King County Homeowners guide to How Septic Systems Work

by Lillys Septic Tank Pumping, Installation & Repair Service

The Septic Tank, Pump Tank and The Drainfield are what make up the Typical single family Septic System. Your Septic System will include the septic and pump tank (if a pressure system) that are concrete or fiberglass rectangles or cylindrical. The Tanks are buried and sit approximately one to two feet below the surface unless risers are installed that bring the lids to the surface for easy maintenance and pumping access. All of the drainswithin the home lead to the septic tank, so every drop of water that is used in the house goes into the septic tank.

When the wastewater enters the the tank it then separated into three parts, the scum layer which consists of fats, oils and greases.

The sludge layer that consists of the heavier solids that sink to the bottom and then the natural bacteria action produces digested sludge and dangerous gases. The mid water layer is simply suspended solid particles and wastewater.

Homes built up until about 1975 usually have single compartment 750 gallon Tanks and those built after 1975 typically will have a two compartment 900 to 1000 gallon tank. Homes built after 1990 will most likely be a pressure distribution system and will also have a 1000 gallon pump tank with a effluent pump to pressure the wastewater to the drainfield.

The Single Compartment Septic Tank:

There are some old wives tales or beliefs that “if a Septic Tank is working properly, you never have to pump it). This is absolutely false and negligent and will cost you thousands of dollars if you do not pump the septic tank regularly. Pumping should be performed every 3 years for a single compartment Tank and 3 to 5 for a 2 compartment Tank, depending on usage and habits.

If the Septic Tank is not pumped regularly the solids will accumulate until eventually they are pushed out the outlet pipe and into the drainfield. Because there is no wall for further treatment and separation, single compartment Tanks are at higher risk of this situation than a 2 compartment Tank. When Solids are pushed into the drainfield the soil and drain lines will become clogged and will not allow the water to dissipate into the soil, sending it to the surface or back into the house. This is when you will have raw sewage backed up into the bathtub or shower and the toilet, causing a health risk for your family. When the sewage water surfaces in the yard you are not only putting your family at risk, but you are risking your pets and neighbors as well. If the scum level reaches 24 inches you are risking the drainfield damage, that is why it is so important to inspect the Septic System yearly and pump a Single compartment Septic Tank every 3 years.

~Following is a cross section of the single compartment Septic Tank~

Typical single compartment Septic Tank

Double compartment septic tank anatomy:

All Septic Tanks need to be pumped every 3-5 years, depending on the tank size, the amount of solids entering the tank and the habits of the users. The only sure way to know is to have the Septic Tank inspected annually. By measuring the sludge and scum layer thickness it can be determined when the Septic Tank needs to be umped.

The Septic Tank should be pumped whenever the bottom of the scum layer is 12 inches thick. The scum layer can move to the second compartment through crossover baffle. The 2 compartment Tank has a wall in the center of the tank separating it into 2 compartments. The 1st compartment holds the 3 layers and the 2nd compartment should only be wastewater, although it often has scum and sludge as well at the end of the pumping schedule.

~The diagram below is a cross section of a 2 compartment Septic Tank~

Typical 2 compartment Septic Tank

Wastewater leaving the septic tank is a liquid called effluent. While it has received some treatment in the tank, it is still unpleasant smelling and contains disease organisms, organic wastes and other pollutants. This effluent requires proper treatment and disposal otherwise there can be significant environmental and public health problems. Discharging effluent onto the ground or into surface and ground water is against Washington State Law and King County Board of Health Codes.

There are many different pretreatment units that are installed today to further treat the effluent prior to hitting round water. Lillys Septic System Service has diagrams and information on these pre treatment units at the website listed at the end of this article.

~ Following are some pictures of some plugged drainlines and surfacing sewage ~

This is what happens when you don't pump the Septic Tank every 3 to 5 years

When you have surfacing sewage, it is time to have the drainfield replaced!

Pump Tanks:

Most systems installed in King County since 2000 include a pump tank. The pump tank contains a submersible sewage pump, high water alarm float and on & off floats. If the system is hooked up to a timer the pump will be activated at specific times for a specific amount of time to pump the effluent out to the drainfield. If the system is on demand, whenever the water level rises and reaches the “on” float level the pump will be activated to pump the effluent to the drainfield, once the water level reaches the “off” float level the pump will turn off until the water rises again to the “on” float level. If you have a pump failure or plugged drainfield and the water cannot leave the Pump Tank a high water level alarm float is installed, if the water level rises to the alarm float an alarm will sound. Your alarm is located on the pump control panel on the side of the house near the septic tanks, under the kitchen sink or in the garage. The location of the alarm device should be known by the homeowner (see your as-built for information for details). Once this alarm is activated there is some emergency storage space before the wastewater over flows out the top of the lids or backs up into the house.  The alarm can be deactivated but will not solve the problem. You should immediately begin emergency water conservation measures and call a Lilly’s Septic Tank Service at 425-432-3084 to send a technician out to troubleshoot the situation.

~Following is a typical Pump Tank ~

typical pump tank

The Drainfield:

The drainfield is generally located in a stretch of lawn in the back or side yard of a property. The size and type of drainfield depends on the estimated daily wastewater use of the house hold, the more bedrooms a home has them larger the drainfield will need to be. The drainfield is mad up of gravel lined trenches with either corrugated pipes or pvc pipes with holes drilled for the water to disburse through. The water flows from the septic tank to a D-Box and is then directed evenly to each line in the field. the water flows out of the holes in the lines and into the gravel underneath, where it filters through to the soil where further treatment happens naturally prior to the water entering the ground water.

Your Septic System is your Largest underground investment.

Your septic System should be treated as though your home depends on it, It Does! The Septic Tanks and drainfield area should be protected from Cars being parked on it, any type of structure such as carports, decks sport courts or sheds. You will not want to put down any type of landscape plastic or allow farm animals to graze in the area as they can compact the soil creating possible drainfield failure or broken lines. The best solution over your septic system is simply lawn, roots from shrubs and trees can also be detrimental to the drainfield area as the roots can intrude into the lines or the septic tank and cause blockages. Your property will also require a “Reserve area” in case your Septic System fails and a new drainfield must be installed.

~Following is a diagram of a typical septic system~

typical septic system in king county

Lilly’s Septic Tank Service has been providing Expert Septic System Service to King county Homeowners since 1990 including - Maple Valley, Enumclaw, Black Diamond, Ravensdale, Covington, Kent, Auburn, Renton, Issaquah, Renton.

Learn more about your Septic Tank System at the Septic System and Drainfield Experts main website at:  www.LillySeptic.com

Lilly’s Septic Tank Pumping Service

King County Septic System and Drainfield Experts

Keeping Your Septic Tank System Healthy

Guidelines for a Healthy Septic Tank and Drainfield

By following a few simple rules, you won’t have to think about your system on a day-to-day basis.

Indeed, with proper use, conventional onsite Septic Tank systems can operate between Tank Pumping without much management.

Septic System Maintenance begins with sound water use and waste disposal habits. Since your family will determine which materials enter the system, we encourage you to set rules and stick to them,  Here is a partial list of the items to keep OUT of your Septic Tank. Do not introduce any of the following:

• Grease or cooking oils
• Disposable diapers
• BABY WIPES
• Feminine hygiene products
• Any latex products
• Paper towels
• Plastics
• Cat litter
• Latex paint, pesticides, or any hazardous chemicals

Many homes have garbage disposals to help manage vegetable and other food waste. Excessive use of your garbage disposal may introduce a high level of unwanted solids into your system. Use disposals moderately and consider composting as an option to handle vegetable waste.  If you use a garbage disposal the septic Tank will need to be pumped every 3 years to ensure that solids to not reach the baffle level and potentially damage the drainfield.

Do not put too much water into the septic tank system. Excess water puts too much strain on the decomposition process and can cause problems. Do not do all loads of laundry in one day, try to stager laundry over the week.  Maximum water use should be about 50 gallons per day for each person in the family. Estimate by using the following numbers per person so you can keep track:

• Shower: 2.5 gallons per minute - 10 minute shower = 25 gallons
• Toilet: 2 gallons per flush (for toilets bought in the last 20 years)
• Washing machine: 40 gallons per load
• Dishwasher cycle: 10 gallons

With large families, keeping track of water use can be hard. But laying down guidelines can help everyone do their part. Also consider getting energy and water-wise appliances when you need to replace your current models. Visit EnergyStar.gov for suggestions.

Be aware that your system is sized to handle the number of people anticipated to be using it when it is installed. If that number increases, you may need a larger system.

Do not use harsh drain openers for a clogged drain. The best alternative to conventional, caustic drain openers is to use boiling water or a drain snake to clear clogs. Though this approach may be a little messier, the chemicals in drain cleaners can cause havoc with your septic system.

Use mild or natural cleaners for your bathroom and kitchen. They should either be okay ed for use in septic systems or marked biodegradable, Although you cannot trust these detergents that are labeled “Septic Safe”.  We find that when some particular brands of Laundry detergent labeled “Septic Safe” are innocently used, the Septic Tank looks like there was paint poured into it as well as a thick layer of gray clay like material build up in the bottom of the Tank.  This thick clay like matter is then pushed out to the drainfield clogging up the Drainfield lines!

Be aware that bleaches and antibacterial soaps can inhibit the enzymatic action necessary to help bacteria break down the solids in the tank.

Again, harsh chemicals can cause expensive and unpleasant problems in your system.

If you use or intend to use a water softener in the home, let your installer or maintenance contractor know. Under certain soil conditions, the salt recharge solution must be handled carefully and the size of your absorption field may need to be increased.

Have the solids pumped out of the septic tank on a regular basis. Your Septic Tank Pumping contractor or your local health department can give you guidelines.  Lilly’s Septic Tank Service recommends Septic Tank Pumping every 3 to 5 years.  If your septic tank is 500 to 900 gallon single compartment, the tank should be pumped every 3 years to protect your drainfield.  A 900 to 1500 gallon Septic Tank should be pumped every 3 to 5 years depending on family size and various factors of individual usage of the system.  Lilly’s Septic Tank Services Expert Technician can recommend the proper pumping frequency for your system by the amount of material accumulated in the Septic Tank since the last pumping.  If you use a garbage disposal seriously consider pumping your Septic Tank every 3 years!

Remember, more sophisticated systems may require additional maintenance. So always ask your installer for details on the recommended Pumping frequency for your Septic System.  As Certified Master Installers for all King County Septic Tank Systems Lilly’s MI (Master Installer) can recommend pumping frequency for your specific Septic Tank system.

For additional maintenance information, Visit  our main Septic Tank Pumping website or give us a call…..  425-432-3084  253-639-3606  360-825-4809

Serving King & Pierce County including: Maple Valley, Ravensdale, Hobart, Enumclaw, Black Diamond, Covington, Issaquah, Sammamish, Kent, Renton,  Auburn, Federal Way, Des Moines, Tukwilla, Seatttle - Greenwater, Buckley, Lake Tapps, Sumner, Puyallup, Tacoma

Septic Tank System Repairs and Upgrades

You can rely on Lilly’s Septic Tank Service whenever you need a septic system repair or upgrade. We repair septic systems, upgrade and maintain all Septic Tank Systems, Install Septic Tank Systems.  If you are adding on to your home, most likely the Septic Tank System will need to be updated to current code.  You can count on Lilly’s Septic Tank Service to propose an upgrade and install the most economical system to comply with King County Code.  You can count on Lilly’s Septic Tank Service if you need to have your Septic Tanks moved or the drainfield replaced with a new system when you are doing a remodel.

Owner, Darren McCullough takes pride in finding the most economical solution for the homeowner as possible when it comes to replacing or repairing a septic system.  See the Septic System Installation page at our main website for more information on our Septic System Installation Services.

Lilly’s Septic Tank Pumping is your local experts in King County for Septic System upgrades, System remodels, Drainfield Replacements and new Septic Tank Installations.

Find out how to prevent Septic System & Drainfield Failure at the main Website www.LillySeptic.com

If you are experiencing problems with your drainfield - Give us a call, we are here to help and will do our best to get you back in the flow as soon as possible in the most easy and painless way possible.

Give us a call today!

425-432-3084   *  360-825-4809   *  253-639-3606

Lilly’s Septic Tank Systems - Upgrades, Repairs and Installs Septic Tank Systems in King County Washington including the following cities of King County, Enumclaw, Ravensdale, Maple Valley, Black Diamond, Hobart, Covington, Kent, Auburn, Renton, Federal Way, Sea Tac, Tukwilla, Seattle, Mercer Island, Kirkland, Bellevue, New Castle,Woodinville, Duvall, Carnation, Fall City, Preston, Snoqualmie, North bend, Sammamish, Issaquah.