What causes septic systems to fail?
There are many causes of septic system failure. Poor installation, improper maintenance, tree roots, hydraulic overload (using too much water!,) high-strength waste (restaurants for example,) seasonal groundwater table, physical damage, etc…Proper failure investigations determine the most likely cause of the failure, which determines the best option for repairing the system.
One of the most common causes of failure is sometimes referred to as the “creeping crud” or “old-age” or Biomat failure. Several factors contribute to the development of the biomat; time, wastewater strength, hydraulic load, groundwater saturation, and maintenance are the major ones.
The pictures below show the progression of the “creeping
crud” and how it eventually causes sewage to surface over the drainfield. The first view shows a newer drainfield line
with the effluent moving downward through the soil. The second shows how the biomat grows along
the bottom of the trench, and then slowly up the sidewall. The third is a progression of growth along
the sidewall of the drainfield, and the fourth picture demonstrates total
encapsulation of the drainfield causing sewage to surface over the top of the
drainfield rather than moving downward through the soil.
When this happens, you have two choices for fixing the problem... drainfield replacement (digging up your yard!) OR Remediation.