly maintaining your on-site wastewater system will not only save you money in the long run, it's also important for protecting groundwater supplies and ensuring safe drinking water for you, your family, and your neighbors. Systems should be inspected every one to two years by a professional and pumped when necessary. What else can I do?

If maintained correctly, your wastewater treatment system can be beneficial and environmentally-friendly, but without regular maintenance, it has the potential to affect groundwater supplies and cause harm you and those around you. Having your wastewater treatment system regularly inspected and pumped can avoid unnecessary expenses, damage to your property, damage to neighbor’s properties, damage to the environment, and damage to the health of you, your family, and families around your property.

More information and resources
Groundwater Foundation Get Pumped! Septic Education Toolkit
U.S. EPA Septic System Information
National Environmental Services Center

BLOG: "Flushable" Wipes Aren't Flushable After All

by Jennifer Wemhoff, The Groundwater Foundation

What does "flushable" truly mean? If you define it as being capable of being flushed down a toilet as "flushable" then yes, flushable wipes are indeed flushable.

Flushable wipes going through the sewer system without causing a problem? Inconceivable! I'm reminded of a scene from one of my very favorite movies:

However, just because you conceivably can flush wipes, does it mean you should flush them?

The answer is a resounding "NO."

According to wastewater experts, the only things that should get flushed are human waste and toilet paper. The rest - wipes, feminine hygiene products, tissues, paper towels, cotton swabs, dental floss - all belong in the trash can for disposal. Medications should also never be flushed. Wastewater treatment facilities aren't typically able to remove these compounds. Seek out local take-back options instead (like the Nebraska MEDS Initiative) or utilize DEA's National Drug Take-Back Days.

What can happen if too much other stuff is flushed down drains or toilets? A whole lotta yuck, that's what. Take this example in Charleston, South Carolina. A series of clogs from wipes required employees to work 24 hours a day for five days to clear them, and even worse, divers to go down 80-90 feet into their system through raw sewage to find the clog.

If you have a septic system, flushing these items is also a terrible idea, filling the tank faster and affecting the system's ability to effectively treat wastewater.

The City of Spokane did a series of experiments showing what happens when common items are flushed down the toilet:

So do your local wastewater utility or septic system a favor - unless it's #1, #2, or toilet paper, keep it out of the toilet!

The Carmel, Indiana (a Groundwater Guardian team) Utility also has a great educational video about improperly flushing items.

Protect Groundwater by Maintaining Your Septic System

by Jennifer Wemhoff, the Groundwater Foundation

With proper construction and maintenance, septic systems can be an effective way of treating wastewater for homeowners not connected to a centralized wastewater treatment system. But it's up to the homeowner to take care of the system and ensure it's not negatively impacting groundwater.

Regular Inspections. Your septic system should be inspected annually to ensure that it's working properly and if the tank needs to be pumped. Having your system inspected and pumped regularly can help you avoid the high cost of septic system failure. Find a professional septic system contractor. An inspection will locate the system, uncover the manhole and inspection ports, check connections, measure the scum and sludge layers, and check the tank and drainfield.

Keep Records. It's important to keep records of all permits, inspections, pumpings, repairs, and other maintenance. It's also a good idea to keep a sketch of where your system is located. Having this information is handy for service providers.

Protect the Drainfield. The septic system's drainfield is delicate, and needs to be protected. Don't plant anything but grass over the drainfield. Roots from shrubs and trees can cause damage. Also, don't drive, park, or operate heavy machinery over any part of the system, and don't build anything on top of the drainfield. Grass is the best cover for a drainfield.

Be Careful What You Flush. What you put into your septic system greatly affects its ability to do its job. Your septic system contains living organisms that digest and treat waste. Septic systems are not designed to be a garbage can. In the kitchen, don't put food scraps, coffee grinds, grease, cooking oils, or other food items down the drain. In the bathroom, never flush plastics, paper towels, facial tissues, tampons, sanitary napkins, cigarette butts, dental floss, disposable diapers, condoms, medications, or kitty litter in the toilet. The only things that should be flushed down the toilet are wastewater and toilet paper.

Conserve Water. Water conservation is a very important part of septic system maintenance. Continual saturation of the drainfield's soil can affect its ability to remove contaminants from wastewater. Look for and fix leaky fixtures and toilets, only wash full loads in the dish and clothes washers, and take short showers.

Find out more about how you can protect groundwater through septic system maintenance here, here, and here.