The Rules for Septic Systems

My septic tanks

A lot of the rule of thumb advice on septic systems available in brochures from various government entities was developed for basic or “typical” septic systems that are the most common systems out there. These rules assume typical systems and average household water use. Really, you can’t go wrong following the sensible and conservative rules of septic management generally offered up. These days there are vast differences in system design and sizing, the age of systems as well as how systems are used to make many of the old rules of living with a septic system not applicable to all systems and all households. However, if all you want is the basic rules, then here you go:

1. Have a traditional septic system inspected at least every 3 years by a professional and your tank pumped as recommended by the inspector. This requires that the access to your tank and inspection ports not be buried. If the bottom of the scum layer is within 6-8 inches of the bottom of the outlet tee or the top of the sludge layer is within 12 inches of the outlet tee, your tank needs to be pumped. How often you really need to pump your septic tank depends primarily on the size of your tank, the number of people in the household, the volume of solids in your wastewater and whether you use a garbage disposal or have a water treatment system and of course local regulations. 
2. Manage your household water use. The septic system does not have unlimited capacity. Practice mindful water use. Doing all the household laundry in one day might over load your septic system. With an alternative system that has a timed pump and level alarms you will get a high water alarm. Doing load after load of laundry or excessive water use (all the relatives are staying with you) does not allow your septic tank time to adequately treat wastes. In an older system the waste will simply flow into the drainfield in a newer system, the system will alarm and then back up into the house (unless you force it to pump). 
3. Dispose of hazardous household wastes at an appropriate waste disposal facility or drop-off. Most landfills and city trash programs have these drop-offs. Do not put hazardous household wastes down the drain or in the toilet EVER. Do not wash paint brushes or containers in the sink they can destroy the biological treatment system. Minimize the use of bleach, chemical disinfectants and antibacterial agents. 
4. Most septic system additives do not have a positive effect on the operation of a septic system, and can contaminate groundwater aquifers, render septic drainfields dysfunctional, and result in costly repairs to homeowners. There is no additive on the market that will eliminate the need to pump a tank and some products can damage septic systems, interfere with treatment of wastewater, and contaminate groundwater.
5. Your septic system is not a trash can. Do not flush dental floss, feminine hygiene products, condoms, diapers, cotton swabs, cigarette butts, coffee grounds, cat litter, paper towels, and other kitchen and bathroom items down the drain. At best they accumulate in the bottom of the tank and shorten the time between pump outs, but they can also damage your septic system. Items that float and are carried over to clog the distribution ports. 
6. Know where your drainfield is. Plant only grass over and near your septic system. Roots from nearby trees or shrubs might clog and damage the drainfield. Also, pay attention to your drainfield, a muddy drainfield is a sign of failure. Septic drainfields and alternative secondary treatments like peat tanks and sand mounds also have a limited life. The life of a septic drainfield is dependent on how the system is managed, the frequency of septic tank pump outs, and the number of people living in a house, but 20-30 years may be the life of those systems- even when well managed.
7. Don’t drive or park vehicles on any part of your septic system. The weight of the equipment will compact the soil in your drainfield or damage the pipes. 
8. Pumping your tank regularly is the single most important thing you can do. The newest rule of thumb from the U.S. Environmental Protection Agency is to pump every three years. In the Chesapeake Bay watershed many homes are within areas designated resource protected areas that requires pump out at least every five years, but that may not be frequent enough depending primarily on the size of your tank, the number of people in the household contributing to the volume of your wastewater, the volume of solids in your wastewater and whether you use a garbage disposal or have a water treatment system.