Septic in Ada County
Homes in Boise are generally on city sewer, but many properties in rural Ada County and the surrounding area rely on septic systems and private wells. If you're outside the city's sewer service area, find out where your system is and when it was last pumped.
Frost and freezing
The City of Boise's adopted code amendments set a minimum frost depth of 24 inches for footings, and NOAA's engineering weather data for Boise records about 78 freeze-thaw cycles a year. Septic lines and tanks can freeze when they're shallow, when snow cover over them is compacted by vehicles or foot traffic, when the house is vacant, or when a leaking fixture sends a slow trickle into the line. Keep snow, mulch or grass over the system in winter, fix leaks, and don't drive or plow over the tank and drain field.
Snowmelt and spring saturation
The National Weather Service notes that most of Boise's precipitation falls from November through May. Snowmelt and spring rain can saturate soil over the drain field, making it harder for effluent to soak in. Reduce water use during spring melt, keep downspouts and surface water away from the drain field, and watch for soggy ground or odors.
Irrigation
Many rural properties in the Treasure Valley have pressurized irrigation or irrigation rights. Keep irrigation water off the drain field and away from the tank. Saturated soil can't treat wastewater properly.
Wells and septic
Private wells and septic systems often share the same property. Proper separation distances, regular pumping and a healthy drain field protect your water. Test your well water regularly.
Growth and older systems
Rapid growth in the area means many older rural homes are being remodeled or expanded. Adding bedrooms can exceed a septic system's design capacity. Check with the local health district and a septic contractor before expanding.
Permits
Septic repairs and new systems require a permit from the regional public health district. Soil tests determine what kind of system is allowed.
Before you hire
Ask Boise-area septic contractors whether they'll pump through the main access and inspect baffles and filters, how they handle frozen lines, whether they evaluate the drain field, and who handles permits. Look up the contractor's Idaho registration with DOPL.
Signs of trouble after winter
In spring, walk the area over the tank and drain field. Soggy patches, sewage odors or unusually green strips of grass, slow drains in the house and gurgling toilets are signs the system is struggling. Catching a problem in spring, before summer water use peaks, gives you time to have it pumped, inspected and repaired.
Water softeners
Some homes discharge water softener regeneration water into the septic system. Ask a septic contractor whether your system can handle it, and how the softener is set up.