When today’s safe septic systems are running efficiently, they can circulate wastewater back into the ground once sufficiently treated. But if nearby water sources can risk contamination due to flawed system planning, installation and maintenance.
Groundwater
If you were to start digging now, the first level of porous earth saturated with water you would reach is called the water table. The water below the water table is called groundwater. Groundwater flowing underneath a leaching field retains any remaining contaminants the septic system releases.
The watershed is the part of the ground where runoff collects and drains. This drainage basin or catchment area draws the water from any number of creeks, rivers and streams, into the groundwater, into aquifers (the saurated rock layer that releases springs) or into surface bodies of water.
Drinking Water Well
Wells drilled into the aquifers draw drinking water upto the surface. A well is more likely to become contaminated in the path of groundwater flowing beneath a septic system.
A well has a reduced risk of contamination:
- the farther apart the well is from your septic system
- the deeper the well is drilled, especially if separated by a defined layer of silt, clay or bedrock
- the more regularly it’s serviced and pumped
A well has an increased risk of contamination if:
- it’s shallow and in permeable soil
- the groundwater flows from the septic system towards the well
- multiple homes are on septic systems near the well
- it’s poorly constructed or maintained
Surface water
Filtering wastewater through the soil removes most bacteria and viruses (also known as pathogens) and some nutrients. While soil can treat many contaminants, it cannot remove all of them (e.g., medicines, cleaning products, other potentially harmful chemicals). If untreated wastewater surfaces in the yard, wastewater may contaminate the streams, lakes, or coastal waters near your home. Avoid putting chemicals or medications down the drain or toilet since they could end up in surface waters, too.
How can I keep local water sources safe?
Follow these tips from the Environmental Protection Agency to keep your septic system running safely.
- Don’t flush cleaners or chemicals down your toilet. Dispose of hazardous materials as advised by your local disposal facility.
- Use a composting toilet to limit the amount of nitrogen and phosphorus entering your system.
- Use phosphate-free household cleaning products designed for use with a septic system,
- Throw out or compost food waste instead of using the garbage disposal, to protect local water sources and extend the life of your system.
- Maintenance and inspections keep your system clean, up-to-date, and operating at its most effective levels.
- The farther the setback distance between your leachingfield and any local bodies of water the safer for everyone.