HOUSEHOLDWASTEWATER: Septic Systems and Other Treatment Methods
by Barbara Kneen Avery, College of Human Ecology, Cornell Cooperative Extension
This chapter covers three factors that affect your pollution risks:
1. Septic System Design and Location. Topics covered in this section include knowing your septic tank capacity, soil type in the drainfield, and system's location.
2.On-Site System Maintenance. Pumping the septic tank, protecting the drainfield, and watching for signs of trouble are discussed in this section.
3. Septic or Sewage System Inputs. Reducing the amount of water, solids, and harmful chemicals going into your individual septic or municipal wastewater treatment system is reviewed in this section.
This chapter will help you evaluate your septic system andpinpoint risks before they become problems. It provides general guidelines for safe management of household wastewater. State and local laws, however, may impose more stringent or additional requirements. For example, some systems, such as cesspools, may be banned locally. Contact your nearest Cooperative Extension office, a local health or environmental agency, or a septic system contractor foradvice.
Why should you be concerned?
Wastewater treatment systems help protect your health and the environment. Household wastewater from sinks, toilets, washing machines, and showers carries dirt, soap, food, grease, and bodily wastes "down the drain" and out of your house (figure 4.1).
| |Figure 4.1. Household wastewater carries, dirt, soap, food, grease, and bodilywastes "down the drain" and out|
| |of your house to an on-site septic or municipal wastewater treatment system. |
Wastewater also carries disease-causing bacteria, viruses, and other pathogens as well as nutrients like nitrogen, phosphorus, and organic wastes. Such nutrients promote weed growth and lower oxygen levels in surfacewater and thus affect fishing and recreational use of rivers and lakes.
Wastewater treatment systems are designed to remove or break down these contaminants before they enter groundwater--the source of drinking water via wells--or nearby lakes, streams, or wetlands.
Wastewater treatment is often out-of-sight and out-of-mind until problems occur. Knowing the basics about your household system andtaking simple precautions can prevent problems. It's a wise investment to keep your system working well. Replacing a failed system can cost thousands of dollars.
Where is your wastewater treated?
Do you have a septic system or other on-site system to treat wastewater?
This chapter is geared primarily toward homeowners or tenants who have septic systems buried in their yards. A typical septicsystem consists of a septic tank and drainfield, which is also known as a soil absorption field, leach field, or tile field (see figure 4.1 on the previous page). It is important to maintain your wastewater treatment system and use it wisely whether you have a holding tank or septic tank followed by a mound, sand filter, or other alternative on-site treatment system. (These types of systems arediscussed further on the following pages.)
Are you hooked up to a city or community sewer system?
Even if wastewater is not treated on your home site, there are still ways you can reduce the impact your wastewater has on your community and the environment. Conserving water and being careful about what you put down the drain are easy ways to help (this is discussed in part 3 of this chapter). Using yourmunicipal sewage treatment system wisely saves taxpayers' dollars and protects our water resources.
How does a conventional septic system work?
First, wastewater flows through a sewer pipe out of your house and into the septic tank, a box or cylinder commonly made out of concrete (figure 4.2). Fiberglass and polyethylene tanks are also used. The tank must be watertight to keep sewage from...