The digging is usually two to four days. The timeline that matters is the one before it: soil evaluation, design and permit approval commonly run three to eight weeks depending on the municipality and the season.
What decides the price
The soil writes the quote, not the catalogue
Two houses on the same street can need systems that differ by tens of thousands. Sandy loam that drains freely takes a modest conventional bed. Heavy clay, a high water table or shallow bedrock forces a raised bed, imported fill or an aerobic treatment unit, and each of those changes the number substantially.
That is why the perc test comes before the quote rather than after. Anyone who prices a full system over the phone is pricing a guess, and the difference lands on you at the point where the excavator is already on site.
Once the rate is known, sizing follows from bedroom count and daily flow, and the drawings go in for permit. Ranges for each system type are set out on septic system cost, and if the existing tank is sound the job may only be a field replacement.
Before the quote
Soil evaluation
Filed for you
Permit
Included
Final grade
