(1) What happens to the solids and wastewater that go into a properly maintained septic tank?
Wastewater stays in the tank long enough for solids to separate and settle (forming sludge) and grease and lighter particles to float (forming scum). Bacterial action partially decomposes some of the solids, which goes into the drainfield as effluent. Solids that are not decomposed remain in the tank.
(2) What are some possible warning signs of septic problems?
Any of these can mean a problem with the septic system, contact a qualified septic professional.
(3) What effects can a failing septic system have on the environment?
A malfunctioning system can become a source of pollution and public health concern, causing property damage, ground and surface water pollution, and disease outbreaks.
(4) If you use a garbage disposal, should your septic system be pumped more frequently?
Garbage disposal waste can build up quickly in a septic tank, and depending on usage, your septic may need pumping twice as often than if you don’t use a disposal.
(5) What should not be put down the sink?
Coffee grounds, egg shells, grease, fats, and oils in the septic tank cause additional buildup of sludge and scum, requiring the tank to be pumped more frequently.
(6) What can be planted on or near the drainfield?
Grass is the best planting over a drainfield. Trees and shrubs should be at least 50 feet away from the drainfield.
(7) What can home occupants do to keep a septic system working well?
All of these practices help reduce strain on your septic system and keep it healthy and functioning for as long as possible.
(8) The septic tank is an aerobic environment and where most of the system treatment occurs.
The septic tank is an anaerobic (low or no oxygen) environment whose primary function is settling solids from liquids and scum.
(9) The drainfield is an aerobic environment in order for sewage to be treated fully by the biomat at the bottom of the drainfield.
Shallow underground area in dry soil where treatment occurs. Pipes distribute wastewater into the soil through porous media or constructed components. The soil and soil microbes accept, treat, and disperse wastewater as it soaks through the soil, ultimately discharging to groundwater. Wastewater percolates into the soil which recharges groundwater and possibly reclaims.
(10) What would happen in the drainfield if the air supply was cut off by compacted soil above it, paving the ground above it, or if it is flooded with water?
The drainfield requires the presence of oxygen in order to fully treat sewage. In the drainfield, oxygen loving bacteria consume the harmful components of the septic effluent before it joins the clean groundwater.
(11) The primary purpose of the septic tank is to settle and separate solids and liquids before going to the drainfield for further treatment.
The septic tank is should ideally have a retention time of 24-72 hours to allow any incoming waste water from the home to settle out into sludge, clear zone effluent and scum.
(12) What is the primary purpose of the drainfield?
While the function of the septic tank is to separate, the function of the drainfield is to reduce the amount of bacteria, viruses, and pathogens in waste water, before it joins the groundwater where it impacts drinking water and the health and wellbeing of our communities and environment.
(13) When is it time to call a septic tank pumping company to have the tank(s) pumped?
When the scum and sludge together make up 33% or more by volume of the septic tank.
(14) Which of the following is NOT a public health concern for septic systems?
While green lawns are nice, we aren't too concerned about that. We are concerned more with the public and environmental health risks that waste water presents to the general public.
(15) Why is the Skagit County Public Health Department interested in the design and operation of each septic system in the County?
There are a lot of ways to design and install a septic system. Skagit County Public Health works to ensure that any system installed will effectively treat the waste water coming from that home or business before it has the ability to impact public goods.
(16) Homeowners in Skagit County that have a conventional gravity system need to have their system inspected every
As per Washington Administrative Code WAC 246-272A-0270 and Skagit County Code SCC 12.05.160.
(17) Homeowners in Skagit County that have a septic system with a pump (not a conventional gravity septic system) need to have their system inspected at an interval of:
As per Washington Administrative Code WAC 246-272A-0270 and Skagit County Code SCC 12.05.160.
(18) What will eventually happen if a septic tank is never pumped and fills too much with scum and sludge solids?
Ideally, wastes entering the septic tank from a home should have 24-72 hours "residence time" in the septic tank to settle out solid particles and allow lighter materials (like toilet paper, oils and greases) to float. If the tank is more than 33% full, there will not be enough time for materials to separate, and solid material will eventually enter your drainfield causing problems. Inspections are a great way to check out if your septic system needs to be pumped too! An inspected septic system means an informed septic system owner!
(19) Commercial septic system additives, yeast, cabbage and/or raw meat need to be added to a septic tank to help it clarify the sewage.
Studies have recently shown that additives and enzymes for septic tanks do nothing or are detrimental to your overall tank health. A septic tank is a natural and biological environment, save yourself some cash and put those additives back on the shelf.
(20) Septic systems need to be inspected in order to keep them working for a long time (30+ years) and to assure they are adequately treating sewage.
Yes. Just like your car needs oil changes in order to maintain it in prime condition, your septic system needs regular inspections to catch problems early and protect your property, health and investment.
