Proper Care and Feeding of a Septic System
How your septic system works and how to maintain it.
By Bruce Lunsford, Able Home Inspections
As a home inspector located in
As the title suggests a septic system is a common living breathing component of homes and as such, it has special needs. It is the only system that depends on live microorganisms to function properly. If properly designed and maintained, it is nearly a perfect system with little environmental impact. Unlike public sanitation, it does not require the dumping of millions of gallons of tainted water into public waterways. It cleans your waste water so effectively that it eventually returns to the water table where it is available for use again, as pure as the day it was originally pumped out.
Before we discuss how to care for this critical and expensive system, let’s talk about how it works.
HOW IT WORKS
A typical septic system has 2 basic components and the pipes that interconnect them. Although there are many minor variations on these, most installed systems are pretty much the same, and the all work on the same principal. When there are variations in design, the primary reasons are poor soil permeability, limited space and high water tables.
The Septic Tank
The septic tank is the first stop in this private sewage treatment system. It is responsible for collecting and digesting the solid material in the drain lines, then sending the liquid (called effluent) out to the next component, the drainfield. It is absolutely critical that the solid materials do not leave the tank and enter the drainfield. Common residential sizes of the tank are in the 1,500 to 2,000 gallon range with the actual size determined by the number of bedrooms. The tank has a series of baffles or compartments that ensure the solids settle to the bottom and the floating scum layer stays on top of the water. Over time bacteria and other microorganisms digest the materials and reduce their bulk. The effluent then moves out to the Drainfield / Absorption Field.
Drainfield / Absorption Field
The drainfield rests on top of the absorption field and is little more than lengths of pipes with holes in them. The effluent enters these pipes and leaks out into the absorption field. The absorption field is simply a bed of effluent specially designed to allow the effluent to drain through it. The most common materials are gravel and sand. The size of the field is determined by the number of bedrooms in the home and the permeability of the soil. The soil provides filtration for the effluent and hosts additional bacteria and microorganisms that further clean the effluent. While a small amount of the effluent evaporates or is absorbed by plants, most of it eventually returns to the water table.
How to Care for Your System
Rule #1. Nothing goes down the drains that doesn’t have to, especially if it isn’t readily biodegradable. Sanitary napkins, washing out paint brushes, dumping mop water, and scraping partially eaten food into the disposal etc. should be avoided. I even recommend using paper towels to remove grease from pans prior to washing them. If you have to have a garbage disposal, use it sparingly. Things like grease and egg shells should never be put down the disposal because they don’t easily break down. Starting an outdoor compost pile is always a great way to get rid of those organic items you wisely don’t put into your septic system.
Rule #2. DO NOT use additives in your system. There are numerous additives available at hardware stores that claim to keep your system clean. I don’t want to get into brand names, but you’ve seen the commercials on TV. “Simply add our product to your system once a month and keep it trouble free.” This has been a source of controversy for some time, so the Federal Department of Health actually did a study on this and came to the conclusion that they most likely do no good, and are more likely to cause harm. If you wish to read the study, follow this link. http://www.doh.wa.gov/EHP/ts/WW/Septic-Additives-SFQ-Wint2002.pdf I won’t bore you with the details of the study. I will however tell you that using these additives are absolutely not a substitute for proper routine maintenance.
Rule #3. This is the most important of all. Have your tank pumped out every 3 to 5 years, depending on age, size and usage. This is absolutely critical. Although the bacteria does a wonderful job of reducing your solid wastes, it cannot completely eliminate it. If the tank is not periodically pumped, this sludge eventually builds up high enough that it is forced to enter the drainfield. When that happens, you ruin the drainfield and you’re looking at a new system which commonly costs in the $3,000 to $5,000 range. If you take nothing else away from this article, please remember to have your system pumped out every 3 to 5 years! If you do this, your system should last decades instead of years. If everything is done perfectly, your system could theoretically last indefinitely.
Rule #4. Keep trees out of the system. Tree roots can destroy the system so keep a healthy distance between trees and other large plants and your septic system.
The last bit of advice I can give is to be sure and get your septic system thoroughly inspected prior to purchasing your home. The last thing you want is to move in and find out a few weeks later that you have no operational sewage system. Imagine the inconvenience of not being able to flush your toilets or take a shower for a few weeks while a new system is installed. Not to mention the privilege of paying thousands of dollars for the new septic system, then getting to replace the sod in your yard.
Following these simple guidelines will help ensure you have a septic system that gives decades of trouble free service.
Note: Bruce Lunsford has over 25 years of experience in inspecting, engineering and construction. Bruce has performed over 8,000 inspections to date and is a certified member of ASHI and FABI, the highest certifications available to inspectors.