Cost of Septic System Replacement
According to ABC Cesspool and G. Nichols Construction, two of the most frequent septic installers in Acton, the total cost of septic replacement in West Acton ranges from $18,000 to $50,000, with an average of $30,000. This includes installation ($25,000), system design ($3,000 - 5,000) and permit ($1000).
The West Acton Sewer Action Advisory Committee has asserted that the total cost of septic replacement in West Acton ranges from $30,900 to $49,900 with an average of $38,900.
We find this assertion very puzzling. The Committee cites Acton's Community Septic Loan Program as its data source. But when we looked at the loan applications we found:
There are only three septic replacements in the dataset. (Three points are too few to form the basis of an accurate average.)
The three replacement costs were $22,350, $27,900 and $37,400.
None of the replacements occurred in West Acton.
We happen to know the homeowner on Spencer Road with the highest replacement cost ($37,400). This septic replacement was unusually expensive due to an unusual circumstance: his old septic system was accidentally placed on his neighbor's property and had to be completely removed from the ground.
As it happens, the average of the three septic replacements in the loan program is $29,200, which is in accordance with the average provided by septic installation companies. But there is no basis for the Committee's average replacement cost of $38,900. Therefore, in our cost analysis we will use the replacement cost estimate of $30,000 provided by frequent installers of septic systems in West Acton.
Cost of Septic Maintenance
The Committee stated that the average annual cost of septic system maintenance is $600 and references Acton's septic replacement loan program. But the loan applications contain no information about maintenance cost. In October of 2019, the Committee's estimate of maintenance cost fell from $600 to $300 per year. But $300/year is still much higher than most homeowners pay to maintain their septic system. Given that the Board of Health states that septic systems should be pumped once every two years, we can determine annual cost by dividing the typical pumping cost by two. According to ABC Cesspool, the cost to pump a 1500-gallon tank is $340, making the annual maintenance cost $170. The corresponding annual cost for 1000-gallon tanks is $70 per year. For 2000 gallons, $220 per year. Most residential septic tanks are either 1000 or 1500 gallons.
With credible replacement and maintenance costs, we can now reliably compare the cost of septic systems to sewers.